WPAC: DORA - Post-Tropical - Discussion
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Sciencerocks
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Sciencerocks
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Re: WPAC: DORA - Typhoon - Discussion
WTPN32 PGTW 122100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TYPHOON 05E (DORA) WARNING NR 050//
RMKS/
1. TYPHOON 05E (DORA) WARNING NR 050
02 ACTIVE TROPICAL CYCLONES IN NORTHWESTPAC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
121800Z --- NEAR 17.6N 176.4E
MOVEMENT PAST SIX HOURS - 300 DEGREES AT 14 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 064 KT WINDS - 020 NM NORTHEAST QUADRANT
010 NM SOUTHEAST QUADRANT
010 NM SOUTHWEST QUADRANT
020 NM NORTHWEST QUADRANT
RADIUS OF 050 KT WINDS - 030 NM NORTHEAST QUADRANT
020 NM SOUTHEAST QUADRANT
020 NM SOUTHWEST QUADRANT
030 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 070 NM NORTHEAST QUADRANT
030 NM SOUTHEAST QUADRANT
030 NM SOUTHWEST QUADRANT
055 NM NORTHWEST QUADRANT
REPEAT POSIT: 17.6N 176.4E
---
FORECASTS:
12 HRS, VALID AT:
130600Z --- 18.5N 174.2E
MAX SUSTAINED WINDS - 060 KT, GUSTS 075 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 030 NM NORTHEAST QUADRANT
010 NM SOUTHEAST QUADRANT
010 NM SOUTHWEST QUADRANT
030 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 060 NM NORTHEAST QUADRANT
030 NM SOUTHEAST QUADRANT
030 NM SOUTHWEST QUADRANT
050 NM NORTHWEST QUADRANT
VECTOR TO 24 HR POSIT: 295 DEG/ 10 KTS
---
24 HRS, VALID AT:
131800Z --- 19.3N 172.2E
MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 020 NM NORTHEAST QUADRANT
010 NM SOUTHEAST QUADRANT
000 NM SOUTHWEST QUADRANT
010 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 060 NM NORTHEAST QUADRANT
030 NM SOUTHEAST QUADRANT
020 NM SOUTHWEST QUADRANT
050 NM NORTHWEST QUADRANT
VECTOR TO 36 HR POSIT: 300 DEG/ 09 KTS
---
36 HRS, VALID AT:
140600Z --- 20.2N 170.5E
MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 030 NM NORTHEAST QUADRANT
000 NM SOUTHEAST QUADRANT
000 NM SOUTHWEST QUADRANT
020 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 060 NM NORTHEAST QUADRANT
020 NM SOUTHEAST QUADRANT
010 NM SOUTHWEST QUADRANT
040 NM NORTHWEST QUADRANT
VECTOR TO 48 HR POSIT: 315 DEG/ 08 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
141800Z --- 21.4N 169.3E
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 060 NM NORTHEAST QUADRANT
020 NM SOUTHEAST QUADRANT
020 NM SOUTHWEST QUADRANT
030 NM NORTHWEST QUADRANT
VECTOR TO 72 HR POSIT: 345 DEG/ 08 KTS
---
72 HRS, VALID AT:
151800Z --- 24.6N 168.5E
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT
030 NM SOUTHEAST QUADRANT
030 NM SOUTHWEST QUADRANT
030 NM NORTHWEST QUADRANT
VECTOR TO 96 HR POSIT: 010 DEG/ 09 KTS
---
LONG RANGE OUTLOOK:
---
96 HRS, VALID AT:
161800Z --- 28.2N 169.1E
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT
050 NM SOUTHEAST QUADRANT
030 NM SOUTHWEST QUADRANT
050 NM NORTHWEST QUADRANT
VECTOR TO 120 HR POSIT: 030 DEG/ 14 KTS
---
120 HRS, VALID AT:
171800Z --- 33.3N 172.3E
MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
WIND RADII VALID OVER OPEN WATER ONLY
BECOMING EXTRATROPICAL
RADIUS OF 050 KT WINDS - 020 NM NORTHEAST QUADRANT
030 NM SOUTHEAST QUADRANT
030 NM SOUTHWEST QUADRANT
020 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 090 NM NORTHEAST QUADRANT
080 NM SOUTHEAST QUADRANT
040 NM SOUTHWEST QUADRANT
070 NM NORTHWEST QUADRANT
---
REMARKS:
122100Z POSITION NEAR 17.8N 175.9E.
12AUG23. TYPHOON 05E (DORA), LOCATED APPROXIMATELY 810 NM WEST OF
JOHNSTON ISLAND, HAS TRACKED WEST-NORTHWESTWARD AT 14 KNOTS OVER
THE PAST SIX HOURS.
MINIMUM CENTRAL PRESSURE AT 81218Z IS 991 MB. MAXIMUM SIGNIFICANT
WAVE HEIGHT AT 121800Z IS 27 FEET. NEXT WARNINGS AT 130300Z,
130900Z, 131500Z AND 132100Z.
REFER TO TYPHOON 07W (LAN) WARNINGS (WTPN31 PGTW)
FOR SIX-HOURLY UPDATES.
//
NNNN
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TYPHOON 05E (DORA) WARNING NR 050//
RMKS/
1. TYPHOON 05E (DORA) WARNING NR 050
02 ACTIVE TROPICAL CYCLONES IN NORTHWESTPAC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
121800Z --- NEAR 17.6N 176.4E
MOVEMENT PAST SIX HOURS - 300 DEGREES AT 14 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 064 KT WINDS - 020 NM NORTHEAST QUADRANT
010 NM SOUTHEAST QUADRANT
010 NM SOUTHWEST QUADRANT
020 NM NORTHWEST QUADRANT
RADIUS OF 050 KT WINDS - 030 NM NORTHEAST QUADRANT
020 NM SOUTHEAST QUADRANT
020 NM SOUTHWEST QUADRANT
030 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 070 NM NORTHEAST QUADRANT
030 NM SOUTHEAST QUADRANT
030 NM SOUTHWEST QUADRANT
055 NM NORTHWEST QUADRANT
REPEAT POSIT: 17.6N 176.4E
---
FORECASTS:
12 HRS, VALID AT:
130600Z --- 18.5N 174.2E
MAX SUSTAINED WINDS - 060 KT, GUSTS 075 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 030 NM NORTHEAST QUADRANT
010 NM SOUTHEAST QUADRANT
010 NM SOUTHWEST QUADRANT
030 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 060 NM NORTHEAST QUADRANT
030 NM SOUTHEAST QUADRANT
030 NM SOUTHWEST QUADRANT
050 NM NORTHWEST QUADRANT
VECTOR TO 24 HR POSIT: 295 DEG/ 10 KTS
---
24 HRS, VALID AT:
131800Z --- 19.3N 172.2E
MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 020 NM NORTHEAST QUADRANT
010 NM SOUTHEAST QUADRANT
000 NM SOUTHWEST QUADRANT
010 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 060 NM NORTHEAST QUADRANT
030 NM SOUTHEAST QUADRANT
020 NM SOUTHWEST QUADRANT
050 NM NORTHWEST QUADRANT
VECTOR TO 36 HR POSIT: 300 DEG/ 09 KTS
---
36 HRS, VALID AT:
140600Z --- 20.2N 170.5E
MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 030 NM NORTHEAST QUADRANT
000 NM SOUTHEAST QUADRANT
000 NM SOUTHWEST QUADRANT
020 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 060 NM NORTHEAST QUADRANT
020 NM SOUTHEAST QUADRANT
010 NM SOUTHWEST QUADRANT
040 NM NORTHWEST QUADRANT
VECTOR TO 48 HR POSIT: 315 DEG/ 08 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
141800Z --- 21.4N 169.3E
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 060 NM NORTHEAST QUADRANT
020 NM SOUTHEAST QUADRANT
020 NM SOUTHWEST QUADRANT
030 NM NORTHWEST QUADRANT
VECTOR TO 72 HR POSIT: 345 DEG/ 08 KTS
---
72 HRS, VALID AT:
151800Z --- 24.6N 168.5E
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT
030 NM SOUTHEAST QUADRANT
030 NM SOUTHWEST QUADRANT
030 NM NORTHWEST QUADRANT
VECTOR TO 96 HR POSIT: 010 DEG/ 09 KTS
---
LONG RANGE OUTLOOK:
---
96 HRS, VALID AT:
161800Z --- 28.2N 169.1E
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT
050 NM SOUTHEAST QUADRANT
030 NM SOUTHWEST QUADRANT
050 NM NORTHWEST QUADRANT
VECTOR TO 120 HR POSIT: 030 DEG/ 14 KTS
---
120 HRS, VALID AT:
171800Z --- 33.3N 172.3E
MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
WIND RADII VALID OVER OPEN WATER ONLY
BECOMING EXTRATROPICAL
RADIUS OF 050 KT WINDS - 020 NM NORTHEAST QUADRANT
030 NM SOUTHEAST QUADRANT
030 NM SOUTHWEST QUADRANT
020 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 090 NM NORTHEAST QUADRANT
080 NM SOUTHEAST QUADRANT
040 NM SOUTHWEST QUADRANT
070 NM NORTHWEST QUADRANT
---
REMARKS:
122100Z POSITION NEAR 17.8N 175.9E.
12AUG23. TYPHOON 05E (DORA), LOCATED APPROXIMATELY 810 NM WEST OF
JOHNSTON ISLAND, HAS TRACKED WEST-NORTHWESTWARD AT 14 KNOTS OVER
THE PAST SIX HOURS.
MINIMUM CENTRAL PRESSURE AT 81218Z IS 991 MB. MAXIMUM SIGNIFICANT
WAVE HEIGHT AT 121800Z IS 27 FEET. NEXT WARNINGS AT 130300Z,
130900Z, 131500Z AND 132100Z.
REFER TO TYPHOON 07W (LAN) WARNINGS (WTPN31 PGTW)
FOR SIX-HOURLY UPDATES.
//
NNNN
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USTropics
- Category 5
- Posts: 2420
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- Location: Florida State University
Re: WPAC: DORA - Typhoon - Discussion
Cyclenall wrote:I'm surprised how fast Dora is disintegrating.
It had such a small radius for its inner core near the end, I think an advisory said 6 nm at one point. Smaller systems are more susceptible to sudden changes in shear direction.
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cycloneye
- Admin
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- Age: 67
- Joined: Thu Oct 10, 2002 10:54 am
- Location: San Juan, Puerto Rico
Re: WPAC: DORA - Tropical Storm - Discussion
WDPN32 PGTW 130900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 05E (DORA) WARNING NR
052//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
SUMMARY:
INITIAL POSITION: 18.3N 174.2E
INITIAL INTENSITY: 55 KTS
GEOGRAPHIC REFERENCE: 937 NM WEST OF JOHNSTON ISLAND
MOVEMENT PAST 6 HOURS: WEST-NORTHWESTWARD AT 10 KTS
SIGNIFICANT WAVE HEIGHT: 23 FEET
SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A PARTIALLY
EXPOSED LOW LEVEL CIRCULATION CENTER (LLCC) THAT IS BECOMING MORE
EXPOSED BY THE MINUTE DUE TO THE PERSISTENT SOUTHWESTERLY SHEAR. A
130605Z SSMIS 91GHZ MICROWAVE IMAGE REVEALS A SMALL NAKED
CIRCULATION WITH A SMALL BLOOM OF CONVECTION EVIDENT TO THE
NORTHEAST OF THE LLCC. THE INITIAL POSITION IS PLACED WITH HIGH
CONFIDENCE BASED ON MSI AND SSMIS IMAGERY. THE INITIAL INTENSITY OF
55 KTS IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON PGTW AND KNES
DVORAK INTENSITY ESTIMATES TOGETHER WITH CIMSS AIDT INDICATING
55KTS, WHILE CIMSS ADT AND D-PRINT INDICATE SLIGHTLY HIGHER AT 63
KTS AND 67KTS RESPECTIVELY.
INITIAL WIND RADII BASIS: PERSISTENCE
CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE TO THE NORTHEAST
AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T4.0 - 65 KTS
RJTD: T4.5 - 77 KTS
KNES: T3.5 - 55 KTS
CIMSS ADT: 67 KTS AT 130530Z
FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY
UNFAVORABLE
VWS: 15-20 KTS
SST: 28-29 CELSIUS
OUTFLOW: MODERATE POLEWARD
ANALYSIS CONFIDENCE:
INITIAL POSITION: HIGH
INITIAL INTENSITY: MEDIUM
INITIAL WIND RADII: LOW
3. FORECAST REASONING.
SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO
THE FORECAST FROM THE PREVIOUS WARNING.
FORECAST DISCUSSION: TROPICAL STORM DORA (05E) IS FORECAST TO
CONTINUE WEST-NORTHWESTWARD OVER THE NEXT 24 HOURS. DURING THIS
TIME, PERSISTENT SOUTHWESTERLY SHEAR WILL CONTINUE TO EAT AWAY AT
THE SYSTEM, RESULTING IN GRADUAL WEAKENING. AS THE SYSTEM CROSSES
THE 20TH PARALLEL, 05E WILL BE FORCED BETWEEN THE CURRENT STR AND A
NEW RIDGE THAT BUILDS TO THE NORTHWEST, THIS COMBINED STEERING
EFFECT WILL FORCE THE SYSTEM GENERALLY POLEWARD. THE INTENSITY OF
THE SYSTEM AFTER TAU 36 IS ENTIRELY DEPENDENT ON ITS TRACK. IF THE
SYSTEM IS ABLE TO WITHSTAND THE CURRENT VERTICAL WIND SHEAR AND
ENTER THE NORTHWARD TURN WITH A MAJORITY OF ITS STRENGTH, 05E WILL
TREND ON A MORE EASTWARD COURSE AS SEEN IN GFS AND NVGM. THIS
INSIDE TRACK WOULD BRING DORA INTO A REGION OF LOWER VERTICAL WIND
SHEAR AND THE UP-SHEAR ENVIRONMENT WOULD MOISTEN, FACILITATING A
PERIOD OF REINTENSIFICATION. ON THE OTHER HAND, THERE REMAINS A
CHANCE THAT DORA DISSIPATES BEFORE THIS OPPORTUNITY TO REINTENSIFY,
AS SHOWN BY THE ECMWF AND HWRF. THE JTWC OUTLOOK CONTINUES TO LEAN
TOWARDS A MORE RIGHT OF TRACK APPROACH WITH A MARGINAL AMOUNT OF
REINTENSIFICATION. AS THE SYSTEM PROGRESSES INTO THE HIGHER
LATITUDES, IT WILL BEGIN TO INTERACT WITH STRONG BAROCLINIC FORCES
THAT WILL INITIATE EXTRATROPICAL TRANSITION BY TAU 120.
MODEL DISCUSSION: NUMERICAL MODELS ARE IN GOOD AGREEMENT THROUGH
TAU 24 WITH MINIMAL CROSS TRACK SPREADING. AS THE TIMING AND EXTENT
OF THE NORTHWARD TURN VARIES AMONGST THE MEMBERS, THE CONSENSUS
BEYOND TAU 24 IS NOT AS TIGHT AND THEREFORE OF LOWER CONFIDENCE. FOR
THIS REASON THE JTWC TRACK FORECAST IS PLACED INITIALLY WITH MEDIUM
CONFIDENCE AND WITH LOW CONFIDENCE THEREAFTER. RELIABLE MODEL
INTENSITY GUIDANCE IS IN FAIR AGREEMENT WITH ALL MEMBERS GENERALLY
FOLLOWING THE MULTI-MODEL CONSENSUS THROUGH THE FORECAST PERIOD. AS
MENTIONED ABOVE, THERE IS A STRONG AND DIRECT CORRELATION BETWEEN
TRACK AND INTENSITY BEYOND TAU 36. THE JTWC FORECAST INTENSITY IS
THEREFORE PLACED WITH THE SAME CONFIDENCE AS THE TRACK FORECAST.
FORECAST CONFIDENCE:
TRACK 0 - 72 HR: MEDIUM
TRACK 72-120 HR: LOW
INTENSITY 0 - 72 HR: MEDIUM
INTENSITY 72-120 HR: LOW//
NNNN
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 05E (DORA) WARNING NR
052//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
SUMMARY:
INITIAL POSITION: 18.3N 174.2E
INITIAL INTENSITY: 55 KTS
GEOGRAPHIC REFERENCE: 937 NM WEST OF JOHNSTON ISLAND
MOVEMENT PAST 6 HOURS: WEST-NORTHWESTWARD AT 10 KTS
SIGNIFICANT WAVE HEIGHT: 23 FEET
SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A PARTIALLY
EXPOSED LOW LEVEL CIRCULATION CENTER (LLCC) THAT IS BECOMING MORE
EXPOSED BY THE MINUTE DUE TO THE PERSISTENT SOUTHWESTERLY SHEAR. A
130605Z SSMIS 91GHZ MICROWAVE IMAGE REVEALS A SMALL NAKED
CIRCULATION WITH A SMALL BLOOM OF CONVECTION EVIDENT TO THE
NORTHEAST OF THE LLCC. THE INITIAL POSITION IS PLACED WITH HIGH
CONFIDENCE BASED ON MSI AND SSMIS IMAGERY. THE INITIAL INTENSITY OF
55 KTS IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON PGTW AND KNES
DVORAK INTENSITY ESTIMATES TOGETHER WITH CIMSS AIDT INDICATING
55KTS, WHILE CIMSS ADT AND D-PRINT INDICATE SLIGHTLY HIGHER AT 63
KTS AND 67KTS RESPECTIVELY.
INITIAL WIND RADII BASIS: PERSISTENCE
CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE TO THE NORTHEAST
AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T4.0 - 65 KTS
RJTD: T4.5 - 77 KTS
KNES: T3.5 - 55 KTS
CIMSS ADT: 67 KTS AT 130530Z
FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY
UNFAVORABLE
VWS: 15-20 KTS
SST: 28-29 CELSIUS
OUTFLOW: MODERATE POLEWARD
ANALYSIS CONFIDENCE:
INITIAL POSITION: HIGH
INITIAL INTENSITY: MEDIUM
INITIAL WIND RADII: LOW
3. FORECAST REASONING.
SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO
THE FORECAST FROM THE PREVIOUS WARNING.
FORECAST DISCUSSION: TROPICAL STORM DORA (05E) IS FORECAST TO
CONTINUE WEST-NORTHWESTWARD OVER THE NEXT 24 HOURS. DURING THIS
TIME, PERSISTENT SOUTHWESTERLY SHEAR WILL CONTINUE TO EAT AWAY AT
THE SYSTEM, RESULTING IN GRADUAL WEAKENING. AS THE SYSTEM CROSSES
THE 20TH PARALLEL, 05E WILL BE FORCED BETWEEN THE CURRENT STR AND A
NEW RIDGE THAT BUILDS TO THE NORTHWEST, THIS COMBINED STEERING
EFFECT WILL FORCE THE SYSTEM GENERALLY POLEWARD. THE INTENSITY OF
THE SYSTEM AFTER TAU 36 IS ENTIRELY DEPENDENT ON ITS TRACK. IF THE
SYSTEM IS ABLE TO WITHSTAND THE CURRENT VERTICAL WIND SHEAR AND
ENTER THE NORTHWARD TURN WITH A MAJORITY OF ITS STRENGTH, 05E WILL
TREND ON A MORE EASTWARD COURSE AS SEEN IN GFS AND NVGM. THIS
INSIDE TRACK WOULD BRING DORA INTO A REGION OF LOWER VERTICAL WIND
SHEAR AND THE UP-SHEAR ENVIRONMENT WOULD MOISTEN, FACILITATING A
PERIOD OF REINTENSIFICATION. ON THE OTHER HAND, THERE REMAINS A
CHANCE THAT DORA DISSIPATES BEFORE THIS OPPORTUNITY TO REINTENSIFY,
AS SHOWN BY THE ECMWF AND HWRF. THE JTWC OUTLOOK CONTINUES TO LEAN
TOWARDS A MORE RIGHT OF TRACK APPROACH WITH A MARGINAL AMOUNT OF
REINTENSIFICATION. AS THE SYSTEM PROGRESSES INTO THE HIGHER
LATITUDES, IT WILL BEGIN TO INTERACT WITH STRONG BAROCLINIC FORCES
THAT WILL INITIATE EXTRATROPICAL TRANSITION BY TAU 120.
MODEL DISCUSSION: NUMERICAL MODELS ARE IN GOOD AGREEMENT THROUGH
TAU 24 WITH MINIMAL CROSS TRACK SPREADING. AS THE TIMING AND EXTENT
OF THE NORTHWARD TURN VARIES AMONGST THE MEMBERS, THE CONSENSUS
BEYOND TAU 24 IS NOT AS TIGHT AND THEREFORE OF LOWER CONFIDENCE. FOR
THIS REASON THE JTWC TRACK FORECAST IS PLACED INITIALLY WITH MEDIUM
CONFIDENCE AND WITH LOW CONFIDENCE THEREAFTER. RELIABLE MODEL
INTENSITY GUIDANCE IS IN FAIR AGREEMENT WITH ALL MEMBERS GENERALLY
FOLLOWING THE MULTI-MODEL CONSENSUS THROUGH THE FORECAST PERIOD. AS
MENTIONED ABOVE, THERE IS A STRONG AND DIRECT CORRELATION BETWEEN
TRACK AND INTENSITY BEYOND TAU 36. THE JTWC FORECAST INTENSITY IS
THEREFORE PLACED WITH THE SAME CONFIDENCE AS THE TRACK FORECAST.
FORECAST CONFIDENCE:
TRACK 0 - 72 HR: MEDIUM
TRACK 72-120 HR: LOW
INTENSITY 0 - 72 HR: MEDIUM
INTENSITY 72-120 HR: LOW//
NNNN
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doomhaMwx
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Re: WPAC: DORA - Tropical Storm - Discussion
~09Z ASCAT pass only found max winds of 35kts in the exposed center, much weaker than Dvorak estimates. JTWC and JMA gave 40kts and 55kts respectively at 12Z (55kts and 60kts at 09Z).
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cycloneye
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- Location: San Juan, Puerto Rico
Re: WPAC: DORA - Tropical Storm - Discussion
WDPN32 PGTW 131500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 05E (DORA) WARNING NR
053//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
SUMMARY:
INITIAL POSITION: 18.0N 172.9E
INITIAL INTENSITY: 40 KTS
GEOGRAPHIC REFERENCE: 362 NM EAST OF WAKE ISLAND
MOVEMENT PAST 6 HOURS: WEST-SOUTHWESTWARD AT 13 KTS
SIGNIFICANT WAVE HEIGHT: 15 FEET
SATELLITE ANALYSIS, INITIAL POSITION, AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY (GOES H-8 PROXY
VIS) SHOWS A RAPIDLY DETERIORATING SYSTEM WITH ITS CENTRAL
CONVECTION DECAPITATED AND SEVERELY SHEARED NORTHEASTWARD. THE
INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE FULLY
EXPOSED LOW LEVEL CIRCULATION IN THE EIR LOOP. THE INITIAL
INTENSITY OF 40KTS IS ALSO PLACED WITH HIGH CONFIDENCE BASED ON A
130915Z ASCAT BULLSEYE PASS. ANALYSIS INDICATES THE ENVIRONMENT HAS
BECOME HIGHLY UNFAVORABLE WITH WARM SST AND STRONG POLEWARD
OUTFLOW GREATLY OFFSET BY STRONG SOUTHWESTERLY VWS.
INITIAL WIND RADII BASIS: SCATTEROMETER DATA.
CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE (STR) TO THE
NORTHEAST.
AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T3.0 - 45 KTS
RJTD: T4.0 - 65 KTS
RCTP: T2.5 - 35 KTS
KNES: T3.5 - 55 KTS
PHFO: T3.0 - 45 KTS
CIMSS ADT: 59 KTS AT 130830Z
FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: HIGHLY UNFAVORABLE
VWS: 25+ KTS
SST: 28-29 CELSIUS
OUTFLOW: STRONG POLEWARD
ANALYSIS CONFIDENCE:
INITIAL POSITION: HIGH
INITIAL INTENSITY: HIGH
INITIAL WIND RADII: HIGH
3. FORECAST REASONING.
SIGNIFICANT FORECAST CHANGES: FORECAST TRACK SHORTENED TO TAU 48 DUE
TO EARLY DISSIPATION.
FORECAST DISCUSSION: TS DORA WILL CONTINUE ON A MORE NORTHWESTWARD
TRACK PASSING WAKE ISLAND APPROXIMATELY 147NM TO THE SOUTHWEST BY
141800Z. THE HIGHLY UNFAVORABLE ENVIRONMENT WILL ERODE THE SYSTEM
TO DISSIPATION BY TAU 48, POSSIBLY SOONER.
MODEL DISCUSSION: NUMERICAL MODELS ARE IN GOOD AGREEMENT; HOWEVER,
GIVEN THE INHERENT ERRATIC STORM MOTION OF AN EXPOSED LLC, THERE IS
LOW CONFIDENCE IN THE JTWC TRACK FORECAST.
FORECAST CONFIDENCE:
TRACK 0 - 72 HR: LOW
INTENSITY 0 - 72 HR: MEDIUM//
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 05E (DORA) WARNING NR
053//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
SUMMARY:
INITIAL POSITION: 18.0N 172.9E
INITIAL INTENSITY: 40 KTS
GEOGRAPHIC REFERENCE: 362 NM EAST OF WAKE ISLAND
MOVEMENT PAST 6 HOURS: WEST-SOUTHWESTWARD AT 13 KTS
SIGNIFICANT WAVE HEIGHT: 15 FEET
SATELLITE ANALYSIS, INITIAL POSITION, AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY (GOES H-8 PROXY
VIS) SHOWS A RAPIDLY DETERIORATING SYSTEM WITH ITS CENTRAL
CONVECTION DECAPITATED AND SEVERELY SHEARED NORTHEASTWARD. THE
INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE FULLY
EXPOSED LOW LEVEL CIRCULATION IN THE EIR LOOP. THE INITIAL
INTENSITY OF 40KTS IS ALSO PLACED WITH HIGH CONFIDENCE BASED ON A
130915Z ASCAT BULLSEYE PASS. ANALYSIS INDICATES THE ENVIRONMENT HAS
BECOME HIGHLY UNFAVORABLE WITH WARM SST AND STRONG POLEWARD
OUTFLOW GREATLY OFFSET BY STRONG SOUTHWESTERLY VWS.
INITIAL WIND RADII BASIS: SCATTEROMETER DATA.
CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE (STR) TO THE
NORTHEAST.
AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T3.0 - 45 KTS
RJTD: T4.0 - 65 KTS
RCTP: T2.5 - 35 KTS
KNES: T3.5 - 55 KTS
PHFO: T3.0 - 45 KTS
CIMSS ADT: 59 KTS AT 130830Z
FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: HIGHLY UNFAVORABLE
VWS: 25+ KTS
SST: 28-29 CELSIUS
OUTFLOW: STRONG POLEWARD
ANALYSIS CONFIDENCE:
INITIAL POSITION: HIGH
INITIAL INTENSITY: HIGH
INITIAL WIND RADII: HIGH
3. FORECAST REASONING.
SIGNIFICANT FORECAST CHANGES: FORECAST TRACK SHORTENED TO TAU 48 DUE
TO EARLY DISSIPATION.
FORECAST DISCUSSION: TS DORA WILL CONTINUE ON A MORE NORTHWESTWARD
TRACK PASSING WAKE ISLAND APPROXIMATELY 147NM TO THE SOUTHWEST BY
141800Z. THE HIGHLY UNFAVORABLE ENVIRONMENT WILL ERODE THE SYSTEM
TO DISSIPATION BY TAU 48, POSSIBLY SOONER.
MODEL DISCUSSION: NUMERICAL MODELS ARE IN GOOD AGREEMENT; HOWEVER,
GIVEN THE INHERENT ERRATIC STORM MOTION OF AN EXPOSED LLC, THERE IS
LOW CONFIDENCE IN THE JTWC TRACK FORECAST.
FORECAST CONFIDENCE:
TRACK 0 - 72 HR: LOW
INTENSITY 0 - 72 HR: MEDIUM//
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Sciencerocks
- Category 5
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wxman57
- Moderator-Pro Met
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- Age: 66
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- Location: Houston, TX (southwest)
Re: WPAC: DORA - Tropical Storm - Discussion
Bones says Dora is history. Doesn't really qualify as a depression, much less a storm. Winds are likely less than 35 kts now, nine hours after that ASCAT pass indicated 35 kts.
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cycloneye
- Admin
- Posts: 139494
- Age: 67
- Joined: Thu Oct 10, 2002 10:54 am
- Location: San Juan, Puerto Rico
Re: WPAC: DORA - Tropical Storm - Discussion
WDPN32 PGTW 140300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 05E (DORA) WARNING NR
055//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
SUMMARY:
INITIAL POSITION: 18.7N 170.1E
INITIAL INTENSITY: 40 KTS
GEOGRAPHIC REFERENCE: 204 NM EAST OF WAKE ISLAND
MOVEMENT PAST 6 HOURS: WEST-NORTHWESTWARD AT 13 KTS
SIGNIFICANT WAVE HEIGHT: 15 FEET
SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY (GOES-H9 PROXY
VIS) SHOWS A LOW-LEVEL CIRCULATION CENTER (LLCC) RAPIDLY TRACKING
WESTWARD WITH A GRADUAL TURN TOWARD THE NORTHWEST OVER THE LAST 3
HOURS. THE SHEARED TOPS OBSERVABLE IN THE PREVIOUS WARNING (54) HAVE
SINCE ENTIRELY DISSIPATED INTO THE SOUTHWESTERLY FLOW. SMALL, BRIEF
CELLS OF FLARING CONVECTION HAVE PERSISTED 30NM NORTH OF THE LLCC BUT
ARE QUICKLY SHEARED OFF WITH THE MID TO UPPER-LEVEL SOUTHWESTERLY
FLOW. MOST NOTABLY, THE LOW TO MID LEVELS APPEAR TO BE STRENGTHENING
AND EXPANDING WITH CONVECTIVE BANDING VISIBLE UP TO 100NM FROM THE
LLCC (AN INCREASE OF 33NM OVER 6 HOURS). THE INITIAL POSITION IS
PLACED WITH HIGH CONFIDENCE BASED ON AN EXPOSED LLCC IN A 140000Z HM9
VISIBLE IMAGE. THE INITIAL INTENSITY OF 40KTS IS ASSESSED WITH MEDIUM
CONFIDENCE BASED ON PERSISTENCE AND SUBJECTIVE DVORAK ESTIMATES FROM
MULTIPLE AGENCIES. ENVIRONMENTAL ANALYSIS INDICATES THE ENVIRONMENT IS
MARGINALLY UNFAVORABLE WITH WARM SST AND STRONG POLEWARD OUTFLOW
OFFSET BY VERY STRONG SOUTHWESTERLY VWS.
INITIAL WIND RADII BASIS: PERSISTENCE
CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE (STR) TO THE
NORTHEAST.
AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T2.5 - 35 KTS
RJTD: T3.0 - 45 KTS
RCTP: T2.5 - 35 KTS
KNES: T2.5 - 35 KTS
PHFO: T2.0 - 30 KTS
CIMSS ADT: 27 KTS AT 132350Z
FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY
UNFAVORABLE
VWS: 20-25 KTS
SST: 28-29 CELSIUS
OUTFLOW: STRONG POLEWARD
ANALYSIS CONFIDENCE:
INITIAL POSITION: HIGH
INITIAL INTENSITY: MEDIUM
INITIAL WIND RADII: MEDIUM
3. FORECAST REASONING.
SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO
THE FORECAST FROM THE PREVIOUS WARNING.
FORECAST DISCUSSION: TS DORA WILL CONTINUE ON A NORTHWESTWARD TRACK
PASSING APPROXIMATELY 95NM TO THE NORTHEAST OF WAKE ISLAND BY
141600Z. DESPITE THE MARGINALLY UNFAVORABLE ENVIRONMENT PRESENTED
BY THE AFOREMENTIONED VWS, THE SYSTEM IS ANTICIPATED TO PERSIST AS
A TROPICAL STORM THROUGH TAU 72. A WEAK STEERING RIDGE OFFSET BY
EXCEPTIONAL MODEL CONGRUENCE CONTRIBUTED TO AN OVERALL MEDIUM
CONFIDENCE OF TRACK AND INTENSITY FORECASTS THROUGH TAU 72,
FOLLOWED BY LOW CONFIDENCE THEREAFTER.
MODEL DISCUSSION: NUMERICAL MODELS ARE IN GOOD AGREEMENT WITH A
CROSS-TRACK SPREAD OF 120NM AT TAU 72. SINCE THE 132100Z WARNING
(54), INTENSITY GUIDANCE HAS SHIFTED SLIGHTLY TO INDICATE THE
SYSTEM WILL PERSIST AT TROPICAL STORM INTENSITY THROUGH TAU 72 AND
SLOWLY WEAKEN TO A TROPICAL DEPRESSION THEREAFTER.
FORECAST CONFIDENCE:
TRACK 0 - 72 HR: MEDIUM
TRACK 72-120 HR: LOW
INTENSITY 0 - 72 HR: MEDIUM
INTENSITY 72-120 HR: LOW//
NNNN
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 05E (DORA) WARNING NR
055//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
SUMMARY:
INITIAL POSITION: 18.7N 170.1E
INITIAL INTENSITY: 40 KTS
GEOGRAPHIC REFERENCE: 204 NM EAST OF WAKE ISLAND
MOVEMENT PAST 6 HOURS: WEST-NORTHWESTWARD AT 13 KTS
SIGNIFICANT WAVE HEIGHT: 15 FEET
SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY (GOES-H9 PROXY
VIS) SHOWS A LOW-LEVEL CIRCULATION CENTER (LLCC) RAPIDLY TRACKING
WESTWARD WITH A GRADUAL TURN TOWARD THE NORTHWEST OVER THE LAST 3
HOURS. THE SHEARED TOPS OBSERVABLE IN THE PREVIOUS WARNING (54) HAVE
SINCE ENTIRELY DISSIPATED INTO THE SOUTHWESTERLY FLOW. SMALL, BRIEF
CELLS OF FLARING CONVECTION HAVE PERSISTED 30NM NORTH OF THE LLCC BUT
ARE QUICKLY SHEARED OFF WITH THE MID TO UPPER-LEVEL SOUTHWESTERLY
FLOW. MOST NOTABLY, THE LOW TO MID LEVELS APPEAR TO BE STRENGTHENING
AND EXPANDING WITH CONVECTIVE BANDING VISIBLE UP TO 100NM FROM THE
LLCC (AN INCREASE OF 33NM OVER 6 HOURS). THE INITIAL POSITION IS
PLACED WITH HIGH CONFIDENCE BASED ON AN EXPOSED LLCC IN A 140000Z HM9
VISIBLE IMAGE. THE INITIAL INTENSITY OF 40KTS IS ASSESSED WITH MEDIUM
CONFIDENCE BASED ON PERSISTENCE AND SUBJECTIVE DVORAK ESTIMATES FROM
MULTIPLE AGENCIES. ENVIRONMENTAL ANALYSIS INDICATES THE ENVIRONMENT IS
MARGINALLY UNFAVORABLE WITH WARM SST AND STRONG POLEWARD OUTFLOW
OFFSET BY VERY STRONG SOUTHWESTERLY VWS.
INITIAL WIND RADII BASIS: PERSISTENCE
CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE (STR) TO THE
NORTHEAST.
AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T2.5 - 35 KTS
RJTD: T3.0 - 45 KTS
RCTP: T2.5 - 35 KTS
KNES: T2.5 - 35 KTS
PHFO: T2.0 - 30 KTS
CIMSS ADT: 27 KTS AT 132350Z
FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY
UNFAVORABLE
VWS: 20-25 KTS
SST: 28-29 CELSIUS
OUTFLOW: STRONG POLEWARD
ANALYSIS CONFIDENCE:
INITIAL POSITION: HIGH
INITIAL INTENSITY: MEDIUM
INITIAL WIND RADII: MEDIUM
3. FORECAST REASONING.
SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO
THE FORECAST FROM THE PREVIOUS WARNING.
FORECAST DISCUSSION: TS DORA WILL CONTINUE ON A NORTHWESTWARD TRACK
PASSING APPROXIMATELY 95NM TO THE NORTHEAST OF WAKE ISLAND BY
141600Z. DESPITE THE MARGINALLY UNFAVORABLE ENVIRONMENT PRESENTED
BY THE AFOREMENTIONED VWS, THE SYSTEM IS ANTICIPATED TO PERSIST AS
A TROPICAL STORM THROUGH TAU 72. A WEAK STEERING RIDGE OFFSET BY
EXCEPTIONAL MODEL CONGRUENCE CONTRIBUTED TO AN OVERALL MEDIUM
CONFIDENCE OF TRACK AND INTENSITY FORECASTS THROUGH TAU 72,
FOLLOWED BY LOW CONFIDENCE THEREAFTER.
MODEL DISCUSSION: NUMERICAL MODELS ARE IN GOOD AGREEMENT WITH A
CROSS-TRACK SPREAD OF 120NM AT TAU 72. SINCE THE 132100Z WARNING
(54), INTENSITY GUIDANCE HAS SHIFTED SLIGHTLY TO INDICATE THE
SYSTEM WILL PERSIST AT TROPICAL STORM INTENSITY THROUGH TAU 72 AND
SLOWLY WEAKEN TO A TROPICAL DEPRESSION THEREAFTER.
FORECAST CONFIDENCE:
TRACK 0 - 72 HR: MEDIUM
TRACK 72-120 HR: LOW
INTENSITY 0 - 72 HR: MEDIUM
INTENSITY 72-120 HR: LOW//
NNNN
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Re: WPAC: DORA - Tropical Storm - Discussion
I don't know if anyone mentioned this but Dora has exceeded 50 units of ACE, making it the 3rd to do so this year (after Freddy and Mawar). If I'm not mistaken, this is the most amount of 50+ ACE TCs in a year, tied with 1997.
2 likes
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cycloneye
- Admin
- Posts: 139494
- Age: 67
- Joined: Thu Oct 10, 2002 10:54 am
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Re: WPAC: DORA - Tropical Storm - Discussion
WDPN32 PGTW 140900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 05E (DORA) WARNING NR
056//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
SUMMARY:
INITIAL POSITION: 19.3N 169.2E
INITIAL INTENSITY: 35 KTS
GEOGRAPHIC REFERENCE: 145 NM EAST OF WAKE ISLAND
MOVEMENT PAST 6 HOURS: NORTHWESTWARD AT 10 KTS
SIGNIFICANT WAVE HEIGHT: 12 FEET
SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY (GOES H-8 PROXY
VIS) SHOWS A SYSTEM WITH ITS FLARING CENTRAL CONVECTION SEVERELY
SHEARED NORTHEASTWARD, INTERMITTENTLY EXPOSING THE LOW-LEVEL
CIRCULATION (LLC). THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE
BASED ON THE MOSTLY EXPOSED LLC IN THE EIR LOOP. THE INITIAL INTENSITY
OF 35KTS IS PLACED WITH MEDIUM CONFIDENCE BASED ON OVERALL ASSESSMENT
OF AGENCY AND AUTOMATED DVORAK ESTIMATES AND REFLECTS THE SLIGHT 6-HR
CONVECTIVE DEGRADATION. ANALYSIS INDICATES A MARGINAL ENVIRONMENT WITH
WARM SST AND STRONG POLEWARD OUTFLOW GREATLY OFFSET BY STRONG
SOUTHWESTERLY VWS.
INITIAL WIND RADII BASIS: PERSISTENCE.
CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE (STR) TO THE
NORTHEAST.
AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T2.5 - 35 KTS
RJTD: T3.0 - 45 KTS
KNES: T2.0 - 30 KTS
PHFO: T3.0 - 45 KTS
CIMSS ADT: 32 KTS AT 140540Z
FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINAL
VWS: 20+ KTS
SST: 28-29 CELSIUS
OUTFLOW: STRONG POLEWARD
ANALYSIS CONFIDENCE:
INITIAL POSITION: HIGH
INITIAL INTENSITY: MEDIUM
INITIAL WIND RADII: MEDIUM
3. FORECAST REASONING.
SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO
THE FORECAST FROM THE PREVIOUS WARNING.
FORECAST DISCUSSION: TS DORA WILL CONTINUE ON A NORTHWESTWARD TRACK
PASSING APPROXIMATELY 105NM NORTHEAST OF WAKE ISLAND BY 141600Z.
AFTER TAU 12, THE CYCLONE WILL TRACK NORTHWARD AS THE STR RECEDES
EASTWARD. THE MARGINAL ENVIRONMENT WILL SUSTAIN THE CURRENT
INTENSITY UP TO TAU 72. AFTERWARD, INCREASED OUTFLOW AHEAD OF A
MID-LATITUDE TROUGH WILL WEAKEN THE STR AND DRIVE THE SYSTEM
NORTHEASTWARD, INCREASE THE POLEWARD OUTFLOW AND SLIGHTLY INTENSIFY
THE SYSTEM TO 40KTS BY TAU 96 BEFORE STRONG VWS ONCE AGAIN OFFSETS
THE STRONG OUTFLOW, REDUCING IT BACK TO 35KTS BY TAU 120. THERE IS
A DISTINCT POSSIBILITY THAT STRONG VWS WILL BE OVERWHELMING AND
DISSIPATE THE SYSTEM BEFORE TAU 120.
MODEL DISCUSSION: NUMERICAL MODELS ARE IN GOOD AGREEMENT; HOWEVER,
GIVEN THE INHERENT ERRATIC STORM MOTION OF AN EXPOSED LLC AND THE
POSSIBILITY OF AN EARLY DISSIPATION, THERE IS MEDIUM CONFIDENCE IN THE
JTWC TRACK AND INTENSITY FORECASTS UP TO TAU 72, THEN LOW CONFIDENCE
AFTERWARD.
FORECAST CONFIDENCE:
TRACK 0 - 72 HR: MEDIUM
TRACK 72-120 HR: LOW
INTENSITY 0 - 72 HR: MEDIUM
INTENSITY 72-120 HR: LOW//
NNNN
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 05E (DORA) WARNING NR
056//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
SUMMARY:
INITIAL POSITION: 19.3N 169.2E
INITIAL INTENSITY: 35 KTS
GEOGRAPHIC REFERENCE: 145 NM EAST OF WAKE ISLAND
MOVEMENT PAST 6 HOURS: NORTHWESTWARD AT 10 KTS
SIGNIFICANT WAVE HEIGHT: 12 FEET
SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY (GOES H-8 PROXY
VIS) SHOWS A SYSTEM WITH ITS FLARING CENTRAL CONVECTION SEVERELY
SHEARED NORTHEASTWARD, INTERMITTENTLY EXPOSING THE LOW-LEVEL
CIRCULATION (LLC). THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE
BASED ON THE MOSTLY EXPOSED LLC IN THE EIR LOOP. THE INITIAL INTENSITY
OF 35KTS IS PLACED WITH MEDIUM CONFIDENCE BASED ON OVERALL ASSESSMENT
OF AGENCY AND AUTOMATED DVORAK ESTIMATES AND REFLECTS THE SLIGHT 6-HR
CONVECTIVE DEGRADATION. ANALYSIS INDICATES A MARGINAL ENVIRONMENT WITH
WARM SST AND STRONG POLEWARD OUTFLOW GREATLY OFFSET BY STRONG
SOUTHWESTERLY VWS.
INITIAL WIND RADII BASIS: PERSISTENCE.
CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE (STR) TO THE
NORTHEAST.
AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T2.5 - 35 KTS
RJTD: T3.0 - 45 KTS
KNES: T2.0 - 30 KTS
PHFO: T3.0 - 45 KTS
CIMSS ADT: 32 KTS AT 140540Z
FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINAL
VWS: 20+ KTS
SST: 28-29 CELSIUS
OUTFLOW: STRONG POLEWARD
ANALYSIS CONFIDENCE:
INITIAL POSITION: HIGH
INITIAL INTENSITY: MEDIUM
INITIAL WIND RADII: MEDIUM
3. FORECAST REASONING.
SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO
THE FORECAST FROM THE PREVIOUS WARNING.
FORECAST DISCUSSION: TS DORA WILL CONTINUE ON A NORTHWESTWARD TRACK
PASSING APPROXIMATELY 105NM NORTHEAST OF WAKE ISLAND BY 141600Z.
AFTER TAU 12, THE CYCLONE WILL TRACK NORTHWARD AS THE STR RECEDES
EASTWARD. THE MARGINAL ENVIRONMENT WILL SUSTAIN THE CURRENT
INTENSITY UP TO TAU 72. AFTERWARD, INCREASED OUTFLOW AHEAD OF A
MID-LATITUDE TROUGH WILL WEAKEN THE STR AND DRIVE THE SYSTEM
NORTHEASTWARD, INCREASE THE POLEWARD OUTFLOW AND SLIGHTLY INTENSIFY
THE SYSTEM TO 40KTS BY TAU 96 BEFORE STRONG VWS ONCE AGAIN OFFSETS
THE STRONG OUTFLOW, REDUCING IT BACK TO 35KTS BY TAU 120. THERE IS
A DISTINCT POSSIBILITY THAT STRONG VWS WILL BE OVERWHELMING AND
DISSIPATE THE SYSTEM BEFORE TAU 120.
MODEL DISCUSSION: NUMERICAL MODELS ARE IN GOOD AGREEMENT; HOWEVER,
GIVEN THE INHERENT ERRATIC STORM MOTION OF AN EXPOSED LLC AND THE
POSSIBILITY OF AN EARLY DISSIPATION, THERE IS MEDIUM CONFIDENCE IN THE
JTWC TRACK AND INTENSITY FORECASTS UP TO TAU 72, THEN LOW CONFIDENCE
AFTERWARD.
FORECAST CONFIDENCE:
TRACK 0 - 72 HR: MEDIUM
TRACK 72-120 HR: LOW
INTENSITY 0 - 72 HR: MEDIUM
INTENSITY 72-120 HR: LOW//
NNNN
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cycloneye
- Admin
- Posts: 139494
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- Location: San Juan, Puerto Rico
Re: WPAC: DORA - Tropical Storm - Discussion
WDPN32 PGTW 141500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 05E (DORA) WARNING NR
057//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
SUMMARY:
INITIAL POSITION: 19.8N 168.4E
INITIAL INTENSITY: 40 KTS
GEOGRAPHIC REFERENCE: 110 NM EAST-NORTHEAST OF WAKE ISLAND
MOVEMENT PAST 6 HOURS: NORTHWESTWARD AT 09 KTS
SIGNIFICANT WAVE HEIGHT: 14 FEET
SATELLITE ANALYSIS, INITIAL POSITION, AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY (GOES H-8
PROXY VIS) SHOWS A SYSTEM WITH ITS FLARING CENTRAL CONVECTION SEVERELY
SHEARED NORTHEASTWARD, INTERMITTENTLY EXPOSING THE LOW LEVEL
CIRCULATION (LLC). THE INITIAL POSITION AND INTENSITY ARE PLACED
WITH HIGH CONFIDENCE BASED ON EXTRAPOLATION FROM THE 141032Z ASCAT
BULLSEYE PASS. INITIAL INTENSITY OF 40KTS IS ALSO SUPPORTED BY AN
OVERALL ASSESSMENT OF AGENCY AND AUTOMATED DVORAK ESTIMATES AND
REFLECTS THE 6-HR CONVECTIVE INCREASE. ANALYSIS INDICATES A
MARGINAL ENVIRONMENT WITH WARM SST AND STRONG POLEWARD OUTFLOW
GREATLY OFFSET BY STRONG SOUTHWESTERLY VWS.
INITIAL WIND RADII BASIS: SCATTEROMETER DATA.
CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE (STR) TO THE
NORTHEAST.
AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T3.0 - 45 KTS
RJTD: T3.0 - 45 KTS
RCTP: T2.5 - 35 KTS
KNES: T2.0 - 30 KTS
CIMSS ADT: 41 KTS AT 141350Z
FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINAL
VWS: 20+ KTS
SST: 28-29 CELSIUS
OUTFLOW: STRONG POLEWARD
ANALYSIS CONFIDENCE:
INITIAL POSITION: HIGH
INITIAL INTENSITY: HIGH
INITIAL WIND RADII: HIGH
3. FORECAST REASONING.
SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO
THE FORECAST FROM THE PREVIOUS WARNING.
FORECAST DISCUSSION: TS DORA WILL CONTINUE ON A NORTHWESTWARD TRACK
PASSING APPROXIMATELY 105NM NORTHEAST OF WAKE ISLAND BY 141400Z.
AFTER TAU 12, THE CYCLONE WILL TRACK NORTHWARD AS THE STR RECEDES
EASTWARD. THE MARGINAL ENVIRONMENT WILL SUSTAIN THE CURRENT
INTENSITY UP TO TAU 48. AFTERWARD, INCREASED OUTFLOW AHEAD OF A
MID-LATITUDE TROUGH WILL WEAKEN THE STR AND DRIVE THE SYSTEM
NORTHEASTWARD, INCREASE THE POLEWARD OUTFLOW AND SLIGHTLY INTENSIFY
THE SYSTEM TO 45KTS UP TO TAU 96 BEFORE STRONG VWS ONCE AGAIN
OFFSETS THE STRONG OUTFLOW, REDUCING IT TO 35KTS BY TAU 120. THERE
IS A DISTINCT POSSIBILITY THAT STRONG VWS WILL BE OVERWHELMING AND
DISSIPATE THE SYSTEM BEFORE TAU 120.
MODEL DISCUSSION: NUMERICAL MODELS ARE IN GOOD AGREEMENT; HOWEVER,
GIVEN THE INHERENT ERRATIC STORM MOTION OF AN INTERMITTENTLY
EXPOSED LLC AND THE POSSIBILITY OF AN EARLY DISSIPATION, THERE IS
ONLY MEDIUM CONFIDENCE IN THE JTWC TRACK AND INTENSITY FORECASTS UP
TO TAU 72, THEN LOW CONFIDENCE AFTERWARD.
FORECAST CONFIDENCE:
TRACK 0 - 72 HR: MEDIUM
TRACK 72-120 HR: LOW
INTENSITY 0 - 72 HR: MEDIUM
INTENSITY 72-120 HR: LOW//
NNNN
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 05E (DORA) WARNING NR
057//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
SUMMARY:
INITIAL POSITION: 19.8N 168.4E
INITIAL INTENSITY: 40 KTS
GEOGRAPHIC REFERENCE: 110 NM EAST-NORTHEAST OF WAKE ISLAND
MOVEMENT PAST 6 HOURS: NORTHWESTWARD AT 09 KTS
SIGNIFICANT WAVE HEIGHT: 14 FEET
SATELLITE ANALYSIS, INITIAL POSITION, AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY (GOES H-8
PROXY VIS) SHOWS A SYSTEM WITH ITS FLARING CENTRAL CONVECTION SEVERELY
SHEARED NORTHEASTWARD, INTERMITTENTLY EXPOSING THE LOW LEVEL
CIRCULATION (LLC). THE INITIAL POSITION AND INTENSITY ARE PLACED
WITH HIGH CONFIDENCE BASED ON EXTRAPOLATION FROM THE 141032Z ASCAT
BULLSEYE PASS. INITIAL INTENSITY OF 40KTS IS ALSO SUPPORTED BY AN
OVERALL ASSESSMENT OF AGENCY AND AUTOMATED DVORAK ESTIMATES AND
REFLECTS THE 6-HR CONVECTIVE INCREASE. ANALYSIS INDICATES A
MARGINAL ENVIRONMENT WITH WARM SST AND STRONG POLEWARD OUTFLOW
GREATLY OFFSET BY STRONG SOUTHWESTERLY VWS.
INITIAL WIND RADII BASIS: SCATTEROMETER DATA.
CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE (STR) TO THE
NORTHEAST.
AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T3.0 - 45 KTS
RJTD: T3.0 - 45 KTS
RCTP: T2.5 - 35 KTS
KNES: T2.0 - 30 KTS
CIMSS ADT: 41 KTS AT 141350Z
FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINAL
VWS: 20+ KTS
SST: 28-29 CELSIUS
OUTFLOW: STRONG POLEWARD
ANALYSIS CONFIDENCE:
INITIAL POSITION: HIGH
INITIAL INTENSITY: HIGH
INITIAL WIND RADII: HIGH
3. FORECAST REASONING.
SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO
THE FORECAST FROM THE PREVIOUS WARNING.
FORECAST DISCUSSION: TS DORA WILL CONTINUE ON A NORTHWESTWARD TRACK
PASSING APPROXIMATELY 105NM NORTHEAST OF WAKE ISLAND BY 141400Z.
AFTER TAU 12, THE CYCLONE WILL TRACK NORTHWARD AS THE STR RECEDES
EASTWARD. THE MARGINAL ENVIRONMENT WILL SUSTAIN THE CURRENT
INTENSITY UP TO TAU 48. AFTERWARD, INCREASED OUTFLOW AHEAD OF A
MID-LATITUDE TROUGH WILL WEAKEN THE STR AND DRIVE THE SYSTEM
NORTHEASTWARD, INCREASE THE POLEWARD OUTFLOW AND SLIGHTLY INTENSIFY
THE SYSTEM TO 45KTS UP TO TAU 96 BEFORE STRONG VWS ONCE AGAIN
OFFSETS THE STRONG OUTFLOW, REDUCING IT TO 35KTS BY TAU 120. THERE
IS A DISTINCT POSSIBILITY THAT STRONG VWS WILL BE OVERWHELMING AND
DISSIPATE THE SYSTEM BEFORE TAU 120.
MODEL DISCUSSION: NUMERICAL MODELS ARE IN GOOD AGREEMENT; HOWEVER,
GIVEN THE INHERENT ERRATIC STORM MOTION OF AN INTERMITTENTLY
EXPOSED LLC AND THE POSSIBILITY OF AN EARLY DISSIPATION, THERE IS
ONLY MEDIUM CONFIDENCE IN THE JTWC TRACK AND INTENSITY FORECASTS UP
TO TAU 72, THEN LOW CONFIDENCE AFTERWARD.
FORECAST CONFIDENCE:
TRACK 0 - 72 HR: MEDIUM
TRACK 72-120 HR: LOW
INTENSITY 0 - 72 HR: MEDIUM
INTENSITY 72-120 HR: LOW//
NNNN
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Sciencerocks
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cycloneye
- Admin
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- Joined: Thu Oct 10, 2002 10:54 am
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Re: WPAC: DORA - Tropical Storm - Discussion
WDPN32 PGTW 142100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 05E (DORA) WARNING NR
058//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
SUMMARY:
INITIAL POSITION: 20.5N 168.4E
INITIAL INTENSITY: 35 KTS
GEOGRAPHIC REFERENCE: 125 NM NORTHEAST OF WAKE ISLAND
MOVEMENT PAST 6 HOURS: NORTH-NORTHWESTWARD AT 09 KTS
SIGNIFICANT WAVE HEIGHT: 15 FEET
SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A RAGGED,
SHEARED AND DISORGANIZED SYSTEM, WITH FLARING CONVECTION DISPLACED
TO THE EAST OF A PARTIALLY EXPOSED LOW LEVEL CIRCULATION CENTER
(LLCC). THE PRESENCE OF STRONG TUTT-CELL ONLY A COUPLE HUNDRED
MILES TO THE WEST IS PRODUCING OFFSETTING INFLUENCES ON TROPICAL
STORM (TS) 05E (DORA). FIRST, THE CLOSE PROXIMITY OF THE TUTT IS
INDUCING CONVERGENT AND SUBSIDENT NORTHWESTERLY FLOW ON THE WESTERN
SIDE OF THE SYSTEM. THE DIVERGENT PORTION OF THE TUTT LIES JUST
EAST OF THE LLCC, WHICH IS ENHANCING THE CONVECTIVE DEVELOPMENT ON
THE EASTERN SIDE OF THE SYSTEM. A 141633Z SSMIS 89GHZ MICROWAVE
IMAGE SHOWED THE EXPOSED AND VERY SMALL LLCC, WITH FRAGMENTARY AND
DISORGANIZED CONVECTION DISPLACED TO THE EAST. THE INITIAL POSITION
IS ASSESSED WITH HIGH CONFIDENCE BASED ON COMBINATION OF THE
PARTIALLY EXPOSED LLCC AND AN EXTRAPOLATION OF THE MICROWAVE
IMAGERY. THE INITIAL INTENSITY IS ASSESSED WITH LOW CONFIDENCE,
PRIMARILY BASED ON PERSISTENCE WITH EARLIER SCATTEROMETER DATA
WHICH SHOWED A SMALL REGION OF 35 KNOT WINDS IN THE NORTHEASTERN
QUADRANT. SUBJECTIVE AND OBJECTIVE DVORAK INTENSITY ESTIMATES USING
THE SHEAR METHOD ARE GENERATING INTENSITY ESTIMATES IN AGREEMENT
WITH THE JTWC ASSESSMENT.
INITIAL WIND RADII BASIS: PERSISTENCE WITH EARLIER SCATTEROMETER
DATA
CURRENT STEERING MECHANISM: WESTERN PERIPHERY OF A DEEP-LAYER
SUBTROPICAL RIDGE (STR) TO THE EAST.
AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T3.0 - 45 KTS
RJTD: T3.0 - 45 KTS
RCTP: T2.0 - 30 KTS
CIMSS ADT: 41 KTS AT 141430Z
FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINAL
VWS: 10-15 KTS
SST: 28-29 CELSIUS
OUTFLOW: STRONG POLEWARD
OTHER FACTORS: CONVERGENT SUBSIDENT FLOW ON THE WESTERN SIDE
ANALYSIS CONFIDENCE:
INITIAL POSITION: HIGH
INITIAL INTENSITY: LOW
INITIAL WIND RADII: LOW
3. FORECAST REASONING.
SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO
THE FORECAST FROM THE PREVIOUS WARNING.
FORECAST DISCUSSION: TS DORA IS EXPECTED TO SLOWLY TRACK TOWARDS
THE NORTH ALONG THE WESTERN SIDE OF THE STEERING RIDGE, THROUGH THE
MAJORITY OF THE FORECAST PERIOD. A SERIES OF DEEP MID-LATITUDE
TROUGHS ARE EXPECTED TO PASS BY TO THE NORTH OF THE SYSTEM THROUGH
THE NEXT FEW DAYS. THE FIRST OF THESE TROUGHS WILL PASS WITHOUT
MUCH INFLUENCE ON THE SYSTEM. THE SECOND OF THESE TROUGHS WILL ALSO
PASS BY TO THE NORTH BUT HAVE A GREATER IMPACT ON THE SYSTEM.
THROUGH THE NEXT 24 HOURS, THE CLOSE PROXIMITY OF THE TUTT-CELL TO
THE NORTHWEST WILL INDUCE NEGATIVE EFFECTS OF CONVERGENT FLOW ALOFT
AND MODERATE WESTERLY SHEAR, LEADING TO A GENTLE WEAKENING DOWN TO
30 KNOTS. AFTER TAU 24, THE TUTT BEGINS TO SHIFT TO THE SOUTHWEST
WHILE TS DORA MOVES NORTH, AND AT THE SAME TIME THE SECOND TROUGH
PASSES BY TO THE NORTH. THE COMBINED EFFECTS OF THESE PATTERN
SHIFTS WILL LEAD TO IMPROVED UPPER-LEVEL DIVERGENCE, AND DECREASED
SHEAR, SUPPORTING A SPURT OF INTENSIFICATION TO 45 KNOTS BY TAU 72.
AFTER TAU 72, THE THIRD IN THE TRAIN OF UPPER-LEVEL TROUGHS WILL
MOVE IN FROM THE WEST, AND TURN TS DORA ONTO A MORE NORTHEASTWARD
TRACK THROUGH THE REMAINDER OF THE FORECAST PERIOD. AS THE SYSTEM
MOVES INTO THE BASE OF THE MID-LATITUDE TROUGH AND ASSOCIATED JET
FINGER, IT WILL BEGIN EXTRATROPICAL TRANSITION (ETT), WITH
TRANSITION TO A GALE-FORCE LOW PRESSURE AREA BY TAU 120.
MODEL DISCUSSION: TRACK GUIDANCE IS IN GOOD AGREEMENT ON OVERALL
TRACK SCENARIO, WITH MINIMAL CROSS-TRACK SPREAD THROUGH THE ENTIRE
FORECAST PERIOD. ALONG-TRACK SPREAD INCREASES SHARPLY AFTER TAU 96
AS THE SYSTEM BEGINS ETT, LENDING HIGH CONFIDENCE THROUGH THE FIRST
72 HOURS OF THE FORECAST, TRENDING TO LOW CONFIDENCE THROUGH THE
ETT PHASE. INTENSITY GUIDANCE IS MIXED, WITH THE SHIPS (GFS AND
NAVGEM), ALONG WITH BOTH VERSIONS OF COAMPS-TC INDICATING
INTENSIFICATION FROM THE GET-GO, TO A PEAK AS HIGH AS 60 KNOTS BY
TAU 96. MEANWHILE THE GFS AND HAFS-A SUGGEST NEAR-TERM WEAKENING,
FOLLOWED BY REINTENSIFICATION TO A PEAK AROUND 40-45 KNOTS FOLLOWED
BY WEAKENING DURING ETT. BASED ON THE OVERALL ASSESSMENT OF THE
ENVIRONMENTAL PARAMETERS, THE JTWC FORECAST CLOSELY FOLLOWS THE
HAFS-A FORECAST WITH MEDIUM CONFIDENCE.
FORECAST CONFIDENCE:
TRACK 0 - 72 HR: HIGH
TRACK 72-120 HR: LOW
INTENSITY 0 - 72 HR: MEDIUM
INTENSITY 72-120 HR: MEDIUM//
NNNN
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 05E (DORA) WARNING NR
058//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
SUMMARY:
INITIAL POSITION: 20.5N 168.4E
INITIAL INTENSITY: 35 KTS
GEOGRAPHIC REFERENCE: 125 NM NORTHEAST OF WAKE ISLAND
MOVEMENT PAST 6 HOURS: NORTH-NORTHWESTWARD AT 09 KTS
SIGNIFICANT WAVE HEIGHT: 15 FEET
SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A RAGGED,
SHEARED AND DISORGANIZED SYSTEM, WITH FLARING CONVECTION DISPLACED
TO THE EAST OF A PARTIALLY EXPOSED LOW LEVEL CIRCULATION CENTER
(LLCC). THE PRESENCE OF STRONG TUTT-CELL ONLY A COUPLE HUNDRED
MILES TO THE WEST IS PRODUCING OFFSETTING INFLUENCES ON TROPICAL
STORM (TS) 05E (DORA). FIRST, THE CLOSE PROXIMITY OF THE TUTT IS
INDUCING CONVERGENT AND SUBSIDENT NORTHWESTERLY FLOW ON THE WESTERN
SIDE OF THE SYSTEM. THE DIVERGENT PORTION OF THE TUTT LIES JUST
EAST OF THE LLCC, WHICH IS ENHANCING THE CONVECTIVE DEVELOPMENT ON
THE EASTERN SIDE OF THE SYSTEM. A 141633Z SSMIS 89GHZ MICROWAVE
IMAGE SHOWED THE EXPOSED AND VERY SMALL LLCC, WITH FRAGMENTARY AND
DISORGANIZED CONVECTION DISPLACED TO THE EAST. THE INITIAL POSITION
IS ASSESSED WITH HIGH CONFIDENCE BASED ON COMBINATION OF THE
PARTIALLY EXPOSED LLCC AND AN EXTRAPOLATION OF THE MICROWAVE
IMAGERY. THE INITIAL INTENSITY IS ASSESSED WITH LOW CONFIDENCE,
PRIMARILY BASED ON PERSISTENCE WITH EARLIER SCATTEROMETER DATA
WHICH SHOWED A SMALL REGION OF 35 KNOT WINDS IN THE NORTHEASTERN
QUADRANT. SUBJECTIVE AND OBJECTIVE DVORAK INTENSITY ESTIMATES USING
THE SHEAR METHOD ARE GENERATING INTENSITY ESTIMATES IN AGREEMENT
WITH THE JTWC ASSESSMENT.
INITIAL WIND RADII BASIS: PERSISTENCE WITH EARLIER SCATTEROMETER
DATA
CURRENT STEERING MECHANISM: WESTERN PERIPHERY OF A DEEP-LAYER
SUBTROPICAL RIDGE (STR) TO THE EAST.
AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T3.0 - 45 KTS
RJTD: T3.0 - 45 KTS
RCTP: T2.0 - 30 KTS
CIMSS ADT: 41 KTS AT 141430Z
FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINAL
VWS: 10-15 KTS
SST: 28-29 CELSIUS
OUTFLOW: STRONG POLEWARD
OTHER FACTORS: CONVERGENT SUBSIDENT FLOW ON THE WESTERN SIDE
ANALYSIS CONFIDENCE:
INITIAL POSITION: HIGH
INITIAL INTENSITY: LOW
INITIAL WIND RADII: LOW
3. FORECAST REASONING.
SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO
THE FORECAST FROM THE PREVIOUS WARNING.
FORECAST DISCUSSION: TS DORA IS EXPECTED TO SLOWLY TRACK TOWARDS
THE NORTH ALONG THE WESTERN SIDE OF THE STEERING RIDGE, THROUGH THE
MAJORITY OF THE FORECAST PERIOD. A SERIES OF DEEP MID-LATITUDE
TROUGHS ARE EXPECTED TO PASS BY TO THE NORTH OF THE SYSTEM THROUGH
THE NEXT FEW DAYS. THE FIRST OF THESE TROUGHS WILL PASS WITHOUT
MUCH INFLUENCE ON THE SYSTEM. THE SECOND OF THESE TROUGHS WILL ALSO
PASS BY TO THE NORTH BUT HAVE A GREATER IMPACT ON THE SYSTEM.
THROUGH THE NEXT 24 HOURS, THE CLOSE PROXIMITY OF THE TUTT-CELL TO
THE NORTHWEST WILL INDUCE NEGATIVE EFFECTS OF CONVERGENT FLOW ALOFT
AND MODERATE WESTERLY SHEAR, LEADING TO A GENTLE WEAKENING DOWN TO
30 KNOTS. AFTER TAU 24, THE TUTT BEGINS TO SHIFT TO THE SOUTHWEST
WHILE TS DORA MOVES NORTH, AND AT THE SAME TIME THE SECOND TROUGH
PASSES BY TO THE NORTH. THE COMBINED EFFECTS OF THESE PATTERN
SHIFTS WILL LEAD TO IMPROVED UPPER-LEVEL DIVERGENCE, AND DECREASED
SHEAR, SUPPORTING A SPURT OF INTENSIFICATION TO 45 KNOTS BY TAU 72.
AFTER TAU 72, THE THIRD IN THE TRAIN OF UPPER-LEVEL TROUGHS WILL
MOVE IN FROM THE WEST, AND TURN TS DORA ONTO A MORE NORTHEASTWARD
TRACK THROUGH THE REMAINDER OF THE FORECAST PERIOD. AS THE SYSTEM
MOVES INTO THE BASE OF THE MID-LATITUDE TROUGH AND ASSOCIATED JET
FINGER, IT WILL BEGIN EXTRATROPICAL TRANSITION (ETT), WITH
TRANSITION TO A GALE-FORCE LOW PRESSURE AREA BY TAU 120.
MODEL DISCUSSION: TRACK GUIDANCE IS IN GOOD AGREEMENT ON OVERALL
TRACK SCENARIO, WITH MINIMAL CROSS-TRACK SPREAD THROUGH THE ENTIRE
FORECAST PERIOD. ALONG-TRACK SPREAD INCREASES SHARPLY AFTER TAU 96
AS THE SYSTEM BEGINS ETT, LENDING HIGH CONFIDENCE THROUGH THE FIRST
72 HOURS OF THE FORECAST, TRENDING TO LOW CONFIDENCE THROUGH THE
ETT PHASE. INTENSITY GUIDANCE IS MIXED, WITH THE SHIPS (GFS AND
NAVGEM), ALONG WITH BOTH VERSIONS OF COAMPS-TC INDICATING
INTENSIFICATION FROM THE GET-GO, TO A PEAK AS HIGH AS 60 KNOTS BY
TAU 96. MEANWHILE THE GFS AND HAFS-A SUGGEST NEAR-TERM WEAKENING,
FOLLOWED BY REINTENSIFICATION TO A PEAK AROUND 40-45 KNOTS FOLLOWED
BY WEAKENING DURING ETT. BASED ON THE OVERALL ASSESSMENT OF THE
ENVIRONMENTAL PARAMETERS, THE JTWC FORECAST CLOSELY FOLLOWS THE
HAFS-A FORECAST WITH MEDIUM CONFIDENCE.
FORECAST CONFIDENCE:
TRACK 0 - 72 HR: HIGH
TRACK 72-120 HR: LOW
INTENSITY 0 - 72 HR: MEDIUM
INTENSITY 72-120 HR: MEDIUM//
NNNN
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cycloneye
- Admin
- Posts: 139494
- Age: 67
- Joined: Thu Oct 10, 2002 10:54 am
- Location: San Juan, Puerto Rico
Re: WPAC: DORA - Tropical Depression - Discussion
WDPN32 PGTW 150300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 05E (DORA) WARNING
NR 059//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
SUMMARY:
INITIAL POSITION: 20.5N 167.8E
INITIAL INTENSITY: 30 KTS
GEOGRAPHIC REFERENCE: 100 NM NORTHEAST OF WAKE ISLAND
MOVEMENT PAST 6 HOURS: WEST-NORTHWESTWARD AT 06 KTS
SIGNIFICANT WAVE HEIGHT: 12 FEET
SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
TROPICAL DEPRESSION (TD) 05E (DORA) HAS OVER THE PAST SIX HOURS,
COMPLETELY CHANGED IN CHARACTER. OVERNIGHT, UP TO SIX HOURS AGO,
THE SYSTEM DISPLAYED DEEP, WELL-ORGANIZED CONVECTION, WITH A
LOW LEVEL CIRCULATION CENTER (LLCC) TUCKED UNDER THE CONVECTIVE
MASS. IN THE HOURS SINCE 1800Z, ANIMATED MULTISPECTRAL SATELLITE
IMAGERY (MSI) INDICATES THE CONVECTION HAS DISSIPATED AND THE LLCC,
SUCH AS IT IS, HAS PEAKED OUT TO THE WEST AND IS NOW FULLY EXPOSED.
A RECENT 142304Z ASCAT-B PASS, WHILE NOT CAPTURING THE EASTERN
SEMICIRCLE, WHERE THE HIGHEST WINDS LIKELY LURK, DID SHOW THAT THE
REMAINDER OF THE WIND FIELD IS ANEMIC, WITH MAXIMUM WINDS OF 20-25
KNOTS. THUS THE INITIAL INTENSITY IS LOWERED TO 30 KNOTS ON THE
ASSUMPTION THAT HIGHER WINDS REMAIN IN THE EASTERN SEMICIRCLE.
DVORAK-BASED INTENSITY ESTIMATES OF T2.0 TO T2.5, MOSTLY USING THE
SHEAR TECHNIQUE, ARE GENERALLY CONSISTENT WITH THE SCATTEROMETER
DATA AND PROVIDE MODERATE LEVELS OF CONFIDENCE TO THE INITIAL
INTENSITY. ENVIRONMENTALLY, TD 05E IS A TALE OF TWO SYSTEMS. THE
LLCC HAS MOVED CLOSER THAN ORIGINALLY ANTICIPATED TO THE STRONG
TUTT-CELL LOCATED NEAR 26N 166E, WHICH HAS THROUGH A COMBINATION OF
SUBSIDENCE AND CONVERGENCE ALOFT AND WESTERLY SHEAR, BASICALLY
SMOTHERED TD 05E. THE FAR EASTERN PERIPHERY OF THE CIRCULATION IS
STILL UNDER THE DIVERGENT PORTION OF THE TUTT-CELL RELATED FLOW
ALOFT ACCORDING TO WATER VAPOR VISIBLE IMAGERY, AND THUS CONTINUES
TO EXHIBIT FLARING BUT DISORGANIZED CONVECTION. AFTER BEGIN
DECAPITATED AND SMOTHERED, THE REMNANT LOW-LEVEL VORTEX HAS COME
UNDER THE STEERING INFLUENCE OF THE LOW TO MID-LEVEL FLOW,
CURRENTLY DOMINATED BY A GENERALLY EAST-WEST ORIENTED RIDGE AXIS
ALONG THE 30N LATITUDE.
INITIAL WIND RADII BASIS: NOT APPLICABLE (THERE ARE NO INITIAL WIND
RADII).
CURRENT STEERING MECHANISM: LOW TO MID-LEVEL SUBTROPICAL RIDGE
(STR) TO THE NORTH.
AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T2.5 - 35 KTS
RCTP: T2.0 - 30 KTS
KNES: T2.0 - 30 KTS
CIMSS ADT: 45 KTS AT 142330Z
FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: UNFAVORABLE
VWS: 15-20 KTS
SST: 28-29 CELSIUS
OUTFLOW: MODERATE POLEWARD
ANALYSIS CONFIDENCE:
INITIAL POSITION: HIGH
INITIAL INTENSITY: MEDIUM
INITIAL WIND RADII: NOT APPLICABLE
3. FORECAST REASONING.
SIGNIFICANT FORECAST CHANGES: THIS IS A SIGNIFICANT FORECAST
PHILOSOPHY CHANGE, TRUNCATING THE FORECAST TO 72 HOURS AND CHANGING
THE END-PHASE FROM EXTRATROPICAL TRANSITION (ETT) TO DISSIPATION.
FORECAST DISCUSSION: NOW THAT THE SYSTEM HAS WEAKENING AND
SHALLOWED OUT, IT IS NOW BEING STEERED BY THE LOW-LEVEL FLOW, WHICH
IS GENERALLY GOING TO PUSH IT TOWARDS THE WEST-NORTHWEST, ALTHOUGH
THE WEAK GRADIENT MEANS THAT TRACK SPEEDS WILL BE FAIRLY LOW. AFTER
TAU 36 THE SYSTEM WILL PICK UP SPEED AND TRACK NORTHEAST AS IT GETS
PICKED UP BY THE TAIL END OF A WEAK FRONTAL BOUNDARY. AS DISCUSSED
ABOVE, THE MOVEMENT OF THE TUTT-CELL TO THE EAST AND TD 05E
MOVEMENT TO THE WEST HAS RESULTED IN THE LLCC MOVING UNDER THE
DIRECT INFLUENCE OF THE TUTT-CELL. AS LONG AS THESE TWO FEATURES
REMAIN IN THE SAME GENERAL SPATIAL RELATIONSHIP, TD 05E WILL HAVE
LITTLE TO NO CHANCE OF SURVIVAL. THE LATEST MODEL GUIDANCE SHOWS
EXACTLY THIS OUTCOME, AND WITH THAT, THE FORECAST HAS BEEN
SIGNIFICANTLY TRUNCATED. SHORT-LIVED FLARE-UPS OF CONVECTION REMAIN
POSSIBLE, PARTICULARLY ON THE EASTERN PERIPHERY OF THE SYSTEM AND
MOST LIKELY DURING DIURNAL MAXIMUM. HOWEVER, THE CONTINUED PRESENCE
OF THE TUTT WILL MEAN THAT THIS CONVECTION WILL REMAIN DISORGANIZED
AND THE LLCC WILL MOST LIKELY REMAIN NAKED AND AFRAID, UNDER THE
SMOTHERING INFLUENCE OF THE SUBSIDENCE ALOFT. THE LLCC WILL TAKE
TIME TO SPIN DOWN, AND THUS THE FORECAST CALLS FOR A SLOW WEAKENING
TO DISSIPATION BY TAU 72. HOWEVER, IT IS POSSIBLE THAT THE SYSTEM
WEAKENS MORE QUICKLY, AND DISSIPATES AS EARLY AS TAU 48.
MODEL DISCUSSION: THE JTWC FORECAST TRACK DEVIATES FROM THE
CONSENSUS GUIDANCE, WHICH IS STILL STEERING THE SYSTEM BASED ON THE
DEEP-LAYER STEERING PATTERN. BUT THIS OBVIOUSLY IS NOT THE CASE,
AND THE FORECAST TRACK IS BASED PRIMARILY ON ANALYSIS OF THE 850MB
MEAN WIND FLOW. AS A RESULT, CONFIDENCE IS HARD TO QUANTIFY, BUT DUE
TO
THE RAPIDLY CHANGING CONDITIONS AND SIGNIFICANT FORECAST CHANGE,
CONFIDENCE IS CURRENTLY ASSESSED AS LOW. INTENSITY GUIDANCE IS
SIMILARLY CHALLENGED, WITH ALL CONSENSUS MEMBERS EXCEPT FOR HAFS-A
REMAINING EXCITED ABOUT THE SYSTEM, INTENSIFYING IT EVEN MORE THAN
THE PREVIOUS FORECAST PACKAGE. COAMPS-TC TAKES IT UP TO DIZZYING
HEIGHTS OF NEAR 60 KNOTS BY TAU 72. THE JTWC FORECAST DEVIATES FROM
THE GUIDANCE AND DISSIPATES THE SYSTEM BY TAU 72. IN A SIMILAR
MANNER TO THE TRACK FORECAST, CONFIDENCE IS LOW.
FORECAST CONFIDENCE:
TRACK 0 - 72 HR: LOW
INTENSITY 0 - 72 HR: LOW//
NNNN
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 05E (DORA) WARNING
NR 059//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
SUMMARY:
INITIAL POSITION: 20.5N 167.8E
INITIAL INTENSITY: 30 KTS
GEOGRAPHIC REFERENCE: 100 NM NORTHEAST OF WAKE ISLAND
MOVEMENT PAST 6 HOURS: WEST-NORTHWESTWARD AT 06 KTS
SIGNIFICANT WAVE HEIGHT: 12 FEET
SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
TROPICAL DEPRESSION (TD) 05E (DORA) HAS OVER THE PAST SIX HOURS,
COMPLETELY CHANGED IN CHARACTER. OVERNIGHT, UP TO SIX HOURS AGO,
THE SYSTEM DISPLAYED DEEP, WELL-ORGANIZED CONVECTION, WITH A
LOW LEVEL CIRCULATION CENTER (LLCC) TUCKED UNDER THE CONVECTIVE
MASS. IN THE HOURS SINCE 1800Z, ANIMATED MULTISPECTRAL SATELLITE
IMAGERY (MSI) INDICATES THE CONVECTION HAS DISSIPATED AND THE LLCC,
SUCH AS IT IS, HAS PEAKED OUT TO THE WEST AND IS NOW FULLY EXPOSED.
A RECENT 142304Z ASCAT-B PASS, WHILE NOT CAPTURING THE EASTERN
SEMICIRCLE, WHERE THE HIGHEST WINDS LIKELY LURK, DID SHOW THAT THE
REMAINDER OF THE WIND FIELD IS ANEMIC, WITH MAXIMUM WINDS OF 20-25
KNOTS. THUS THE INITIAL INTENSITY IS LOWERED TO 30 KNOTS ON THE
ASSUMPTION THAT HIGHER WINDS REMAIN IN THE EASTERN SEMICIRCLE.
DVORAK-BASED INTENSITY ESTIMATES OF T2.0 TO T2.5, MOSTLY USING THE
SHEAR TECHNIQUE, ARE GENERALLY CONSISTENT WITH THE SCATTEROMETER
DATA AND PROVIDE MODERATE LEVELS OF CONFIDENCE TO THE INITIAL
INTENSITY. ENVIRONMENTALLY, TD 05E IS A TALE OF TWO SYSTEMS. THE
LLCC HAS MOVED CLOSER THAN ORIGINALLY ANTICIPATED TO THE STRONG
TUTT-CELL LOCATED NEAR 26N 166E, WHICH HAS THROUGH A COMBINATION OF
SUBSIDENCE AND CONVERGENCE ALOFT AND WESTERLY SHEAR, BASICALLY
SMOTHERED TD 05E. THE FAR EASTERN PERIPHERY OF THE CIRCULATION IS
STILL UNDER THE DIVERGENT PORTION OF THE TUTT-CELL RELATED FLOW
ALOFT ACCORDING TO WATER VAPOR VISIBLE IMAGERY, AND THUS CONTINUES
TO EXHIBIT FLARING BUT DISORGANIZED CONVECTION. AFTER BEGIN
DECAPITATED AND SMOTHERED, THE REMNANT LOW-LEVEL VORTEX HAS COME
UNDER THE STEERING INFLUENCE OF THE LOW TO MID-LEVEL FLOW,
CURRENTLY DOMINATED BY A GENERALLY EAST-WEST ORIENTED RIDGE AXIS
ALONG THE 30N LATITUDE.
INITIAL WIND RADII BASIS: NOT APPLICABLE (THERE ARE NO INITIAL WIND
RADII).
CURRENT STEERING MECHANISM: LOW TO MID-LEVEL SUBTROPICAL RIDGE
(STR) TO THE NORTH.
AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T2.5 - 35 KTS
RCTP: T2.0 - 30 KTS
KNES: T2.0 - 30 KTS
CIMSS ADT: 45 KTS AT 142330Z
FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: UNFAVORABLE
VWS: 15-20 KTS
SST: 28-29 CELSIUS
OUTFLOW: MODERATE POLEWARD
ANALYSIS CONFIDENCE:
INITIAL POSITION: HIGH
INITIAL INTENSITY: MEDIUM
INITIAL WIND RADII: NOT APPLICABLE
3. FORECAST REASONING.
SIGNIFICANT FORECAST CHANGES: THIS IS A SIGNIFICANT FORECAST
PHILOSOPHY CHANGE, TRUNCATING THE FORECAST TO 72 HOURS AND CHANGING
THE END-PHASE FROM EXTRATROPICAL TRANSITION (ETT) TO DISSIPATION.
FORECAST DISCUSSION: NOW THAT THE SYSTEM HAS WEAKENING AND
SHALLOWED OUT, IT IS NOW BEING STEERED BY THE LOW-LEVEL FLOW, WHICH
IS GENERALLY GOING TO PUSH IT TOWARDS THE WEST-NORTHWEST, ALTHOUGH
THE WEAK GRADIENT MEANS THAT TRACK SPEEDS WILL BE FAIRLY LOW. AFTER
TAU 36 THE SYSTEM WILL PICK UP SPEED AND TRACK NORTHEAST AS IT GETS
PICKED UP BY THE TAIL END OF A WEAK FRONTAL BOUNDARY. AS DISCUSSED
ABOVE, THE MOVEMENT OF THE TUTT-CELL TO THE EAST AND TD 05E
MOVEMENT TO THE WEST HAS RESULTED IN THE LLCC MOVING UNDER THE
DIRECT INFLUENCE OF THE TUTT-CELL. AS LONG AS THESE TWO FEATURES
REMAIN IN THE SAME GENERAL SPATIAL RELATIONSHIP, TD 05E WILL HAVE
LITTLE TO NO CHANCE OF SURVIVAL. THE LATEST MODEL GUIDANCE SHOWS
EXACTLY THIS OUTCOME, AND WITH THAT, THE FORECAST HAS BEEN
SIGNIFICANTLY TRUNCATED. SHORT-LIVED FLARE-UPS OF CONVECTION REMAIN
POSSIBLE, PARTICULARLY ON THE EASTERN PERIPHERY OF THE SYSTEM AND
MOST LIKELY DURING DIURNAL MAXIMUM. HOWEVER, THE CONTINUED PRESENCE
OF THE TUTT WILL MEAN THAT THIS CONVECTION WILL REMAIN DISORGANIZED
AND THE LLCC WILL MOST LIKELY REMAIN NAKED AND AFRAID, UNDER THE
SMOTHERING INFLUENCE OF THE SUBSIDENCE ALOFT. THE LLCC WILL TAKE
TIME TO SPIN DOWN, AND THUS THE FORECAST CALLS FOR A SLOW WEAKENING
TO DISSIPATION BY TAU 72. HOWEVER, IT IS POSSIBLE THAT THE SYSTEM
WEAKENS MORE QUICKLY, AND DISSIPATES AS EARLY AS TAU 48.
MODEL DISCUSSION: THE JTWC FORECAST TRACK DEVIATES FROM THE
CONSENSUS GUIDANCE, WHICH IS STILL STEERING THE SYSTEM BASED ON THE
DEEP-LAYER STEERING PATTERN. BUT THIS OBVIOUSLY IS NOT THE CASE,
AND THE FORECAST TRACK IS BASED PRIMARILY ON ANALYSIS OF THE 850MB
MEAN WIND FLOW. AS A RESULT, CONFIDENCE IS HARD TO QUANTIFY, BUT DUE
TO
THE RAPIDLY CHANGING CONDITIONS AND SIGNIFICANT FORECAST CHANGE,
CONFIDENCE IS CURRENTLY ASSESSED AS LOW. INTENSITY GUIDANCE IS
SIMILARLY CHALLENGED, WITH ALL CONSENSUS MEMBERS EXCEPT FOR HAFS-A
REMAINING EXCITED ABOUT THE SYSTEM, INTENSIFYING IT EVEN MORE THAN
THE PREVIOUS FORECAST PACKAGE. COAMPS-TC TAKES IT UP TO DIZZYING
HEIGHTS OF NEAR 60 KNOTS BY TAU 72. THE JTWC FORECAST DEVIATES FROM
THE GUIDANCE AND DISSIPATES THE SYSTEM BY TAU 72. IN A SIMILAR
MANNER TO THE TRACK FORECAST, CONFIDENCE IS LOW.
FORECAST CONFIDENCE:
TRACK 0 - 72 HR: LOW
INTENSITY 0 - 72 HR: LOW//
NNNN
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Re: WPAC: DORA - Tropical Depression - Discussion
cycloneye wrote:WDPN32 PGTW 150300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 05E (DORA) WARNING
NR 059//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
SUMMARY:
INITIAL POSITION: 20.5N 167.8E
INITIAL INTENSITY: 30 KTS
GEOGRAPHIC REFERENCE: 100 NM NORTHEAST OF WAKE ISLAND
MOVEMENT PAST 6 HOURS: WEST-NORTHWESTWARD AT 06 KTS
SIGNIFICANT WAVE HEIGHT: 12 FEET
SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
TROPICAL DEPRESSION (TD) 05E (DORA) HAS OVER THE PAST SIX HOURS,
COMPLETELY CHANGED IN CHARACTER. OVERNIGHT, UP TO SIX HOURS AGO,
THE SYSTEM DISPLAYED DEEP, WELL-ORGANIZED CONVECTION, WITH A
LOW LEVEL CIRCULATION CENTER (LLCC) TUCKED UNDER THE CONVECTIVE
MASS. IN THE HOURS SINCE 1800Z, ANIMATED MULTISPECTRAL SATELLITE
IMAGERY (MSI) INDICATES THE CONVECTION HAS DISSIPATED AND THE LLCC,
SUCH AS IT IS, HAS PEAKED OUT TO THE WEST AND IS NOW FULLY EXPOSED.
A RECENT 142304Z ASCAT-B PASS, WHILE NOT CAPTURING THE EASTERN
SEMICIRCLE, WHERE THE HIGHEST WINDS LIKELY LURK, DID SHOW THAT THE
REMAINDER OF THE WIND FIELD IS ANEMIC, WITH MAXIMUM WINDS OF 20-25
KNOTS. THUS THE INITIAL INTENSITY IS LOWERED TO 30 KNOTS ON THE
ASSUMPTION THAT HIGHER WINDS REMAIN IN THE EASTERN SEMICIRCLE.
DVORAK-BASED INTENSITY ESTIMATES OF T2.0 TO T2.5, MOSTLY USING THE
SHEAR TECHNIQUE, ARE GENERALLY CONSISTENT WITH THE SCATTEROMETER
DATA AND PROVIDE MODERATE LEVELS OF CONFIDENCE TO THE INITIAL
INTENSITY. ENVIRONMENTALLY, TD 05E IS A TALE OF TWO SYSTEMS. THE
LLCC HAS MOVED CLOSER THAN ORIGINALLY ANTICIPATED TO THE STRONG
TUTT-CELL LOCATED NEAR 26N 166E, WHICH HAS THROUGH A COMBINATION OF
SUBSIDENCE AND CONVERGENCE ALOFT AND WESTERLY SHEAR, BASICALLY
SMOTHERED TD 05E. THE FAR EASTERN PERIPHERY OF THE CIRCULATION IS
STILL UNDER THE DIVERGENT PORTION OF THE TUTT-CELL RELATED FLOW
ALOFT ACCORDING TO WATER VAPOR VISIBLE IMAGERY, AND THUS CONTINUES
TO EXHIBIT FLARING BUT DISORGANIZED CONVECTION. AFTER BEGIN
DECAPITATED AND SMOTHERED, THE REMNANT LOW-LEVEL VORTEX HAS COME
UNDER THE STEERING INFLUENCE OF THE LOW TO MID-LEVEL FLOW,
CURRENTLY DOMINATED BY A GENERALLY EAST-WEST ORIENTED RIDGE AXIS
ALONG THE 30N LATITUDE.
INITIAL WIND RADII BASIS: NOT APPLICABLE (THERE ARE NO INITIAL WIND
RADII).
CURRENT STEERING MECHANISM: LOW TO MID-LEVEL SUBTROPICAL RIDGE
(STR) TO THE NORTH.
AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T2.5 - 35 KTS
RCTP: T2.0 - 30 KTS
KNES: T2.0 - 30 KTS
CIMSS ADT: 45 KTS AT 142330Z
FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: UNFAVORABLE
VWS: 15-20 KTS
SST: 28-29 CELSIUS
OUTFLOW: MODERATE POLEWARD
ANALYSIS CONFIDENCE:
INITIAL POSITION: HIGH
INITIAL INTENSITY: MEDIUM
INITIAL WIND RADII: NOT APPLICABLE
3. FORECAST REASONING.
SIGNIFICANT FORECAST CHANGES: THIS IS A SIGNIFICANT FORECAST
PHILOSOPHY CHANGE, TRUNCATING THE FORECAST TO 72 HOURS AND CHANGING
THE END-PHASE FROM EXTRATROPICAL TRANSITION (ETT) TO DISSIPATION.
FORECAST DISCUSSION: NOW THAT THE SYSTEM HAS WEAKENING AND
SHALLOWED OUT, IT IS NOW BEING STEERED BY THE LOW-LEVEL FLOW, WHICH
IS GENERALLY GOING TO PUSH IT TOWARDS THE WEST-NORTHWEST, ALTHOUGH
THE WEAK GRADIENT MEANS THAT TRACK SPEEDS WILL BE FAIRLY LOW. AFTER
TAU 36 THE SYSTEM WILL PICK UP SPEED AND TRACK NORTHEAST AS IT GETS
PICKED UP BY THE TAIL END OF A WEAK FRONTAL BOUNDARY. AS DISCUSSED
ABOVE, THE MOVEMENT OF THE TUTT-CELL TO THE EAST AND TD 05E
MOVEMENT TO THE WEST HAS RESULTED IN THE LLCC MOVING UNDER THE
DIRECT INFLUENCE OF THE TUTT-CELL. AS LONG AS THESE TWO FEATURES
REMAIN IN THE SAME GENERAL SPATIAL RELATIONSHIP, TD 05E WILL HAVE
LITTLE TO NO CHANCE OF SURVIVAL. THE LATEST MODEL GUIDANCE SHOWS
EXACTLY THIS OUTCOME, AND WITH THAT, THE FORECAST HAS BEEN
SIGNIFICANTLY TRUNCATED. SHORT-LIVED FLARE-UPS OF CONVECTION REMAIN
POSSIBLE, PARTICULARLY ON THE EASTERN PERIPHERY OF THE SYSTEM AND
MOST LIKELY DURING DIURNAL MAXIMUM. HOWEVER, THE CONTINUED PRESENCE
OF THE TUTT WILL MEAN THAT THIS CONVECTION WILL REMAIN DISORGANIZED
AND THE LLCC WILL MOST LIKELY REMAIN NAKED AND AFRAID, UNDER THE
SMOTHERING INFLUENCE OF THE SUBSIDENCE ALOFT. THE LLCC WILL TAKE
TIME TO SPIN DOWN, AND THUS THE FORECAST CALLS FOR A SLOW WEAKENING
TO DISSIPATION BY TAU 72. HOWEVER, IT IS POSSIBLE THAT THE SYSTEM
WEAKENS MORE QUICKLY, AND DISSIPATES AS EARLY AS TAU 48.
MODEL DISCUSSION: THE JTWC FORECAST TRACK DEVIATES FROM THE
CONSENSUS GUIDANCE, WHICH IS STILL STEERING THE SYSTEM BASED ON THE
DEEP-LAYER STEERING PATTERN. BUT THIS OBVIOUSLY IS NOT THE CASE,
AND THE FORECAST TRACK IS BASED PRIMARILY ON ANALYSIS OF THE 850MB
MEAN WIND FLOW. AS A RESULT, CONFIDENCE IS HARD TO QUANTIFY, BUT DUE
TO
THE RAPIDLY CHANGING CONDITIONS AND SIGNIFICANT FORECAST CHANGE,
CONFIDENCE IS CURRENTLY ASSESSED AS LOW. INTENSITY GUIDANCE IS
SIMILARLY CHALLENGED, WITH ALL CONSENSUS MEMBERS EXCEPT FOR HAFS-A
REMAINING EXCITED ABOUT THE SYSTEM, INTENSIFYING IT EVEN MORE THAN
THE PREVIOUS FORECAST PACKAGE. COAMPS-TC TAKES IT UP TO DIZZYING
HEIGHTS OF NEAR 60 KNOTS BY TAU 72. THE JTWC FORECAST DEVIATES FROM
THE GUIDANCE AND DISSIPATES THE SYSTEM BY TAU 72. IN A SIMILAR
MANNER TO THE TRACK FORECAST, CONFIDENCE IS LOW.
FORECAST CONFIDENCE:
TRACK 0 - 72 HR: LOW
INTENSITY 0 - 72 HR: LOW//
NNNN
Thread title needs updating to Tropical Depression Dora.
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Re: WPAC: DORA - Post-Tropical - Discussion
Now a subtropical depression according to JTWC.
Edit: also still officially a TD per JMA:
ABPW10 PGTW 181500 COR
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE WESTERN AND SOUTH
PACIFIC OCEANS CORRECTED/181500Z-190600ZAUG2023//
RMKS/
1. WESTERN NORTH PACIFIC AREA (180 TO MALAY PENINSULA):
A. TROPICAL CYCLONE SUMMARY: NONE.
B. TROPICAL DISTURBANCE SUMMARY: NONE.
C. SUBTROPICAL SYSTEM SUMMARY:
(1) AN AREA OF CONVECTION (INVEST 05E) HAS PERSISTED NEAR 32.3N
165.6E, APPROXIMATELY 1304 NM EAST OF YOKOSUKA, JAPAN. THE SYSTEM IS
CURRENTLY CLASSIFIED AS A SUBTROPICAL DEPRESSION, GENERALLY
CHARACTERIZED AS HAVING BOTH TROPICAL AND MIDLATITUDE CYCLONE FEATURES.
ANIMATED ENHANCED INFRARED SATELLITE IMAGERY AND A 181331Z GMI 89GHZ
PASS DEPICT A BROAD, FULLY EXPOSED SYSTEM WITH FLARING CONVECTION
DISPLACED 40 NM TO THE SOUTHEAST OF THE CIRCULATION. ENVIRONMENTAL
ANALYSIS REVEALS UNFAVORABLE CONDITIONS FOR TROPICAL TRANSITION WITH
WARM (27-28C) SEA SURFACE TEMPERATURES AND STRONG EQUATORWARD OUTFLOW
ALOFT GREATLY OFFSET BY HIGH (30KT) VERTICAL WIND SHEAR AND DRY AIR
BEING ADVECTED INTO THE CIRCULATION. GLOBAL MODELS ARE IN GENERAL
AGREEMENT THAT INVEST 05E WILL TRACK NORTHEASTWARD WITH A BROAD AND
ASYMMETRIC WIND FIELD. FOR HAZARDS AND WARNINGS, REFERENCE THE FLEET
WEATHER CENTER SAN DIEGO HIGH WINDS AND SEAS PRODUCT OR REFER TO LOCAL
WMO DESIGNATED FORECAST AUTHORITY. MAXIMUM SUSTAINED SURFACE WINDS ARE
ESTIMATED AT 20 TO 25 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO
BE NEAR 1008 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT
TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS LOW.
(2) NO OTHER SUBTROPICAL SYSTEMS.
2. SOUTH PACIFIC AREA (WEST COAST OF SOUTH AMERICA TO 135 EAST):
A. TROPICAL CYCLONE SUMMARY: NONE.
B. TROPICAL DISTURBANCE SUMMARY: NONE.
C. SUBTROPICAL SYSTEM SUMMARY: NONE.
(2) NO OTHER SUBTROPICAL SYSTEMS.
3. JUSTIFICATION FOR CORRECTION: CLARIFIED NAMING CONVENTION OF SYSTEM
AND ADDED HAZARDS AND WARNINGS STATEMENT.//
NNNN
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE WESTERN AND SOUTH
PACIFIC OCEANS CORRECTED/181500Z-190600ZAUG2023//
RMKS/
1. WESTERN NORTH PACIFIC AREA (180 TO MALAY PENINSULA):
A. TROPICAL CYCLONE SUMMARY: NONE.
B. TROPICAL DISTURBANCE SUMMARY: NONE.
C. SUBTROPICAL SYSTEM SUMMARY:
(1) AN AREA OF CONVECTION (INVEST 05E) HAS PERSISTED NEAR 32.3N
165.6E, APPROXIMATELY 1304 NM EAST OF YOKOSUKA, JAPAN. THE SYSTEM IS
CURRENTLY CLASSIFIED AS A SUBTROPICAL DEPRESSION, GENERALLY
CHARACTERIZED AS HAVING BOTH TROPICAL AND MIDLATITUDE CYCLONE FEATURES.
ANIMATED ENHANCED INFRARED SATELLITE IMAGERY AND A 181331Z GMI 89GHZ
PASS DEPICT A BROAD, FULLY EXPOSED SYSTEM WITH FLARING CONVECTION
DISPLACED 40 NM TO THE SOUTHEAST OF THE CIRCULATION. ENVIRONMENTAL
ANALYSIS REVEALS UNFAVORABLE CONDITIONS FOR TROPICAL TRANSITION WITH
WARM (27-28C) SEA SURFACE TEMPERATURES AND STRONG EQUATORWARD OUTFLOW
ALOFT GREATLY OFFSET BY HIGH (30KT) VERTICAL WIND SHEAR AND DRY AIR
BEING ADVECTED INTO THE CIRCULATION. GLOBAL MODELS ARE IN GENERAL
AGREEMENT THAT INVEST 05E WILL TRACK NORTHEASTWARD WITH A BROAD AND
ASYMMETRIC WIND FIELD. FOR HAZARDS AND WARNINGS, REFERENCE THE FLEET
WEATHER CENTER SAN DIEGO HIGH WINDS AND SEAS PRODUCT OR REFER TO LOCAL
WMO DESIGNATED FORECAST AUTHORITY. MAXIMUM SUSTAINED SURFACE WINDS ARE
ESTIMATED AT 20 TO 25 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO
BE NEAR 1008 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT
TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS LOW.
(2) NO OTHER SUBTROPICAL SYSTEMS.
2. SOUTH PACIFIC AREA (WEST COAST OF SOUTH AMERICA TO 135 EAST):
A. TROPICAL CYCLONE SUMMARY: NONE.
B. TROPICAL DISTURBANCE SUMMARY: NONE.
C. SUBTROPICAL SYSTEM SUMMARY: NONE.
(2) NO OTHER SUBTROPICAL SYSTEMS.
3. JUSTIFICATION FOR CORRECTION: CLARIFIED NAMING CONVENTION OF SYSTEM
AND ADDED HAZARDS AND WARNINGS STATEMENT.//
NNNN
Edit: also still officially a TD per JMA:
WWJP27 RJTD 181800
...
TROPICAL DEPRESSION 1012 HPA AT 33N 167E ALMOST STATIONARY.
...
TROPICAL DEPRESSION 1012 HPA AT 33N 167E ALMOST STATIONARY.
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DISCLAIMER: I am not a meteorologist. Any posts I made, unless copied from some official agency, are only my opinion and is unofficial and often exaggerated. Please refer to your official RSMC for official products and warnings.
Re: WPAC: DORA - Post-Tropical - Discussion
Correction it's nothing to do with Dora
Last edited by ChrisH-UK on Mon Aug 21, 2023 7:49 am, edited 1 time in total.
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