WPAC: 01W - Tropical Depression

[cycloneye]

Tropical Cyclone Formation Alert

WTPN21 PGTW 012030
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
A 120 NM RADIUS OF 8.6N 111.4E WITHIN THE NEXT 12 TO 24 HOURS.
AVAILABLE DATA DOES NOT JUSTIFY ISSUANCE OF NUMBERED TROPICAL
CYCLONE WARNINGS AT THIS TIME. WINDS IN THE AREA ARE ESTIMATED TO
BE 15 TO 20 KNOTS. METSAT IMAGERY AT 012000Z INDICATES THAT A
CIRCULATION CENTER IS LOCATED NEAR 8.6N 111.4E. THE SYSTEM IS
QUASI-STATIONARY.
2. REMARKS: THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 8.8N
111.9E, IS NOW LOCATED NEAR 8.6N 111.4E, APPROXIMATELY 305 NM EAST-
SOUTHEAST OF HO CHI MINH CITY, VIETNAM. ANIMATED INFRARED SATELLITE
IMAGERY DEPICTS A PARTIALLY-EXPOSED, WELL-DEFINED LOW-LEVEL
CIRCULATION CENTER (LLCC) WITH DEEP COVECTION FLARING OVER THE
CENTER AND ALONG THE NORTHWEST FLANK. A 011417Z ASCAT IMAGE DEPICTS
A SYMMETRIC LLCC WITH 15-20 KNOT WINDS NEAR THE CENTER AND 20-25
KNOT NORTH-NORTHEASTERLY WINDS DISPLACED OVER THE NORTHWEST
PERIPHERY. A 011308Z TRMM 37 GHZ IMAGE INDICATES AN ORGANIZED LLCC
WITH LOW-LEVEL BANDING WRAPPING FROM THE NORTHEAST QUADRANT INTO THE
EAST QUADRANT OF THE SYSTEM. OVERALL, THE LLCC IS LOCATED WITHIN A
MARGINAL ENVIRONMENT (SOUTH OF THE SUBTROPICAL RIDGE AXIS)
CHARACTERIZED BY MODERATE, EASTERLY VERTICAL WIND SHEAR. MAXIMUM
SUSTAINED SURFACE WINDS ARE ESTIMATED AT 15 TO 20 KNOTS. MINIMUM SEA
LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1005 MB. DYNAMIC MODELS
INDICATE WEAK DEVELOPMENT, ENHANCED BY THE NORTHEAST SURGE, AND THE
CIRCULATION HAS STRENGTHENED DESPITE THE LACK OF DEEP CONVECTIVE
BANDING, THEREFORE, THE POTENTIAL FOR THE DEVELOPMENT OF A
SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS GOOD.

[cycloneye]

[Chacor]

WTPN31 PGTW 020300
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE WARNING//
REF/A/MSG/NAVMARFCSTCEN PEARL HARBOR HI/012021ZAPR2011//
AMPN/REF A IS A TROPICAL CYCLONE FORMATION ALERT.//
RMKS/
1. TROPICAL DEPRESSION 01W (ONE) WARNING NR 001
01 ACTIVE TROPICAL CYCLONE IN NORTHWESTPAC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
020000Z --- NEAR 9.3N 111.3E
MOVEMENT PAST SIX HOURS - 325 DEGREES AT 04 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT
WIND RADII VALID OVER OPEN WATER ONLY
REPEAT POSIT: 9.3N 111.3E
---
FORECASTS:
12 HRS, VALID AT:
021200Z --- 9.3N 111.1E
MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
WIND RADII VALID OVER OPEN WATER ONLY
VECTOR TO 24 HR POSIT: 225 DEG/ 01 KTS
---
24 HRS, VALID AT:
030000Z --- 9.2N 111.0E
MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
WIND RADII VALID OVER OPEN WATER ONLY
VECTOR TO 36 HR POSIT: 225 DEG/ 01 KTS
---
36 HRS, VALID AT:
031200Z --- 9.0N 110.8E
MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
VECTOR TO 48 HR POSIT: 215 DEG/ 02 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
040000Z --- 8.6N 110.5E
MAX SUSTAINED WINDS - 020 KT, GUSTS 030 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
VECTOR TO 72 HR POSIT: 230 DEG/ 03 KTS
---
72 HRS, VALID AT:
050000Z --- 7.9N 109.7E
MAX SUSTAINED WINDS - 020 KT, GUSTS 030 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
---
REMARKS:
020300Z POSITION NEAR 9.3N 111.2E.
TROPICAL DEPRESSION (TD) 01W, LOCATED APPROXIMATELY 285 NM EAST-
SOUTHEAST OF HO CHI MINH CITY, VIETNAM, HAS TRACKED NORTHWESTWARD AT
04 KNOTS OVER THE PAST SIX HOURS. THIS WARNING SUPERSEDES AND
CANCELS REF A, NAVMARFCSTCEN 012021Z APR 11 TROPICAL CYCLONE
FORMATION ALERT (WTPN21 PGTW 012030). MAXIMUM SIGNIFICANT WAVE
HEIGHT AT 020000Z IS 8 FEET. NEXT WARNINGS AT 020900Z, 021500Z,
022100Z AND 030300Z.//

[Chacor]

WDPN31 PGTW 020300
MSGID/GENADMIN/NAVPACMETOCCEN PEARL HARBOR HI/JTWC//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 01W (ONE) WARNING
NR 01//
RMKS/
1. FOR METEOROLOGISTS.
2. 12 HOUR SUMMARY AND ANALYSIS.
TROPICAL DEPRESSION (TD) 01W, LOCATED APPROXIMATELY 285 NM EAST-
SOUTHEAST OF HO CHI MINH CITY, VIETNAM, HAS TRACKED NORTHWESTWARD AT
04 KNOTS OVER THE PAST SIX HOURS. DESPITE THE VERY SLOW, RECENT
NORTHWESTWARD DRIFT, THE OVERALL MOTION HAS BEEN QUASI-STATIONARY.
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A PARTIALLY-
EXPOSED LOW-LEVEL CIRCULATION CENTER (LLCC) WITH WEAK BANDING OVER
THE NORTHERN SEMI-CIRCLE AND SOUTHWEST QUADRANT. OVER THE PAST 24
HOURS, THE CONVECTION HAS STRUGGLED TO ORGANIZE DUE TO MODERATE,
EASTERLY VERTICAL WIND SHEAR (VWS)OF 20 KNOTS BUT HAS SLOWLY
IMPROVED OVER THE PAST 12 HOURS. THE CIRCULATION ITSELF HAS
STRENGTHENED WITH A 011416Z ASCAT IMAGE INDICATING 20-25 KNOT WINDS
WITH 25-30 KNOT WINDS DISPLACED AWAY FROM THE CENTER, OVER THE
NORTHWEST PERIPHERY OF THE SYSTEM. THE SYSTEM HAS DEVELOPED MAINLY
AS A RESULT OF ITS PROXIMITY TO NORTHERLY FLOW ASSOCIATED WITH A
SURGE EVENT. EARLIER MICROWAVE IMAGERY HAD INDICATED MULTIPLE BANDS
WRAPPING INTO A WELL-DEFINED LLCC, AND A 012306Z SSMIS 37 GHZ IMAGE
CONTINUES TO SHOW TIGHTLY-CURVED LOW-LEVEL BANDING AND A CLEAR
CENTER. BASED ON THIS IMAGERY AND THE EXPOSED LLCC IN MSI, THERE IS
GOOD CONFIDENCE IN THE CURRENT POSITION AND MOTION. THE CURRENT
INTENSITY IS BASED ON THE ASCAT DATA, THE MICROWAVE SIGNATURE AND
DVORAK ESTIMATES OF 25 KNOTS.
3. FORECAST REASONING
A. THIS IS THE FIRST PROGNOSTIC REASONING MESSAGE FOR TD 01W.
B. TD 01W IS CURRENTLY TRACKING SLOWLY NORTHWESTWARD, HOWEVER,
MOTION HAS BEEN QUASI-STATIONARY (QS) OVER THE PAST 24 HOURS AND IS
EXPECTED TO REMAIN QS THROUGH TAU 36-48. TD 01W IS EXPECTED TO
REMAIN AT TD STRENGTH UNTIL IT DISSIPATES BY TAU 48 (POSSIBLY
EARLIER). THE SYSTEM WILL THEN ACCELERATE SOUTHWESTWARD UNDER THE
VIGOROUS NORTHERLY TO NORTHEASTERLY FLOW AND WEAKEN BELOW 25 KNOTS.
MODEL GUIDANCE IS LIMITED BUT SUPPORTS THIS TRACK AS THE LIKELIEST
SOLUTION.//

[Chacor]

JMA:

WARNING.
TROPICAL DEPRESSION 1006 HPA
AT 08.7N 111.3E SOUTH CHINA SEA MOVING WEST SLOWLY.
POSITION POOR.
MAX WINDS 30 KNOTS NEAR CENTER.

[HURAKAN]

Latest visible

[HURAKAN]

Track

[Chacor]

WTPN31 PGTW 020900
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE WARNING//
RMKS/
1. TROPICAL DEPRESSION 01W (ONE) WARNING NR 002
01 ACTIVE TROPICAL CYCLONE IN NORTHWESTPAC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
020600Z --- NEAR 9.3N 111.2E
MOVEMENT PAST SIX HOURS - 270 DEGREES AT 01 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT
WIND RADII VALID OVER OPEN WATER ONLY
REPEAT POSIT: 9.3N 111.2E
---
FORECASTS:
12 HRS, VALID AT:
021800Z --- 9.3N 111.1E
MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
WIND RADII VALID OVER OPEN WATER ONLY
VECTOR TO 24 HR POSIT: 225 DEG/ 01 KTS
---
24 HRS, VALID AT:
030600Z --- 9.2N 111.0E
MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
WIND RADII VALID OVER OPEN WATER ONLY
VECTOR TO 36 HR POSIT: 225 DEG/ 01 KTS
---
36 HRS, VALID AT:
031800Z --- 9.1N 110.9E
MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
VECTOR TO 48 HR POSIT: 225 DEG/ 01 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
040600Z --- 9.0N 110.8E
MAX SUSTAINED WINDS - 020 KT, GUSTS 030 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
---
REMARKS:
020900Z POSITION NEAR 9.3N 111.2E.
TROPICAL DEPRESSION (TD) 01W (ONE), LOCATED APPROXIMATELY 280 NM
EAST-SOUTHEAST OF HO CHI MINH CITY, VIETNAM, HAS REMAINED
QUASI-STATIONARY OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL
IMAGERY SHOWS THE LOW LEVEL CIRCULATION CENTER HAS BECOME FULLY
EXPOSED WITH WEAK AND FRAGMENTED CONVECTION DISPLACED WESTWARD. THE
INITIAL POSITION IS BASED ON THE ABOVE ANIMATION WITH A FAIR DEGREE
OF CONFIDENCE AND THE INITIAL INTENSITY IS BASED ON A DVORAK ESTIMATE
OF 25 KNOTS FROM PGTW AND KNES. UPPER LEVEL ANALYSIS INDICATES THE
SYSTEM IS TO THE SOUTH OF A RIDGE AXIS IN AN AREA OF MODERATE
EASTERLY VERTICAL WIND SHEAR (VWS). LOW LEVEL STREAMLINE ANALYSIS
INDICATES THE CIRCULATION IS BEING ENHANCED BY A SURGE OF
NORTHEASTERLY WINDS IN THE SOUTH CHINA SEA ASSOCIATED WITH THE
NORTHEAST MONSOON. TD 01W IS EXPECTED TO BE SHORT-LIVED, DISSIPATING
WITHIN 48 HOURS MAINLY DUE TO PERSISTENT VWS. MAXIMUM SIGNIFICANT
WAVE HEIGHT AT 020600Z IS 9 FEET. NEXT WARNINGS AT 021500Z, 022100Z,
030300Z AND 030900Z.//

[Chacor]

WWJP25 RJTD 020600
WARNING AND SUMMARY 020600.
WARNING VALID 030600.
WARNING IS UPDATED EVERY 6 HOURS.

--

WARNING.
TROPICAL DEPRESSION 1004 HPA
AT 09.5N 111.3E SOUTH CHINA SEA MOVING WESTNORTHWEST SLOWLY.
POSITION POOR.
MAX WINDS 30 KNOTS NEAR CENTER.

[RobWESTPACWX]

ASCAT imagery, even though it looks horrible on the IR this does show a closed circulation.



Any how I guess point is first storm of the season, take that Atlantic! Naa, I really would be happy if nothing developed up right now. That would make me happy. Thus am glad it is going to remain weak. There is way to much shear in the area.

[cycloneye]

Is forecast to dissipate in the next 24 hours.

WTPN31 PGTW 022100
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE WARNING//
RMKS/
1. TROPICAL DEPRESSION 01W (ONE) WARNING NR 004
01 ACTIVE TROPICAL CYCLONE IN NORTHWESTPAC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
021800Z --- NEAR 9.5N 111.6E
MOVEMENT PAST SIX HOURS - 155 DEGREES AT 02 KTS
POSITION ACCURATE TO WITHIN 040 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
WIND RADII VALID OVER OPEN WATER ONLY
REPEAT POSIT: 9.5N 111.6E
---
FORECASTS:
12 HRS, VALID AT:
030600Z --- 9.2N 111.8E
MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
VECTOR TO 24 HR POSIT: 180 DEG/ 03 KTS
---
24 HRS, VALID AT:
031800Z --- 8.5N 111.8E
MAX SUSTAINED WINDS - 020 KT, GUSTS 030 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
VECTOR TO 36 HR POSIT: 195 DEG/ 04 KTS
---
36 HRS, VALID AT:
040600Z --- 7.8N 111.6E
MAX SUSTAINED WINDS - 020 KT, GUSTS 030 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
---
REMARKS:
022100Z POSITION NEAR 9.4N 111.7E.
TROPICAL DEPRESSION (TD) 01W (ONE), LOCATED APPROXIMATELY 300 NM
EAST-SOUTHEAST OF HO CHI MINH CITY, VIETNAM HAS REMAINED QUASI-
STATIONARY OVER THE PAST SIX HOURS. ANIMATED INFRARED SATELLITE
IMAGERY CLEARLY DEPICTS AN EXPOSED, WELL-DEFINED LOW-LEVEL
CIRCULATION CENTER (LLCC) WITH AN ISOLATED BURST OF DEEP CONVECTION
OVER THE NORTHWEST QUADRANT. DEEP CONVECTION HAS CONTINUED TO
STRUGGLE DUE TO MODERATE TO HIGH (20-25 KNOTS) VERTICAL WIND SHEAR
(VWS). REGARDLESS OF THE LACK OF DEEP CONVECTION, THE SYSTEM HAS
MAINTAINED TROPICAL DEPRESSION STRENGTH BASED ON RECENT
OBSERVATIONAL DATA. SHIP OBSERVATIONS, ABOUT 100 NM WEST OF THE
CENTER, HAVE INDICATED 25-30 KNOT NORTHERLY WINDS WHILE A 021026Z
WINDSAT IMAGE SHOWED 20-25 KNOT WINDS NEAR THE CENTER AND 25-30 KNOT
NORTHERLY WINDS OVER THE WESTERN PERIPHERY OF THE SYSTEM. THERE IS
GOOD CONFIDENCE IN THE CURRENT POSITION BASED ON THE EXPOSED CENTER.
THE CURRENT INTENSITY OF 30 KNOTS IS BASED LARGELY ON THE SHIP
OBSERVATIONS AND WINDSAT DATA. TD 01W IS FORECAST TO REMAIN QUASI-
STATIONARY THROUGH THE PERIOD BUT WILL LIKELY TRACK SOUTHWARD AS IT
WEAKENS. THE SYSTEM WILL ALMOST CERTAINLY WEAKEN DUE TO PERSISTENT,
UNFAVORABLE VWS AND DRY AIR ENTRAINMENT. OBSERVATIONS INDICATE DRY
AIR WEST AND NORTH OF THE SYSTEM ASSOCIATED WITH THE NORTHEAST
MONSOON SURGE WITH DEW POINTS UNDER 20C. THE SYSTEM IS FORECAST TO
WEAKEN BELOW 25 KNOTS AFTER TAU 12 AND TO DISSIPATE BY TAU 24.
MAXIMUM SIGNIFICANT WAVE HEIGHT AT 021800Z IS 9 FEET. NEXT WARNINGS
AT 030300Z, 030900Z, 031500Z AND 032100Z.//
NNNN

[cycloneye]

WTPN31 PGTW 030300
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE WARNING//
RMKS/
1. TROPICAL DEPRESSION 01W (ONE) WARNING NR 005
01 ACTIVE TROPICAL CYCLONE IN NORTHWESTPAC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
030000Z --- NEAR 9.3N 111.8E
MOVEMENT PAST SIX HOURS - 160 DEGREES AT 03 KTS
POSITION ACCURATE TO WITHIN 040 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
WIND RADII VALID OVER OPEN WATER ONLY
REPEAT POSIT: 9.3N 111.8E
---
FORECASTS:
12 HRS, VALID AT:
031200Z --- 8.8N 111.9E
MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
VECTOR TO 24 HR POSIT: 190 DEG/ 04 KTS
---
24 HRS, VALID AT:
040000Z --- 8.1N 111.8E
MAX SUSTAINED WINDS - 020 KT, GUSTS 030 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
VECTOR TO 36 HR POSIT: 200 DEG/ 04 KTS
---
36 HRS, VALID AT:
041200Z --- 7.3N 111.5E
MAX SUSTAINED WINDS - 020 KT, GUSTS 030 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
---
REMARKS:
030300Z POSITION NEAR 9.2N 111.8E.
TROPICAL DEPRESSION (TD) 01W (ONE), LOCATED APPROXIMATELY 315 NM
EAST-SOUTHEAST OF HO CHI MINH CITY, VIETNAM HAS TRACKED SOUTH-
SOUTHEASTWARD AT 03 KNOTS OVER THE PAST SIX HOURS. MAXIMUM
SIGNIFICANT WAVE HEIGHT AT 030000Z IS 9 FEET. NEXT WARNINGS AT
030900Z, 031500Z, 032100Z AND 040300Z.//

[P.K.]

06Z.

WARNING.
TROPICAL DEPRESSION 1004 HPA
AT 09.5N 111.9E SOUTH CHINA SEA ALMOST STATIONARY.
POSITION FAIR.
MAX WINDS 30 KNOTS NEAR CENTER.

[supercane]

JMA still holding on to this. 0Z summary info:
TROPICAL DEPRESSION 1008 HPA AT 08N 113E SE SLOWLY.

[Chacor]

TROPICAL DEPRESSION 1008 HPA AT 08N 114E SE SLOWLY.