WPAC: JELAWAT - Post-Tropical

[dexterlabio]

Latest discussion from JTWC. Man I hate this kind of systems moving over weak steering environment.

WDPN31 PGTW 210300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 18W (JELAWAT) WARNING
NR 03//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL STORM (TS) 18W (JELAWAT), LOCATED APPROXIMATELY 575 NM
EAST OF MANILA, PHILIPPINES, HAS TRACKED WEST-SOUTHWESTWARD AT 07
KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE
IMAGERY (MSI) SHOWS CENTRAL CONVECTION CONSOLIDATING AROUND THE LOW
LEVEL CIRCULATION CENTER (LLCC) WITH AN OUTER BAND OF DEEP
CONVECTION WRAPPING AROUND THE SYSTEM'S WESTERN AND SOUTHERN
PERIPHERY. A 202320Z SSMIS 91GHZ IMAGE DEPICTS TIGHTLY CURVED
BANDING WRAPPING INTO THE LLCC, WITH THE DEEPEST CONVECTION IN THE
WESTERN SEMI-CIRCLE. DESPITE FAVORABLE CONDITIONS OVERALL, 18W HAS
STRUGGLED TO MAINTAIN ITS ORGANIZATION. THE INITIAL POSITION IS
BASED ON ANIMATED MSI AND AN EXTRAPOLATION FROM A 202129Z WINDSAT
37GHZ IMAGE. THE INITIAL INTENSITY IS ASSESSED AT 35 KTS, IN
AGREEMENT WITH DVORAK ESTIMATES FROM PGTW, KNES AND RJTD. UPPER-
LEVEL ANALYSIS INDICATES THE SYSTEM IS IN A FAIR ENVIRONMENT, WITH
LOW (05-10 KNOT) VERTICAL WIND SHEAR (VWS) AND GOOD EQUATORWARD
OUTFLOW APPARENT IN ANIMATED WATER VAPOR IMAGERY. A LARGE AREA OF
DEEP SUBTROPICAL RIDGING TO THE NORTHEAST IS CONSTRAINING POLEWARD
OUTFLOW TO A SMALL RIBBON AND AN APPROACHING MID-LATITUDE TROUGH HAS
PROVIDED LITTLE ADDITIONAL OUTFLOW. THE CYCLONE IS TRACKING ALONG
THE SOUTHWESTERN EXTENSION OF THE SUBTROPICAL RIDGE (STR) ANCHORED
EAST OF JAPAN. WARM (28-30 DEGREE) SEA SURFACE TEMPERATURES (SSTS)
EXIST THROUGHOUT THE PHILIPPINE SEA.
3. FORECAST REASONING.
A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
B. THE EASTWARD MOVING MID-LATITUDE TROUGH MOVING OVER THE KOREAN
PENINSULA WILL CONTINUE TO WEAKEN THE STEERING STR, CAUSING TS 18W
TO SLOW DOWN AND BECOME QUASI-STATIONARY. WITH LOW VWS, SUSTAINED
EQUATORWARD OUTFLOW, AND FAVORABLE SSTS, THE SYSTEM IS FORECAST TO
STEADILY INTENSIFY INTO A TYPHOON PRIOR TO TAU 48. BETWEEN TAUS 36-
48, THE STR WILL REBUILD AND START TO TURN 18W TO THE NORTHWEST.
THERE IS A LARGE SPREAD IN THE NUMERICAL MODEL GUIDANCE AS THE
SYSTEM ENTERS A WEAK STEERING ENVIRONMENT. SOME OF THE SPREAD IS
ATTRIBUTED TO DIFFERENCES IN SPEED, WHILE SOME MODELS APPEAR TO OVER-
ANALYZE THE IMPACT OF THE MID-LATITUDE TROUGH AND TURN THE SYSTEM TO
THE NORTH AS A RESULT. DUE TO THIS LARGE MODEL SPREAD AND
UNCERTAINTIES ASSOCIATED WITH QUASI-STATIONARY MOTION, THERE IS LOW
CONFIDENCE IN THIS PORTION OF THE FORECAST.
C. DURING THE EXTENDED TAUS, THE REBUILDING STR TO THE NORTHEAST
WILL STEER THE SYSTEM IN A NORTHWESTWARD DIRECTION AS THE PRIMARY
STEERING MECHANISM GRADUALLY TRANSITIONS TO ANOTHER STR OVER EASTERN
CHINA. THIS CHANGE IN STEERING MECHANISMS MAY EVENTUALLY RESULT IN A
MORE WESTWARD TRACK MOTION BEYOND THE FORECAST PERIOD.
GRADUAL INTENSIFICATION SHOULD CONTINUE THROUGHOUT THE FORECAST
PERIOD, REACHING 95 KTS AT TAU 120. THE NUMERICAL GUIDANCE AT TAU
120 HAS A SPREAD OF OVER 600 NM, HOWEVER, THE CONSENSUS HAS REMAINED
FAIRLY CONSISTENT, WITH A TRACK TOWARD THE LUZON STRAIT. THE
FORECAST IS SLIGHTLY SLOWER AND WEST OF CONSENSUS TO ACCOUNT FOR
EGRR WHICH ERRONEOUSLY TURNS THE SYSTEM NORTH INTO THE RIDGE. DUE TO
THE LARGE MODEL SPREAD, THERE IS LOW CONFIDENCE IN THIS PORTION OF
THE FORECAST.//
NNNN

[ManilaTC]

With the uncertainty, weak steering environment and low model confidence from 48 hours out looks like watching where is storm goes will be very tiring and nervously taxing process.

As of now we can only look as far as 48 hours. After that its anybody's ballgame.

It should be enough to put the Entire Luzon and Taiwan islands on edge for the next few days on end.

[euro6208]

CI# /Pressure/ Vmax
2.7 /1003.6mb/ 39.0kt


Final T# Adj T# Raw T#
2.7 3.1 3.8

[euro6208]

Ridiculous amount of heat content...surely this will be a very interesting storm in the next few days...

[Meow]

Jelawat becomes a severe tropical storm.



STS 1217 (JELAWAT)
Issued at 06:45 UTC, 21 September 2012

<Analyses at 21/06 UTC>
Scale -
Intensity -
Center position N12°50'(12.8°)
E130°25'(130.4°)
Direction and speed of movement WSW 15km/h(8kt)
Central pressure 992hPa
Maximum wind speed near the center 25m/s(50kt)
Maximum wind gust speed 35m/s(70kt)
Area of 30kt winds or more ALL280km(150NM)

<Forecast for 22/06 UTC>
Intensity -
Center position of probability circle N12°35'(12.6°)
E129°35'(129.6°)
Direction and speed of movement Almost stationary
Central pressure 975hPa
Maximum wind speed near the center 30m/s(60kt)
Maximum wind gust speed 45m/s(85kt)
Radius of probability circle 130km(70NM)
Storm warning area ALL220km(120NM)

<Forecast for 23/06 UTC>
Intensity Strong
Center position of probability circle N13°50'(13.8°)
E128°30'(128.5°)
Direction and speed of movement NW Slowly
Central pressure 960hPa
Maximum wind speed near the center 40m/s(75kt)
Maximum wind gust speed 55m/s(105kt)
Radius of probability circle 200km(110NM)
Storm warning area ALL310km(170NM)

<Forecast for 24/06 UTC>
Intensity Strong
Center position of probability circle N15°25'(15.4°)
E127°35'(127.6°)
Direction and speed of movement NNW Slowly
Central pressure 945hPa
Maximum wind speed near the center 40m/s(80kt)
Maximum wind gust speed 60m/s(115kt)
Radius of probability circle 300km(160NM)
Storm warning area ALL440km(240NM)

[dexterlabio]

5-day extended forecast map from JMA



STS 1217 (JELAWAT)
Issued at 06:45 UTC, 21 September 2012

<Analyses at 21/06 UTC>
Scale -
Intensity -
Center position N12°50'(12.8°)
E130°25'(130.4°)
Direction and speed of movement WSW 15km/h(8kt)
Central pressure 992hPa
Maximum wind speed near the center 25m/s(50kt)
Maximum wind gust speed 35m/s(70kt)
Area of 30kt winds or more ALL280km(150NM)

<Forecast for 22/06 UTC>
Intensity -
Center position of probability circle N12°35'(12.6°)
E129°35'(129.6°)
Direction and speed of movement Almost stationary
Central pressure 975hPa
Maximum wind speed near the center 30m/s(60kt)
Maximum wind gust speed 45m/s(85kt)
Radius of probability circle 130km(70NM)
Storm warning area ALL220km(120NM)

<Forecast for 23/06 UTC>
Intensity Strong
Center position of probability circle N13°50'(13.8°)
E128°30'(128.5°)
Direction and speed of movement NW Slowly
Central pressure 960hPa
Maximum wind speed near the center 40m/s(75kt)
Maximum wind gust speed 55m/s(105kt)
Radius of probability circle 200km(110NM)
Storm warning area ALL310km(170NM)

<Forecast for 24/06 UTC>
Intensity Strong
Center position of probability circle N15°25'(15.4°)
E127°35'(127.6°)
Direction and speed of movement NNW Slowly
Central pressure 945hPa
Maximum wind speed near the center 40m/s(80kt)
Maximum wind gust speed 60m/s(115kt)
Radius of probability circle 300km(160NM)
Storm warning area ALL440km(240NM)

<Forecast for 25/06 UTC>
Center position of probability circle N17°00'(17.0°)
E126°25'(126.4°)
Direction and speed of movement NW Slowly
Radius of probability circle 440km(240NM)

<Forecast for 26/06 UTC>
Center position of probability circle N18°00'(18.0°)
E124°20'(124.3°)
Direction and speed of movement WNW 10km/h(6kt)
Radius of probability circle 560km(300NM)


...can anyone access the JTWC site? it seems the site won't open but maybe that's just my browser...

[dexterlabio]

lol guess what. euro now favors a recurve scenario towards mainland Japan.

[phwxenthusiast]

lol guess what. euro now favors a recurve scenario towards mainland Japan.

both the euro and the cmc are showing an interaction with a cyclone that could form near Guam by this weekend... while i'm still siding with the GFS (track towards the northwest) we do have to keep watching that area near Guam because if it does develop, it may just very well add another layer of complexity regarding Jelawat's track

Here is my Video Update on it along with the possible solutions as being shown by the models... comments are welcome!
[youtube]http://www.youtube.com/watch?v=T2yRectecuQ[/youtube]

Personal Forecast Disclaimer:
The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

[DukeDevil91]

The waters here are still incredibly warm. Strong sheer coming off of China right now, but it will stay way south of that and gain great intensity. This could rival Sanba.

[dexterlabio]

both the euro and the cmc are showing an interaction with a cyclone that could form near Guam by this weekend... while i'm still siding with the GFS (track towards the northwest) we do have to keep watching that area near Guam because if it does develop, it may just very well add another layer of complexity regarding Jelawat's track

Here is my Video Update on it along with the possible solutions as being shown by the models... comments are welcome!

Very nice video update! I like that you talked about that potential TC near Guam. I'm not sure if some models are saying that there'll be a DCI between the potential storm and Jelawat OR the storm will 'intrude' the STR east of Japan, introducing a weakness and allowing Jelawat to move towards the NE. That IMO is possible only if that phantom storm will be a strong system as it tracks north...but I still doubt if it will be strong enough to affect Jelawat's behavior or if it can introduce such weakness to the STR.

Hopefully we can see a brighter picture of things tomorrow. This kind of setup makes me go nuts.

Personal Forecast Disclaimer:
The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data.

[euro6208]

no problem for me dexterlabio..........now 100 knots forecast!


WTPN31 PGTW 211500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE WARNING//
RMKS/
1. TROPICAL STORM 18W (JELAWAT) 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:
211200Z --- NEAR 12.4N 129.9E
MOVEMENT PAST SIX HOURS - 245 DEGREES AT 07 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT
045 NM SOUTHEAST QUADRANT
045 NM SOUTHWEST QUADRANT
050 NM NORTHWEST QUADRANT
REPEAT POSIT: 12.4N 129.9E
---
FORECASTS:
12 HRS, VALID AT:
220000Z --- 12.2N 129.2E
MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 065 NM NORTHEAST QUADRANT
060 NM SOUTHEAST QUADRANT
060 NM SOUTHWEST QUADRANT
065 NM NORTHWEST QUADRANT
VECTOR TO 24 HR POSIT: 280 DEG/ 03 KTS
---
24 HRS, VALID AT:
221200Z --- 12.3N 128.6E
MAX SUSTAINED WINDS - 060 KT, GUSTS 075 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 030 NM NORTHEAST QUADRANT
030 NM SOUTHEAST QUADRANT
030 NM SOUTHWEST QUADRANT
030 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 080 NM NORTHEAST QUADRANT
075 NM SOUTHEAST QUADRANT
075 NM SOUTHWEST QUADRANT
080 NM NORTHWEST QUADRANT
VECTOR TO 36 HR POSIT: 310 DEG/ 02 KTS
---
36 HRS, VALID AT:
230000Z --- 12.6N 128.2E
MAX SUSTAINED WINDS - 070 KT, GUSTS 085 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 064 KT WINDS - 025 NM NORTHEAST QUADRANT
025 NM SOUTHEAST QUADRANT
025 NM SOUTHWEST QUADRANT
025 NM NORTHWEST QUADRANT
RADIUS OF 050 KT WINDS - 040 NM NORTHEAST QUADRANT
040 NM SOUTHEAST QUADRANT
040 NM SOUTHWEST QUADRANT
040 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 110 NM NORTHEAST QUADRANT
100 NM SOUTHEAST QUADRANT
095 NM SOUTHWEST QUADRANT
105 NM NORTHWEST QUADRANT
VECTOR TO 48 HR POSIT: 330 DEG/ 04 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
231200Z --- 13.3N 127.8E
MAX SUSTAINED WINDS - 080 KT, GUSTS 100 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 064 KT WINDS - 030 NM NORTHEAST QUADRANT
030 NM SOUTHEAST QUADRANT
030 NM SOUTHWEST QUADRANT
030 NM NORTHWEST QUADRANT
RADIUS OF 050 KT WINDS - 055 NM NORTHEAST QUADRANT
055 NM SOUTHEAST QUADRANT
050 NM SOUTHWEST QUADRANT
055 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 130 NM NORTHEAST QUADRANT
120 NM SOUTHEAST QUADRANT
115 NM SOUTHWEST QUADRANT
120 NM NORTHWEST QUADRANT
VECTOR TO 72 HR POSIT: 335 DEG/ 03 KTS
---
72 HRS, VALID AT:
241200Z --- 14.5N 127.2E
MAX SUSTAINED WINDS - 090 KT, GUSTS 110 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 064 KT WINDS - 035 NM NORTHEAST QUADRANT
035 NM SOUTHEAST QUADRANT
035 NM SOUTHWEST QUADRANT
035 NM NORTHWEST QUADRANT
RADIUS OF 050 KT WINDS - 060 NM NORTHEAST QUADRANT
060 NM SOUTHEAST QUADRANT
060 NM SOUTHWEST QUADRANT
060 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 130 NM NORTHEAST QUADRANT
125 NM SOUTHEAST QUADRANT
115 NM SOUTHWEST QUADRANT
125 NM NORTHWEST QUADRANT
VECTOR TO 96 HR POSIT: 330 DEG/ 05 KTS
---
LONG RANGE OUTLOOK:
---
96 HRS, VALID AT:
251200Z --- 16.1N 126.2E
MAX SUSTAINED WINDS - 095 KT, GUSTS 115 KT
WIND RADII VALID OVER OPEN WATER ONLY
VECTOR TO 120 HR POSIT: 320 DEG/ 07 KTS
---
120 HRS, VALID AT:
261200Z --- 18.2N 124.4E
MAX SUSTAINED WINDS - 100 KT, GUSTS 125 KT
WIND RADII VALID OVER OPEN WATER ONLY
---
REMARKS:
211500Z POSITION NEAR 12.4N 129.7E.
TROPICAL STORM (TS) 18W (JELAWAT), LOCATED APPROXIMATELY 535 NM
EAST-SOUTHEAST OF MANILA, PHILIPPINES, HAS TRACKED WEST-SOUTHWESTWARD
AT 07 KNOTS OVER THE PAST SIX HOURS. MAXIMUM SIGNIFICANT WAVE HEIGHT
AT 211200Z IS 14 FEET. NEXT WARNINGS AT 212100Z, 220300Z, 220900Z AND
221500Z. //
NNNN

[euro6208]

Latest Discussion...



WDPN31 PGTW 211500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 18W (JELAWAT) WARNING
NR 05//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL STORM (TS) 18W (JELAWAT), LOCATED APPROXIMATELY 535 NM
EAST-SOUTHEAST OF MANILA, PHILIPPINES, HAS TRACKED WEST-SOUTHWESTWARD
AT 07 KNOTS OVER THE PAST SIX HOURS. ANIMATED INFRARED (IR) SATELLITE
IMAGERY SHOWS THE SYSTEM HAS MAINTAINED CENTRAL DEEP CONVECTION
SLIGHTLY WEST OF THE LOW LEVEL CIRCULATION CENTER. THE INITIAL
POSITION IS BASED ON THE IR ANIMATION AND EXTRAPOLATED FROM A NOTCH
FEATURE ON A 210901Z SSMI-S MICROWAVE IMAGE. THE INITIAL INTENSITY IS
BASED ON CONGRUENT DVORAK ESTIMATES OF 45 KNOTS FROM PGTW AND RJTD.
TS 18W LIES SLIGHTLY EQUATORWARD OF AN UPPER-LEVEL RIDGE AXIS IN AN
AREA OF LIGHT EASTERLY VERTICAL WIND SHEAR AND LIMITED OUTFLOW ALOFT.
THE CYCLONE CONTINUES TO TRACK ALONG THE SOUTHWESTERN EXTENSION OF
THE SUBTROPICAL RIDGE (STR) ANCHORED EAST OF JAPAN.
3. FORECAST REASONING.
A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
B. TS 18W IS EXPECTED TO TRACK SLOWLY WESTWARD OVER THE NEXT 48
HOURS AS A MID-LATITUDE TROUGH APPROACHING FROM THE NORTHWEST
WEAKENS THE CURRENT STEERING RIDGE AND THE CYCLONE ENTERS A WEAK
STEERING ENVIRONMENT. LOW VERTICAL WIND SHEAR, PASSAGE OVER WARM
WATER, AND IMPROVING OUTFLOW ALOFT AHEAD OF THE APPROACHING TROUGH
WILL ALLOW TS 18W TO STEADILY INTENSIFY DURING THIS PERIOD. AFTER
THE TROUGH TRANSLATES EASTWARD, SUBTROPICAL RIDGING IS EXPECTED TO
BUILD IN ITS WAKE AND TURN TS 18W ON A NORTHWESTWARD TRAJECTORY.
C. DURING THE EXTENDED TAUS, THE REBUILDING STR TO THE NORTHEAST
IS EXPECTED TO STEER THE SYSTEM IN A NORTHWESTWARD DIRECTION AS THE
PRIMARY STEERING MECHANISM GRADUALLY TRANSITIONS TO ANOTHER
SUBTROPICAL RIDGE OVER EASTERN CHINA. ENVIRONMENTAL CONDITIONS ARE
EXPECTED TO DRIVE CONTINUED INTENSIFICATION DURING THIS PERIOD. THE
NUMERICAL MODEL GUIDANCE REMAINS WIDELY SPREAD. THE CURRENT FORECAST
IS ADJUSTED LEFT OF CONSENSUS TO OFFSET UNLIKELY INTRUSION OF THE
VORTEX INTO THE STR, AS DEPICTED BY A HANDFUL OF TRACKERS INCLUDING
GFS AND ECMWF. THERE IS LOW CONFIDENCE IN THE CURRENT TRACK FORECAST.
//
NNNN

[euro6208]

CI# /Pressure/ Vmax
3.4 / 996.3mb/ 53.0kt


Final T# Adj T# Raw T#
3.4 3.4 3.4

[cycloneye]

WTPN31 PGTW 212100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE WARNING//
RMKS/
1. TROPICAL STORM 18W (JELAWAT) WARNING NR 006
01 ACTIVE TROPICAL CYCLONE IN NORTHWESTPAC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
211800Z --- NEAR 12.2N 129.7E
MOVEMENT PAST SIX HOURS - 225 DEGREES AT 03 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT
045 NM SOUTHEAST QUADRANT
045 NM SOUTHWEST QUADRANT
050 NM NORTHWEST QUADRANT
REPEAT POSIT: 12.2N 129.7E
---
FORECASTS:
12 HRS, VALID AT:
220600Z --- 12.2N 129.1E
MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 025 NM NORTHEAST QUADRANT
025 NM SOUTHEAST QUADRANT
025 NM SOUTHWEST QUADRANT
025 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 080 NM NORTHEAST QUADRANT
070 NM SOUTHEAST QUADRANT
070 NM SOUTHWEST QUADRANT
080 NM NORTHWEST QUADRANT
VECTOR TO 24 HR POSIT: 290 DEG/ 03 KTS
---
24 HRS, VALID AT:
221800Z --- 12.4N 128.6E
MAX SUSTAINED WINDS - 070 KT, GUSTS 085 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 064 KT WINDS - 025 NM NORTHEAST QUADRANT
020 NM SOUTHEAST QUADRANT
020 NM SOUTHWEST QUADRANT
025 NM NORTHWEST QUADRANT
RADIUS OF 050 KT WINDS - 045 NM NORTHEAST QUADRANT
040 NM SOUTHEAST QUADRANT
040 NM SOUTHWEST QUADRANT
040 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 110 NM NORTHEAST QUADRANT
100 NM SOUTHEAST QUADRANT
095 NM SOUTHWEST QUADRANT
105 NM NORTHWEST QUADRANT
VECTOR TO 36 HR POSIT: 330 DEG/ 03 KTS
---
36 HRS, VALID AT:
230600Z --- 12.9N 128.3E
MAX SUSTAINED WINDS - 080 KT, GUSTS 100 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 064 KT WINDS - 030 NM NORTHEAST QUADRANT
030 NM SOUTHEAST QUADRANT
030 NM SOUTHWEST QUADRANT
030 NM NORTHWEST QUADRANT
RADIUS OF 050 KT WINDS - 055 NM NORTHEAST QUADRANT
050 NM SOUTHEAST QUADRANT
050 NM SOUTHWEST QUADRANT
050 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 120 NM NORTHEAST QUADRANT
115 NM SOUTHEAST QUADRANT
105 NM SOUTHWEST QUADRANT
110 NM NORTHWEST QUADRANT
VECTOR TO 48 HR POSIT: 340 DEG/ 03 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
231800Z --- 13.5N 128.1E
MAX SUSTAINED WINDS - 090 KT, GUSTS 110 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 064 KT WINDS - 035 NM NORTHEAST QUADRANT
035 NM SOUTHEAST QUADRANT
035 NM SOUTHWEST QUADRANT
035 NM NORTHWEST QUADRANT
RADIUS OF 050 KT WINDS - 060 NM NORTHEAST QUADRANT
060 NM SOUTHEAST QUADRANT
055 NM SOUTHWEST QUADRANT
060 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 125 NM NORTHEAST QUADRANT
120 NM SOUTHEAST QUADRANT
110 NM SOUTHWEST QUADRANT
120 NM NORTHWEST QUADRANT
VECTOR TO 72 HR POSIT: 345 DEG/ 04 KTS
---
72 HRS, VALID AT:
241800Z --- 15.2N 127.6E
MAX SUSTAINED WINDS - 105 KT, GUSTS 130 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 064 KT WINDS - 040 NM NORTHEAST QUADRANT
040 NM SOUTHEAST QUADRANT
040 NM SOUTHWEST QUADRANT
040 NM NORTHWEST QUADRANT
RADIUS OF 050 KT WINDS - 070 NM NORTHEAST QUADRANT
065 NM SOUTHEAST QUADRANT
065 NM SOUTHWEST QUADRANT
065 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 130 NM NORTHEAST QUADRANT
125 NM SOUTHEAST QUADRANT
120 NM SOUTHWEST QUADRANT
125 NM NORTHWEST QUADRANT
VECTOR TO 96 HR POSIT: 330 DEG/ 05 KTS
---
LONG RANGE OUTLOOK:
---
96 HRS, VALID AT:
251800Z --- 17.0N 126.5E
MAX SUSTAINED WINDS - 115 KT, GUSTS 140 KT
WIND RADII VALID OVER OPEN WATER ONLY
VECTOR TO 120 HR POSIT: 315 DEG/ 06 KTS
---
120 HRS, VALID AT:
261800Z --- 18.6N 124.8E
MAX SUSTAINED WINDS - 110 KT, GUSTS 135 KT
WIND RADII VALID OVER OPEN WATER ONLY
---
REMARKS:
212100Z POSITION NEAR 12.2N 129.6E.
TROPICAL STORM (TS) 18W (JELAWAT), LOCATED APPROXIMATELY 520 NM
EAST-SOUTHEAST OF MANILA, PHILIPPINES, HAS TRACKED SOUTHWESTWARD
AT 03 KNOTS OVER THE PAST SIX HOURS. MAXIMUM SIGNIFICANT WAVE HEIGHT
AT 211800Z IS 15 FEET. NEXT WARNINGS AT 220300Z, 220900Z, 221500Z
AND 222100Z.//
NNNN

[dexterlabio]

continues to dip but is now quasi-stationary.

STS 1217 (JELAWAT)
Issued at 21:35 UTC, 21 September 2012

<Analyses at 21/21 UTC>
Scale -
Intensity -
Center position N11°40'(11.7°)
E129°20'(129.3°)
Direction and speed of movement SW 15km/h(7kt)
Central pressure 990hPa
Maximum wind speed near the center 25m/s(50kt)
Maximum wind gust speed 35m/s(70kt)
Area of 30kt winds or more ALL220km(120NM)

<Forecast for 22/21 UTC>
Intensity Strong
Center position of probability circle N12°20'(12.3°)
E128°50'(128.8°)
Direction and speed of movement Almost stationary
Central pressure 970hPa
Maximum wind speed near the center 35m/s(65kt)
Maximum wind gust speed 50m/s(95kt)
Radius of probability circle 130km(70NM)
Storm warning area ALL220km(120NM)

<Forecast for 23/18 UTC>
Intensity Strong
Center position of probability circle N13°40'(13.7°)
E128°05'(128.1°)
Direction and speed of movement NNW Slowly
Central pressure 950hPa
Maximum wind speed near the center 40m/s(80kt)
Maximum wind gust speed 60m/s(115kt)
Radius of probability circle 200km(110NM)
Storm warning area ALL330km(180NM)

<Forecast for 24/18 UTC>
Intensity Very Strong
Center position of probability circle N15°20'(15.3°)
E127°00'(127.0°)
Direction and speed of movement NNW Slowly
Central pressure 940hPa
Maximum wind speed near the center 45m/s(85kt)
Maximum wind gust speed 60m/s(120kt)
Radius of probability circle 300km(160NM)
Storm warning area ALL460km(250NM)

[dexterlabio]

5-day forecast from JMA

[cycloneye]

MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE WARNING//
RMKS/
1. TROPICAL STORM 18W (JELAWAT) WARNING NR 007
01 ACTIVE TROPICAL CYCLONE IN NORTHWESTPAC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
220000Z --- NEAR 11.7N 129.9E
MOVEMENT PAST SIX HOURS - 200 DEGREES AT 03 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 065 NM NORTHEAST QUADRANT
060 NM SOUTHEAST QUADRANT
060 NM SOUTHWEST QUADRANT
065 NM NORTHWEST QUADRANT
REPEAT POSIT: 11.7N 129.9E
---
FORECASTS:
12 HRS, VALID AT:
221200Z --- 11.8N 129.3E
MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 020 NM NORTHEAST QUADRANT
020 NM SOUTHEAST QUADRANT
020 NM SOUTHWEST QUADRANT
020 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 080 NM NORTHEAST QUADRANT
070 NM SOUTHEAST QUADRANT
070 NM SOUTHWEST QUADRANT
080 NM NORTHWEST QUADRANT
VECTOR TO 24 HR POSIT: 320 DEG/ 03 KTS
---
24 HRS, VALID AT:
230000Z --- 12.3N 128.9E
MAX SUSTAINED WINDS - 070 KT, GUSTS 085 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 064 KT WINDS - 025 NM NORTHEAST QUADRANT
020 NM SOUTHEAST QUADRANT
020 NM SOUTHWEST QUADRANT
025 NM NORTHWEST QUADRANT
RADIUS OF 050 KT WINDS - 045 NM NORTHEAST QUADRANT
040 NM SOUTHEAST QUADRANT
040 NM SOUTHWEST QUADRANT
040 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 110 NM NORTHEAST QUADRANT
100 NM SOUTHEAST QUADRANT
095 NM SOUTHWEST QUADRANT
105 NM NORTHWEST QUADRANT
VECTOR TO 36 HR POSIT: 340 DEG/ 03 KTS
---
36 HRS, VALID AT:
231200Z --- 12.8N 128.7E
MAX SUSTAINED WINDS - 080 KT, GUSTS 100 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 064 KT WINDS - 030 NM NORTHEAST QUADRANT
030 NM SOUTHEAST QUADRANT
030 NM SOUTHWEST QUADRANT
030 NM NORTHWEST QUADRANT
RADIUS OF 050 KT WINDS - 055 NM NORTHEAST QUADRANT
050 NM SOUTHEAST QUADRANT
050 NM SOUTHWEST QUADRANT
050 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 120 NM NORTHEAST QUADRANT
115 NM SOUTHEAST QUADRANT
105 NM SOUTHWEST QUADRANT
110 NM NORTHWEST QUADRANT
VECTOR TO 48 HR POSIT: 345 DEG/ 04 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
240000Z --- 13.5N 128.5E
MAX SUSTAINED WINDS - 090 KT, GUSTS 110 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 064 KT WINDS - 035 NM NORTHEAST QUADRANT
035 NM SOUTHEAST QUADRANT
035 NM SOUTHWEST QUADRANT
035 NM NORTHWEST QUADRANT
RADIUS OF 050 KT WINDS - 060 NM NORTHEAST QUADRANT
060 NM SOUTHEAST QUADRANT
055 NM SOUTHWEST QUADRANT
060 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 125 NM NORTHEAST QUADRANT
120 NM SOUTHEAST QUADRANT
110 NM SOUTHWEST QUADRANT
120 NM NORTHWEST QUADRANT
VECTOR TO 72 HR POSIT: 340 DEG/ 05 KTS
---
72 HRS, VALID AT:
250000Z --- 15.5N 127.7E
MAX SUSTAINED WINDS - 105 KT, GUSTS 130 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 064 KT WINDS - 040 NM NORTHEAST QUADRANT
040 NM SOUTHEAST QUADRANT
040 NM SOUTHWEST QUADRANT
040 NM NORTHWEST QUADRANT
RADIUS OF 050 KT WINDS - 070 NM NORTHEAST QUADRANT
065 NM SOUTHEAST QUADRANT
065 NM SOUTHWEST QUADRANT
065 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 130 NM NORTHEAST QUADRANT
125 NM SOUTHEAST QUADRANT
120 NM SOUTHWEST QUADRANT
125 NM NORTHWEST QUADRANT
VECTOR TO 96 HR POSIT: 315 DEG/ 05 KTS
---
LONG RANGE OUTLOOK:
---
96 HRS, VALID AT:
260000Z --- 17.0N 126.2E
MAX SUSTAINED WINDS - 115 KT, GUSTS 140 KT
WIND RADII VALID OVER OPEN WATER ONLY
VECTOR TO 120 HR POSIT: 300 DEG/ 06 KTS
---
120 HRS, VALID AT:
270000Z --- 18.2N 124.0E
MAX SUSTAINED WINDS - 110 KT, GUSTS 135 KT
WIND RADII VALID OVER OPEN WATER ONLY
---
REMARKS:
220300Z POSITION NEAR 11.7N 129.8E.
TROPICAL STORM (TS) 18W (JELAWAT), LOCATED APPROXIMATELY 540 NM
EAST-SOUTHEAST OF MANILA, PHILIPPINES, HAS TRACKED SOUTH-
SOUTHWESTWARD AT 03 KNOTS OVER THE PAST SIX HOURS. MAXIMUM
SIGNIFICANT WAVE HEIGHT AT 220000Z IS 16 FEET. NEXT WARNINGS AT
220900Z, 221500Z, 222100Z AND 230300Z.//

[euro6208]

latest discussion...very interesting one too...


WDPN31 PGTW 220300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 18W (JELAWAT) WARNING
NR 07//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL STORM (TS) 18W (JELAWAT), LOCATED APPROXIMATELY 540 NM
EAST-SOUTHEAST OF MANILA, PHILIPPINES, HAS TRACKED SOUTH-
SOUTHWESTWARD AT 03 KNOTS OVER THE PAST SIX HOURS. ANIMATED
MULTISPECTRAL SATELLITE IMAGERY (MSI) SHOWS A TIGHTLY WRAPPED
SYSTEM WITH DEEP CONVECTION WRAPPING INTO THE LOW LEVEL CIRCULATION
CENTER (LLCC). A 212132Z SSMIS 91GHZ MICROWAVE IMAGE SHOWS SEVERAL
DISPLACED DEEP CONVECTIVE BANDS OVER THE SOUTHERN SEMI-CIRCLE BUT
VERY MINIMAL CONVECTIVE ACTIVITY OVER THE NORTHERN SEMICIRCLE.
ANIMATED WATER VAPOR IMAGERY REVEALS A TUTT CELL HAS FORMED
NORTHEAST OF THE SYSTEM WHICH IS WHAT IS SUPPRESSING THE CONVECTIVE
ACTIVITY TO THE NORTH. FURTHER UPPER-LEVEL ANALYSIS DEPICTS THAT TS
18W LIES EQUATORWARD OF AN UPPER-LEVEL RIDGE AXIS WITH EXCELLENT
EQUATORWARD OUTFLOW DUE TO SPEED DIVERGENCE TO THE SOUTH AND HAS
LIMITED POLEWARD OUTFLOW DUE TO THE NEWLY FORMED TUTT CELL TO THE
NORTHEAST. THE INITIAL POSITION IS BASED ON THE AFOREMENTIONED
IMAGERY. THE INITIAL INTENSITY IS BASED ON AN AVERAGE OF DVORAK
ESTIMATES OF 45 TO 55 KNOTS FROM RJTD AND PGTW, RESPECTIVELY. TS
18W IS IN A WEAK STEERING ENVIRONMENT AS AN APPROACHING MID-
LATITUDE TROUGH HAS WEAKENED THE SUBTROPICAL RIDGE (STR) THAT WAS
THE DOMINANT STEERING INFLUENCE.
3. FORECAST REASONING.
A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
B. TS 18W IS EXPECTED TO DRIFT SLOWLY WEST-SOUTHWESTWARD OVER
THE NEXT 24 HOURS AS THE MID-LATITUDE TROUGH APPROACHING FROM THE
NORTHWEST WEAKENS THE CURRENT STEERING RIDGE. AFTER THE TROUGH
PASSES, THE SUBTROPICAL RIDGE WILL BEGIN TO REBUILD AND TURN TS 18W
SLOWLY ON A MORE NORTH-NORTHWESTWARD TRACK. TS 18W WILL CONTINUALLY
INTENSIFY AS IT DEVELOPS A POLEWARD OUTFLOW CHANNEL FROM THE
PASSING TROUGH WITH THE POSSIBILITY OF RAPID INTENSIFICATION BASED
ON THE FAVORABLE ENVIRONMENTAL CONDITIONS.
C. IN THE EXTENDED TAUS, A SUBTROPICAL RIDGE THAT IS CURRENTLY
OVER EASTERN CHINA IS FORECASTED TO AMPLIFY AND BECOME TS 18W'S
DOMINANT STEERING MECHANISM, WHICH WILL TURN THE SYSTEM MORE
TOWARDS THE WEST. DUE TO FORECASTED FAVORABLE ENVIRONMENTAL
CONDITIONS, A PEAK INTENSITY OF 115 KNOTS IS FORECASTED AT TAU 96.
NUMERICAL MODEL GUIDANCE REMAINS WIDELY SPREAD. THE CURRENT
FORECAST REMAINS LEFT OF CONSENSUS TO OFFSET AN UNLIKELY SHARP
NORTHERN TRACK INTO THE STR, WHICH IS DEPICTED BY GFS, EGRR AND
JGSM. DUE TO THE LARGE SPREAD IN MODEL GUIDANCE, THERE IS LOW
CONFIDENCE IN THE CURRENT TRACK FORECAST.//
NNNN

[phwxenthusiast]

Very nice video update! I like that you talked about that potential TC near Guam. I'm not sure if some models are saying that there'll be a DCI between the potential storm and Jelawat OR the storm will 'intrude' the STR east of Japan, introducing a weakness and allowing Jelawat to move towards the NE. That IMO is possible only if that phantom storm will be a strong system as it tracks north...but I still doubt if it will be strong enough to affect Jelawat's behavior or if it can introduce such weakness to the STR.

Hopefully we can see a brighter picture of things tomorrow. This kind of setup makes me go nuts.

Personal Forecast Disclaimer:
The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data.

thanks! yeah you're probably right with that DCI thing... it just seems odd how they were bringing Jelawat towards the northeast... i do think the northwestward track will prevail in the end but we still have to watch that LPA (now Invest 93W) though may surprise us in the next few days hehe...

as of right now though, it looks like EURO has finally shifted and is showing a track towards Luzon... only the CMC remains in bringing Jelawat to the northeast...

Personal Forecast Disclaimer:
The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

[euro6208]

55 knots and forecast to reach 115 knots as it skirts luzon...

WTPN31 PGTW 221500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE WARNING//
RMKS/
1. TROPICAL STORM 18W (JELAWAT) WARNING NR 009
01 ACTIVE TROPICAL CYCLONE IN NORTHWESTPAC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
221200Z --- NEAR 11.8N 129.8E
MOVEMENT PAST SIX HOURS - 270 DEGREES AT 03 KTS
POSITION ACCURATE TO WITHIN 045 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 035 NM NORTHEAST QUADRANT
035 NM SOUTHEAST QUADRANT
035 NM SOUTHWEST QUADRANT
035 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 065 NM NORTHEAST QUADRANT
065 NM SOUTHEAST QUADRANT
065 NM SOUTHWEST QUADRANT
065 NM NORTHWEST QUADRANT
REPEAT POSIT: 11.8N 129.8E
---
FORECASTS:
12 HRS, VALID AT:
230000Z --- 12.1N 129.3E
MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 045 NM NORTHEAST QUADRANT
040 NM SOUTHEAST QUADRANT
040 NM SOUTHWEST QUADRANT
045 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 090 NM NORTHEAST QUADRANT
085 NM SOUTHEAST QUADRANT
085 NM SOUTHWEST QUADRANT
085 NM NORTHWEST QUADRANT
VECTOR TO 24 HR POSIT: 310 DEG/ 04 KTS
---
24 HRS, VALID AT:
231200Z --- 12.6N 128.7E
MAX SUSTAINED WINDS - 075 KT, GUSTS 090 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 064 KT WINDS - 025 NM NORTHEAST QUADRANT
025 NM SOUTHEAST QUADRANT
025 NM SOUTHWEST QUADRANT
025 NM NORTHWEST QUADRANT
RADIUS OF 050 KT WINDS - 050 NM NORTHEAST QUADRANT
050 NM SOUTHEAST QUADRANT
050 NM SOUTHWEST QUADRANT
050 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 105 NM NORTHEAST QUADRANT
100 NM SOUTHEAST QUADRANT
095 NM SOUTHWEST QUADRANT
100 NM NORTHWEST QUADRANT
VECTOR TO 36 HR POSIT: 330 DEG/ 04 KTS
---
36 HRS, VALID AT:
240000Z --- 13.3N 128.3E
MAX SUSTAINED WINDS - 085 KT, GUSTS 105 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 064 KT WINDS - 030 NM NORTHEAST QUADRANT
030 NM SOUTHEAST QUADRANT
030 NM SOUTHWEST QUADRANT
030 NM NORTHWEST QUADRANT
RADIUS OF 050 KT WINDS - 060 NM NORTHEAST QUADRANT
055 NM SOUTHEAST QUADRANT
055 NM SOUTHWEST QUADRANT
055 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 115 NM NORTHEAST QUADRANT
110 NM SOUTHEAST QUADRANT
105 NM SOUTHWEST QUADRANT
110 NM NORTHWEST QUADRANT
VECTOR TO 48 HR POSIT: 330 DEG/ 05 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
241200Z --- 14.2N 127.8E
MAX SUSTAINED WINDS - 095 KT, GUSTS 115 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 064 KT WINDS - 040 NM NORTHEAST QUADRANT
035 NM SOUTHEAST QUADRANT
035 NM SOUTHWEST QUADRANT
035 NM NORTHWEST QUADRANT
RADIUS OF 050 KT WINDS - 065 NM NORTHEAST QUADRANT
060 NM SOUTHEAST QUADRANT
060 NM SOUTHWEST QUADRANT
060 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 125 NM NORTHEAST QUADRANT
120 NM SOUTHEAST QUADRANT
115 NM SOUTHWEST QUADRANT
115 NM NORTHWEST QUADRANT
VECTOR TO 72 HR POSIT: 325 DEG/ 05 KTS
---
72 HRS, VALID AT:
251200Z --- 16.0N 126.6E
MAX SUSTAINED WINDS - 115 KT, GUSTS 140 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 064 KT WINDS - 040 NM NORTHEAST QUADRANT
040 NM SOUTHEAST QUADRANT
040 NM SOUTHWEST QUADRANT
040 NM NORTHWEST QUADRANT
RADIUS OF 050 KT WINDS - 070 NM NORTHEAST QUADRANT
065 NM SOUTHEAST QUADRANT
065 NM SOUTHWEST QUADRANT
070 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 130 NM NORTHEAST QUADRANT
125 NM SOUTHEAST QUADRANT
120 NM SOUTHWEST QUADRANT
125 NM NORTHWEST QUADRANT
VECTOR TO 96 HR POSIT: 310 DEG/ 07 KTS
---
LONG RANGE OUTLOOK:
---
96 HRS, VALID AT:
261200Z --- 17.8N 124.5E
MAX SUSTAINED WINDS - 115 KT, GUSTS 140 KT
WIND RADII VALID OVER OPEN WATER ONLY
VECTOR TO 120 HR POSIT: 300 DEG/ 07 KTS
---
120 HRS, VALID AT:
271200Z --- 19.2N 121.8E
MAX SUSTAINED WINDS - 100 KT, GUSTS 125 KT
WIND RADII VALID OVER OPEN WATER ONLY
---
REMARKS:
221500Z POSITION NEAR 11.9N 129.7E.
TROPICAL STORM (TS) 18W (JELAWAT), LOCATED APPROXIMATELY 545
NM EAST-SOUTHEAST OF MANILA, PHILIPPINES, HAS TRACKED WESTWARD
AT 03 KNOTS OVER THE PAST SIX HOURS. MAXIMUM SIGNIFICANT WAVE
HEIGHT AT 221200Z IS 16 FEET. NEXT WARNINGS AT 222100Z,
230300Z, 230900Z AND 231500Z.//
NNNN



WDPN31 PGTW 221500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 18W (JELAWAT) WARNING
NR 09//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL STORM (TS) 18W (JELAWAT), LOCATED APPROXIMATELY 545 NM
EAST-SOUTHEAST OF MANILA, PHILIPPINES, HAS TRACKED WESTWARD AT 03
KNOTS OVER THE PAST SIX HOURS. ANIMATED INFRARED SATELLITE IMAGERY
DEPICTS A SLOWLY CONSOLIDATING LOW-LEVEL CIRCULATION CENTER (LLCC)
WITH A 130NM DIAMETER CENTRAL DENSE OVERCAST (CDO) AND MULTIPLE
CONVECTIVE BANDS WRAPPING INTO THE SYSTEM. A 220848Z SSMIS 37GHZ
IMAGE INDICATES TIGHTLY-CURVED CONVECTIVE BANDING WRAPPING INTO A
WELL-DEFINED CENTER, THEREFORE, THERE IS INCREASED CONFIDENCE IN THE
INITIAL POSITION AND RECENT MOTION WESTWARD. ANIMATED WATER VAPOR
IMAGERY INDICATES THAT THE LLCC IS LOCATED JUST SOUTHWEST OF AN
UPPER-LEVEL ANTICYCLONE, WHICH IS PRODUCING WEAK, NORTHEASTERLY
VERTICAL WIND SHEAR (VWS) AS WELL AS STRONG DIFFLUENCE; HOWEVER, VWS
APPEARS TO HAVE ABATED SLIGHTLY AND POLEWARD OUTFLOW HAS IMPROVED
DUE TO A DEVELOPING TUTT CELL NEAR 15N 137E. THE INITIAL INTENSITY
IS ASSESSED AT 55 KNOTS BASED ON THE IMPROVED ORGANIZATION AND
DVORAK ESTIMATES OF 55 KNOTS FROM BOTH KNES, RJTD AND PGTW. TS 18W
IS CURRENTLY LOCATED WITHIN A WEAK STEERING ENVIRONMENT. THE 22/00Z
500MB ANALYSIS DEPICTS A LARGE BREAK BETWEEN THE WESTERN SUBTROPICAL
RIDGE (STR) AND THE EASTERN STR DUE TO A BROAD TROUGH POSITIONED
OVER ASIA. THE WESTERN STR EXTENDS FROM HAINAN ISLAND EASTWARD ALONG
20N TO ABOUT 130E WHILE THE EASTERN STR IS POSITIONED EAST OF 140E.
3. FORECAST REASONING.
A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
B. TS 18W IS FORECAST TO DRIFT SLOWLY WEST-NORTHWESTWARD THROUGH
TAU 24 UNDER THE STEERING INFLUENCE OF THE WEAK WESTERN STR
POSITIONED NORTH OF THE SYSTEM. THIS STEERING INFLUENCE IS EXPECTED
TO BE SHORT-LIVED AS A MIDLATITUDE SHORTWAVE TROUGH DEEPENS OVER THE
EAST CHINA SEA IN THE NEXT 12 HOURS. AFTER THIS TROUGH PROPAGATES
EASTWARD, THE EASTERN STR IS FORECAST TO BUILD NORTHEAST OF 18W
DRIVING THE SYSTEM NORTHWESTWARD; HOWEVER, TRACK SPEEDS ARE STILL
EXPECTED TO BE SLOW (04-05 KNOTS). WITH THE EXCEPTION OF THE JGSM
MODEL, DYNAMIC MODEL GUIDANCE IS IN BETTER AGREEMENT WITH A 135NM
SPREAD AT TAU 72; HOWEVER, GFDN, NOGAPS, JGSM AND UKMO HAVE BEEN
ERRATIC. BASED ON THE UPPER-LEVEL ANALYSIS, THE JTWC FORECAST
CONTINUES TO FAVOR THE WESTWARD TO NORTHWESTWARD TRACK, AS DEPICTED
BY THE ECMWF MODEL, OVER THE UNLIKELY NORTHWARD TRACK INTO THE STR
(MOST NOTABLY JGSM, UKMO, WBAR). DUE TO THE WEAK STEERING
ENVIRONMENT, THERE IS LOW CONFIDENCE IN THE FORECAST TRACK.
C. IN THE EXTENDED TAUS, TS 18W IS FORECAST TO TURN INCREASINGLY
WEST-NORTHWESTWARD AS IT TRANSITIONS TO THE STEERING INFLUENCE OF
THE WESTERN STR. DYNAMIC MODEL GUIDANCE CONTINUES TO DIVERGE WITH A
LARGE SPREAD IN SOLUTIONS, THERFORE, THERE IS LOW CONFIDENCE IN THE
EXTENDED FORECAST. TS 18W SHOULD CONTINUE TO INTENSIFY THROUGH THE
PERIOD AND IS EXPECTED TO REACH A PEAK INTENSITY OF 115 KNOTS NEAR
TAU 72.//
NNNN