WPAC: INVEST 93W - JTWC Tropical Depression 25W

[euro6208]

very near malaysia in the south china sea...

[RobWESTPACWX]

Wow, I'm really surprised this got pushed up to invest. So late in the year now. The west pac is always full of surprises.

[francis327]

Will keep an eye on this one. I'm from northern peninsula Malaysia

[francis327]

Latest satellite image on infrared red band, visible band and 24 hour rain intensity estimation

[euro6208]

WTPN21 PGTW 040800
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
190 NM EITHER SIDE OF A LINE FROM 6.5N 114.8E TO 9.1N 109.8E
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 18 TO 23 KNOTS. METSAT IM-
AGERY AT 040730Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 7.5N 114.3E. THE SYSTEM IS MOVING NORTH-NORTHEASTWARD AT 11
KNOTS.
2. REMARKS: THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 6.5N
113.9E, IS NOW LOCATED NEAR 7.5N 114.3E, APPROXIMATELY 155 NM
NORTH-NORTHWEST OF BRUNEI. RECENT ANIMATED MULTISPECTRAL SATELLITE
IMAGERY SHOWS DEEP FLARING CENTRAL CONVECTION THAT IS BEING SHEARED
TO THE WEST OF A PARTLY EXPOSED LOW LEVEL CIRCULATION CENTER (LLCC).
A 040614Z AMSU IMAGE SHOWS A FORMATIVE RAINBAND TO THE NORTH OF THE
LLCC ASSOCIATED WITH STRONG NORTHEASTERLY MONSOONAL FLOW CONVERGING
WITH EASTERLIES FROM THE CYCLONIC CIRCULATION. ADDITIONALLY, THE
FLARING DEEP CENTRAL CONVECTION ASSOCIATED WITH THE LLCC FANS OUT IN
AN A DIFFUSE PATTERN OVER THE WESTERN PERIPHERY OF THE LLCC. A
040124Z ASCAT PASS SHOWS 20 KNOT WINDS NEAR THE LLCC WITH STRONGER
SOUTHWESTERLIES TO THE SOUTH. UPPER LEVEL ANALYSIS INDICATES THAT
THE LLCC IS APPROXIMATELY 08 DEGREES SOUTH OF THE SUBTROPICAL RIDGE
AXIS UNDER MODERATE (20-25 KNOT) EASTERLY VERTICAL WINDSHEAR WHICH
IS PARTIALLY OFFSET BY STRONG DIVERGENCE ALOFT. SEA SURFACE
TEMPERATURES ALONG THE COAST OF BRUNEI AND IN THE SOUTH CHINA SEA
ARE BETWEEN 28 AND 30 DEGREES CELSIUS. MAXIMUM SUSTAINED SURFACE
WINDS ARE ESTIMATED AT 18 TO 23 KNOTS. MINIMUM SEA LEVEL PRESSURE IS
ESTIMATED TO BE NEAR 1006 MB. DUE TO THE PERSISTENT, BUT SHEARED,
CENTRAL CONVECTION THE POTENTIAL FOR THE DEVELOPMENT OF A
SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS HIGH.
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY
050800Z.//
NNNN

[francis327]

Model projected that it will move north north-east before curving back to Vietnam and probably Laos. Any possibility for this to go westward and affect the Peninsula Malaysia or even the Borneo?

[francis327]

Updated to HIGH by JTWC

[francis327]

ABPW10 PGTW 040930
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE WESTERN AND
/SOUTH PACIFIC OCEANS REISSUED/040930Z-050600ZDEC2011//
REF/A/MSG/NAVMARFCSTCEN PEARL HARBOR HI/JTWC/040751ZDEC2011//
AMPN/REF A IS A TROPICAL CYCLONE FORMATION ALERT.
RMKS/
1. WESTERN NORTH PACIFIC AREA (180 TO MALAY PENINSULA):
A. TROPICAL CYCLONE SUMMARY: NONE.
B. TROPICAL DISTURBANCE SUMMARY:
(1) THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 6.5N
113.9E, IS NOW LOCATED NEAR 7.5N 114.3E, APPROXIMATELY 155 NM
NORTH-NORTHWEST OF BRUNEI. RECENT ANIMATED MULTISPECTRAL SATELLITE
IMAGERY SHOWS DEEP FLARING CENTRAL CONVECTION THAT IS BEING SHEARED
TO THE WEST OF A PARTLY EXPOSED LOW LEVEL CIRCULATION CENTER (LLCC).
A 040614Z AMSU IMAGE SHOWS A FORMATIVE RAINBAND TO THE NORTH OF THE
LLCC ASSOCIATED WITH STRONG NORTHEASTERLY MONSOONAL FLOW CONVERGING
WITH EASTERLIES FROM THE CYCLONIC CIRCULATION. ADDITIONALLY, THE
FLARING DEEP CENTRAL CONVECTION ASSOCIATED WITH THE LLCC FANS OUT IN
AN A DIFFUSE PATTERN OVER THE WESTERN PERIPHERY OF THE LLCC. A
040124Z ASCAT PASS SHOWS 20 KNOT WINDS NEAR THE LLCC WITH STRONGER
SOUTHWESTERLIES TO THE SOUTH. UPPER LEVEL ANALYSIS INDICATES THAT
THE LLCC IS APPROXIMATELY 08 DEGREES SOUTH OF THE SUBTROPICAL RIDGE
AXIS UNDER MODERATE (20-25 KNOT) EASTERLY VERTICAL WINDSHEAR WHICH
IS PARTIALLY OFFSET BY STRONG DIVERGENCE ALOFT. SEA SURFACE
TEMPERATURES ALONG THE COAST OF BRUNEI AND IN THE SOUTH CHINA SEA
ARE BETWEEN 28 AND 30 DEGREES CELSIUS. MAXIMUM SUSTAINED SURFACE
WINDS ARE ESTIMATED AT 18 TO 23 KNOTS. MINIMUM SEA LEVEL PRESSURE IS
ESTIMATED TO BE NEAR 1006 MB. SEE REF A (WTPN21 PGTW 040800) FOR
FURTHER DETAILS. DUE TO THE PERSISTENT, BUT SHEARED, CENTRAL
CONVECTION THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT
TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS UPGRADED TO HIGH.
(2) NO OTHER SUSPECT AREAS.
2. SOUTH PACIFIC AREA (WEST COAST OF SOUTH AMERICA TO 135 EAST):
A. TROPICAL CYCLONE SUMMARY: NONE.
B. TROPICAL DISTURBANCE SUMMARY: NONE.
3. JUSTIFICATION FOR REISSUE: UPGRADED AREA IN PARA 1.B.(1) TO
HIGH.//
NNNN

[francis327]

Rough Sea warning by the Malaysia Met Department

THIRD CATEGORY WARNING

WARNING ON STRONG WINDS AND ROUGH SEAS



SECTION A : WARNING ON STRONG WINDS AND ROUGH SEAS (THIRD CATEGORY) –Upgrade from Second Category Warning Issued at 6.33am, 28/11/11
Strong Northeasterly winds over 60 kmph with waves more than 5.5 metres occurring over waters off Pahang, East Johore, Sarawak, Tioman, Bunguran, Condore, Reef North, Reef South and Layang-Layang are expected to continue until Tuesday, 13th December 2011.

In addition, coastal areas Pahang and Johor Timur are vulnerable to sea level rise due to strong wind and battering waves. This condition is expected to continue until 4th December 2011.

This condition of strong winds and rough seas is dangerous to all coastal and shipping activities including workers on oil platform.

SECTION B: WARNING ON STRONG WINDS AND ROUGH SEAS (SECOND CATEGORY)- Upgrade from First Category Warning Issued at 6.33am, 28/11/11

Strong Northeasterly winds of 50-60 kmph with waves up to 4.5 metres occurring over the waters off Kelantan, Terengganu, FT Labuan, Sabah (Interior, West Coast dan Kudat), Samui and Palawan are expected to continue until Tuesday, 13th December 2011.

In addition, coastal areas of Kelantan and Terengganu are vulnerable to sea level rise due to strong wind and battering waves. This condition is expected to continue until 4th November 2011.

This condition of strong winds and rough seas is dangerous to all shipping and coastal activities including fishing and ferry services.

SECTION C: WIDESPREAD THUNDERSTORM WARNING-Update

Thunderstorm activities occurring over waters off Perak, Selangor, Pahang, Sarawak(Mukah, Bintulu and Miri), Labuan FT, Sabah (Interior and Kudat), Reef South, Reef North, Layang-layang, Palawan and Sulu are expected to continue until early night, Sunday, 4th December 2011.

This condition may cause strong winds up to 50kmph and rough seas with wave height up to 3.5 metres and dangerous to small boat.

[Chacor]

Fairly interesting to see the JTWC upgrade to a TCFA. JMA does not even have it as a low pressure area in their high seas forecast.

[RobWESTPACWX]

Well, I am really surprised by this one, really did not expect JTWC to warn on it.

[Chacor]

Only T1.5 from KNES as well.

WDPN31 PGTW 091500
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 25W
WARNING NR 01//
RMKS/
1. FOR METEOROLOGISTS.
2. 12 HOUR SUMMARY AND ANALYSIS.
A. TROPICAL DEPRESSION (TD) 25W LOCATED APPROXIMATELY 440 NM
EAST-SOUTHEAST OF HO CHI MINH CITY, VIETNAM, HAD TRACKED NORTH-
NORTHWESTWARD AT 12 KNOTS OVER THE PAST SIX HOURS. ANIMATED INFRARED
SATELLITE IMAGERY SHOWS PERSISTENT FLARING DEEP CENTRAL CONVECTION
THAT IS BEING SHEARED TO THE WEST OF A PARTLY EXPOSED LOW LEVEL
CIRCULATION CENTER (LLCC). A 041210Z SSMIS 37 GHZ IMAGE DEPICTS
TIGHTLY CURVED BANDING OVER THE NORTHERN AND WESTERN PORTIONS OF THE
LLCC. RECENT SCATTEROMETRY DATA SHOWS STRONG (25-35 KNOT)
NORTHEASTERLY MONSOONAL FLOW WEST OF THE LLCC WITH SOME 30- KNOT
WINDS WRAPPING INTO THE SYSTEM CENTER. THE INITIAL POSITION IS BASED
ON THE AFOREMENTIONED SATELLITE IMAGERY WITH LOW CONFIDENCE. THE
INITIAL INTENSITY IS BASED ON THE RECENT SCATTEROMETRY DATA. UPPER
LEVEL ANALYSIS INDICATES THAT TD 25W LIES APPROXIMATELY 08 DEGREES
SOUTH OF THE SUBTROPICAL RIDGE AXIS ANCHORED OVER THE WESTERN
TROPICAL PACIFIC. TD 25W IS CURRENTLY UNDER MODERATE (20-25 KNOT)
EASTERLY VERTICAL WINDSHEAR (VWS) WHICH IS SOMEWHAT OFFSET BY GOOD
UPPER LEVEL DIVERGENCE ALLOWING FOR THE PERSISTENT FLARES OF CENTRAL
CONVECTION. TD 25W IS CURRENTLY BEING STEERED BY THE SOUTHERN
PERIPHERY OF A LOW- TO MID-LEVEL SUBTROPICAL RIDGE.
3. A. THIS IS THE FIRST PROGNOSTIC REASONING BULLETIN ISSUED FOR TD
25W AND THEREFORE SETS THE FORECAST PHILOSOPHY.
B. TD 25W WILL CONTINUE TO STEER ALONG THE SOUTHERN PERIPHERY OF
THE LOW- TO MID-LEVEL SUBTROPICAL RIDGE AND SHOULD SLOWLY INTENSIFY
TO 40 KNOTS BY TAU 24 DUE TO CONTINUED INTERACTION WITH MODERATE
VWS. BY TAU 48 TD 25W SHOULD BEGIN TO SLOWLY WEAKEN DUE TO A POCKET
OF COOLER SEA SURFACE TEMPERATURES AND CONTINUED VWS.
C. BY TAU 72 TD 25W SHOULD MAKE LANDFALL OVER SOUTHERN VIETNAM
AND DISSIPATE AS THE LLCC INTERACTS WITH LAND. THE NUMERICAL MODEL
GUIDANCE IS IN GOOD AGREEMENT IN REGARDS TO A GENERAL WESTWARDS
TRACK. THE GFS PORTRAYS LANDFALL BY TAU 48 TO THE NORTH OF HO CHI
MINH CITY. THE NOGAPS AND GFDN INDICATE A TRACK OVER THE SOUTH CHINA
SEA, THEREBY MISSING LANDFALL OVER VIETNAM AND CONTINUING TOWARDS
MALAYSIA. THIS FORECAST IS INLINE WITH THE MODEL CONSENSUS DUE TO
THE FIRMLY ENTRENCHED EAST-WEST ORIENTATED LOW- TO MID-LEVEL
SUBTROPICAL RIDGE WHICH SHOULD STEER TD 25W WESTWARDS.//

[francis327]

ABPW10 PGTW 041500
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE WESTERN AND
/SOUTH PACIFIC OCEANS REISSUED/041500Z-050600ZDEC2011//
REF/A/MSG/NAVMARFCSTCEN PEARL HARBOR HI/JTWC/041351ZDEC2011//
AMPN/REF A IS A TROPICAL CYCLONE WARNING.
RMKS/
1. WESTERN NORTH PACIFIC AREA (180 TO MALAY PENINSULA):
A. TROPICAL CYCLONE SUMMARY:
(1) AT 041500Z TROPICAL DEPRESSION (TD) 25W WAS LOCATED NEAR
8.8N 113.8E, APPROXIMATELY 440 NM EAST-SOUTHEAST OF HO CHI MINH
CITY, VIETNAM, AND HAD TRACKED NORTH-NORTHWESTWARD AT 12 KNOTS OVER
THE PAST SIX HOURS. RECENT SCATTEROMETRY AND MICROWAVE DATA INDICATE
30 KNOT WINDS AT THE SYSTEM CENTER. SEE REF A (WTPN31 PGTW 041500)
FOR FURTHER DETAILS.
(2) NO OTHER TROPICAL CYCLONES.
B. TROPICAL DISTURBANCE SUMMARY:
(1) THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 7.5N
114.3E, IS NOW THE SUBJECT OF A TROPICAL CYCLONE WARNING. SEE PARA
1.A.(1) FOR FURTHER DETAILS.
(2) NO OTHER SUSPECT AREAS.
2. SOUTH PACIFIC AREA (WEST COAST OF SOUTH AMERICA TO 135 EAST):
A. TROPICAL CYCLONE SUMMARY: NONE.
B. TROPICAL DISTURBANCE SUMMARY: NONE.
3. JUSTIFICATION FOR REISSUE: UPGRADED AREA IN PARA 1.B.(1) TO
WARNING STATUS.//
NNNN

It is now a Tropical Cyclone Warning

[P.K.]

Also T1.5 from the JTWC at 12Z. I don't see anything from any other agencies right now and the JMA don't even have a LPA.

[francis327]

WTPN31 PGTW 041500
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE WARNING//
REF/A/NAVMARFCSTCEN PEARL HARBOR HI/JTWC/040751Z DEC 11//
AMPN/TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. TROPICAL DEPRESSION 25W (TWENTYFIVE) 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:
041200Z --- NEAR 8.6N 113.9E
MOVEMENT PAST SIX HOURS - 340 DEGREES AT 12 KTS
POSITION ACCURATE TO WITHIN 060 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: 8.6N 113.9E
---
FORECASTS:
12 HRS, VALID AT:
050000Z --- 9.4N 113.3E
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
VECTOR TO 24 HR POSIT: 285 DEG/ 06 KTS
---
24 HRS, VALID AT:
051200Z --- 9.7N 112.1E
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 035 NM NORTHEAST QUADRANT
030 NM SOUTHEAST QUADRANT
030 NM SOUTHWEST QUADRANT
040 NM NORTHWEST QUADRANT
VECTOR TO 36 HR POSIT: 270 DEG/ 08 KTS
---
36 HRS, VALID AT:
060000Z --- 9.7N 110.4E
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 035 NM NORTHEAST QUADRANT
030 NM SOUTHEAST QUADRANT
030 NM SOUTHWEST QUADRANT
040 NM NORTHWEST QUADRANT
VECTOR TO 48 HR POSIT: 265 DEG/ 10 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
061200Z --- 9.6N 108.3E
MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
WIND RADII VALID OVER OPEN WATER ONLY
VECTOR TO 72 HR POSIT: 280 DEG/ 07 KTS
---
72 HRS, VALID AT:
071200Z --- 10.0N 105.5E
MAX SUSTAINED WINDS - 020 KT, GUSTS 030 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND
---
REMARKS:
041500Z POSITION NEAR 8.8N 113.8E.
TROPICAL DEPRESSION (TD) 25W LOCATED APPROXIMATELY 440 NM EAST-
SOUTHEAST OF HO CHI MINH CITY, VIETNAM, HAD TRACKED NORTH-
NORTHWESTWARD AT 12 KNOTS OVER THE PAST SIX HOURS. RECENT
SCATTEROMETRY AND MICROWAVE DATA INDICATE 30 KNOT WINDS AT THE
SYSTEM CENTER. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 041200Z IS 12 FEET.
NEXT WARNINGS AT 042100Z, 050300Z, 050900Z AND 051500Z. THIS WARNING
SUPERSEDES AND CANCELS REF A, NAVMARFCSTCEN 040751Z DEC 11 TROPICAL
CYCLONE FORMATION ALERT (WTPN21 PGTW 040800).//
NNNN

[P.K.]

18Z:

LOW PRESSURE AREA 1008 HPA NEAR 10N 114E WNW SLOWLY

[RobWESTPACWX]

What Im curios is how can this one be a TD but the one south west of Indonesia is not upgraded, that was is very organized.

[P.K.]

I'm wondering myself why Meteo-France haven't issued anything on that yet as well when that is getting T2.0/2.0 from the SAB and JTWC!

For the record at 18Z this was T1.5/1.5 from the SAB and T1.0/1.5 from the JTWC.

[francis327]

Final warning from JTWC, TD25W is weakening

WTPN31 PGTW 050300
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE WARNING//
RMKS/
1. TROPICAL DEPRESSION 25W (TWENTYFIVE) WARNING NR 003
01 ACTIVE TROPICAL CYCLONE IN NORTHWESTPAC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
050000Z --- NEAR 11.9N 110.5E
MOVEMENT PAST SIX HOURS - 310 DEGREES AT 18 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: 11.9N 110.5E
---
FORECASTS:
12 HRS, VALID AT:
051200Z --- 12.2N 109.4E
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: 285 DEG/ 09 KTS
---
24 HRS, VALID AT:
060000Z --- 12.6N 107.6E
MAX SUSTAINED WINDS - 020 KT, GUSTS 030 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND
---
REMARKS:
050300Z POSITION NEAR 12.0N 110.2E.
TROPICAL DEPRESSION (TD) 25W, LOCATED APPROXIMATELY 235 NM EAST-
NORTHEAST OF HO CHI MINH CITY, VIETNAM, HAS TRACKED NORTHWESTWARD AT
18 KNOTS OVER THE PAST SIX HOURS. TD 25W HAS RAPIDLY DETERIORATED
DUE TO INTERACTION WITH THE COLD AND DRY NORTHEASTERLY FLOW. THE
SYSTEM IS EXPECTED TO DISSIPATE AS A SIGNIFICANT TROPICAL CYCLONE
WITHIN THE NEXT 12 HOURS AS IT ENCOUNTERS THE VIETNAM COAST. THIS IS
THE FINAL WARNING ON THIS SYSTEM BY THE JOINT TYPHOON WARNING CENTER
(NAVMARFCSTCEN). THE SYSTEM WILL BE CLOSELY MONITORED FOR SIGNS OF
REGENERATION. MAXIMUM SIGNIFICANT WAVE HEIGHT MAXIMUM SIGNIFICANT
WAVE HEIGHT AT 050000Z IS 8 FEET.//
NNNN