WPAC: HAITANG - Tropical Depression (21W)

[Extratropical94]

In the South China Sea, W of Manila

97WINVEST.15kts-NAmb-190N-1190E



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[StormingB81]

Wonder if this was the one on yesterday's ECMWF to the west of PI? although it wasnt on this morning

[euro6208]

ecmwf develops this but weak until landfall in vietnam...

[euro6208]

AN AREA OF CONVECTION HAS PERSISTED NEAR 17.9N 114.3E,
APPROXIMATELY 260 NM SOUTH OF HONG KONG. ANIMATED MULTI-SPECTRAL
SATELLITE IMAGERY DEPICTS A BROAD, ELONGATED LOW LEVEL CIRCULATION
CENTER (LLCC) WITH FLARING CONVECTION. A 210153Z PARTIAL ASCAT PASS
ALSO SHOWS AN ELONGATED CIRCULATION WITH 10-15 KNOTS OF
NORTHEASTERLY AND SOUTHWESTERLY FLOW ALONG THE PERIPHERIES AND WEAK
5-10 KNOT WINDS NEAR THE CENTER. UPPER LEVEL ANALYSIS INDICATES THAT
THE LLCC IS LOCATED JUST TO THE SOUTH OF AN ANTICYCLONE IN A REGION
OF LOW VERTICAL WIND SHEAR AND MODERATE DIFFLUENCE ALOFT. MAXIMUM
SUSTAINED SURFACE WINDS ARE ESTIMATED AT 10 TO 15 KNOTS. MINIMUM SEA
LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1010 MB. THE POTENTIAL FOR
THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24
HOURS IS LOW.

still expected to develop but weak until landfall in vietnam

[StormingB81]

LOW PRESSURE AREA 1006 HPA NEAR 15N 112E ALMOST STATIONARY.

[euro6208]

THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 19.4N
113.9E, IS NOW LOCATED NEAR 18.1N 111.8E, APPROXIMATELY 285 NM
SOUTH-SOUTHWEST OF HONG KONG. ANIMATED MULTI-SPECTRAL SATELLITE
IMAGERY SHOWS A BROAD, ELONGATED LOW LEVEL CIRCULATION CENTER
(LLCC), DEEPLY EMBEDDED WITHIN THE MONSOON TROUGH, AND MINIMAL DEEP
CONVECTION DISPLACED ON THE NORTHEASTERN, AND SOUTHWESTERN
PERIPHERIES. THIS IS ALSO EVIDENT IN A 231035Z SSMIS MICROWAVE
IMAGE. UPPER LEVEL ANALYSIS SHOWS THAT THE LLCC LIES JUST TO THE
SOUTH OF THE SUBTROPICAL RIDGE AXIS, IN A REGION OF LOW (5 TO 10
KNOT) VERTICAL WIND SHEAR, AND CONVERGENCE. SEA SURFACE TEMPERATURES
IN THE AREA ARE APPROXIMATELY 29 DEGREES CELSIUS. MAXIMUM SUSTAINED
SURFACE WINDS ARE ESTIMATED AT 10 TO 15 KNOTS. MINIMUM SEA LEVEL
PRESSURE, BASED ON NEARBY SHIP OBSERVATIONS, IS ESTIMATED TO BE NEAR
1006 MB. DUE TO THE UNFAVORABLE UPPER LEVEL ENVIRONMENT AND
ELONGATED SURFACE SIGNATURE, MAXIMUM SUSTAINED SURFACE WINDS ARE
ESTIMATED AT 10 TO 15 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED
TO BE NEAR 1006 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A
SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS REMAINS LOW.

development going down...

[euro6208]

T1.0/1.0 97W

very deep convection. i wouldn't be surprised if this contained some tropical storm force winds...

[euro6208]

WTPN21 PGTW 240500
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
A 180 NM RADIUS OF 15.4N 111.1E WITHIN THE NEXT 03 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 IMAGERY AT 240430Z INDICATES THAT A
CIRCULATION CENTER IS LOCATED NEAR 15.4N 111.2E. THE SYSTEM IS
MOVING WEST-SOUTHWESTWARD AT 02 KNOTS.
2. REMARKS: THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 18.1N
111.8E, IS NOW LOCATED NEAR 15.4N 111.2E, APPROXIMATELY 200 NM
SOUTH-SOUTHEAST OF HAINAN ISLAND, CHINA. ANIMATED MULTISPECTRAL
SATELLITE IMAGERY DEPICTS AN EXPOSED, WELL-DEFINED LOW-LEVEL
CIRCULATION CENTER (LLCC) WITH DEEP CONVECTION SHEARED 30 NM
SOUTHWEST OF THE CENTER. A 232309Z SSMIS 37 GHZ IMAGE INDICATES WEAK
CONVECTIVE BANDING NORTH WRAPPING INTO THE WEST QUADRANT. A 240229Z
ASCAT IMAGE DEPICTS NUMEROUS UNFLAGGED 20-25 KNOT WINDS OVER THE
WEST AND SOUTH QUADRANTS WITH SOME ISOLATED 30 KNOT WINDS. A BUOY
OBSERVATION (9VDD2) 94 NM SOUTH-SOUTHEAST SHOWS WINDS AT 230/22
KNOTS. THE LLCC IS CURRENTLY LOCATED WITHIN A MARGINAL ENVIRONMENT
WITH MODERATE EASTERLY VERTICAL WIND SHEAR (20 KNOTS) AND BROAD
DIFFLUENCE ALOFT. THE SYSTEM IS FORECAST TO DRIFT NORTH INTO A
SLIGHTLY MORE FAVORABLE ENVIRONMENT OVER THE NEXT 24-36 HOURS. IT
WILL LIKELY CONTINUE TO STRUGGLE CONVECTIVELY, HOWEVER, THE LLCC HAS
STRENGTHENED OVER THE PAST 12 HOURS. MAXIMUM SUSTAINED SURFACE WINDS
ARE ESTIMATED AT 18 TO 23 KNOTS. MINIMUM SEA LEVEL PRESSURE IS
ESTIMATED TO BE NEAR 1002 MB. 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
250500Z.//
NNNN

[phwxenthusiast]

JMA now including this on their "Tropical Cyclone Information" Page...

TD
Issued at 07:15 UTC, 24 September 2011
<Analyses at 24/06 UTC>
Scale -
Intensity-TD
Center position N15°20'(15.3°) E111°10'(111.2°)
Direction and speed of movement SE Slowly
Central pressure 998hPa
Maximum wind speed near the center 15m/s(30kt)
Maximum wind gust speed 23m/s(45kt)

[P.K.]

WTPQ21 RJTD 240600
RSMC TROPICAL CYCLONE ADVISORY
NAME TD
ANALYSIS
PSTN 240600UTC 15.3N 111.2E FAIR
MOVE SE SLOWLY
PRES 998HPA
MXWD 030KT
GUST 045KT
FORECAST
24HF 250600UTC 16.0N 112.0E 100NM 70%
MOVE NE SLOWLY
PRES 996HPA
MXWD 035KT
GUST 050KT =

[dexterlabio]

NOW TD21W according to JTWC.

WTPN32 PGTW 241500
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE WARNING//
REF/A/MSG/NAVMARFCSTCEN PEARL HARBOR HI/240451ZSEP2011//
AMPN/REF A IS A TROPICAL CYCLONE FORMATION ALERT.//
RMKS/
1. TROPICAL DEPRESSION 21W (TWENTY-ONE) WARNING NR 001
02 ACTIVE TROPICAL CYCLONES IN NORTHWESTPAC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
241200Z --- NEAR 15.4N 112.3E
MOVEMENT PAST SIX HOURS - 090 DEGREES AT 06 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: 15.4N 112.3E
---
FORECASTS:
12 HRS, VALID AT:
250000Z --- 15.7N 112.7E
MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
WIND RADII VALID OVER OPEN WATER ONLY
VECTOR TO 24 HR POSIT: 330 DEG/ 05 KTS
---
24 HRS, VALID AT:
251200Z --- 16.5N 112.2E
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
VECTOR TO 36 HR POSIT: 295 DEG/ 07 KTS
---
36 HRS, VALID AT:
260000Z --- 17.1N 110.8E
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
VECTOR TO 48 HR POSIT: 285 DEG/ 10 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
261200Z --- 17.6N 108.8E
MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
WIND RADII VALID OVER OPEN WATER ONLY
VECTOR TO 72 HR POSIT: 280 DEG/ 10 KTS
---
72 HRS, VALID AT:
271200Z --- 18.4N 104.8E
MAX SUSTAINED WINDS - 020 KT, GUSTS 030 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND
---
REMARKS:
241500Z POSITION NEAR 15.5N 112.4E.
TROPICAL DEPRESSION (TD) 21W, LOCATED APPROXIMATELY 280 NM EAST-
SOUTHEAST OF HUE, VIETNAM, HAS TRACKED EASTWARD AT 06 KNOTS OVER THE
PAST SIX HOURS. THIS WARNING SUPERSEDES AND CANCELS REF A,
NAVMARFCSTCEN 240451Z SEP 11 TROPICAL CYCLONE FORMATION ALERT
(WTPN21 PGTW 240500). MAXIMUM SIGNIFICANT WAVE HEIGHT AT 241200Z IS
8 FEET. NEXT WARNINGS AT 242100Z, 250300Z, 250900Z AND 251500Z.
REFER TO TROPICAL STORM 20W (NESAT) WARNINGS (WTPN31 PGTW)
FOR SIX-HOURLY UPDATES.//
NNNN

[Extratropical94]

Next name on the list is Haitang.

[Chacor]

A big supertyphoon in 2005, it would be interesting it this year's Haitang did similar.

[euro6208]

Haitang means The Chinese flowering crabapple.

submitted by china...

WTPN32 PGTW 242100
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE WARNING//
RMKS/
1. TROPICAL DEPRESSION 21W (TWENTY-ONE) WARNING NR 002
02 ACTIVE TROPICAL CYCLONES IN NORTHWESTPAC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
241800Z --- NEAR 15.9N 113.0E
MOVEMENT PAST SIX HOURS - 055 DEGREES AT 08 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY A COMBINATION OF
SATELLITE AND SYNOPTIC DATA
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
WIND RADII VALID OVER OPEN WATER ONLY
REPEAT POSIT: 15.9N 113.0E
---
FORECASTS:
12 HRS, VALID AT:
250600Z --- 16.4N 113.0E
MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
WIND RADII VALID OVER OPEN WATER ONLY
VECTOR TO 24 HR POSIT: 300 DEG/ 06 KTS
---
24 HRS, VALID AT:
251800Z --- 17.0N 112.0E
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
VECTOR TO 36 HR POSIT: 285 DEG/ 08 KTS
---
36 HRS, VALID AT:
260600Z --- 17.4N 110.4E
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
VECTOR TO 48 HR POSIT: 280 DEG/ 08 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
261800Z --- 17.7N 108.7E
MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
WIND RADII VALID OVER OPEN WATER ONLY
VECTOR TO 72 HR POSIT: 285 DEG/ 10 KTS
---
72 HRS, VALID AT:
271800Z --- 18.6N 104.7E
MAX SUSTAINED WINDS - 015 KT, GUSTS 025 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND
---
REMARKS:
242100Z POSITION NEAR 16.0N 113.0E.
TROPICAL DEPRESSION (TD) 21W, LOCATED APPROXIMATELY 310 NM EAST OF
HUE, VIETNAM, HAS TRACKED NORTHEASTWARD AT 08 KNOTS OVER THE PAST
SIX HOURS. ANIMATED INFRARED SATELLITE IMAGERY SHOWS A BROAD AND
DISORGANIZED SYSTEM WITH A PARTLY EXPOSED LOW LEVEL CIRCULATION
CENTER. DEEP CONVECTION EXISTS IN THE CONVERGENT SOUTHWESTERLIES
OVER THE SOUTHWEST QUADRANT. A 241808Z AMSRE IMAGE, HOWEVER, SHOWS
THAT THE CONVECTIVE BANDING IS BETTER ORGANIZED THAN THE SATELLITE
IMAGERY INDICATES. ANIMATED WATER VAPOR IMAGERY REVEALS EXCELLENT
EQUATORWARD OUTFLOW. THE 241200Z PGTW UPPER LEVEL STREAMLINE
ANALYSIS DEPICTS AN ANTICYCLONE BETWEEN TAIWAN AND LUZON, WHICH IS
PRODUCING 15 TO 20 KNOTS OF VERTICAL WIND SHEAR OVER THE SYSTEM. THE
SHEAR IS BEING COMPENSATED SOMEWHAT BY THE HIGHLY DIFFLUENT FLOW OUT
OF THE SOUTHWEST QUADRANT OF THE ANTICYCLONE. AMSUB RADIAL CROSS
SECTIONS REVEAL A WEAK AND LOW WARM ANOMALY. SEA SURFACE TEMPERATURE
IN THE AREA IS 31 DEGREES. THE CURRENT INTENSITY IS BASED ON A
241458Z OCEANSAT IMAGE AND SHIP REPORTS IN THE VICINITY OF THE
SYSTEM. TD 21W ORIGINATED IN THE MONSOON TROUGH AND IS SITUATED
WITHIN A WEAK STEERING ENVIRONMENT. IT IS EXPECTED TO DRIFT
NORTHEASTWARD THROUGH THE NEAR TERM BUT SHOULD BEGIN TO REVERSE
COURSE AND TRACK WESTWARD AS THE LOW-LEVEL SUBTROPICAL RIDGE RE-
BUILDS OVER EASTERN CHINA AND SURGES INTO THE GULF OF TONKIN. MODEL
GUIDANCE IS LIMITED, BUT THERE IS CONSISTENT AGREEMENT WITH A TRACK
INTO NORTHERN VIETNAM. INTENSIFICATION WILL BE LIMITED DUE TO THE
MODERATE VERTICAL WIND SHEAR, THUS TD 21W IS EXPECTED TO REMAIN NEAR
ITS CURRENT INTENSITY UNTIL IT MAKES LANDFALL. MAXIMUM SIGNIFICANT
WAVE HEIGHT AT 241800Z IS 10 FEET. NEXT WARNINGS AT 250300Z,
250900Z, 251500Z AND 252100Z. REFER TO TROPICAL STORM 20W (NESAT)
WARNINGS (WTPN31 PGTW)FOR SIX-HOURLY UPDATES.//
NNNN

[euro6208]

A big supertyphoon in 2005, it would be interesting it this year's Haitang did similar.

category 5 super typhoon...

[dexterlabio]

is now TS HAITANG

[dexterlabio]

TS 1118 (HAITANG)
Issued at 01:25 UTC, 25 September 2011

<Analyses at 25/00 UTC>
Scale -
Intensity -
Center position N16°05'(16.1°)
E112°40'(112.7°)
Direction and speed of movement ENE Slowly
Central pressure 996hPa
Maximum wind speed near the center 18m/s(35kt)
Maximum wind gust speed 25m/s(50kt)
Area of 30kt winds or more ALL280km(150NM)

<Forecast for 26/00 UTC>
Intensity -
Center position of probability circle N16°05'(16.1°)
E110°55'(110.9°)
Direction and speed of movement W Slowly
Central pressure 992hPa
Maximum wind speed near the center 23m/s(45kt)
Maximum wind gust speed 35m/s(65kt)
Radius of probability circle 130km(70NM)

<Forecast for 27/00 UTC>
Intensity -
Center position of probability circle N16°30'(16.5°)
E108°35'(108.6°)
Direction and speed of movement W 10km/h(6kt)
Central pressure 990hPa
Maximum wind speed near the center 23m/s(45kt)
Maximum wind gust speed 35m/s(65kt)
Radius of probability circle 200km(110NM)

<Forecast for 28/00 UTC>
Intensity -
TD
Center position of probability circle N16°55'(16.9°)
E105°40'(105.7°)
Direction and speed of movement W 15km/h(7kt)
Central pressure 1002hPa
Radius of probability circle 300km(160NM

[P.K.]

WTPQ21 RJTD 261800
RSMC TROPICAL CYCLONE ADVISORY
NAME TS 1118 HAITANG (1118)
ANALYSIS
PSTN 261800UTC 16.5N 108.4E FAIR
MOVE W 10KT
PRES 998HPA
MXWD 035KT
GUST 050KT
30KT 120NM
FORECAST
24HF 271800UTC 16.9N 105.0E 70NM 70% TROPICAL DEPRESSION =

[Chacor]

WTPQ21 RJTD 270600
RSMC TROPICAL CYCLONE ADVISORY
NAME TD DOWNGRADED FROM TS 1118 HAITANG (1118)
ANALYSIS
PSTN 270600UTC 17N 106E
MOVE W 10KT
PRES 1000HPA =