WPAC: Sepat - Post-Tropical

[dexterlabio]

EURO nothing...GFS has some modest strengthening...

I'm thinking the models now see this disturbance struggling to get stronger because of the subsidence being introduced by the Meiyu front to the north...plus I can spot what looks to be an upper level low spinning at a location that would disrupt this system.

If I'd be allowed to wishcast here, I hope this can develop and track out to sea/to the northeast, just enough to draw moisture from the southwest monsoon and alleviate the effects of El Nino in the Philippines.

[Tailspin]

Yeah agree there is a ull and its likely causing northerly shear.

[euro6208]

Wish the WPAC can start classifying these Subtropical systems. If the Atlantic can do it... to increase the numbers.

THE AREA OF CONVECTION (INVEST 94W) PREVIOUSLY LOCATED
NEAR 8.5N 139.0E, IS NOW LOCATED NEAR 11.1N 137.0E, APPROXIMATELY
119 NM NORTHWEST OF YAP. ANIMATED MULTISPECTRAL SATELLITE IMAGERY
SHOWS A VERY WEAK, ILL-DEFINED LOW LEVEL CIRCULATION (LLC) WITH
MINOR FLARING CONVECTION ON THE PERIPHERY. A 220018Z MHS METOP-A
89GHZ MICROWAVE IMAGE SHOWS VERY LITTLE STRUCTURE AND NO SIGNIFICANT
CENTRAL CONVECTION. A 220058Z METOP-C ASCAT PASS SHOWS THAT THE LLC
IS A VERY ELONGATED, EAST-WEST ORIENTED CIRCULATION WITH A SMALL
SWATH OF 15 TO 20 KNOT WINDS ON THE NORTH SIDE. 94W IS CURRENTLY IN
A MARGINAL ENVIRONMENT WITH WARM (29-30 CELSIUS) SEA SURFACE
TEMPERATURE BEING OFFSET BY WEAK WESTWARD UPPER LEVEL OUTFLOW AND
MODERATE (20-25 KNOT) VERTICAL WIND SHEAR. GLOBAL MODELS ALL AGREE
THAT 94W WILL TRACK GENERALLY NORTHWESTWARD. THE MODELS DIFFER,
HOWEVER, ON POTENTIAL INTENSIFICATION WITH ECMWF, NAVGEM, AND JGSM
SHOWING NO SIGNIFICANT DEVELOPMENT WHILE UKMET AND GFS SHOW
INTENSIFICATION AFTER 84 HRS, POSSIBLY AS A SUBTROPICAL SYSTEM.
MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 15 TO 20 KNOTS.
MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1005 MB. THE
POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE
WITHIN THE NEXT 24 HOURS REMAINS MEDIUM.

[Hayabusa]

HWRF not budging insisting a decent TC.

[euro6208]

HWRF not budging insisting a decent TC.

Yeah close to a Cat 3...

[1900hurricane]

For posterity's sake, this is a JMA TD.

WWJP27 RJTD 220600
WARNING AND SUMMARY 220600.
WARNING VALID 230600.
WARNING IS UPDATED EVERY 6 HOURS.
GALE WARNING.
DEVELOPING LOW 996 HPA
AT 33N 139E SEA SOUTH OF JAPAN MOVING NE 25 KNOTS.
WARM FRONT FROM 33N 139E TO 33N 143E 33N 146E.
COLD FRONT FROM 33N 139E TO 30N 137E 28N 134E.
STATIONARY FRONT FROM 28N 134E TO 28N 131E 28N 129E 27N 123E 28N 117E
27N 112E 27N 106E.
WINDS 30 TO 35 KNOTS WITHIN 300 MILES OF LOW.
EXPECTED WINDS 30 TO 35 KNOTS WITHIN 400 MILES OF LOW SOUTH
SEMICIRCLE AND 300 MILES ELSEWHERE FOR NEXT 18 HOURS.
GALE WARNING.
DEVELOPING LOW 996 HPA
AT 49N 172E SEA SOUTH OF ALEUTIANS MOVING ENE 15 KNOTS.
OCCLUDED FRONT FROM 49N 172E TO 49N 175E 47N 179E.
WARM FRONT FROM 47N 179E TO 45N 179E 41N 180E.
COLD FRONT FROM 47N 179E TO 42N 175E 39N 167E.
STATIONARY FRONT FROM 39N 167E TO 39N 163E 35N 156E 34N 151E 33N
146E.
WINDS 30 TO 35 KNOTS WITHIN 500 MILES OF LOW SOUTHEAST SEMICIRCLE AND
300 MILES ELSEWHERE.
EXPECTED WINDS 30 TO 35 KNOTS WITHIN 500 MILES OF LOW SOUTHEAST
SEMICIRCLE AND 300 MILES ELSEWHERE FOR NEXT 12 HOURS.
WARNING.
DENSE FOG OBSERVED LOCALLY OVER SEA OF OKHOTSK SEA OF JAPAN YELLOW
SEA EAST CHINA SEA.
WARNING.
DENSE FOG OBSERVED LOCALLY OVER WATERS BOUNDED BY 42N 141E 46N 152E
60N 164E 60N 180E 40N 180E 30N 170E 30N 150E 25N 148E 25N 140E 35N
140E 39N 142E 42N 141E.
SUMMARY.
LOW 1000 HPA AT 28N 129E ENE 20 KT.
LOW 1002 HPA AT 39N 136E ENE SLOWLY.
TROPICAL DEPRESSION 1004 HPA AT 11N 136E WNW SLOWLY.
HIGH 1008 HPA AT 37N 116E SE 15 KT.
HIGH 1020 HPA AT 48N 154E EAST 10 KT.

JAPAN METEOROLOGICAL AGENCY.=

[Hayabusa]

The GFS barely develops 94W but the total rainfall amount forecast that 94W combined with the southwest monsoon would bring to the Western Philippines is a little crazy...

[euro6208]

Scrambled eggs.

[euro6208]

THE AREA OF CONVECTION (INVEST 94W) PREVIOUSLY LOCATED
NEAR 11.1N 137.0E, IS NOW LOCATED NEAR 14.1N 132.0E, APPROXIMATELY
757 NM SOUTH-SOUTHEAST OF KADENA AB, OKINAWA, JAPAN. ANIMATED
MULTISPECTRAL SATELLITE IMAGERY AND A 222207Z 91GHZ SSMIS MICROWAVE
SATELLITE IMAGE DEPICT A WELL DEFINED LOW LEVEL CIRCULATION (LLC)
WITH FLARING CONVECTION BEING SHEARED FROM THE NORTHEAST. THE
ENVIRONMENT IS OVERALL MARGINAL FOR TROPICAL CYCLONE DEVELOPMENT,
WITH VERY WARM (29-31C) SEA SURFACE TEMPERATURES, STRONG
NORTHEASTERLY FLOW ALOFT AND THE AFOREMENTIONED MODERATE (15-25 KT)
VERTICAL WIND SHEAR (VWS). WHILE THE LOW LEVELS ARE ORGANIZED,
CONVECTION HAS CONTINUED TO STRUGGLE WITHOUT WRAPPING IN IN LIGHT OF
THE MODERATE VWS AND LIMITED DIFFLUENCE ALOFT. GLOBAL DYNAMIC MODELS
ARE IN OVERALL AGREEMENT THAT 94W WILL CONTINUE ON A NORTH-
NORTHWESTWARD TRACK, BEFORE LATER BEING ABSORBED INTO A TRANSITORY
LOW ALONG THE BAIYU FRONT THAT COULD STILL BRING ELEVATED WINDS TO
SOUTHERN JAPAN. HOWEVER, THE 221200Z UKMO RUN STILL MAINTAINS 94W AS
AN INDEPENDENT DISTURBANCE TRACKING TOWARDS TAIWAN. MAXIMUM
SUSTAINED SURFACE WINDS ARE ESTIMATED AT 15 TO 20 KNOTS. MINIMUM SEA
LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1005 MB. THE POTENTIAL FOR
THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24
HOURS IS DOWNGRADED TO LOW.

[euro6208]

THE AREA OF CONVECTION (INVEST 94W) PREVIOUSLY LOCATED
NEAR 11.1N 137.0E, IS NOW LOCATED NEAR 13.8N 132.0E, APPROXIMATELY
639 NM EAST OF MANILA, PHILIPPINES. ANIMATED MULTISPECTRAL SATELLITE
IMAGERY DEPICTS A PARTIALLY EXPOSED LOW LEVEL CIRCULATION CENTER
(LLC) WITH FLARING DEEP CONVECTION BEING SHEARED TO THE SOUTHWEST. A
230111Z MHS METOP-B 89GHZ MICROWAVE IMAGE SHOWS VERY LITTLE
STRUCTURE AND NO SIGNIFICANT CONVECTION. A 230111Z METOP-B ASCAT
PASS SHOWS BROAD LOW LEVEL TURNING. 94W IS CURRENTLY IN AN
UNFAVORABLE ENVIRONMENT WITH WARM (30 TO 31 CELSIUS) SEA SURFACE
TEMPERATURES BEING OFFSET BY UNFAVORABLE (30 TO 35 KNOT) VERTICAL
WIND SHEAR AND LIMITED UPPER LEVEL OUTFLOW. GLOBAL MODELS ARE IN
GOOD AGREEMENT THAT 94W WILL TRACK GENERALLY NORTHWEST WITHOUT
INTENSIFICATION. GFS, AS A MINOR OUTLIER, DOES SHOW THE POTENTIAL
FOR INTENSIFICATION AS 94W BECOMES EMBEDDED IN THE BAIYU FRONT AND
BECOMES A SUBTROPICAL LOW. MAXIMUM SUSTAINED SURFACE WINDS ARE
ESTIMATED AT 15 TO 20 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED
TO BE NEAR 1005 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A
SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS REMAINS LOW.

[euro6208]

Well well well...EURO has this strengthening yet again...997 mb...GFS also deepens this a bit more...989 mb...with a path close to Okinawa.

[euro6208]

Also HWRF coming in stronger. Maybe the models are caving in?

[Hayabusa]

We are already at the peak shear according to this chart it should go down soon and TC development could finally happen while the shear is down 94W could finally take advantage of the untapped OHC and SST east of the Philippines, though there was no HWRF 18Z run. Interesting how would 94W develop while interacting with the front. Could we finally have Sepat or a subtropical cyclone?

[Tailspin]

la mierda, onzin, 擲骰子, 'ōpiopio
Google translator for crap.

[euro6208]

Back up to MEDIUM.

THE AREA OF CONVECTION (INVEST 94W) PREVIOUSLY LOCATED
NEAR 13.8N 132.0E, IS NOW LOCATED NEAR 16.4N 128.5E, APPROXIMATELY
594 NM SOUTH OF KADENA AB, OKINAWA. ANIMATED MULTISPECTRAL SATELLITE
IMAGERY REVEALS THE LOW LEVEL CIRCULATION (LLC) IS BEING OBSCURED BY
FLARING DEEP CONVECTION. A 240115Z MHS METOP-A 89GHZ PARTIAL
MICROWAVE IMAGE SHOWS SCATTERED POCKETS OF DEEP CONVECTION IN THE
VICINITY OF THE LLC. 94W IS IN A MARGINAL ENVIRONMENT WITH VERY WARM
(30 TO 31 CELSIUS) SEA SURFACE TEMPERATURES BEING PARTIALLY OFFSET
BY LOW-TO-MODERATE (10 TO 20 KNOT) VERTICAL WIND SHEAR AND FAIR
EQUATORWARD UPPER LEVEL OUTFLOW. GLOBAL MODELS AGREE THAT 94W WILL
CONTINUE TO TRACK NORTHWEST BEFORE RECURVING TO THE NORTHEAST AND
INTENSIFYING IN APPROXIMATELY 72 HOURS LIKELY DEVELOPING INTO A
SUBTROPICAL LOW. NAVGEM IS CURRENTLY AN OUTLIER, SHOWING
SIGNIFICANTLY MORE DEVELOPMENT THAN THE OTHER GLOBAL MODELS.
MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 15 TO 20 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 IS UPGRADED TO MEDIUM.

[euro6208]

The models are very poor...

[Nancy Smar]

WTPN21 PGTW 250200
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 94W)/
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
200 NM EITHER SIDE OF A LINE FROM 16.9N 126.8E TO 25.1N 127.9E
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 20 TO 25 KNOTS. METSAT IMAGERY AT
250130Z INDICATES THAT A CIRCULATION CENTER IS LOCATED NEAR 18.2N
126.5E. THE SYSTEM IS MOVING NORTH-NORTHWESTWARD AT 07 KNOTS.
2. REMARKS: THE AREA OF CONVECTION (INVEST 94W) PREVIOUSLY LOCATED
NEAR 16.4N 128.5E IS NOW LOCATED NEAR 18.2N 126.5E, APPROXIMATELY
490 NM SOUTH OF KADENA AB, OKINAWA. ANIMATED MULTISPECTRAL SATELLITE
IMAGERY AND A 242130Z SSMIS 37GHZ MICROWAVE IMAGE DEPICT A BROAD,
PARTIALLY-EXPOSED LOW LEVEL CIRCULATION (LLC) WITH DEEP CONVECTION
DISPLACED TO THE NORTHEAST. UPPER-LEVEL ANALYSIS INDICATES A
MARGINALLY-FAVORABLE ENVIRONMENT WITH LOW-TO-MODERATE (10 TO 20
KNOT) VERTICAL WIND SHEAR OFFSET BY GOOD EQUATORWARD OUTFLOW.
ADDITIONALLY, WARM (29 TO 30 CELSIUS) SEA SURFACE TEMPERATURES ARE
CONDUCIVE. GLOBAL MODELS ARE IN GOOD AGREEMENT THAT 94W WILL
TRACK NORTHWARD NEAR OKINAWA WITHIN THE NEXT 2 DAYS. THE SYSTEM IS
EXPECTED TO GRADUALLY STRENGTHEN AND TRANSITION INTO A SUBTROPICAL
LOW AS IT INTERACTS WITH A SHARP, DEEP SHORTWAVE TROUGH OVER THE
EAST CHINA SEA. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 20
TO 25 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1004
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
260200Z.//
NNNN

TCFA

[Nancy Smar]

THE LOW PRESSURE AREA EAST OF APARRI, CAGAYAN HAS DEVELOPED INTO A TROPICAL DEPRESSION AND WAS NAMED "DODONG".

WTPH20 RPMM 250600
TROPICAL CYCLONE WARNING 01
TROPICAL DEPRESSION
ANALYSIS 250600UTC
PSTN 19.4N 127.0E
MOVE NE 010KT
PRES 1006HPA
MXWD 025KT
FORECAST 24H 260600UTC
PSNT 23.9N 127.8E
CATE TROPICAL DEPRESSION
FORECAST 48H 270600UTC
PSTN 31.5N 132.6E
CATE TROPICAL DEPRESSION
NEXT WARNING 251200 UTC
PHILIPPINE ATMOSPHERIC GEOPHYSICAL AND
ASTRONOMICAL SERVICES ADMINISTRATION=

[euro6208]

[euro6208]