WPAC: MINDULLE - Post-Tropical

[Hayabusa]

99W.INVEST

99W INVEST 210921 0000 10.3N 154.6E WPAC 15 0

The mother of all invest is here, let's see how strong it will be

[Hayabusa]

[ElectricStorm]

Might have a chance to become the third super typhoon of the season if the GFS is right.

[Hayabusa]

ABPW10 PGTW 210230
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE WESTERN AND
/SOUTH PACIFIC OCEANS REISSUED/210230Z-210600ZSEP2021//
RMKS/
1. WESTERN NORTH PACIFIC AREA (180 TO MALAY PENINSULA):
A. TROPICAL CYCLONE SUMMARY: NONE.
B. TROPICAL DISTURBANCE SUMMARY:
(1) AN AREA OF CONVECTION (INVEST 99W) HAS PERSISTED NEAR
10.3N 154.6E, APPROXIMATELY 703 NM EAST-SOUTHEAST OF GUAM. ANIMATED
MULTISPECTRAL SATELLITE IMAGERY (MSI) REVEALS AN ENLONGATED WAVE
AXIS WITH THE LOW LEVEL CONVERGENCE OF SOUTHWESTERLY AND EASTERLY
WINDS SUPPORTING AN AREA OF DEEP CONVECTION ON THE SOUTH SIDE OF
THE WAVE AXIS. A 202347Z ASCAT-B IMAGE DEPICTS BROAD BELT OF 15-20
KT WINDS ACCOMPANIED BY STRONG FLARING CONVECTION IN THE SOUTHERN
HALF OF THE AREA. ENVIRONMENTAL ANALYSIS INDICATES A FAVORABLE
ENVIRONMENT FOR DEVELOPMENT WITH A COMBINATION OF POLEWARD AND
EQUATORWORD OUTFLOW, LOW (5-10 KT) VWS AND WARM (30-31C) SEA
SURFACE TEMPERATURES. GLOBAL MODELS ARE IN AGREEMENT THAT INVEST
99W WILL TRACK TO THE NORTHWEST. HOWEVER, THEY ARE SPLIT ON THE
DEGREE OF DEVELOPMENT, WITH GFS BEING THE MOST AGGRESSIVE. MAXIMUM
SUSTAINED SURFACE WINDS ARE ESTIMATED AT 15 TO 20 KNOTS. MINIMUM
SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1008 MB. THE POTENTIAL
FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE
NEXT 24 HOURS IS LOW.

[ElectricStorm]

0z GFS gets into the 930's again just like the last several runs

[Hayabusa]

Now up to medium

ABPW10 PGTW 210600
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE WESTERN AND
/SOUTH PACIFIC OCEANS/210600Z-220600ZSEP2021//
RMKS/
1. WESTERN NORTH PACIFIC AREA (180 TO MALAY PENINSULA):
A. TROPICAL CYCLONE SUMMARY: NONE.
B. TROPICAL DISTURBANCE SUMMARY:
(1) THE AREA OF CONVECTION (INVEST 99W) PREVIOUSLY LOCATED
NEAR 10.3N 154.6E IS NOW LOCATED NEAR 10.3N 154.7E, APPROXIMATELY
612 NM EAST-SOUTHEAST OF GUAM. ANIMATED MULTISPECTRAL SATELLITE
IMAGERY (MSI) REVEALS AN ENLONGATED WAVE AXIS WITH THE LOW LEVEL
CONVERGENCE OF SOUTHWESTERLY AND EASTERLY WINDS SUPPORTING AN AREA
OF DEEP CONVECTION ON THE SOUTH SIDE OF THE WAVE AXIS. A 202347Z
ASCAT-B IMAGE DEPICTS BROAD BELT OF 15-20 KT WINDS ACCOMPANIED BY
STRONG FLARING CONVECTION IN THE SOUTHERN HALF OF THE AREA. THE
SCATTEROMETER DATA AND ANIMATED VISIBLE IMAGERY SHOW STRONG LOW
LEVEL CONVERGENCE ON THE EAST SIDE OF THE WAVE ENVELOPE, AND THIS IS
THE MOST LIKELY REGION FOR DEVELOPMENT. ENVIRONMENTAL ANALYSIS
INDICATES A FAVORABLE ENVIRONMENT FOR DEVELOPMENT WITH A COMBINATION
OF POLEWARD AND EQUATORWARD OUTFLOW, LOW (5-10 KT) VWS AND WARM (30-
31C) SEA SURFACE TEMPERATURES. RECENT ANIMATED WATER VAPOR IMAGERY
SEEMS TO SUPPORT THE BEGINNINGS OF AN UPPER-LEVEL ANTICYCLONE OVER
THE SYSTEM, WHICH IS SOMETHING THE GLOBAL MODELS HAVE BEEN DEPICTING
AS WELL, WHICH IF PROVEN OUT, WILL PROVIDE ADDITIONAL SUPPORT TO THE
DEVELOPMENT OF THE SYSTEM. GLOBAL MODELS ARE IN AGREEMENT THAT
INVEST 99W WILL TRACK TO THE NORTHWEST. HOWEVER, THEY ARE SPLIT ON
THE DEGREE OF DEVELOPMENT. GFS AND ITS ENSEMBLE AND NAVGEM ARE THE
MOST AGGRESSIVE, SHOWING DEVELOPMENT OF A TROPICAL DEPRESSION WITHIN
THE NEXT 48 HOURS OR LESS. ECMWF AND ITS ENSEMBLE HOWEVER ARE MUCH
MORE BEARISH, INDICATING LITTLE TO NO DEVELOPMENT WITH THIS SYSTEM.
BASED ON THE POTENTIAL FOR ACCELERATED DEVELOPMENT TIMELINE AND
PROXIMITY TO GUAM AND THE NORTHERN MARIANAS, THE SYSTEM IS UPGRADED
TO MEDIUM. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 15 TO
20 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1008
MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL
CYCLONE WITHIN THE NEXT 24 HOURS IS UPGRADED TO MEDIUM.

[Hayabusa]

Many strong members this latest run
GEFS

EPS

[Hayabusa]

The potential to be another great one is there

[mrbagyo]

99W INVEST 210921 0600 10.4N 153.5E WPAC 15 1005

[Hayabusa]

TCFA, pretty fast given it was only tagged 12 hours ago

WTPN21 PGTW 211230
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 99W)//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
140 NM EITHER SIDE OF A LINE FROM 11.1N 151.6E TO 13.6N 146.6E
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
IMAGERY AT 211200Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 11.2N 151.5E. THE SYSTEM IS MOVING WEST-NORTHWESTWARD AT 11
KNOTS.
2. REMARKS: A 211052Z METOP-B PASS SHOWS THAT A DISCREET LOW-LEVEL
CIRCULATION CENTER (LLCC) HAS CONSOLIDATED OVER THE PAST 12 HOURS,
WITH A SMALL BUT WELL-DEFINED CIRCULATION SURROUNDED BY 12-17 KNOT
WINDS. A BAND OF 20-25 KNOT WINDS EXTENDS FROM SOUTH TO SOUTHEAST OF
THE CENTER. ANIMATED ENHANCED INFRARED IMAGERY AND A 210811Z SSMIS
91GHZ IMAGE DEPICTS FLARING DISORGANIZED CONVECTION PRIMARILY ON THE
SOUTH AND EAST SIDE OF THE ROTATION. ENVIRONMENTAL ANALYSIS
INDICATES A FAVORABLE ENVIRONMENT FOR DEVELOPMENT WITH A COMBINATION
OF STRONG OUTFLOW ALOFT WITH A POINT SOURCE OR ANTICYCLONE ALOFT
DIRECTION OVERHEAD THE LLCC, LOW (10 KT) VERTICAL WIND SHEAR (VWS)
AND VERY WARM (30-31C) SEA SURFACE TEMPERATURES (SST). GLOBAL MODELS
ARE GOOD IN AGREEMENT THAT INVEST 99W WILL CONTINUE TRACKING
NORTHWESTWARD OVER THE NEXT 24-48 HOURS HOWEVER, THEY ARE SPLIT ON
THE DEGREE OF DEVELOPMENT. GFS, ITS ENSEMBLE, AND NAVGEM ARE THE
MOST AGGRESSIVE, INDICATING FAIRLY RAPID CONSOLIDATION AND
INTENSIFICATION, REACHING TROPICAL DEPRESSION STRENGTH WITHIN THE
NEXT 24 HOURS AND TROPICAL STORM STRENGTH WITHIN THE NEXT 48 HOURS
OR LESS, PRIOR TO PASSAGE THROUGH THE MARIANAS ISLAND CHAIN. ECMWF
AND ITS ENSEMBLE ARE MUCH MORE RESERVED, INDICATING LITTLE TO NO
DEVELOPMENT UNTIL AFTER TAU 48, WELL TO THE WEST OF THE MARIANAS. OF
NOTE, THE ASCAT PASS VERIFIED THE 1200Z GFS MODEL FORECAST POSITION
AND WIND FIELD WITH HIGH CONFIDENCE, LENDING INCREASED CONFIDENCE TO
THE GFS FORECAST. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT
18 TO 23 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 HIGH.
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY
221230Z.
//
NNNN

[Hayabusa]

06Z Euro op still weak in the near term

[aspen]

Future Dianmu has quite a lot of potential. We’ll most likely get the WPAC’s third major out of this, perhaps the third Super Typhoon too.

The 12z HWRF bottoms out around 930mb.

[Iceresistance]

Future Dianmu has quite a lot of potential. We’ll most likely get the WPAC’s third major out of this, perhaps the third Super Typhoon too.

The 12z HWRF bottoms out around 930mb.

So does the 12z GFS, except it's closer at 929 MB (Close Enough! )

[ElectricStorm]

18z GFS gets this to 923mb

This should be a fun one to track

[Hayabusa]

NAVGEM makes it into a 150 knot cat 5

[Hayabusa]

[Hayabusa]

WWJP25 RJTD 220000
WARNING AND SUMMARY 220000.
WARNING VALID 230000.
WARNING IS UPDATED EVERY 6 HOURS.
TROPICAL DEPRESSION 1008 HPA AT 10N 150E WEST SLOWLY.

[Hayabusa]

ICON paints a different forecast, it splits 99W into two storms with the stronger one heading to the Philippines, I would disregard it typically especially if it's the only outlier but then UKMET also shows a similar forecast.

[Hayabusa]

Navgem still on fire and Euro strongest run yet

[Hayabusa]

20W.TWENTY
20W TWENTY 210922 1200 11.2N 148.6E WPAC 25 1004