WPAC: Tropical Depression 07W - Post-Tropical

[Hayabusa]

96W.INVEST

96W.INVEST.15kts.1000mb.10.1N.136.7E

[Hayabusa]

[Hayabusa]

[Hayabusa]

06Z

Euro is more interested on the left side system...

[Hayabusa]

ABPW10 PGTW 021830
MSGID/GENADMIN/JOINT TYPHOON WRNCEN/PEARL/HARBOR/HI//
SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE WESTERN AND SOUTH
PACIFIC OCEANS REISSUED/021830Z-030600ZJUL2021//
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 96W) HAS PERSISTED NEAR
10.5N 133.9E, APPROXIMATELY 195 NM NORTH-NORTHWEST OF PALAU.
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY AND A 021700Z GMI
89GHZ MICROWAVE IMAGE DEPICT FLARING CONVECTION SURROUNDING A WAVE
AXIS. A 021230Z ASCAT-B IMAGE SHOWS THE SYSTEM HAS NOT DEVELOPED A
CIRCULATION AT THIS TIME. ENVIRONMENTAL ANALYSIS SHOWS MODERATELY
FAVORABLE CONDITIONS FOR DEVELOPMENT, WITH GOOD EQUATORWARD OUTFLOW,
LOW (10-15 KTS) VERTICAL WIND SHEAR (VWS), AND VERY WARM (30-31C)
SEA SURFACE TEMPERATURES (SST). NUMERICAL MODELS ARE IN GENERAL
AGREEMENT THAT 96W WILL TRACK NORTHWESTWARD BUT ARE SPLIT REGARDING
INTENSIFICATION, WITH GFS AND NAVGEM SHOWING DEVELOPMENT OVER THE
NEXT FEW DAYS BUT ECMWF AND JMA STAYING BELOW WARNING CRITERIA.
MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 15 TO 20 KNOTS.
MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1007 MB. THE
POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE
WITHIN THE NEXT 24 HOURS IS UPGRADED TO LOW.

[Hayabusa]

WWJP27 RJTD 030000
WARNING AND SUMMARY 030000.
WARNING VALID 040000.
WARNING IS UPDATED EVERY 6 HOURS.
LOW PRESSURE AREA 1008 HPA NEAR 12N 131E ALMOST STATIONARY.

96W INVEST 210703 0000 10.2N 133.6E WPAC 20 1007

[Hayabusa]

Still a polar opposite, Euro ensemble is more interested on possible 97W than 96W

GFS

[Hayabusa]

ABPW10 PGTW 031530
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE WESTERN AND
SOUTH PACIFIC OCEANS REISSUED/031530Z-040600ZJUL2021//
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 96W) PREVIOUSLY LOCATED
NEAR 10.6N 134.1E IS NOW LOCATED NEAR 10.4N 133.8E, APPROXIMATELY
190 NM NORTH-NORTHWEST OF PALAU. ANIMATED ENHANCED INFRARED
SATELLITE IMAGERY (EIR) AND A 031234Z MHS 89GHZ MICROWAVE IMAGE
DEPICT A BROAD CIRCULATION WITH IMPROVED CURVED BANDING IN THE
SOUTHERN SEMICIRCLE. ENVIRONMENTAL ANALYSIS SHOWS FAVORABLE
CONDITIONS FOR DEVELOPMENT, WITH AN UPPER-LEVEL TROUGH REORIENTING
TO THE NORTHWEST INCREASING POLEWARD OUTFLOW, LOW (10-15 KTS)
VERTICAL WIND SHEAR (VWS), AND VERY WARM (30-31C) SEA SURFACE
TEMPERATURES (SST). NUMERICAL MODELS ARE IN GENERAL AGREEMENT THAT
96W WILL TRACK NORTHWESTWARD BUT ARE SPLIT REGARDING
INTENSIFICATION, WITH GFS AND NAVGEM SHOWING DEVELOPMENT OVER THE
NEXT 24-48 HOURS BUT ECMWF AND JMA STAYING BELOW WARNING CRITERIA.
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.

[doomhaMwx]

WTPN21 PGTW 031930

REMARKS:
THE AREA OF CONVECTION (INVEST 96W) PREVIOUSLY LOCATED
NEAR 10.4N 133.8E IS NOW LOCATED NEAR 11.0N 133.2E, APPROXIMATELY
240 NM NORTH-NORTHWEST OF PALAU. ANIMATED ENHANCED INFRARED
SATELLITE IMAGERY (EIR) AND A 031605Z GMI 89GHZ MICROWAVE IMAGE
DEPICT A BROAD CIRCULATION WITH IMPROVED CURVED BANDING IN THE
NORTHERN PERIPHERY. ENVIRONMENTAL ANALYSIS SHOWS FAVORABLE
CONDITIONS FOR DEVELOPMENT, WITH AN UPPER-LEVEL TROUGH REORIENTING
TO THE NORTHWEST INCREASING POLEWARD OUTFLOW, MODERATE (15-20 KTS)
VERTICAL WIND SHEAR (VWS), AND VERY WARM (30-31C) SEA SURFACE
TEMPERATURES (SST). NUMERICAL MODELS ARE IN GENERAL AGREEMENT THAT
96W WILL TRACK NORTHWESTWARD BUT ARE SPLIT REGARDING
INTENSIFICATION, WITH GFS AND NAVGEM SHOWING DEVELOPMENT IN THE NEXT
24 HOURS BUT ECMWF AND JMA STAYING BELOW WARNING CRITERIA. A 031241Z
PARTIAL METOP-C ASCAT PASS SHOWS A LARGE WIND FIELD WITH SMALL
POCKETS OF 25-30 KNOT WINDS CONFINED TO THE NORTHEAST QUADRANT,
VERIFYING MODEL INITIALIZATION. THIS INDICATES THE HIGHER POTENTIAL
FOR INTENSIFICATION AND CONSOLIDATION SHOWN BY GFS AND NAVGEM
MODELS. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 18 TO 23
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.

GFS has been on track with development so far and may be right in this case. It continues to show a midget-sized typhoon passing near/over Batanes and southern Taiwan in ~48hrs. Taiwan is nearly on a two-year streak of no landfalling TCs (the last one was in Aug 2019).

[Hayabusa]

WWJP27 RJTD 031800
WARNING AND SUMMARY 031800.
WARNING VALID 041800.
WARNING IS UPDATED EVERY 6 HOURS.
TROPICAL DEPRESSION 1004 HPA AT 11N 133E NW SLOWLY

[Hayabusa]

[Hayabusa]

WDPN31 PGTW 042100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 07W (SEVEN)
WARNING NR 001//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
INITIAL POSITION: 16.7N 127.2E
INITIAL INTENSITY: 25 KTS
GEOGRAPHIC REFERENCE: 380 NM EAST-NORTHEAST OF MANILA,
PHILIPPINES
MOVEMENT PAST 6 HOURS: NORTHWESTWARD AT 17 KTS
SIGNIFICANT WAVE HEIGHT: 12 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS AN
ASYMMETRIC SYSTEM, WITH FLARING DEEP CONVECTION EXTENDING WELL TO
THE SOUTH ALONG THE EASTERN PERIPHERY OF THE CIRCULATION. A 041658Z
AMSR2 37GHZ AND COLORIZED 89GHZ MICROWAVE IMAGE SHOWED THE
ELONGATED CONVECTIVE BAND EXTENDING SOUTH, BUT ALSO INDICATED THE
DEVELOPMENT OF WEAK SPIRAL BANDING ON THE WESTERN AND SOUTHERN
PORTIONS OF THE LOW LEVEL CIRCULATION. THE INITIAL POSITION IS
PLACED JUST WEST OF THE FLARING CONVECTION WITH MODERATE CONFIDENCE
BASED ON THE AFOREMENTIONED AMSR2 PASS. THE INITIAL INTENSITY IS
SET AT 25 KNOTS, THOUGH A 041309Z ASCAT-B SHOWED THE PRESENCE OF 30
KNOT WINDS IN THE EASTERN THROUGH NORTHERN QUADRANTS OF THE LARGER
CIRCULATION. HOWEVER, WIND SPEEDS IN THE REMAINDER OF THE
CIRCULATION ARE BELOW 20 KNOTS, AND THUS, THE HIGHER WINDS ON THE
EASTERN PERIPHERY ARE NOT REPRESENTATIVE OF THE OVERALL INTENSITY
AT THIS TIME.

INITIAL WIND RADII BASIS: NOT APPLICABLE (THERE ARE NO INITIAL WIND
RADII).

CURRENT STEERING MECHANISM: DEEP LAYER SUBTROPICAL RIDGE (STR)
CENTERED TO THE NORTHEAST.

AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T1.5 - 25 KTS
KNES: T1.5 - 25 KTS

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
VWS: 0-5 KTS
SST: 30-31 CELSIUS
OUTFLOW: MODERATE POLEWARD AND EQUATORWARD

ANALYSIS CONFIDENCE:
INITIAL POSITION: MEDIUM
INITIAL INTENSITY: MEDIUM
INITIAL WIND RADII: NOT APPLICABLE

3. FORECAST REASONING.

SIGNIFICANT FORECAST CHANGES: THIS INITIAL PROGNOSTIC REASONING
MESSAGE ESTABLISHES THE FORECAST PHILOSOPHY.

FORECAST DISCUSSION: TROPICAL DEPRESSION 07W (SEVEN) WILL TRACK
NORTHWESTWARD ALONG THE SOUTHWESTERN PERIPHERY OF THE STEERING
RIDGE THROUGH THE DURATION OF THE FORECAST PERIOD. THE SYSTEM IS
EXPECTED TO PASS THROUGH THE LUZON STRAIT WITHIN THE NEXT 24 HOURS
BEFORE TURNING SLIGHTLY MORE WEST-NORTHWESTERWARD AS LOW TO
MID-LEVEL RIDGING BUILDS IN TO THE NORTH ACROSS CENTRAL CHINA. SOME
MODELS ARE SUGGESTING THE SYSTEM WILL MAKE LANDFALL ALONG THE
SOUTHEAST COAST OF TAIWAN, BUT THE BUILDING OF THE LOW TO MID-LEVEL
RIDGE TO THE NORTH SHOULD KEEP THE TRACK OFFSHORE. THE SYSTEM IS
FORECAST TO MAKE LANDFALL ALONG THE COAST OF SOUTHEASTERN CHINA
NEAR TAU 60. OVER THE NEXT 12 TO 24 HOURS, IT IS EXPECTED THAT THE
LOW LEVEL VORTEX WILL CONTINUE TO TIGHTEN AND CONSOLIDATE, ENABLING
GENERATION AND MAINTENANCE OF DEEP CORE CONVECTION. AT THE SAME
TIME, VERY WARM (30-31C) SSTS, LOW (LESS THAN 10 KTS) VWS AND
RELATIVELY GOOD POLEWARD OUTFLOW ARE FORECAST TO CONTINUE,
RESULTING IN A PERIOD OF QUICK INTENSIFICATION THROUGH TAU 24.
AFTER CROSSING SOUTH OF TAIWAN, VWS IS EXPECTED TO INCREASE AND
OUTFLOW BECOME SLIGHTLY LESS FAVORABLE, WHICH WILL SLOW THE RATE OF
INTENSIFICATION, PEAKING AT 55 KNOTS BY TAU 36. AFTER LANDFALL THE
SYSTEM WILL RAPIDLY DISSIPATE DUE TO TERRAIN INTERACTION.

MODEL DISCUSSION: NUMERICAL MODEL GUIDANCE IS IN GENERAL AGREEMENT
ON THE OVERALL TRACK, BUT DOES SHOW A MODERATE DEGREE OF SPREAD.
SPREAD BETWEEN THE HWRF ON THE RIGHT, AND THE ECMWF ENSEMBLE ON THE
LEFT IS 120 NM AT TAU 24, INCREASING TO 360 NM BY TAU 48. ANALYSIS
OF THE GLOBAL MODEL FIELDS INDICATES THE HWRF, GFS ENSEMBLE AND
UKMET ENSEMBLE ARE UNREALISTICALLY RUNNING THE SYSTEM INTO AN
EXTENSION OF THE STR THAT BUILDS OVER CENTRAL CHINA, WHILE THE
REMAINDER OF THE CONSENUS MEMBERS REFLECT OR MORE LIKELY JOG
SLIGHTLY MORE WEST-NORTHWESTWARD IN RESPONSE TO THE STRENGTHENING
OF THE RIDGE. THE JTWC FORECAST TRACK LIES JUST TO THE EAST AND
SLIGHTLY SLOWER THAN THE MULTI-MODEL CONSENSUS TRACK THROUGH THE
DURATION OF THE FORECAST PERIOD, KEEPING THE TRACK OFFSHORE OF
TAIWAN AND THROUGH THE LUZON STRAIT. INTENSITY GUIDANCE MEMBERS ALL
AGREE ON INTENSIFICATION AND THE JTWC FORECAST IS CONSISTENT WITH
THE HWRF AND GFS SOLUTIONS, ABOVE THE MULTI-MODEL CONSENSUS.

FORECAST CONFIDENCE:
TRACK 0 - 72 HR: LOW
INTENSITY 0 - 72 HR: MEDIUM//
NNNN

[doomhaMwx]

Despite the favorable environment, this poor little thing has been struggling due to its swift movement speed.

[Hayabusa]

Euro for the win and another overhyped intensity by the GFS

[NotoSans]

 https://twitter.com/squirtleinhk/status/1412283215847383043