WPAC: KAJIKI - Post-Tropical

[Hayabusa]

90W INVEST 250815 1800 7.2N 169.4E WPAC 15 0

[Hayabusa]

Interesting deep convection in the deep tropics on the month of August... but deterministic and ensemble support is weak

[Hayabusa]

06z gfs show some development

[Hayabusa]

GFS 06Z develops and tracks this towards Northern Luzon, while 00z Euro weak to no development

[Hayabusa]

Euro and Euro AI 12Z now showing development too

[Hayabusa]

18z eps, deterministic peaks at 955 mb

[Hayabusa]

Now medium

ABPW10 PGTW 180600
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE WESTERN AND SOUTH
PACIFIC OCEANS/180600Z-190600ZAUG2025//
REF/A/MSG/ JOINT TYPHOON WRNCEN PEARL HARBOR HI/171421ZAUG2025//
REF/B/MSG/ JOINT TYPHOON WRNCEN PEARL HARBOR HI/180021ZAUG2025//
NARR/REFS A AND B ARE TROPICAL CYCLONE FORMATION ALERTS.//
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 92W) PREVIOUSLY LOCATED NEAR
22.5N 126.9E IS NOW LOCATED NEAR 22.6N 122.5E, APPROXIMATELY 222 NM
SOUTH-SOUTHWEST OF KADENA AFB, OKINAWA. ANIMATED MULTISPECTRAL
SATELLITE IMAGERY (MSI) DEPICTS A PARTIALLY EXPOSED LOW LEVEL
CIRCULATION CENTER (LLCC), EMBEDDED WITHIN A REVERSE ORIENTED MONSOON
TROUGH. RELATIVELY DEEP CONVECTION CONTINUES ALONG THE SOUTHERN
PERIPHERY AND IS CONSOLIDATING INTO FORMATIVE BANDING. ENVIRONMENTAL
ANALYSIS FOR THE AREA INDICATES FAVORABLE CONDITIONS WITH LOW VERTICAL
WIND SHEAR (10-15 KTS), WARM SEA SURFACE TEMPERATURES (29-30 C), AND
STRONG EASTWARD OUTFLOW ALOFT. GLOBAL MODELS ARE IN GOOD AGREEMENT
THAT 92W WILL TRACK GENERALLY NORTHWARD OVER THE NEXT 24 HOURS. ECENS
AND GEFS ENSEMBLE GUIDANCE AGREE THAT 92W WILL DEVELOP, BUT WITH THE
ECENS MODEL BEING MORE FAVORABLE THAN THE GEFS. MAXIMUM SUSTAINED
SURFACE WINDS ARE ESTIMATED AT 23 TO 28 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
REMAINS HIGH. SEE REF A (WTPN21 PGTW 171430) FOR FURTHER DETAILS.
(2) THE AREA OF CONVECTION (INVEST 91W) PREVIOUSLY LOCATED NEAR
19.4N 108.0E IS NOW LOCATED NEAR 19.1N 107.9E, APPROXIMATELY 158 NM
SOUTHEAST OF HANOI, VIETNAM. ANIMATED MULTISPECTRAL SATELLITE IMAGERY
(MSI) DEPICTS DEEP CONVECTION BUILDING OVER A CONSOLIDATING LOW-LEVEL
CIRCULATION CENTER (LLCC), ALSO HAVING CURVED CONVECTIVE BANDING TO
THE SOUTHEAST. A CONTRACTING WIND FIELD AND REDUCTION OF THE RADIUS OF
MAXIMUM WINDS INDICATES THAT A TRANSITION FROM A MONSOON DEPRESSION
INTO A TROPICAL DEPRESSION IS COMMENCING. ENVIRONMENTAL ANALYSIS FOR
THE AREA INDICATES FAVORABLE CONDITIONS FOR DEVELOPMENT WITH LOW
VERTICAL WIND SHEAR (10-15 KTS), WARM SEA SURFACE TEMPERATURES (30-31
C), AND GOOD EQUATORWARD OUTFLOW ALOFT. GLOBAL MODELS ARE IN GOOD
AGREEMENT THAT 91W WILL TRACK NORTHWARD OVER THE NEXT 24-36 HOURS.
MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 23 TO 28 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 REMAINS HIGH. SEE REF B (WTPN22 PGTW 180030) FOR
FURTHER DETAILS.
(3) AN AREA OF CONVECTION (INVEST 90W) HAS PERSISTED NEAR 9.3N
149.5E, APPROXIMATELY 358 NM SOUTHEAST OF ANDERSON AFB, GUAM. ANIMATED
MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS FLARING CONVECTION
BUILDING OVER A SLOWLY CONSOLIDATING CUSP OR LOW-LEVEL CIRCULATION
CENTER (LLCC), AT THE NORTHERN END OF AN EASTERLY WAVE FEATURE. A
COMBINATION OF AN 180015Z AND 172351Z PARTIAL ASCAT PASSES REVEALED
THE FACT THAT 90W REMAINS PRIMARILY A WAVE WITH A RAPIDLY DEVELOPING
CUSP AT THE NORTHERN END OF IT. SOUTHERLY WINDS OF 20-25KTS EXTEND
FROM SOUTHWEST OF CHUUK TO THE NORTHWEST OF FANANU, THEN TURN SHARPLY
TO EASTERLIES AT THE LATITUDE OF 90W, WITH EMBEDDED POCKETS OF 25KT
EASTERLY WINDS EXTENDING TO A POINT ABOUT 290NM SOUTHEAST OF GUAM.
ENVIRONMENTAL CONDITIONS ARE ASSESSED TO BE MODERATELY FAVORABLE WITH
GOOD EQUATORWARD OUTFLOW AND VERY WARM (30-31C) SSTS AND LOW TO
MODERATE (15-20KT) VERTICAL WIND SHEAR. GLOBAL MODELS ARE IN GOOD
AGREEMENT THAT 90W WILL TRACK NORTH-NORTHWEST INTO SUBSTANTIALLY LOWER
SHEAR OVER THE NEXT 24-36 HOURS BUT DO NOT CURRENTLY DEPICT THE SYSTEM
DEVELOPING INTO A TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS. HOWEVER,
ELEVATED WINDS OF 25-30KTS ARE POSSIBLE ALONG THE NORTHERN PERIPHERY
OF THE SYSTEM, IN THE GRADIENT FLOW, AS IT PASSES TO THE SOUTH OF
GUAM. ENSEMBLE DEVELOPMENT IS STRONG ON THIS CIRCULATION WITH ECENS
BEING THE MOST FAVORABLE MODEL INTENSITY WISE HOWEVER GEFS IS STILL IN
AGREEMENT ON A NORTHWESTWARD TRACK. MAXIMUM SUSTAINED SURFACE WINDS
ARE ESTIMATED AT 18 TO 23 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 MEDIUM.

[Hayabusa]

GFS and Euro became weaker since 00z, it's a fast moving system only HWRF makes it a minimal typhoon before landfall, so it's a race against time
06z eps

[Hayabusa]

HWRF 12Z, the outlier of a strong typhoon

[mrbagyo]

[Hayabusa]

Downgraded to low

ABPW10 PGTW 190300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE WESTERN AND SOUTH
PACIFIC OCEANS REISSUED/190300Z-190600ZAUG2025//
REF/A/MSG/JOINT TYPHOON WRNCEN PEARL HARBOR HI/181951ZAUG2025//
REF/B/MSG/JOINT TYPHOON WRNCEN PEARL HARBOR HI/181421ZAUG2025//
AMPN/REF A IS A TROPICAL CYCLONE FINAL WARNING. REF B IS A TROPICAL
CYCLONE FORMATION ALERT.//
RMKS/
1. WESTERN NORTH PACIFIC AREA (180 TO MALAY PENINSULA):
A. TROPICAL CYCLONE SUMMARY:
(1) AT 18AUG25 1800Z, TROPICAL DEPRESSION 17W (SEVENTEEN) WAS
LOCATED NEAR 21.2N 107.3E, APPROXIMATELY 79 NM EAST OF HANOI,
VIETNAM, AND HAD TRACKED NORTHWARD AT 11 KNOTS OVER THE PAST SIX
HOURS. MAXIMUM SUSTAINED SURFACE WINDS WERE ESTIMATED AT 25 KNOTS
GUSTING TO 35 KNOTS. SEE REF A (WTPN31 PGTW 182100) FOR THE FINAL
WARNING ON THIS SYSTEM.
(2) NO OTHER TROPICAL CYCLONES.
B. TROPICAL DISTURBANCE SUMMARY:
(1) THE AREA OF CONVECTION (INVEST 92W) PREVIOUSLY LOCATED NEAR
23.0N 127.4E IS NOW LOCATED NEAR 26.1N 128.1E, APPROXIMATELY 24 NM
NORTHWEST OF KADENA. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI)
DEPICTS A WELL-DEFINED LOW-LEVEL CIRCULATION CENTER (LLCC) BEING
IMPACTED BY A TROPICAL UPPER TROPOSPHERIC TROUGH (TUTT) CELL WITH
CONVECTION EXTENDING FROM THE LLCC. ENVIRONMENTAL ANALYSIS REVEALS A
MARGINAL ENVIRONMENT FOR DEVELOPMENT WITH MODERATE VWS (VERTICAL WIND
SHEAR), POLEWARD OUTFLOW ALOFT AND WARM SEA SURFACE TEMPERATURE (30-
31C). GLOBAL MODELS ARE IN GOOD AGREEMENT THAT INVEST 92W WILL TRACK
STEADILY NORTHWARD OVER THE NEXT 24 HOURS. MAXIMUM SUSTAINED SURFACE
WINDS ARE ESTIMATED AT 18 TO 23 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 REMAINS HIGH.
(2) THE AREA OF CONVECTION (INVEST 90W) PREVIOUSLY LOCATED NEAR
10.9N 141.7E IS NOW LOCATED NEAR 11.1N 138.5E, APPROXIMATELY 97 NM
NORTH-NORTHEAST OF YAP. ANIMATED MULTISPECTRAL SATELLITE IMAGERY
(MSI) DEPICTS A BROAD MID TO UPPER-LEVEL TURNING IN CONJUNCTION WITH
FLARING CONVECTION ALONG THE PRESENT MID-LEVEL CIRCULATION.
ENVIRONMENTAL ANALYSIS REVEALS MARGINAL TO FAVORABLE CONDITIONS FOR
DEVELOPMENT WITH LOW TO MODERATE VWS (VERTICAL WIND SHEAR), GOOD
EQUATORWARD OUTFLOW ALOFT AND WARM SEA SURFACE TEMPERATURE (30-31C).
GLOBAL MODELS ARE IN GOOD AGREEMENT THAT INVEST 90W WILL TRACK NORTH-
NORTHWEST OVER THE NEXT 24-36 HOURS. MAXIMUM SUSTAINED SURFACE WINDS
ARE ESTIMATED AT 18 TO 23 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 DOWNGRADED
TO LOW.
(3) NO OTHER SUSPECT AREAS.
C. SUBTROPICAL SYSTEM SUMMARY: NONE.
2. SOUTH PACIFIC AREA (WEST COAST OF SOUTH AMERICA TO 135 EAST):
A. TROPICAL CYCLONE SUMMARY: NONE.
B. TROPICAL DISTURBANCE SUMMARY: NONE.
C. SUBTROPICAL SYSTEM SUMMARY: NONE.
3. JUSTIFICATION FOR REISSUE: DOWNGRADED AREA IN PARA. 2.B.(2) TO
LOW.//
NNNN

[mrbagyo]

[Hayabusa]

Finally up to medium again with models significantly intensifying after crossing Luzon, maybe a small chance of becoming a TD before landfall

ABPW10 PGTW 211800
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE WESTERN AND SOUTH
PACIFIC OCEANS REISSUED/211800Z-220600ZAUG2025//
REF/A/MSG/JOINT TYPHOON WRNCEN PEARL HARBOR HI/211351ZAUG2025//
AMPN/REF A IS A TROPICAL CYCLONE WARNING.//
RMKS/
1. WESTERN NORTH PACIFIC AREA (180 TO MALAY PENINSULA):
A. TROPICAL CYCLONE SUMMARY:
(1) AT 21AUG25 1200Z, TROPICAL DEPRESSION 18W (LINGLING) WAS
LOCATED NEAR 31.6N 130.9E, APPROXIMATELY 109 NM SOUTHEAST OF SASEBO,
JAPAN, AND HAD TRACKED EASTWARD AT 09 KNOTS OVER THE PAST SIX HOURS.
MAXIMUM SUSTAINED SURFACE WINDS WERE ESTIMATED AT 30 KNOTS GUSTING TO 40
KNOTS. SEE REF A (WTPN32 PGTW 211500) FOR FURTHER DETAILS.
(2) NO OTHER TROPICAL CYCLONES.
B. TROPICAL DISTURBANCE SUMMARY:
(1) THE AREA OF CONVECTION (INVEST 90W) PREVIOUSLY LOCATED NEAR
15.9N 126.8E IS NOW LOCATED NEAR 15.4N 124.4E, APPROXIMATELY 133 NM EAST
OF CASIGURAN, PHILIPPINES. ANIMATED ENHANCED INFRARED IMAGERY (EIR) AS
WELL AS A 211023Z SSMIS 91GHZ F16 MICROWAVE IMAGE DEPICT A BROAD SLOWLY
CONSOLIDATING LOW-LEVEL CIRCULATION CENTER (LLCC) WITH FLARING
CONVECTION ALONG THE SOUTHERN PERIPHERY. FURTHERMORE, A 211251Z METOP-C
ASCAT PASS FURTHER EMPHASIZES THE BROAD NATURE OF THE SYSTEM AS IT
APPROACHES THE EASTERN COAST OF LUZON. THE ASCAT DATA SUGGESTS THAT THE
SYSTEM MAY BE STARTING TO CLOSE-OFF INTO A CLOSED CIRCULATION, THOUGH
ONE THAT REMAINS VERY BROAD. ENVIRONMENTAL ANALYSIS REVEALS A FAVORABLE
ENVIRONMENT FOR DEVELOPMENT WITH LOW (10-15 KNOTS) NORTHERLY VERTICAL
WIND SHEAR, MODERATE OUTFLOW, AND VERY WARM (30-31 C) SEA SURFACE
TEMPERATURES. DETERMINISTIC AND ENSEMBLE MODELS ARE IN AGREEMENT THAT
THE CIRCULATION WILL TRACK WESTWARD OVER LUZON WITH CONSOLIDATION IN THE
SOUTH CHINA SEA OVER THE NEXT 36-48 HOURS. MAXIMUM SUSTAINED SURFACE
WINDS ARE ESTIMATED AT 13 TO 18 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.
(2) NO OTHER SUSPECT AREAS.
C. SUBTROPICAL SYSTEM SUMMARY: NONE.
2. SOUTH PACIFIC AREA (WEST COAST OF SOUTH AMERICA TO 135 EAST):
A. TROPICAL CYCLONE SUMMARY: NONE.
B. TROPICAL DISTURBANCE SUMMARY: NONE.
C. SUBTROPICAL SYSTEM SUMMARY: NONE.
3. JUSTIFICATION FOR REISSUE: UPGRADED AREA IN PARA 1.B(1) TO MEDIUM//
NNNN

[Hayabusa]

TD since 00Z and TCFA

TD b
Issued at 2025/08/22 04:15 UTC
Analysis at 08/22 03 UTC
Grade TD
Scale -
Intensity -
Center position N16°30′ (16.5°)
E122°25′ (122.4°)
Direction and speed of movement WNW 15 km/h (7 kt)
Central pressure 1004 hPa
Maximum sustained wind speed near center 15 m/s (30 kt)
Maximum wind gust speed 23 m/s (45 kt)

WTPN21 PGTW 212230
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 90W)//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
120 NM EITHER SIDE OF A LINE FROM 16.1N 123.4E TO 17.0N 117.1E
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 211800Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 16.1N 123.3E. THE SYSTEM IS MOVING WESTWARD AT 11 KNOTS.
2. REMARKS:THE AREA OF CONVECTION (INVEST 90W) PREVIOUSLY LOCATED NEAR
15.9N 126.8E IS NOW LOCATED NEAR 16.1N 123.3E, APPROXIMATELY 71 NM EAST
OF CASIGURAN, PHILIPPINES. ANIMATED MULTISPECTRAL SATELLITE IMAGERY
(MSI) AND A 212053Z GMI 89GHZ MICROWAVE IMAGE DEPICT A COMPACT,
PARTIALLY EXPOSED LOW-LEVEL CIRCULATION CENTER (LLCC) WITH PERSISTENT
CONVECTION ALONG THE EASTERN PERIPHERY OF THE CIRCULATION. ENVIRONMENTAL
ANALYSIS REVEALS A FAVORABLE ENVIRONMENT FOR DEVELOPMENT WITH LOW (10-15
KNOTS) NORTHERLY VERTICAL WIND SHEAR, STRONG EQUATORWARD OUTFLOW, AND
VERY WARM (30-31 C) SEA SURFACE TEMPERATURES. THE DEFINED CIRCULATION IS
EXPECTED TO QUICKLY MAKE LANDFALL ALONG THE EASTERN COAST OF LUZON AND
EMERGE WITHIN THE SOUTH CHINA SEA. DETERMINISTIC AND ENSEMBLE MODELS ARE
IN AGREEMENT THAT THE SYSTEM WILL TRACK WESTWARD OVER LUZON AND
INTENSIFY WITHIN THE SOUTH CHINA SEA AFTER RECOVERING FROM THE IMMINENT
LANDFALL. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 20 TO 25
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 HIGH.
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY
222230Z.
//
NNNN

[mrbagyo]

HWRF is showing 935 hpa intense typhoon for Central Vietnam.

This could easily join the ranks of Yagi, Damrey, Doksuri And Ketsana if the model projection comes to fruition

[Hayabusa]

19W NINETEEN 250822 1200 16.8N 119.3E WPAC 25 1001

[ElectricStorm]

18z GFS bombs this to 949mb before landfall in around 48 hours or so. Probably too aggressive but the chance for a solid typhoon is there. JTWC has 75kts at peak for now but I could see this getting a little higher than that. Hurricane models aren't running for this system right now for whatever reason.

[mrbagyo]

[mrbagyo]

New convection is exploding over the LLC, some reaching temp colder than -90° C

[StormWeather]

Mods please update this to Kajiki

WTPQ51 RJTD 230000
RSMC TROPICAL CYCLONE ADVISORY
NAME TS 2513 KAJIKI (2513) UPGRADED FROM TD
ANALYSIS
PSTN 230000UTC 17.6N 116.4E FAIR
MOVE W 15KT
PRES 998HPA
MXWD 035KT
GUST 050KT
30KT 120NM
FORECAST
12HF 231200UTC 18.3N 114.2E 40NM 70%
MOVE WNW 11KT
PRES 996HPA
MXWD 040KT
GUST 060KT
24HF 240000UTC 18.3N 111.4E 57NM 70%
MOVE W 13KT
PRES 990HPA
MXWD 050KT
GUST 070KT
48HF 250000UTC 18.4N 107.5E 100NM 70%
MOVE W 09KT
PRES 965HPA
MXWD 070KT
GUST 100KT
72HF 260000UTC 19.1N 103.6E 140NM 70% TROPICAL DEPRESSION =

Also JTWC went with 40kts for 00z according to the ATCF.