WPAC: CO-MAY - Tropical Depression - Discussion

[cycloneye]

Last warning from JMA.

T2508(Co-may)
Issued at 2025/07/26 00:45 UTC
Analysis at 07/26 00 UTC
Grade TD
Scale -
Intensity -
Center position N26°00′ (26.0°)
E125°00′ (125.0°)
Direction and speed of movement NNE 35 km/h (20 kt)
Central pressure 996 hPa

[Hayabusa]

JTWC thinks it's still alive and latest forecast show becoming a TS again, now that would be interesting if it becomes a TS again, would JMA reuse CO-MAY as the name or a new name?

WDPN33 PGTW 262100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 11W (CO-MAY)
WARNING NR 016//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
INITIAL POSITION: 26.8N 127.4E
INITIAL INTENSITY: 25 KTS
GEOGRAPHIC REFERENCE: 28 NM NORTHWEST OF KADENA AB
MOVEMENT PAST 6 HOURS: EAST-SOUTHEASTWARD AT 05 KTS
SIGNIFICANT WAVE HEIGHT: 13 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS AN EXPOSED
LOW-LEVEL CIRCULATION (LLC), WITH FLARING DEEP CONVECTIVE BURSTS ALONG
THE SOUTHERN AND EASTERN PERIPHERIES. ANIMATED RADAR IMAGERY REVEALS
WEAK BANDING WRAPPING INTO AN ELONGATED LLC, WITH FRAGMENTED OUTER
BANDING. SURFACE OBSERVATIONS SUPPORT THE INITIAL POSITION WEST OF
OKINAWA, WITH MAXIMUM WINDS OF 21 KNOTS (10-MINUTE AVERAGE) REPORTED
AT KITAHARA. THE INITIAL POSITION IS ASSESSED WITH MEDIUM CONFIDENCE
BASED ON RADAR IMAGERY, EIR IMAGERY AND SURFACE OBSERVATIONS. THE
INITIAL INTENSITY OF 25 KNOTS IS ASSESSED WITH HIGH CONFIDENCE BASED
ON SURFACE OBSERVATIONS AND RECENT ASCAT DATA. ENVIRONMENTAL
CONDITIONS ARE MARGINALLY FAVORABLE, WITH MODERATE EQUATORWARD OUTFLOW
AND WEAK POLEWARD OUTFLOW, INHIBITED BY A TUTT CELL POSITIONED TO THE
NORTHWEST AND DRY AIR ENTRAINMENT OFFSET BY LOW VERTICAL WIND SHEAR
AND WARM SST VALUES.

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

CURRENT STEERING MECHANISM: COMPETING STEERING ENVIRONMENT, WITH
SUBTROPICAL RIDGE (STR) TO THE EAST AND NORTH AND NEAR-EQUATORIAL
RIDGE (NER) TO THE SOUTH.

AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T1.5 - 25 KTS
CIMSS SATCON: 44 KTS AT 261658Z
CIMSS ADT: 32 KTS AT 261730Z
CIMSS AIDT: 35 KTS AT 261730Z
CIMSS D-MINT: 25 KTS AT 261658Z
CIMSS D-PRINT: 22 KTS AT 261800Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE
VWS: 10-15 KTS
SST: 28-29 CELSIUS
OUTFLOW: MODERATE EQUATORWARD
OTHER FACTORS: DRY AIR ENTRAINMENT

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

3. FORECAST REASONING.

SIGNIFICANT FORECAST CHANGES: MAJOR CHANGE TO THE JTWC FORECAST,
WITH SYSTEM NOW EXPECTED TO REINTENSIFY AND TRACK OVER EASTERN
CHINA.

FORECAST DISCUSSION: TROPICAL DEPRESSION (TD) 11W IS FORECAST TO
TRACK SLOWLY EAST-NORTHEASTWARD THROUGH TAU 12 THEN TURN SHARPLY
NORTHWESTWARD TO WEST-NORTHWESTWARD AS THE STR TO THE NORTH BECOMES
THE DOMINANT STEERING INFLUENCE. THE SYSTEM WILL GRADUALLY INTENSIFY
TO 30 KNOTS BY TAU 24. AFTER TAU 24, TD 11W WILL ACCELERATE WEST-
NORTHWESTWARD ALONG THE SOUTHERN PERIPHERY OF THE STR THROUGH
LANDFALL, WHICH WILL OCCUR SOUTH OF SHANGHAI NEAR TAU 60. TD 11W WILL
SLOWLY INTENSIFY DUE TO DRY AIR ENTRAINMENT. HOWEVER, THE SYSTEM IS
EXPECTED TO RE-MOISTEN JUST PRIOR TO LANDFALL, WITH A PEAK INTENSITY
OF 45 KNOTS NEAR TAU 60. AFTER LANDFALL, THE SYSTEM WILL RECURVE
POLEWARD OVERLAND TOWARD A BREAK IN THE STR TO THE NORTH, WITH STEADY
WEAKENING AND DISSIPATION EXPECTED.

MODEL DISCUSSION: DETERMINISTIC MODEL GUIDANCE IS IN FAIR AGREEMENT,
WITH A 110NM CROSS-TRACK SPREAD AT TAU 48. THE DETERMINISTIC AND
ENSEMBLE MODELS DIVERGE THROUGH THE REMAINDER OF THE JTWC FORECAST,
WITH MEDIUM OVERALL CONFIDENCE IN THE JTWC TRACK FORECAST. RELIABLE
INTENSITY GUIDANCE INDICATES A PEAK INTENSITY RANGING FROM 35 TO 45
KNOTS BETWEEN TAU 36 TO TAU 60.

FORECAST CONFIDENCE:
TRACK 0 - 72 HR: MEDIUM
TRACK 72-120 HR: MEDIUM
INTENSITY 0 - 72 HR: MEDIUM
INTENSITY 72-120 HR: MEDIUM//
NNNN

[Hayabusa]

12Z, for some reason Euro TC name tracker changed from CO-MAY to MAY