SPAC: 07F - Tropical Low

[Subtrop]

95P INVEST 250206 1800 19.8S 148.8E SHEM 15 1003

[Subtrop]

SH, 16, 2025021100, , BEST, 0, 217S, 1624E, 40, 1000, TS, 34, NEQ, 115, 55, 0, 190, 1008, 180, 100, 0, 0, P, 0, , 0, 0, INVEST, S, 0, , 0, 0, 0, 0, TRANSITIONED, shE52025 to sh162025,

WDPS31 PGTW 110300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 16P (SIXTEEN) WARNING
NR 001//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
INITIAL POSITION: 21.7S 162.4E
INITIAL INTENSITY: 40 KTS
GEOGRAPHIC REFERENCE: 207 NM WEST OF NOUMEA, NEW CALEDONIA
MOVEMENT PAST 6 HOURS: EAST-SOUTHEASTWARD AT 18 KTS
SIGNIFICANT WAVE HEIGHT: 15 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A DEEP
CONVECTIVE BURST OBSCURING THE LOW-LEVEL CIRCULATION CENTER OF
TROPICAL CYCLONE (TC) 16P. THE LOW-LEVEL CIRCULATION CENTER (LLCC)
PEEKS OUT OF THE SOUTHWESTERN PERIPHERY OF THE DEEP CONVECTION. THE
LLCC APPEARS ELONGATED ON A NORTHWEST-SOUTHEAST AXIS. WATER VAPOR
IMAGERY REVEALS STRONG RADIAL OUTFLOW ALOFT VIA A POINT SOURCE. THE
INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE
AFOREMENTIONED ANIMATED MSI. THE INITIAL INTENSITY OF 40 KTS IS
ASSESSED WITH HIGH CONFIDENCE BASED ON A 102138Z METOP-B ASCAT
IMAGE DEPICTING 35-40KT WINDS IN THE NORTHEASTERN PERIPHERY OF THE
LLCC.

INITIAL WIND RADII BASIS: OBJECTIVE BEST TRACK

CURRENT STEERING MECHANISM: A NEAR EQUATORIAL RIDGE (NER) TO THE
NORTH

AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T1.0 - 25 KTS
PHFO: T2.5 - 35 KTS
CIMSS D-PRINT: 29 KTS AT 110000Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINAL
VWS: 20-25 KTS
SST: 26-27 CELSIUS
OUTFLOW: STRONG RADIAL

ANALYSIS CONFIDENCE:
INITIAL POSITION: HIGH
INITIAL INTENSITY: MEDIUM
INITIAL WIND RADII: LOW

3. FORECAST REASONING.

SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO
THE FORECAST FROM THE PREVIOUS WARNING.

FORECAST DISCUSSION: TC 16P WILL TRACK EAST-SOUTHEASTWARD FOR THE
REMAINDER OF THE FORECAST PERIOD WHILE UNDER THE STEERING INFLUENCE
OF A NEAR EQUATORIAL RIDGE TO THE NORTHEAST. THE SYSTEM WILL
CONTINUE TO EXIST IN AN ENVIRONMENT OF MODERATE TO HIGH SHEAR WHICH
WILL SLIGHTLY INHIBIT INTENSIFICATION. HOWEVER, STRONG OUTFLOW
ALOFT WILL ENCOURAGE INTENSIFICATION AND PROVIDE AND EXHAUST TO THE
SYSTEM, ALLOWING FOR A PEAK OF 45KTS BY TAU 24. THE SYSTEM WILL
GRADUALLY WEAKEN AS AN INCOMING UPPER-LEVEL TROUGH WILL INDUCE
UNFAVORABLE SHEAR AND DRY AIR WRAPPING INTO THE CIRCULATION. BY TAU
48, BAROCLINIC FORCING FROM THE TROUGH WILL INITIATE EXTRATROPICAL
TRANSITION. EXTRATROPICAL TRANSITION WILL COMPLETE AFTER THE SYSTEM
BECOMES FULLY FRONTAL AT TAU 72 AND PASSES OVER COOL SEA SURFACE
TEMPERATURES.

MODEL DISCUSSION: DETERMINISTIC MODEL GUIDANCE IS IN GOOD AGREEMENT
UNTIL TAU 48 WHEN THE TRACKS OPEN AND SPREAD WIDELY. THIS COULD BE
DUE TO THE SYSTEM BECOMING EMBEDDED WITHIN THE SOUTH PACIFIC
CONVERGENCE ZONE, OR DUE TO THE DIFFICULTY IN TRACKING THE SHALLOW
LOW. THE INTENSITY GUIDANCE IS IN GOOD AGREEMENT THAT THE SYSTEM
WILL INTENSIFY IN THE NEAR-TERM BEFORE WEAKENING AS EXTRATROPICAL
TRANSITION OCCURS.

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

[cycloneye]

TROPICAL DEPRESSION 07F CENTRE [998HPA] WAS ANALYSED NEAR 22.3S 163.0E [WEST OF
NEW CALEDONIA] AT 110600UTC. POSITION FAIR. TD07F MOVING SOUTHEAST AT ABOUT 10
KNOTS.

CONVECTION REMAINS PERSISTENT TO THE EAST OF EXPOSED LLCC WITH PRIMARY BAND
TRYING TO WRAP ONTO THE LLCC FROM THE NORTH. TD07F IS IN A HIGH SHEARED
ENVIRONMENT WITH STRONG UPPER DIVERGENCE WITH GOOD OUTFLOW TO THE SOUTHEAST OF
THE SYSTEM. SST IS AROUND 27 DEGREE CELSIUS.

THE SYSTEM INTERACTION WITH THE NEW CALEDONIA LAND MASS AS WELL AS THE COOLER
SST WILL POTENTIALLY HINDER FURTHER DEVELOPMENT. COOL AND DRY AIR CONTINUE TO
FEED INTO THE SYSTEM FROM THE SOUTHEAST. GLOBAL MODELS HAVE PICKED UP THE SYSTEM
AND MOVE IT SOUTHEASTWARDS WITH LITTLE INTENSIFICATION.

THE POTENTIAL FOR THIS SYSTEM TO DEVELOP INTO A TROPICAL CYCLONE IN THE NEXT 24
TO 48 HOURS IS LOW TO MODERATE.