(3) AN AREA OF CONVECTION (INVEST 99P) HAS PERSISTED NEAR
13.5S 163.5E, APPROXIMATELY 371 NM NORTHWEST OF PORT VILA, VANUATU.
ANIMATED ENHANCED INFRARED SATELLITE IMAGERY AND A 291006Z MHS 89
GHZ MICROWAVE IMAGE DEPICT A CONSOLIDATING LOW LEVEL CIRCULATION
CENTER. ENVIRONMENTAL ANALYSIS SHOWS A MARGINALLY FAVORABLE
ENVIRONMENT WITH MODERATE VERTICAL WIND SHEAR (10-15 KTS), GOOD
EQUATORWARD OUTFLOW, AND WARM (28-30C) SEA SURFACE TEMPERATURES.
GLOBAL MODELS ARE IN GENERAL AGREEMENT THAT 99P WILL INTENSIFY AND
TRACK EASTWARD. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 20
TO 25 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 999
MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL
CYCLONE WITHIN THE NEXT 24 HOURS IS LOW
TROPICAL DISTURBANCE TD07F [1000HPA] WAS LOCATED NEAR 14.2S 162.9E AT
291200 UTC. TD07F SLOW MOVING. POSITION POOR BASED ON HIMAWARI-8 AND
IR IMAGERY AND PERIPHERY SURFACE REPORTS.
THE SYSTEM LIES IN A LOW TO MODERATE SHEARED ENVIRONMENT WITH DEEP
CONVECTION OVER THE NORTH OF SUPPOSED LLCC. THE SYSTEM IS LOCATED TO
THE SOUTH OF AN UPPER RIDGE WITH GOOD EQUATOWARD AND POLEWARD OUT
FLOW AND UPPER DIVERGENCE. SST IS AROUND 29 TO 30 DEGREE CELSIUS.
GLOBAL MODELS ARE MOVING THE SYSTEM EASTWARDS WITH FURTHER DEEPENING
AS IT MOVES TOWARDS FAVOURABLE ENVIRONMENT.
POTENTIAL FOR THIS SYSTEM TO DEVELOP INTO A TROPICAL CYCLONE IN THE
NEXT 12 TO 24 HOURS IS LOW TO MODERATE AND THEN MODERATE TO HIGH
(2) THE AREA OF CONVECTION (INVEST 99P) PREVIOUSLY LOCATED
NEAR 12.9S 163.9E IS NOW LOCATED NEAR 12.6S 165.9E, APPROXIMATELY
336 NM NORTH-NORTHWEST OF PORT VILA, VANUATU. ANIMATED MULTISPECTRAL
SATELLITE IMAGERY AND A 292325Z GMI 89 GHZ MICROWAVE IMAGE DEPICT
FORMATIVE BANDING WRAPPING INTO A CONSOLIDATING LOW LEVEL
CIRCULATION CENTER. ENVIRONMENTAL ANALYSIS SHOWS A MARGINALLY
FAVORABLE ENVIRONMENT WITH MODERATE (20KTS) VERTICAL WIND SHEAR,
FAIR OUTFLOW ALOFT, AND WARM (29-30C) SEA SURFACE TEMPERATURES.
GLOBAL MODELS ARE IN GENERAL AGREEMENT THAT 99P WILL TRACK EASTWARD
WITH STEADY INTENSIFICATION OVER THE NEXT 24 HOURS. MAXIMUM
SUSTAINED SURFACE WINDS ARE ESTIMATED AT 20 TO 25 KNOTS. MINIMUM SEA
LEVEL PRESSURE IS ESTIMATED TO BE NEAR 999 MB. THE POTENTIAL FOR THE
DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24
HOURS IS UPGRADED TO MEDIUM.
WTPS22 PGTW 301700
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 99P)//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
165 NM EITHER SIDE OF A LINE FROM 11.9S 168.8E TO 15.1S 175.7E
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 25 TO 30 KNOTS. METSAT
IMAGERY AT 301200Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 11.9S 169.3E. THE SYSTEM IS MOVING SOUTHEASTWARD AT 17
KNOTS.
2. REMARKS: THE AREA OF CONVECTION (INVEST 99P) PREVIOUSLY LOCATED
NEAR 13.0S 168.8E IS NOW LOCATED NEAR 11.9S 169.3E, APPROXIMATELY
586NM NORTHWEST OF NADI, FIJI. ANIMATED ENHANCED INFRARED SATELLITE
IMAGERY AND A 301406Z AMSR2 89 GHZ MICROWAVE IMAGE DEPICT CONVECTIVE
BANDING WRAPPING INTO A WELL DEFINED LOW LEVEL CIRCULATION CENTER
(LLCC). A PARTIAL 301037Z ASCAT-C PASS INDICATES A TIGHT LLCC WITH
25-30KT WINDS IN THE NORTHERN PERIPHERY. ENVIRONMENTAL ANALYSIS
SHOWS FAVORABLE ENVIRONMENT FOR TROPICAL DEVELOPMENT WITH GOOD
RADIAL OUTFLOW ALOFT, LOW (10-15KTS) VERTICAL WIND SHEAR, AND WARM
(30-31C) SEA SURFACE TEMPERATURES. GLOBAL MODELS ARE IN GENERAL
AGREEMENT THAT 99P WILL TRACK SOUTHEASTWARD WITH STEADY
INTENSIFICATION OVER THE NEXT 24 HOURS. MAXIMUM SUSTAINED SURFACE
WINDS ARE ESTIMATED AT 25 TO 30 KNOTS. MINIMUM SEA LEVEL PRESSURE IS
ESTIMATED TO BE NEAR 998 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
311700Z.
//
NNNN
TROPICAL DISTURBANCE TD07F [998HPA] WAS LOCATED NEAR 12.9S 166.0E AT
300300UTC. TD07F SLOW MOVING. POSITION POOR BASED ON HIMAWARI-8 AND
IR IMAGERY AND PERIPHERY SURFACE REPORTS.
THE SYSTEM LIES IN A LOW TO MODERATE SHEARED ENVIRONMENT WITH DEEP
CONVECTION OVER THE NORTH OF SUPPOSED LLCC. THE SYSTEM IS LOCATED TO
THE NORTH OF AN UPPER RIDGE WITH MODERATE UPPER DIVERGENCE. SST IS
AROUND 28 TO 29 DEGREE CELSIUS.
GLOBAL MODELS ARE MOVING THE SYSTEM EASTWARDS INTO FAVOURABLE
ENVIRONMENT WITH FURTHER DEEPENING AS IT MOVES TOWARDS FAVOURABLE
ENVIRONMENT.
POTENTIAL FOR THIS SYSTEM TO DEVELOP INTO A TROPICAL CYCLONE IN THE
NEXT 12 TO 24 HOURS IS LOW TO MODERATE AND THEN MODERATE TO HIGH.