WTPS22 PGTW 100500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
140 NM EITHER SIDE OF A LINE FROM 13.7S 169.6E TO 17.5S 172.7E
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 AND SYNOPTIC DATA AT 100000Z INDICATE THAT A CIRCULATION
CENTER IS LOCATED NEAR 14.1S 170.0E. THE SYSTEM IS MOVING
SOUTHEASTWARD AT 07 KNOTS.
2. REMARKS: THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 14.1S
170.0E IS NOW LOCATED NEAR 14.1S 170.0E, APPROXIMATELY 480 NM WEST-
NORTHWEST OF NADI, FIJI. RECENT ANIMATED MULTISPECTRAL SATELLITE
IMAGERY REVEALS IMPROVED, DEEP CONVECTIVE BANDING WRAPPING INTO A
WELL-DEFINED LOW-LEVEL CIRCULATION CENTER (LLCC). A 100216Z GPM 36
GHZ IMAGE ALSO DEPICTS A CONSOLIDATING LLCC WITH GOOD SPIRAL BANDING
WRAPPING IN FROM THE NORTH. RECENT SCATTEROMETRY DATA SHOWS 25 TO 30
KNOT WINDS ALONG THE SOUTHERN PERIPHERY WHICH IS IN LINE WITH LATEST
DVORAK INTENSITY ESTIMATES RANGING FROM T1.5-2.0. UPPER LEVEL
ANALYSIS SHOWS A FAVORABLE ENVIRONMENT FOR DEVELOPMENT WITH NEAR
RADIAL OUTFLOW AND LOW-MODERATE (10 TO 20 KNOTS) VERTICAL WIND
SHEAR. GLOBAL MODEL GUIDANCE IS IN GOOD AGREEMENT ON THE DEVELOPMENT
OF THE SYSTEM OVER THE NEXT 24 TO 36 HOURS. MAXIMUM SUSTAINED
SURFACE WINDS ARE ESTIMATED AT 25 TO 30 KNOTS. MINIMUM SEA LEVEL
PRESSURE IS ESTIMATED TO BE NEAR 1000 MB. BASED ON THE CONSOLIDATING
LLCC AND FAVORABLE UPPER LEVEL CONDITIONS, 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
110500Z.//
NNNN
(2) THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 11.8S
168.2E IS NOW LOCATED NEAR 14.1S 170.0E, APPROXIMATELY 470 NM EAST-
SOUTHEAST OF HONIARA, SOLOMON ISLANDS. RECENT ANIMATED MULTISPECTRAL
SATELLITE IMAGERY SHOWS CONVECTIVE BANDING DEVELOPING AROUND A
STRENGTHENING LLCC EVIDENT IN A 092132Z ASCAT PASS. UPPER LEVEL
ANALYSIS INDICATES A FAVORABLE ENVIRONMENT FOR CONTINUED
DEVELOPMENT, WITH LIGHT-MODERATE (10 TO 20 KNOTS) VERTICAL WIND
SHEAR AND FAVORABLE WESTWARD AND POLEWARD OUTFLOW ALOFT. GLOBAL
MODELS PREDICT CONTINUED DEVELOPMENT OF THIS SYSTEM OVER THE NEXT 24
TO 48 HOURS. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 25 TO
30 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1000
MB. BASED ON THE CONSOLIDATING LLCC AND FAVORABLE UPPER LEVEL
CONDITIONS, THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT
TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS UPGRADED TO MEDIUM.
Tropical Disturbance Summary For area Equator to 25S, 160E to 120W
ISSUED FROM RSMC NADI Feb 092336 UTC.
TROPICAL DISTURBANCE 09F [1001HPA] WAS ANALYSED NEAR 15.0S 168.8E AT
092100UTC, MOVING S AT 10 KNOTS. POSITION POOR BASED ON VIS/IR
IMAGERY WITH ANIMATION AND PERIPHERAL OBSERVATIONS. SST AROUND AROUND
29 DEGREES CELCIUS.
CONVECTION REMAINS PERSISTENT. ORGANIZATION POOR. CYCLONIC
CIRCULATION EXTENDS UPTO 700HPA. SYSTEM LIES UNDER AN UPPER RIDGE IN
A LOW SHEARED ENVIRONMENT.
MOST GLOBAL MODELS HAVE PICKED UP THE SYSTEM AND MOVE IT
SOUTHEASTWARDS WITH GRADUAL INTENSIFICATION.
POTENTIAL FOR TD09F TO DEVELOP INTO A TROPICAL CYCLONE IN THE NEXT 24
TO 48 HOURS IS MODERATE.
NO OTHER SIGNIFICANT TROPICAL DISTURBANCE ANALYSED OR FORECAST IN THE
AREA.
(2) AN AREA OF CONVECTION (INVEST 98P) HAS PERSISTED NEAR 9.4S
167.9E, APPROXIMATELY 470 NM EAST OF HONIARA, SOLOMON ISLANDS.
ANIMATED ENHANCED INFRARED SATELLITE IMAGERY DEPICTS A BROAD LOW
LEVEL CIRCULATION CENTER (LLCC) WITH DEEP FLARING CONVECTION
CONSOLIDATING INTO BANDS CONVERGING TOWARDS THE LLCC. A 081001Z
ASCAT PASS CONFIRMS THE LLCC HAS CONSOLIDATED FROM AN AREA OF
TROUGHING OVER THE PAST 12 HOURS, WITH A LARGE SWATH OF 15-20 KNOT
WINDS ON THE NORTHERN SIDE OF THE LLCC. THE UPPER LEVEL ENVIRONMENT
IS MARGINAL WITH MODERATE (15 TO 20 KNOTS) VERTICAL WIND SHEAR (VWS)
BEING OFFSET BY GOOD RADIAL OUTFLOW. GLOBAL MODELS ARE IN GOOD
AGREEMENT ON THE DEVELOPMENT OF THIS SYSTEM. MAXIMUM SUSTAINED
SURFACE WINDS ARE ESTIMATED AT 20 TO 25 KNOTS. MINIMUM SEA LEVEL
PRESSURE IS ESTIMATED TO BE NEAR 1005 MB. THE POTENTIAL FOR THE
DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24
HOURS IS LOW.
Tropical Disturbance Summary For area Equator to 25S, 160E to 120W
ISSUED FROM RSMC NADI Feb 072320 UTC.
TROPICAL DISTURBANCE 09F [1005HPA] ANALYSED NEAR 8.4S 170.6E AT
072100UTC SLOW MOVING. POSITION BASED ON IR IMAGERY WITH ANIMATION
AND PERIPHERAL OBSERVATIONS. SST AROUND AROUND 30 DEGREES CELCIUS.
CONVECTION REMAINS PERSISTENT, HOWEVER, ORGANIZATION IS POOR.
CONVECTION IS DISPLACED TO THE NORTHWEST OF THE SUPPOSED LLCC.
CYCLONIC CIRCULATION EXTENDS FROM THE SURFACE UP TO 500HPA. TD09F
LIES IN A LOW SHEARED ENVIRONMENT. OUTFLOW GOOD TO THE NORTHWEST AND
SOUTH BUT RESTRICTED ELSEWHERE.
MOST GLOBAL MODELS HAVE PICKED UP THE SYSTEM AND ARE MOVING IT
SOUTHEAST WITH GRADUAL INTENSIFICATION.
POTENTIAL FOR TD09F TO DEVELOP INTO A TROPICAL CYCLONE IN THE NEXT 24
TO 48 HOURS IS LOW.
NO OTHER SIGNIFICANT TROPICAL DISTURBANCE ANALYSED OR FORECAST IN THE
AREA.
