WTPN21 PGTW 282130
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
145 NM EITHER SIDE OF A LINE FROM 10.6N 118.1E TO 12.5N 112.3E
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 18 TO 23 KNOTS. METSAT
IMAGERY AT 281800Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 10.8N 117.5E. THE SYSTEM IS MOVING NORTHWESTWARD AT 08
KNOTS.
2. REMARKS:
REMARKS: THE AREA OF CONVECTION (INVEST 98W) PREVIOUSLY LOCATED NEAR
10.2N 118.1E IS NOW LOCATED NEAR 10.8N 117.5E, APPROXIMATELY 95 NM
NORTHWEST OF PUERTO PRINCESA, PALAWAN, PHILIPPINES. ANIMATED
ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A BROAD LOW-LEVEL
CIRCULATION (LLC) WITH FLARING CONVECTION TO THE NORTHWEST. A
281806Z ATMS IMAGE HIGHLIGHTS THE SAME AREA OF CONVECTION TO THE
NORTHWEST OF A POORLY DEFINED LLC. THE INITIAL POSITION IS PLACED
WITH LOW CONFIDENCE DUE TO HIGH CLOUDS OBSCURING THE LOW-LEVELS ON
EIR AND LOW RESOLUTION OF THE RECENT USABLE MICROWAVE IMAGES. A
281253Z ASCAT-C PASS TO THE EAST OF THIS CIRCULATION SHOWS 15 KNOTS
NEAR THE CIRCULATION, SUPPORTING THE INITIAL ESTIMATE OF 18 TO 23
KNOTS. UPPER-LEVEL ANALYSIS REVEALS A MARGINALLY FAVORABLE
ENVIRONMENT WITH LOW VERTICAL WIND SHEAR (VWS) AND DECENT OUTFLOW ON
THE WESTERN SIDE. NUMERICAL WEATHER PREDICTION MODELS INDICATE
DEVELOPMENT TO A TROPICAL DEPRESSION OVER THE NEXT 12-24 HOURS AS
THE SYSTEM TRACKS WEST-NORTHWESTWARD. HOWEVER, ALL MODELS
SIGNIFICANTLY FAVOR STRONGER WINDS TO THE NORTHEAST OF THE
CIRCULATION THROUGHOUT ITS LIFE-CYCLE DUE TO A TIGHTENED PRESSURE
GRADIENT OVER THE SOUTH CHINA SEA AND 25 KNOT WINDS ARE NOT FORECAST
TO FULLY WRAP AROUND THE SYSTEM FOR 24-48 HOURS. MAXIMUM SUSTAINED
SURFACE WINDS ARE ESTIMATED AT 18 TO 23 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 HIGH.
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY
292130Z.//
NNNN
(1) THE AREA OF CONVECTION (INVEST 98W) PREVIOUSLY LOCATED
NEAR 7.5N 127.2E, IS NOW LOCATED NEAR 8.7N 117.7E, APPROXIMATELY 89
NM SOUTHWEST OF PUERTA PRINCESA, PHILIPPINES. ANIMATED MULTISPECTRAL
SATELLITE IMAGERY, ALONG WITH A 280111Z MHS METOP-A 89GHZ MICROWAVE
IMAGE, SHOWS VERY LITTLE INDICATION OF A LOW LEVEL CIRCULATION (LLC)
AND MINIMAL OVERHEAD CONVECTION. 98W IS CURRENTLY IN AN UNFAVORABLE
ENVIRONMENT FOR DEVELOPMENT WITH GOOD EQUATORWARD OUTFLOW, LOW
VERTICAL WIND SHEAR (5 TO 15 KNOT), AND WARM (28 TO 29 CELSIUS) SEA
SURFACE TEMPERATURES BEING OFFSET BY LAND INTERACTION WITH THE
PHILIPPINES. GLOBAL MODELS ARE IN VERY GOOD AGREEMENT THAT 98W WILL
TRACK WESTWARD AND BEGIN TO INTENSIFY AFTER CROSSING INTO THE SOUTH
CHINA SEA. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 15 TO 20
KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1004 MB.
THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE
WITHIN THE NEXT 24 HOURS IS UPGRADED TO MEDIUM.
(1) AN AREA OF CONVECTION (INVEST 98W) HAS PERSISTED NEAR 7.5N
127.2E, APPROXIMATELY 98 NM EAST OF DAVAO, PHILIPPINES. ANIMATED
MULTISPECTRAL SATELLITE IMAGERY, ALONG WITH A 270106Z MHS METOP-B
89GHZ MICROWAVE IMAGE, SHOWS NO INDICATION OF A LOW LEVEL
CIRCULATION (LLC) WITH MINIMAL OVERHEAD CONVECTION. A 270033Z METOP-
C ASCAT PARTIAL PASS DEPICTS SIGNS OF A WEAK, ELONGATED LLC WITH A
COUPLE ISOLATED 15 KNOT WIND BARBS. 98W IS CURRENTLY IN AN
UNFAVORABLE ENVIRONMENT FOR DEVELOPMENT WITH GOOD EQUATORWARD
OUTFLOW, LOW VERTICAL WIND SHEAR (10 TO 15 KNOT), AND WARM (28 TO 29
CELSIUS) SEA SURFACE TEMPERATURES BEING OFFSET BY LAND INTERACTION
WITH THE PHILIPPINES. GLOBAL MODELS ARE IN VERY GOOD AGREEMENT THAT
98W WILL TRACK WESTWARD AND WILL BEGIN TO INTENSIFY AFTER CROSSING
INTO THE SOUTH CHINA SEA. MAXIMUM SUSTAINED SURFACE WINDS ARE
ESTIMATED AT 10 TO 15 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 IS LOW.
