WTPN21 PGTW 260900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 97W)//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
210 NM EITHER SIDE OF A LINE FROM 18.3N 159.7E TO 25.1N 155.8E
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 15 TO 20 KNOTS. METSAT
IMAGERY AT 260600Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 19.2N 159.7E. THE SYSTEM IS MOVING NORTHWARD AT 08 KNOTS.
2. REMARKS: THE AREA OF CONVECTION (INVEST 97W) PREVIOUSLY LOCATED
NEAR 18.9N 160.2E IS NOW LOCATED NEAR 19.2N 159.7E, APPROXIMATELY
391 NM WEST OF WAKE ISLAND. ANIMATED MULTISPECTRAL SATELLITE IMAGERY
DEPICTS A BROAD LOW LEVEL CIRCULATION (LLC) WITH PERSISTENT
CONVECTION IN THE SOUTHERN AND EASTERN SEMICIRCLES. A 260742Z SSMIS
91GHZ IMAGE REVEALS FORMATIVE BANDING IN THE SOUTHERN QUADRANT
WRAPPING INTO THE EASTERN QUADRANT OF THE LLC. UPPER LEVEL ANALYSIS
REVEALS A MARGINALLY FAVORABLE ENVIRONMENT WITH A POINT SOURCE OVER
THE SYSTEM CENTER ENHANCING UPPER LEVEL DIFFLUENCE OFFSET BY AN
UPPER LEVEL LOW HINDERING CONVECTION OVER THE NORTHWESTERN
SEMICIRCLE. INVEST 97W IS EXPERIENCING LOW (<15KTS) VERTICAL WIND
SHEAR AND WARM (30-31C) SEA SURFACE TEMPERATURES. GLOBAL MODELS ARE
IN GOOD AGREEMENT THAT 97W WILL TRACK GENERALLY NORTH-NORTHWESTWARD
WHILE CONTINUING TO SLOWLY CONSOLIDATE; HOWEVER, THE UPPER LEVEL LOW
MAY HINDER CONVECTIVE DEVELOPMENT OVER THE WESTERN SEMICIRCLE.
MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 15 TO 20 KNOTS.
MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1006 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
270900Z.//
NNNN
THE AREA OF CONVECTION (INVEST 97W) PREVIOUSLY LOCATED
NEAR 18.8N 158.2E IS NOW LOCATED NEAR 18.9N 160.2E, APPROXIMATELY
365 NM WEST OF WAKE ISLAND. ANIMATED MULTISPECTRAL SATELLITE IMAGERY
DEPICTS A CONSOLIDATING LOW LEVEL CIRCULATION (LLC) WITH FLARING
CONVECTION IN THE SOUTHWESTERN SEMICIRCLE. A 260248Z 88.2GHZ ATMS
IMAGE REVEALS FORMATIVE BANDING WRAPPING INTO THE LLC. UPPER LEVEL
ANALYSIS REVEALS A MARGINALLY FAVORABLE ENVIRONMENT WITH A POINT
SOURCE OVER THE SYSTEM CENTER ENHANCING UPPER LEVEL DIFFLUENCE
OFFSET BY AN UPPER LEVEL LOW HINDERING CONVECTION OVER THE
NORTHWESTERN SEMICIRCLE. INVEST 97W IS EXPERIENCING LOW (<15KTS)
VERTICAL WIND SHEAR AND WARM (30-31C) SEA SURFACE TEMPERATURES.
GLOBAL MODELS ARE IN GOOD AGREEMENT THAT 97W WILL TRACK GENERALLY
NORTH-NORTHWESTWARD WHILE CONTINUING TO INTENSIFY. MAXIMUM SUSTAINED
SURFACE WINDS ARE ESTIMATED AT 15 TO 20 KNOTS. MINIMUM SEA LEVEL
PRESSURE IS ESTIMATED TO BE NEAR 1006 MB. THE POTENTIAL FOR THE
DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24
HOURS IS UPGRADED TO MEDIUM.
AN AREA OF CONVECTION (INVEST 97W) HAS PERSISTED NEAR
18.8N 158.2E, APPROXIMATELY 848 NM EAST-NORTHEAST OF GUAM. ANIMATED
MULTISPECTRAL SATELLITE IMAGERY DEPICTS A VERY BROAD, ASYMMETRIC LOW
LEVEL CIRCULATION (LLC) WITH A LARGE AREA OF FLARING DEEP CONVECTION
TO THE SOUTH. THIS IS REFLECTED IN A 252028Z SSMIS 91GHZ MICROWAVE
IMAGE, REVEALING A DISTINCT LACK OF CONVECTION OVER THE LLC AND
FRAGMENTED DEEP CONVECTION RELEGATED TO THE SOUTHERN PERIPHERY. A
252252Z METOP-B ASCAT PASS SHOWS A CONFUSED, WEAK WIND FIELD WITH NO
DISTINCT CIRCULATION AND A LARGE SWATH OF 15 TO 20 KNOT WINDS
EXTENDING TO THE NORTH-EAST. 97W IS CURRENTLY EXPERIENCING A
FAVORABLE ENVIRONMENT WITH EXCELLENT EQUATORWARD OUTFLOW, LOW (5 TO
10 KNOT) VERTICAL WIND SHEAR, AND WARM (30 TO 31 CELSIUS) SEA
SURFACE TEMPERATURES. GLOBAL MODELS ARE IN GOOD AGREEMENT THAT 97W
WILL TRACK GENERALLY NORTHWARD WHILE INTENSIFYING. 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.
