99W TCFA - 颱風討論

WTPN21 PGTW 250600 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/
TROPICAL CYCLONE FORMATION ALERT (INVEST 99W)// RMKS/

1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN 140 NM EITHE
R SIDE OF A LINE FROM 9.6N 138.3E TO 13.4N 131.4E WITHIN THE NEXT 12 TO 24 HOU
RS. AVAILABLE DATA DOES NOT JUSTIFY ISSUANCE OF NUMBERED TROPICAL CYCLONE WARN
INGS AT THIS TIME. WINDS IN THE AREA ARE ESTIMATED TO BE 20 TO 25 KNOTS. METSA
T IMAGERY AT 250530Z INDICATES THAT A CIRCULATION CENTER IS LOCATED NEAR 10.0N
138.0E. THE SYSTEM IS MOVING NORTHWESTWARD AT 11 KNOTS.

2. REMARKS: THE AREA OF CONVECTION (INVEST 99W) PREVIOUSLY LOCATED NEAR 7.9N 1
39.5E, IS NOW LOCATED NEAR 10.0N 138.0E, APPROXIMATELY 30 NM NORTH-NORTHWEST O
F YAP. ANIMATED MULTISPECTRAL SATELLITE IMAGERY AND A 242353Z MHS 89GHZ MICROW
AVE IMAGE DEPICT A BROAD LOW LEVEL CIRCULATION WITH FLARING CONVECTION OVER TH
E WESTERN SEMICIRCLE. A 250035Z PARTIAL ASCAT-C IMAGE SHOWS 20-25 KNOT WINDS O
VER THE EASTERN SEMICIRCLE. UPPER LEVEL ANALYSIS REVEALS A MARGINALLY FAVORABL
E ENVIRONMENT WITH MODERATE TO HIGH (20-25 KNOTS) VERTICAL WIND SHEAR OFFSET B
Y STRONG DIFFLUENCE ALOFT. GLOBAL MODELS ARE IN GOOD AGREEMENT SHOWING 99W TRA
CKING WEST-NORTHWESTWARD TOWARD LUZON WITH SLOW CONSOLIDATION OVER THE NEXT TW
O DAYS. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 20 TO 25 KNOTS. MINIM
UM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1004 MB. THE POTENTIAL FOR THE D
EVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS HIGH.


3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY 260600Z.//
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https://www.metoc.navy.mil/jtwc/products/wp9919web.txt

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