30W形成 - 颱風討論

TROPICAL DEPRESSION 30W (THIRTY), LOCATED APPROXIMATELY 531 NM SOUTHEAST OF AN
DERSEN AFB, HAS TRACKED WESTWARD AT 18 KNOTS OVER THE PAST SIX HOURS. ANIMATED
MULTISPECTRAL SATELLITE IMAGERY SHOWS A PARTIALLY EXPOSED CONSOLIDATING LOW L
EVEL CIRCULATION CENTER (LLCC) UNDER A BROAD PERSISTENT AREA OF CONVECTION THA
T ALSO FEATURES AN EQUATORWARD OUTFLOW TAIL. THE INITIAL POSITION IS PLACED WI
TH FAIR CONFIDENCE BASED ON THE MSI LOOP AND A 272220Z AMSU 89GHZ IMAGE. THE I
NITIAL INTENSITY OF 25 KTS IS BASED ON THE PGTW DVORAK ESTIMATE OF T1.5 (25 KT
S), AND IS BELOW THE KNES ESTIMATE OF T2.0 (30 KTS). ENVIRONMENTAL ANALYSIS RE
VEALS MOSTLY EASTERLY DIFFLUENCE ALOFT WITH A SMALL POINT SOURCE DEVELOPING OV
ER TOP OF THE SYSTEM. 30W IS LOCATED ON THE BORDER OF MODERATE TO STRONG (15-2
0 KTS) VERTICAL WIND SHEAR (VWS) WHICH HAS BEEN DELAYING CONSOLIDATION. SEA SU
RFACE TEMPERATURES REMAIN FAVORABLE, BETWEEN 28 AND 29 DEGREES CELSIUS. TD 30W
IS MOVING WESTWARD UNDER THE SUBTROPICAL RIDGE (STR) TO ITS NORTH.

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