
WTPN21 PGTW 010130
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
REF/A/JOINT TYPHOON WRNCEN PEARL HARBOR HI/310130Z OCT 17//
REF/B/JOINT TYPHOON WRNCEN PEARL HARBOR HI/312030Z OCT 17//
NARR/REF A IS TROPICAL CYCLONE FORMATION ALERT (WTPN21 PGTW 310130).
REF B IS TROPICAL CYCLONE FORMATION ALERT (WTPN22 PGTW 312030)//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
160 NM EITHER SIDE OF A LINE FROM 7.0N 108.1E TO 7.7N 102.8E
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 18 TO 23 KNOTS. METSAT
IMAGERY AT 010000Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 7.1N 107.3E. THE SYSTEM IS MOVING EAST-SOUTHEASTWARD AT 04
KNOTS.
2. REMARKS: AN AREA OF CONVECTION (INVEST 95W) HAS PERSISTED NEAR
7.1N 107.3E, 221 NM SSE OF HO CHI MINH CITY, VIETNAM. ANIMATED
ENHANCED INFRARED AND MULTISPECTRAL SATELLITE IMAGERY SHOWS FLARING
DEEP CONVECTION SHEARED TO THE WEST OF A PARTIALLY EXPOSED LOW LEVEL
CIRCULATION CENTER. A 311800Z GCOM 89 GHZ MICROWAVE IMAGE HIGHLIGHTS
THE SHEARED SEPARATION BETWEEN DEEP CONVECTION, CONCENTRATED IN THE
SOUTHWESTERN PORTION OF THE DISTURBANCE, AND LOW LEVEL FEATURES TO
THE NORTHEAST. UPPER-LEVEL ANALYSIS INDICATES A MARGINAL ENVIRONMENT
FOR DEVELOPMENT WITH DECREASING DIVERGENCE ALOFT, AS WINDS ALOFT ARE
MOSTLY EASTERLY OR SOUTHEASTERLY. VERTICAL WIND SHEAR HAS INCREASED
OVER THE DISTURBANCE AS WELL, WITH VALUES NOW RANGING FROM 10-20 KT.
LAND INTERACTION WITH VIETNAM MAY BE ALSO BE HINDERING THE
DISTURBANCES DEVELOPMENT CURRENTLY. SST VALUES ARE FAVORABLE, FROM
28-29C. OVER THE LAST 24 HOURS, 95W HAS BEEN CAUGHT IN A COMPETING
STEERING ENVIRONMENT AND REMAINED QUASI-STATIONARY, BUT MODELS AND
CONSENSUS STILL FORECAST IT TO ULTIMATELY PROPAGATE WESTWARD. GLOBAL
MODELS EITHER FORECAST SLIGHT INTENSIFICATION INTO A COMPACT
CIRCULATION, OR DISSIPATE THE DISTURBANCE ENTIRELY AS IT MOVES
WESTWARD OVER THE MALAY PENINSULA. 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 REMAINS HIGH.
THIS SUPERSEDES REF A.
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY
020130Z.