WTPN21 PGTW 050330

MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//

SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 93W)//

RMKS/

1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN

115 NM EITHER SIDE OF A LINE FROM 7.7N 149.8E TO 8.0N 146.0E

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 050000Z INDICATES THAT A CIRCULATION CENTER IS LOCATED

NEAR 7.7N 149.7E. THE SYSTEM IS MOVING WEST-NORTHWESTWARD AT 03

KNOTS.

2. REMARKS: THE AREA OF CONVECTION (INVEST 93W) PREVIOUSLY

LOCATED NEAR 7.6N 150.0E IS NOW LOCATED NEAR 7.7N 149.7E,

APPROXIMATELY 130 NM WEST OF CHUUK. ANIMATED MULTISPECTRAL

SATELLITE IMAGERY (MSI) DEPICTS AN OBSCURED LOW-LEVEL

CIRCULATION CENTER (LLCC) WITH DEEP CONVECTION BUILDING

OVER THE CENTER AND INCREASING FORMATIVE BANDING EXTENDING

FROM THE NORTHERN QUADRANT CYCLONICALLY INTO THE EASTERN SEMICIRCLE.

ENVIRONMENTAL ANALYSIS DEPICTS A VERY FAVORABLE ENVIRONMENT FOR

CONTINUED DEVELOPMENT, WITH GOOD UPPER-LEVEL OUTFLOW PROVIDED BY

AN ANTICYCLONE ALOFT, LOW VERTICAL WIND SHEAR OF LESS THAN 15 KTS,

AND WARM SEA SURFACE TEMPERATURES BETWEEN 29-30 C. GLOBAL

DETERMINISTIC AND ENSEMBLE MODELS ARE IN GOOD AGREEMENT THAT

93W WILL TRACK WESTWARD OVER THE NEXT 24-36 HOURS AS IT GRADUALLY

INTENSIFIES, HOWEVER, THE DEVELOPMENT TIMELINE DIFFERS SLIGHTLY

BETWEEN ENSEMBLE AND DETERMINISTIC SOLUTIONS. ENSEMBLE MODELS ARE

IN FAVOR OF A MORE RAPID AND INTENSE CONSOLIDATION, WHEREAS

DETERMINISTIC MODELS INTENSIFY THE SYSTEM GRADUALLY AS IT APPROACHES

THE PHILIPPINE SEA. ADDITIONALLY, GFS AND ECMWF DETERMINISTIC

SOLUTIONS CONTINUE TO CHARACTERIZE DRY AIR AND INCREASING VERTICAL

WIND SHEAR AS SIGNIFICANT LIMITING FACTORS THROUGHOUT THE SYSTEMS

WESTWARD TRACK SOUTH OF THE MARIANAS. 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 CYCLONEWITHIN THE NEXT 24 HOURS IS UPGRADED TO

HIGH. 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

060330Z.

//

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