
WTXS21 PGTW 020700
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
140 NM EITHER SIDE OF A LINE FROM 15.0S 68.1E TO 16.2S 63.1E
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 23 TO 28 KNOTS. METSAT IM-
AGERY AT 020630Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 15.1S 67.6E. THE SYSTEM IS MOVING WESTWARD AT 10 KNOTS.
2. REMARKS: THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 15.6S
69.1E IS NOW LOCATED NEAR 15.1S 67.6E, APPROXIMATELY 780 NM EAST-
NORTHEAST OF LA REUNION ISLAND. ANIMATED MULTI-SPECTRAL SATELLITE
IMAGERY DEPICTS A CONSOLIDATING LOW-LEVEL CIRCULATION CENTER (LLCC)
WITH FORMATIVE CONVECTIVE BANDING OVER THE WESTERN SEMI-CIRCLE. THIS
IS CONFIRMED BY A 020152Z SSMI 37GHZ IMAGE WHICH SHOWS AN IMPROVED
LLCC WITH DEEP CONVECTION BUILDING ON THE WESTERN PORTION OF THE
DISTURBANCE. OUTFLOW IS EXPECTED TO CONTINUE IMPROVING DUE TO A
DEVELOPING ANTICYCLONE NEAR THE CENTER, AND AN APPROACHING SHORTWAVE
TROUGH LOCATED SOUTHWEST OF THE SYSTEM THAT WILL MOVE EAST AND
FURTHER ENHANCE OUTFLOW OVER THE NEXT 12 TO 18 HOURS. OVERALL, THE
ENVIRONMENT HAS IMPROVED, HOWEVER MODERATE VERTICAL WIND SHEAR (VWS)
CONTINUES TO LIMIT THE RATE OF DEVELOPMENT. THE SYSTEM WILL LIKELY
DEVELOP SLOWLY OVER THE NEXT 24 TO 48 HOURS AS IT TRACKS WEST-
SOUTHWESTWARD UNDER THESE GENERALLY FAVORABLE CONDITIONS. MAXIMUM
SUSTAINED SURFACE WINDS ARE ESTIMATED AT 23 TO 28 KNOTS. MINIMUM SEA
LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1004 MB. BASED ON THE
IMPROVED CONSOLIDATION AND OUTFLOW, THE POTENTIAL FOR THE
DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24
HOURS IS GOOD.
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY
030700Z.