Subject: Pacific-NW: Ampn/ref A Is A Tropical Cyclone Formation Alert.//

From: SIU Weather Processor <[email-masked]>
Date: Tue, 21 Sep 2010 04:50:08 -0500

WTPN21 PGTW 211000
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE FORMATION ALERT REISSUED//
REF/A/MSG/NAVMARFCSTCEN PEARL HARBOR HI/200530ZSEP2010//
AMPN/REF A IS A TROPICAL CYCLONE FORMATION ALERT.//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
120 NM EITHER SIDE OF A LINE FROM 21.3N 109.2W TO 25.1N 111.7W
WITHIN THE NEXT 06 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
200600Z INDICATES THAT A CIRCULATION CENTER IS LOCATED NEAR 21.5N
109.3W.  THE SYSTEM IS MOVING NORTH-NORTHWESTWARD AT 07 KNOTS.
2. REMARKS: THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 19.0N
107.5E IS NOW LOCATED NEAR 21.5N 109.3E, APPROXIMATELY 90 NM SOUTH-
SOUTHEAST OF CABO SAN LUCAS, MEXICO. PREVIOUS MULTISPECTRAL
SATELLITE IMAGERY AND A 210434Z TRMM MICROWAVE IMAGE REVEALED A WELL-
DEFINED LOW LEVEL CIRCULATION CENTER (LLCC) WITH VERY LITTLE CENTRAL
CONVECTION. HOWEVER, RECENT ANIMATED INRARED SATELLITE IMAGERY
DEPICTS INCREASING CENTRAL CONVECTION, THOUGH IT IS STILL SOMEWHAT
DISORGANIZED. NEVERTHELESS, THE SYSTEM IS SITTING JUST EQUATORWARD
OF AN UPPER-LEVEL ANTICYCLONE IN AN AREA OF LOW VERTICAL WIND SHEAR
AND FAVORABLE DIFFLUENCE ALOFT. MAXIMUM SUSTAINED SURFACE WINDS ARE
ESTIMATED AT 18 TO 22 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED
TO BE NEAR 1006 MB. BASED ON A GOOD LOW LEVEL SIGNATURE IN MICROWAVE
IMAGERY AND INCREASING DEEP CONVECTION, THE POTENTIAL FOR THE
DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24
HOURS REMAINS GOOD. THIS SUPERSEDES REF A.
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY
221000Z.//

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
To unsubscribe from WX-TROPL send e-mail to [email-masked] with
"unsub wx-tropl" in the body of your message. For help with WX-TROPL
write to [email-masked]. For more information on tropical weather products, see the NHC Homepage at http://www.nhc.noaa.gov.