From Mike Powell@1:2320/107 to All on Sat Sep 19 15:52:52 2026
WTPN22 PHNC 190600
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT(INVEST 99E)//
REF/A/JOINT TYPHOON WRNCEN PEARL HARBOR HI/180721Z SEP 26//
AMPN/REF A IS A TROPICAL CYCLONE FORMATION ALERT (WTPN21 PHNC
180730)//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
120 NM EITHER SIDE OF A LINE FROM 8.2N 105.7W TO 14.6N 105.6W
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 190900Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 8.4N 105.7W. THE SYSTEM IS MOVING NORTH-NORTHWESTWARD AT 08
KNOTS.
2. REMARKS: THE AREA OF CONVECTION (INVEST 99E) IS LOCATED NEAR 8.4N
105.7W, APPROXIMATELY 691 NM SOUTH-SOUTHEAST OF SOCORRO. ENHANCED
INFRARED SATELLITE IMAGERY (EIR) DEPICTS A BROAD LOW LEVEL CIRCULATION
CENTER (LLCC) WITH DISORGANIZED CONVECTION ASSOCIATED WITH 99E.
ENVIRONMENTAL ANALYSIS REVEALS MODERATE TO FAVORABLE CONDITIONS FOR DEVELOPMENT WITH LOW TO MODERATE VERTICAL WIND SHEAR (15-20 KNOTS),
GOOD OUTFLOW ALOFT, AND WARM (28-29C) SEA SURFACE TEMPERATURES. GLOBAL FORECAST MODELS ARE IN STRONG CONSENSUS REGARDING THE STEADY
INTENSIFICATION OF INVEST 99E OVER THE NEXT 48 HOURS. HOWEVER BOTH
ECMWF AND GFS SHOW ERRATIC MOVEMENT BEFORE THE SYSTEM IS SET ON A NORTHWESTWARD TRACK. 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
200600Z.
4. SEE REF A FOR DETAILS ON A TROPICAL CYCLONE FORMATION ALERT
LOCATED NEAR 12.2N 117.3W.//
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