t02436

JTWC於22Z發布TCFA

WTPN21 PGTW 062230
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
200 NM EITHER SIDE OF A LINE FROM 8.4N 158.7E TO 13.9N 156.4E
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 062200Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 9.5N 158.3E. THE SYSTEM IS MOVING NORTHWESTWARD AT 06 KNOTS.
2. REMARKS: THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 4.9N
165.2E IS NOW LOCATED NEAR 9.5N 158.3E, APPROXIMATELY 155 NM NORTH
OF POHNPEI. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY DEPICTS
IMPROVED CONVECTIVE BANDING WRAPPING INTO AN ELONGATED LOW LEVEL
CIRCULATION CENTER. A 061830Z SSMIS MICROWAVE IMAGE DEPICTS
CONVECTIVE BANDING THAT IS NOW WRAPPING IN FROM THE SOUTHERN
QUADRANT. UPPER-LEVEL ANALYSIS INDICATES AN INCREASINGLY FAVORABLE
ENVIRONMENT WITH 10 TO 15 KNOTS VERTICAL WIND SHEAR AND GOOD
POLEWARD OUTFLOW. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT
18 TO 23 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR
1005 MB. BASED ON IMPROVED STRUCTURE AND FAVORABLE CONDITIONS, 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
072230Z.
//
NNNN

風場掃描顯示近中心風速約為25kt

t02436

JMA升TD

TROPICAL DEPRESSION 1008 HPA AT 09N 159E WNW SLOWLY.

ben811018

t02436

提升評級至Medium

B. TROPICAL DISTURBANCE SUMMARY:
      (1) THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 4.4N
167.4E, IS NOW LOCATED NEAR 4.9N 165.2E, APPROXIMATELY 275 NM SOUTH-
SOUTHWEST OF KWAJALEIN. ANIMATED MULTISPECTRAL SATELLITE IMAGERY
DEPICTS A WEAK, ILL-DEFINED LOW-LEVEL CIRCULATION CENTER (LLCC) WITH
FLARING DEEP CONVECTION. A 050331Z SSMI IMAGE SHOWS BROAD,
FRAGMENTED DEEP CONVECTION WITH LITTLE EVIDENCE OF A DEFINED LLCC.
UPPER-LEVEL ANALYSIS INDICATES A MARGINAL ENVIRONMENT WITH SOME (10-
20 KTS) VERTICAL WIND SHEAR AND GOOD POLEWARD DIVERGENT FLOW.
DYNAMIC MODELS INDICATE SLOW DEVELOPMENT OVER THE NEXT 48 HOURS WITH
BROAD GENERALIZED DEVELOPMENT.  MAXIMUM SUSTAINED SURFACE WINDS ARE
ESTIMATED AT 12 TO 18 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 UPGRADED TO
MEDIUM.

t02436

JTWC評級Low

B. TROPICAL DISTURBANCE SUMMARY:
      (1) AN AREA OF CONVECTION HAS PERSISTED NEAR 4.4N 167.4E,
APPROXIMATELY 260 NM SOUTH OF KWAJALEIN. ANIMATED MULTISPECTRAL
SATELLITE IMAGERY DEPICTS A WEAK, ILL-DEFINED LOW-LEVEL CIRCULATION
CENTER (LLCC) WITH FLARING, DISORGANIZED DEEP CONVECTION. A 042005Z
SSMIS 37 GHZ IMAGE INDICATES BROAD, FRAGMENTED CONVECTIVE BANDING
WITH NO EVIDENCE OF A DEFINED LLCC. RECENT SCATTEROMETER IMAGERY
INCLUDING A 041039Z ASCAT IMAGE AND A 041827Z WINDSAT PARTIAL IMAGE
SHOW AN ELONGATED CIRCULATION WITH STRONG (20 TO 25 KNOTS),
CONVERGENT WESTERLIES. UPPER-LEVEL ANALYSIS INDICATES A MARGINAL
ENVIRONMENT WITH MODERATE VERTICAL WIND SHEAR AND BROAD, DIVERGENT
SOUTHERLY FLOW, WHICH IS FUELING LARGE, SHORT-LIVED BURSTS OF DEEP
CONVECTION. IN GENERAL, THE DYNAMIC MODELS INDICATE SLOW DEVELOPMENT
OVER THE NEXT TWO DAYS, HOWEVER, GFS, NAVGEM AND ECMWF DIFFER
SIGNIFICANTLY ON THE LOCATION AND EVOLUTION OF THIS SYSTEM. MAXIMUM
SUSTAINED SURFACE WINDS ARE ESTIMATED AT 12 TO 18 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 LOW.

GFS 18Z