![Image](http://i.imgur.com/L0mKOXP.jpg)
WDPN31 PGTW 080300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 22W (AERE) WARNING
NR 11//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL STORM (TS) 22W (AERE), LOCATED APPROXIMATELY 139 NM EAST-
SOUTHEAST OF HONG KONG, HAS TRACKED NORTHEASTWARD AT 03
KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE
IMAGERY DEPICTS A PARTIALLY-EXPOSED, QUASI-STATIONARY LOW-LEVEL
CIRCULATION CENTER (LLCC) WITH PERSISTENT DEEP CONVECTION OVER THE
LLCC. A 07/2245Z WINDSAT 37GHZ IMAGE REVEALS A COMPACT CORE OF
CONVECTION WITH A MICROWAVE EYE FEATURE AND THE BULK OF CONVECTIVE
BANDING LOCATED OVER THE NORTHERN SEMI-CIRCLE. THIS IMAGERY SUPPORTS
THE CURRENT POSITION WITH GOOD CONFIDENCE. THE CURRENT INTENSITY IS
ASSESSED AT 50 KNOTS BASED ON THE RECENT WEAKENING TREND, WHICH IS
CONSISTENT WITH THE DVORAK CURRENT INTENSITY ESTIMATES RANGING FROM
55 TO 65 KNOTS AND A RECENT SATCON ESTIMATE OF 48 KNOTS. UPPER-LEVEL
ANALYSIS SHOWS A MARGINALLY-FAVORABLE ENVIRONMENT WITH LOW,
SOUTHERLY VERTICAL WIND SHEAR (VWS) OFFSET BY GOOD POLEWARD OUTFLOW,
AND WARM SST. TS 22W HAS TRACKED QUASI-STATIONARY DUE ITS POSITION
WITHIN A WEAK, COMPETING STEERING ENVIRONMENT BETWEEN THE RECEDING
SUBTROPICAL RIDGE (STR) TO THE EAST AND A BUILDING STR OVER CHINA.
3. FORECAST REASONING.
A. NO SIGNIFICANT CHANGE TO THE FORECAST PHILOSOPHY FROM THE
PREVIOUS PROGNOSTIC REASONING MESSAGE.
B. TS 22W IS FORECAST TO REMAIN WITHIN A COMPETING STEERING
ENVIRONMENT OVER THE NEXT 36 HOURS, WHICH WILL PRODUCE A SLOW AND
QUASI-STATIONARY MOTION. THE DOMINANT STEERING MECHANISM WILL SLOWLY
TRANSITION TO THE STR BUILDING OVER CHINA NEAR TAU 36. DURING THIS
TIME, LOW VWS AND SLOW TRACK SPEED OVER VERY WARM WATER WILL ALLOW
ADDITIONAL INTENSIFICATION; TS 22W IS EXPECTED TO REACH PEAK
INTENSITY BY TAU 24. AFTER TAU 24, THE SYSTEM IS FORECAST TO
GRADUALLY WEAKEN AS IT ENCOUNTERS INCREASING NORTHERLY VWS AND UPPER-
LEVEL CONVERGENCE ASSOCIATED WITH BUILDING STR.
C. AFTER TAU 72, TS 22W WILL ACCELERATE SOUTHWESTWARD TOWARD
HAINAN ISLAND AS THE STR OVER SOUTHEAST CHINA BUILDS. THE INCREASED
VWS AND UPPER-LEVEL SUBSIDENCE WILL LEAD TO A GRADUAL DECAY, WITH TS
22W DISSIPATING PRIOR TO LANDFALL OVER HAINAN BY TAU 120. DYNAMIC
MODEL GUIDANCE REMAINS WIDELY SPREAD DUE TO THE COMPLEX STEERING
ENVIRONMENT AND HIGH UNCERTAINTY ASSOCIATED WITH THE QUASI-
STATIONARY MOTION. THE JTWC TRACK FORECAST IS PLACED CLOSE TO THE
MULTI-MODEL CONSENSUS WITH LOW CONFIDENCE.//
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