Tropical Storm CHAN-HOM Advisory 04 Ιουλ.

MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 09W (CHAN-HOM) WARNING
NR 14//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TROPICAL STORM (TS) 09W (CHAN-HOM), LOCATED APPROXIMATELY 259 NM
EAST-SOUTHEAST OF ANDERSEN AFB, GUAM HAS TRACKED NORTH-NORTHWESTWARD
AT 04 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED
(EIR) SATELLITE IMAGERY SHOWS CENTRAL CONVECTION HAS BEGUN TO
REDEVELOP OVER THE PREVIOUSLY EXPOSED LOW LEVEL CIRCULATION CENTER
(LLCC). A 031828Z SSMIS 91GHZ MICROWAVE IMAGE SHOWS A BROAD LLCC
WITH LIMITED CONVECTION. A 031145Z SCATTEROMETER PASS SHOWED THE
WELL-DEFINED LLCC WITH STRONGER WINDS LOCATED ALONG THE SOUTHERN
PERIPHERY. THE CURRENT POSITION IS BASED ON THE LLCC IN THE EIR LOOP
AND EXTRAPOLATED FROM THE SCATTEROMETER PASS WITH GOOD CONFIDENCE.
THE INITIAL INTENSITY IS BASED ON THE SCATTEROMETER PASS AND AN
ASSESSMENT OF CURRENT INTENSITY ESTIMATES FROM ALL AGENCIES. THE
SYSTEM IS SLOWLY DRIFTING NORTHWARD DUE TO A SOUTHWESTERLY SURGE TO
THE SOUTHEAST IN THE LOW TO MID LEVELS. THE TUTT CELL THAT HAS BEEN
IMPACTING THE CONVECTION OVER THE SYSTEM IS STILL LOCATED TO THE
NORTHEAST OF THE SYSTEM, CAUSING HIGH VERTICAL WIND SHEAR (VWS) AND
SUBSIDENCE ALOFT.
3. FORECAST REASONING.
   A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
   B. TS 09W WILL CONTINUE TO DRIFT NORTH TO NORTHWESTWARD OVER THE
NEXT 12 HOURS WHILE THE TUTT SLOWLY RETREATS TO THE NORTHEAST WHICH
IS PREVENTING THE SUB-TROPICAL RIDGE (STR) FROM BUILDING IN NORTH OF
THE SYSTEM AND ASSUMING STEERING. DURING THIS TIME EXPECT SLOW
DEVELOPMENT AS VWS SLOWLY REDUCES. BEYOND TAU 12, AS THE TUTT
FURTHER RETREATS AND THE STR BUILDS, TS 09W WILL BEGIN TO ACCELERATE
TO THE NORTHWEST. THE SYSTEM WILL FURTHER INTENSIFY AS OUTFLOW
IMPROVES, VWS REDUCES, AND SEA SURFACE TEMPERATURES (SSTS) REMAIN
FAVORABLE.
   C. IN THE EXTENDED TAUS, TS CHAN-HOM WILL CONTINUE TO TRACK
NORTHWESTWARD AND FURTHER INTENSIFY AS VWS AND OUTFLOW REMAIN
FAVORABLE. TOWARDS THE END OF THE FORECAST PERIOD, SSTS AND OCEAN
HEAT CONTENT REDUCE BEGINNING A SLIGHT WEAKENING TREND. DYNAMIC
MODEL GUIDANCE IS IN GOOD AGREEMENT ON THE OVERALL TRACK; HOWEVER,
DUE TO THE MODELS HANDLING OF THE TUTT INTERACTION, THERE REMAINS
LOW CONFIDENCE IN THE JTWC FORECAST TRACK.//
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