Tropical Storm NANGKA Advisory Fri Jul 03

MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 11W (ELEVEN)
WARNING NR 001//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TROPICAL DEPRESSION 11W (ELEVEN), LOCATED APPROXIMATELY 239 NM
EAST OF KWAJALEIN, HAS TRACKED WEST-NORTHWESTWARD AT 05 KNOTS
OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE
IMAGERY DEPICTS A CONSOLIDATING LOW LEVEL CIRCULATION CENTER WITH
PERSISTENT DEEP CONVECTION DEVELOPING OVERHEAD. A 031003Z METOP-A
MICROWAVE IMAGE REVEALS SPIRAL BANDING CURVATURE WRAPPING INTO THE
SYSTEM CENTER. A 030533Z RAPID SCAT IMAGE ALSO DEPICTS A WELL
DEFINED CIRCULATION CENTER WITH ~25 KT WIND BARBS. THE INITIAL
POSITION IS BASED ON THE AFOREMENTIONED MICROWAVE IMAGE AND IN GOOD
AGREEMENT WITH THE 12Z RJTD FIX POSITION. THE INITIAL INTENSITY IS
ASSESSED AT 25 KTS. BASED ON CONGRUENT DVORAK ESTIMATES FROM PGTW
AND RJTD AS WELL AS EXTRAPOLATED FROM THE PREVIOUSLY MENTIONED RAPID
SCAT IMAGE. UPPER LEVEL ANALYSIS INDICATES A FAVORABLE ENVIRONMENT
WITH 5-15 KTS VERTICAL WIND SHEAR AND IMPROVING OUTFLOW AS THE
TROUGH LIFTS FROM THE NORTH OF THE SYSTEM. TD 11W IS CURRENTLY
TRACKING WEST-NORTHWEST ALONG THE SOUTHERN PERIPHERY OF THE
SUBTROPICAL RIDGE TO THE NORTH.
3. FORECAST REASONING.
   A. THIS IS THE INITIAL PROGNOSTIC REASONING AND SETS THE FORECAST
PHILOSOPHY.
   B. TD 11W IS EXPECTED TO CONTINUE TRACKING WEST-NORTHWEST ALONG
THE SOUTHERN PERIPHERY OF THE STR THROUGH TAU 48. TRACK SPEEDS ARE
FORECASTED TO REMAIN FAIRLY CONSISTENT AROUND 12 KTS. STEADY
INTENSIFICATION IS EXPECTED ALONG TRACK DUE TO FAVORABLE UPPER LEVEL
CONDITIONS AS WELL AS WARM SSTS AND POSITIVE OHC VALUES. AFTER TAU
48 TD 11W IS EXPECTED TO TURN SLIGHTLY MORE POLEWARD AND BEGIN
TRACKING TO THE NORTHWEST. DYNAMIC MODEL GUIDANCE INDICATES A SMALL
COMPACT SYSTEM THROUGH THIS PORTION OF THE FORECAST.
   C. TD 11W IS EXPECTED TO CONTINUE ON THE NORTHWEST TRAJECTORY
THROUGH TAU 120. STEADY INTENSIFICATION IS EXPECTED TO REACH A PEAK
INTENSITY OF 85 KTS BY THE END OF THE FORECAST PERIOD. DYNAMIC MODEL
GUIDANCE IS IN TIGHT AGREEMENT, LENDING HIGH CONFIDENCE TO THE JTWC
FORECAST TRACK. HOWEVER, DUE TO THE DYNAMIC PATTERN CURRENTLY
OBSERVED IN THE WESTERN PACIFIC, CLOSE ATTENTION SHOULD ALSO BE PAID
TO THE EVOLUTION OF TS 09W AND INVEST 98W.//
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