WDPN33 PGTW 030300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 22W (FITOW) WARNING NR 
12//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TROPICAL STORM 22W (FITOW), LOCATED APPROXIMATELY 401 NM SOUTH-
SOUTHEAST OF KADENA AB, HAS TRACKED NORTHWARD AT 05 KNOTS OVER THE 
PAST SIX HOURS ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) 
CONTINUES TO REVEAL A RAGGED LOW-LEVEL CIRCULATION CENTER (LLCC) 
WITH BROKEN DEEP CONVECTIVE BANDING WRAPPING INTO THE LLCC. THE 
CURRENT POSITION IS BASED ON A 022129Z SSMIS MICROWAVE SATELLITE 
IMAGE AND RECENT POSITION FIXES FROM PGTW AND KNES WITH HIGH 
CONFIDENCE. THE CURRENT INTENSITY OF 60 KNOTS IS ON THE HIGH END OF 
DVORAK ESTIMATES TO REFLECT THE SUSTAINED CONVECTIVE SIGNATURE AND 
IS CONSISTENT WITH RECENT DVORAK INTENSITY ESTIMATES FROM PGTW, 
RJTD, AND KNES. UPPER-LEVEL ANALYSIS AND RECENT WATER VAPOR IMAGERY 
INDICATE THE SYSTEM IS IN A FAVORABLE ENVIRONMENT WITH LOW TO 
MODERATE (05 TO 15 KNOT) VERTICAL WIND SHEAR (VWS) AND STRONG RADIAL 
OUTFLOW. TS 22W IS TRACKING ALONG THE WESTERN PERIPHERY OF THE NEAR 
EQUATORIAL RIDGE TO THE EAST.
3. FORECAST REASONING.
   A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS 
PROGNOSTIC REASONING MESSAGE.
   B. TS 22W IS EXPECTED TO CONTINUE TRACKING POLEWARD OVER THE NEXT 
36 HOURS. AFTER TAU 36, A SUBTROPICAL RIDGE (STR) ANCHORED EAST OF 
JAPAN IS FORECAST TO BUILD AND EXTEND WESTWARD AND INFLUENCE THE 
STEERING OF THE CYCLONE. THIS STR WILL PUSH THE SYSTEM ON A MORE 
NORTHWESTWARD TRACK. FAVORABLE ENVIRONMENTAL CONDITIONS, INCLUDING 
LOW VWS, ENHANCED UPPER-LEVEL OUTFLOW, AND WARM (27 TO 28 DEGREES 
CELSIUS) ALONG-TRACK SEA SURFACE TEMPERATURES, WILL ALLOW THE SYSTEM 
TO INTENSIFY THROUGH TAU 72. AVAILABLE MODEL GUIDANCE IS IN GOOD 
AGREEMENT WITH THE POLEWARD TRACK THROUGH TAU 36 AND DIVERGES 
THEREAFTER. BASED ON THE SPREAD IN GUIDANCE AFTER TAU 36, THERE IS 
LOW CONFIDENCE IN THE FORECAST TRACK THROUGH TAU 72.
   C. AFTER TAU 72, TS 22W WILL CONTINUE TRACKING NORTHWESTWARD 
ALONG THE PERIPHERY OF THE STR. THE INTENSITY IS EXPECTED TO SLOWLY 
DECREASE AS COLD AIR ENTRAINMENT STRENGTHENS. FURTHERMORE, VWS IS 
ALSO EXPECTED TO INCREASE AS THE SYSTEM TRACKS NORTHWESTWARD. TS 
FITOW IS EXPECTED TO MAKE LANDFALL SOUTH OF SHANGHAI BY TAU 72 AND 
BEGIN DISSIPATION DUE TO FRICTIONAL EFFECTS. NUMERICAL MODEL 
GUIDANCE CONTINUES TO DIVERGE AFTER TAU 72. GIVEN THE CONTINUED 
SPREAD IN THE MODELS AND THE UNCERTAINTY IN HOW MUCH THE STR IS 
EXPECTED TO BUILD, THERE IS LOW CONFIDENCE IN THE TRACK FORECAST.//
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