WDPN31 PGTW 111500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 14W (BANYAN) 
WARNING NR 03//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TROPICAL STORM 14W (BANYAN), LOCATED APPROXIMATELY 122 NM SOUTH-
SOUTHEAST OF WAKE ISLAND, HAS TRACKED WEST-NORTHWESTWARD AT 14 KNOTS 
OVER THE PAST SIX HOURS. ANIMATED INFRARED SATELLITE IMAGERY SHOWS 
CONVECTIVE BANDING WRAPPING INTO A CENTRAL CONVECTIVE MASS OVER THE 
LOW LEVEL CIRCULATION CENTER (LLCC).  AN 111027Z METOP-B MHS 89 GHZ 
MICROWAVE IMAGE SHOWS WEAKER CONVECTIVE BANDING WRAPPING AROUND THE 
WESTERN AND EASTERN SIDE AND INTO THE CENTRALLY LOCATED DEEP 
CONVECTION. THE MICROWAVE IMAGE ALSO SHOWS THAT THE DEEP CONVECTION 
IS SLIGHTLY DISPLACED TO THE SOUTHEAST. THE INITIAL POSITION IS 
BASED ON THE PGTW FIX AND EXTRAPOLATION FROM AN 111029Z METOP-A 
ASCAT IMAGE WITH HIGH CONFIDENCE. THE INITIAL INTENSITY ASSESSMENT 
OF 35 KNOTS IS BASED ON MULTI-AGENCY DVORAK ESTIMATES OF T2.5 (35 
KNOTS) FROM BOTH RJTD AND PGTW. THE DVORAK ESTIMATES ARE SUPPORTED 
BY THE ASCAT IMAGE THAT SHOWS 40 KNOT WIND BARBS WITHIN THE RAIN-
FLAGGED AREA MEANING THEY ARE BIASED SLIGHTLY HIGH. ENVIRONMENTAL 
ANALYSIS SHOWS THAT THE SYSTEM IS DEVELOPING AN EQUATORWARD OUTFLOW 
CHANNEL IS LOCATED IN AN AREA OF LOW (5-10 KNOTS) VERTICAL WIND 
SHEAR (VWS) AND IS TRACKING THROUGH AN AREA OF WARM SEA SURFACE 
TEMPERATURES (29-30 CELSIUS). TS BANYAN IS CURRENTLY TRACKING 
NORTHWEST ALONG THE WESTERN PERIPHERY OF A SUBTROPICAL STEERING 
RIDGE (STR) LOCATED TO THE NORTHEAST.
3. FORECAST REASONING.
   A. THE FORECAST PHILOSOPHY FOR TS 14W REMAINS UNCHANGED FROM THE 
PREVIOUS PROGNOSTIC REASONING PHILOSOPHY.
   B. TS 14W IS EXPECTED TO INITIALLY TRACK NORTH-NORTHWEST OVER THE 
NEXT 36 HOURS AS IT ROUNDS THE WESTERN EXTENT OF THE STR. AFTER TAU 
36 A DEEP LAYERED MID-LATITUDE TROUGH IS FORECAST TO MOVE IN FROM 
THE WEST AND CAUSE TS 14W TO RECURVE AND TRACK TO THE NORTH-
NORTHEAST. LIMITED INTENSIFICATION WILL OCCUR OVER THE NEXT 36 HOURS 
WITH MAX WINDS REACHING 45 KNOTS. AFTER TAU 36, AS THE TROUGH BEGINS 
TO IMPACT THE AREA, INCREASING VWS COMBINED WITH STRONG GRADIENT 
FLOW WILL BEGIN TO WEAKEN THE SYSTEM. DYNAMIC MODEL GUIDANCE IS NOW 
INITIATING WITH A CLOSED CIRCULATION AND ARE IN STRONG AGREEMENT, 
LENDING HIGH CONFIDENCE IN THIS PORTION OF THE JTWC FORECAST TRACK.
  C. AFTER TAU 72, TS 14W WILL CONTINUE TO TRACK TO THE NORTHEAST AS 
IT IS ABSORBED INTO A BAROCLINIC ZONE ESTABLISHED BY THE MID-
LATITUDE TOUGH. AROUND TAU 72, TS BANYAN WILL BEGIN EXTRA-TROPICAL 
TRANSITION, BECOMING FULLY EXTRATROPICAL BY TAU 96. THE SYSTEM IS 
FORECAST TO CONTINUE TO WEAKEN, HOWEVER, STRONG GRADIENT FLOW IS 
EXPECTED TO PERSIST IN THE BAROCLINIC ZONE, CAUSING WINDS TO REMAIN 
AROUND 25 TO 30 KNOTS FOR THE DURATION OF THE FORECAST PERIOD. 
DYNAMIC MODEL GUIDANCE IS IN GOOD AGREEMENT THAT THE SYSTEM WILL 
TRACK TO THE NORTHEAST HOWEVER THERE IS A SIGNIFICANT SPREAD IN THE 
EXACT DIRECTION LENDING LOW CONFIDENCE IN THIS PORTION OF THE JTWC 
FORECAST TRACK.//
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