WDPN31 PGTW 150300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 14W (BANYAN) 
WARNING NR 17//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TYPHOON 14W (BANYAN), LOCATED APPROXIMATELY 456 NM NORTH-
NORTHWEST OF WAKE ISLAND, HAS TRACKED NORTH-NORTHWESTWARD AT 09
KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE 
IMAGERY DEPICTS A COMPACT SYSTEM WITH TIGHTLY-CURVED BANDING 
WRAPPING INTO A PARTIALLY CLOUD FILLED, 10 NM RAGGED EYE FEATURE. 
THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE 
VISIBLE EYE FEATURE. THE INITIAL INTENSITY OF 90 KNOTS IS BASED ON 
MULTI-AGENCY CURRENT INTENSITY DVORAK ESTIMATES OF T5.0 (90 KNOTS) 
FROM PGTW, KNES, AND RJTD. THE DVORAK ESTIMATES HAVE FLUCTUATED 
SLIGHTLY OVER THE PAST 6 HOURS DUE TO CHANGES IN THE SYSTEMS 
CONVECTIVE STRUCTURE, SPECIFICALLY THE EYE FEATURE, LENDING FAIR 
CONFIDENCE IN THE INTENSITY ESTIMATE. UPPER LEVEL ANALYSIS SHOWS THE 
SYSTEM LACKS A POLEWARD OUTFLOW CHANNEL BUT HAS A STRENGTHENING 
EQUATORWARD OUTFLOW CHANNEL. TY 14W IS CURRENTLY IN A FAVORABLE 
ENVIRONMENT WITH LOW (10-15 KNOTS) VERTICAL WIND SHEAR (VWS), AND IS 
TRACKING THROUGH AN AREA OF WARM (28 CELSIUS) SEA SURFACE 
TEMPERATURES (SST). TY 14W IS CURRENTLY TRACKING NORTH-NORTHWESTWARD 
ALONG THE WESTERN PERIPHERY OF A DEEP-LAYERED SUBTROPICAL RIDGE 
(STR) LOCATED TO THE EAST. 
3. FORECAST REASONING.
   A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS 
PROGNOSTIC REASONING MESSAGE. 
   B. TY 14W WILL CONTINUE TRACKING NORTH-NORTHWESTWARD ALONG THE 
WESTERN EXTENT OF THE STR THROUGH TAU 12. AFTER TAU 12 THE SYSTEM 
WILL ROUND THE NORTHWESTERN EDGE OF THE STR AS IT RECURVES BACK TO 
THE NORTHEAST, ACCELERATES, AND BEGINS EXTRA-TROPICAL TRANSITION 
(ETT). OVER THE NEXT 12 HOURS, A BRIEF PERIOD OF RE-INTENSIFICATION 
IS FORECAST AS A PASSING SHORTWAVE TROUGH PROPAGATES TO THE NORTH OF 
THE SYSTEM CAUSING IMPROVED POLEWARD OUTFLOW. MAXIMUM WINDS DURING 
RE-INTENSIFICATION ARE FORECAST TO BE 95 KNOTS AT AROUND TAU 12. 
AFTER TAU 12, TY 14W WILL TRACK INTO AN AREA OF LOWER (<26 CELSIUS) 
SST AND INCREASED VWS AS IT BEGINS TO WEAKEN AND UNDERGO A SLOW ETT. 
TY BANYAN IS FORECAST TO COMPLETE ETT BY TAU 72 AS IT BECOMES FULLY 
IMBEDDED WITHIN THE STRONG MID-LATITUDE WESTERLIES AND TAKES ON 
FRONTAL CHARACTERISTICS. DYNAMIC MODEL GUIDANCE REMAINS IN STRONG 
AGREEMENT WITH THE EXCEPTION OF NAVGEM AND COAMPS-TC, WHICH TRACK 
THE SYSTEM MORE NORTHERLY THAN THE REMAINING GUIDANCE. DESPITE THE 
NAVGEM AND COAMPS-TC OUTLIERS, THERE IS HIGH OVERALL CONFIDENCE IN 
THE JTWC FORECAST TRACK.//
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