WDPN31 PGTW 170300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 16W (GONI) WARNING NR 13//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TYPHOON (TY) 16W (GONI), LOCATED APPROXIMATELY 230 NM WEST OF
ANATAHAN, HAS TRACKED WEST-NORTHWESTWARD AT 11 KNOTS OVER THE
PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS A 
RAPIDLY CONSOLIDATING LOW-LEVEL CIRCULATION CENTER (LLCC) WITH A 7-
NM PINHOLE EYE. A 152222Z SSMIS 91GHZ IMAGE SHOWS A SMALL EYEWALL 
WITH TIGHTLY-CURVED SPIRAL BANDING WRAPPING INTO THE CENTER. THERE 
IS GOOD CONFIDENCE IN THE CURRENT POSITION. ANIMATED WATER VAPOR 
IMAGERY DEPICTS EXCELLENT OUTFLOW, ESPECIALLY POLEWARD OUTFLOW 
WHICH IS ENHANCED BY THE TUTT POSITIONED TO THE NORTH. TY GONI IS 
UNDERGOING RAPID INTENSIFICATION (RI), INCREASING APPROXIMATELY 60 
KNOTS OVER THE PAST 24 HOURS FROM 55 KNOTS AT 16/00Z TO THE CURRENT 
INTENSITY OF 115 KNOTS. DVORAK INTENSITY ESTIMATES RANGE FROM THE 
KNES T5.5 (102 KNOTS) ESTIMATE AT 16/2030Z TO THE PGTW T6.5 (127 
KNOTS) ESTIMATE AT 16/2330Z. THE CURRENT INTENSITY IS 
CONSERVATIVELY ASSESSED AT 115 KNOTS BASED ON AN AVERAGE OF THESE 
TWO ESTIMATES; THE INTENSITY WILL LIKELY BE INCREASED FURTHER AT 
THE NEXT WARNING CYCLE. TY 16W CONTINUES TO TRACK ALONG THE 
SOUTHERN PERIPHERY OF THE DEEP STR.
3. FORECAST REASONING.
   A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS 
PROGNOSTIC REASONING MESSAGE.
   B. TY 16W WILL CONTINUE TO TRACK WEST-NORTHWESTWARD TO WESTWARD 
THROUGH TAU 72 UNDER THE STEERING INFLUENCE OF THE STR. DUE TO THE 
FAVORABLE ENVIRONMENTAL CONDITIONS, INCLUDING LOW VWS, WARM SST AND 
EXCELLENT OUTFLOW, TY 16W IS FORECAST TO CONTINUE TO INTENSIFY 
RAPIDLY THROUGH TAU 48 WITH A PEAK OF 130 KNOTS. MODEL GUIDANCE IS 
IN TIGHT AGREEMENT AND SUPPORTS THE FORECAST TRACK WITH HIGH 
CONFIDENCE. 
   C. IN THE EXTENDED PERIOD, MODEL GUIDANCE FANS OUT WITH 
INCREASING UNCERTAINTY IN BOTH TRACK SPEEDS AND THE TIMING OF THE 
POLEWARD TURN. CURRENT NUMERICAL GUIDANCE INDICATES AN EXTREMELY 
COMPLEX SYNOPTIC SITUATION AS A DEEP MIDLATITUDE SHORTWAVE TROUGH 
DIGS INTO NORTHEASTERN CHINA, WEAKENING THE STR NORTH OF TY 16W. 
ADDITIONALLY, TY 17W IS FORECAST TO TRACK NORTHWESTWARD SOUTH OF 
HONSHU UNDER THE STEERING INFLUENCE OF THE STR TO ITS NORTH. 
CONSEQUENTLY, TY 16W IS LIKELY TO BECOME EMBEDDED IN A WEAK 
STEERING ENVIRONMENT AND EXHIBIT SLOW AND POSSIBLY EVEN QUASI-
STATIONARY MOTION NEAR TAIWAN. FURTHERMORE, THERE IS NO EVIDENCE 
THAT THE TROUGH WILL BE DEEP ENOUGH TO INDUCE EXTRA-TROPICAL 
TRANSITION AS THE BAROCLINIC ZONE REMAINS WELL NORTH OF 16W IN THE 
WEST SEA. FOR THIS REASON, THERE IS HIGH OVERALL UNCERTAINTY IN THE 
JTWC FORECAST TRACK.//
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