WDPN31 PGTW 190900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 01W (DUJUAN) WARNING 
NR 009//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TROPICAL STORM (TS) 01W (DUJUAN), LOCATED APPROXIMATELY 682 NM 
SOUTHEAST OF MANILA, PHILIPPINES, HAS TRACKED WESTWARD AT 10 KNOTS 
OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY 
(MSI) SHOWS THAT THE SYSTEM IS ONCE AGAIN STRUGGLING TO MAINTAIN THE 
CORE CONVECTION OVER THE LOW LEVEL CIRCULATION CENTER (LLCC), AS 
EASTERLY VWS REMAINS FAIRLY STRONG. THE CIRCULATION CENTER REMAINS 
OBSCURED BY THE CIRRUS SHIELD FROM THE FLARING CONVECTION. A 190435Z 
AMSR2 89GHZ COMPOSITE IMAGE DEPICTS SHALLOW CURVED BANDING WRAPPING 
INTO THE LLCC WITH A SYMMETRICAL AREA OF DEEP CONVECTION DISPLACED 
TO THE NORTHWEST. EVEN WITH THE MICROWAVE IMAGERY HOWEVER, THERE IS 
OVERALL FAIR CONFIDENCE IN THE INITIAL POSITION. THE INITIAL 
INTENSITY REMAINS SET AT 45 KNOTS WITH FAIR CONFIDENCE, IN LINE WITH 
AGENCY DVORAK CURRENT INTENSITY ESTIMATES OF T3.0 (45 KTS) FROM PGTW 
AND KNES, WITH ADDITIONAL SUPPORT PROVIDED BY AN ADT ESTIMATE OF 
T3.0 AND A SATCON ESTIMATE OF 45 KTS. ANALYSIS REVEALS NO MAJOR 
CHANGE IN THE OVERALL ENVIRONMENT WHICH REMAINS MARGINALLY FAVORABLE 
FOR ADDITIONAL DEVELOPMENT, WITH MODERATE (20 KTS) EASTERLY VWS 
BEING OFFSET BY VERY STRONG POLEWARD OUTFLOW. SSTS REMAIN SUPPORTIVE 
AT 29-30C. TS 01W IS TRACKING ALONG THE SOUTHWEST PERIPHERY OF A 
DEEP-LAYERED SUBTROPICAL RIDGE (STR) POSITIONED TO THE NORTHEAST.
3. FORECAST REASONING.
   A. THERE IS NO SIGNIFICANT CHANGE IN THE FORECAST PHILOSOPHY FROM 
THE PREVIOUS PROGNOSTIC REASONING MESSAGE.
   B. TS 01W REMAINS ENSCONCED IN A WEAKNESS IN THE OVERALL STR 
PATTERN, HOWEVER IT HAS ACCELERATED WESTWARD OVER THE PREVIOUS 6-12 
HOURS AS THE STR CENTERED TO THE EAST HAS EXTENDED AND MOVED 
WESTWARD. THE OVERALL TRACK MOTION IS FORECAST TO CONTINUE OVER THE 
NEXT 12 HOURS BEFORE TURNING MORE NORTHWESTWARD AS THE STR CONTINUES 
TO MOVE TO THE SOUTHWEST AND THE WESTERN PERIPHERY SIMULTANEOUSLY 
TAKES ON A MORE NORTHWEST-SOUTHEAST ORIENTATION. TS 01W IS EXPECTED 
TO MAKE LANDFALL OVER NORTHEAST MINDANAO NEAR TAU 36 BEFORE TRACKING 
OVER THE CENTRAL PHILIPPINE ISLANDS AND INTO THE NORTHERN SULU SEA 
BY TAU 72. DUE TO THE PERSISTENT EASTERLY VWS, THE SYSTEM HAS BEEN 
UNABLE TO CONSISTENTLY MAINTAIN A CORE, AND THIS TREND IS EXPECTED 
TO CONTINUE OVER THE NEXT 24 HOURS OR SO, WITH CONSOLIDATION AND 
STRENGTHENING OCCURRING NEAR DIURNAL MAXIMUM, FOLLOWED BY WEAKENING 
DUE THE DIURNAL MINIMUM. THE NET TREND WILL BE A SMALL AMOUNT OF 
INTENSIFICATION TO A PEAK OF 50 KTS BY TAU 12, THEN STEADY WEAKENING 
THROUGH TAU 72 AS VWS INCREASES AND THE SYSTEM INTERACTS WITH THE 
COMPLEX TERRAIN OF THE PHILIPPINE ISLANDS. NUMERICAL MODEL GUIDANCE, 
WITH THE CONTINUED EXCEPTION OF THE UKMET AND UKMET ENSEMBLE, IS IN 
GOOD OVERALL AGREEMENT THROUGH TAU 72 AND THERE IS HIGH CONFIDENCE 
IN THIS PORTION OF THE JTWC FORECAST TRACK. 
   C. AFTER TAU 72, TS 01W WILL CONTINUE TO TRACK WEST-NORTHWESTWARD 
ALONG THE WESTERN PERIPHERY OF THE AFOREMENTIONED STR CENTERED TO 
THE EAST, AND EMERGE INTO THE SOUTH CHINA SEA (SCS) PRIOR TO TAU 96. 
THE STEERING PATTERN WEAKENS AFTER 96, WHICH WILL RESULT IN A SLOWER 
FORWARD MOTION THROUGH TAU 120. ONCE IN THE SCS THE SYSTEM WILL 
ENCOUNTER A DRIER AND COOLER AIR MASS, WHICH COMBINED WITH CONTINUED 
MODERATE TO HIGH VWS AND DECREASED OUTFLOW ALOFT, WILL LEAD TO 
DISSIPATION OVER THE CENTRAL SCS BY TAU 120. NUMERICAL MODEL 
GUIDANCE HAS COME INTO BETTER OVERALL AGREEMENT IN THE EXTENDED 
TAUS, WITH THE NOTABLE EXCEPTION OF THE UKMET AND ITS ENSEMBLE MEAN 
WHICH UNREALISTICALLY MOVE THE SYSTEM NORTHWARD INTO A LOW-LEVEL 
RIDGE. THE REMAINDER OF THE GUIDANCE SHOWS A 270NM SPREAD AT TAU 
120. THE JTWC FORECAST TRACK IS POSITIONED JUST SOUTH OF THE MULTI-
MODEL CONSENSUS AND CLOSELY TRACKS THE NAVGEM SOLUTION, WITH FAIR 
CONFIDENCE.//
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