WDPN32 PGTW 120300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 24W (NARI) WARNING NR 14//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TYPHOON 24W (NARI), LOCATED APPROXIMATELY 147 NM WEST-NORTHWEST 
OF MANILA, PHILIPPINES, HAS TRACKED WESTWARD AT 20 KNOTS OVER THE 
PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) 
INDICATES TY NARI HAS RE-EMERGED IN THE SOUTH CHINA SEA (SCS) WHILE 
MAINTAINING ITS CENTRAL DENSE OVERCAST (CDO) FEATURE WITH IMPROVED 
CONVECTIVE BANDING IN THE SOUTHERN SEMI-CIRCLE. RADAR IMAGERY FROM 
SUBIC BAY, PHILIPPINES, SHOWS THE SYSTEM HAS MAINTAINED A WELL 
DEFINED STRUCTURE AS CONVECTION HAS STARTED TO DEEPEN SINCE MOVING 
BACK OVER THE SCS. THE INITIAL POSITION IS BASED ON THE IR ANIMATION 
AND THE RADAR ANIMATION WITH LOW CONFIDENCE DUE TO THE LLCC BEING 
OBSCURED BY THE CDO FEATURE. THE INITIAL INTENSITY OF 90 KNOTS IS 
BASED ON AN AVERAGE OF DVORAK INTENSITY ESTIMATES THAT RANGE FROM 
102 TO 77 KNOTS FROM PGTW AND RJTD. UPPER LEVEL ANALYSIS REVEALS 
THAT TY 24W HAS MAINTAINED ROBUST OUTFLOW IN AN AREA OF WEAK TO 
MODERATE (10 TO 20 KNOT) EASTERLY VERTICAL WIND SHEAR. TY NARI IS 
TRACKING ALONG THE SOUTHERN PERIPHERY OF THE DEEP-LAYERED STR TO THE 
NORTH.
3. FORECAST REASONING.
   A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE 
PREVIOUS PROGNOSTIC REASONING MESSAGE.
   B. TY 24W IS EXPECTED TO TRACK GENERALLY WESTWARD THROUGH TAU 72 
UNDER THE STEERING INFLUENCE OF THE AFOREMENTIONED STR. AS THE 
SYSTEM TRACKS ACROSS THE WARM OPEN WATERS OF THE SCS, TY 24W WILL 
INTENSIFY TO A PEAK OF 105 KNOTS BY TAU 36 AS FAVORABLE 
ENVIRONMENTAL CONDITIONS PERSIST. AFTER TAU 36, INCREASING LAND 
INTERACTION WILL BEGIN TO HAMPER THE SYSTEM AS TY 24W TREKS INTO THE 
MORE RESTRICTED WATERS OF THE SCS. BY TAU 72, TY 24W WILL MAKE 
LANDFALL NEAR HUE, VIETNAM, AND BEGIN TO MORE RAPIDLY ERODE DUE TO 
THE RUGGED TERRAIN.
   C. IN THE EXTENDED TAUS, TY 24W WILL FURTHER WEAKEN AS IT TRACKS 
WEST UNTIL DISSIPATION OCCURS BY TAU 96. DYNAMIC MODEL GUIDANCE IS 
IN TIGHT AGREEMENT DESPITE ECMWF AND EGRR CONTINUING TO SHOW A 
SLIGHTLY MORE NORTH TRACK THAN AN OTHERWISE, VERY TIGHT GROUPING. 
THERE IS HIGH CONFIDENCE IN THE JTWC FORECAST TRACK WHICH IS LAID 
VERY CLOSE TO THE MULTI-MODEL CONSENSUS DUE TO THE TIGHT ENVELOPE OF 
DYNAMIC MODELS THAT CONSISTENTLY CONTINUE TO DRIVE THE SYSTEM WEST.//
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