WDPN31 PGTW 031500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 08W (EIGHT) 
WARNING NR 03//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TROPICAL DEPRESSION (TD) 08W (EIGHT), LOCATED APPROXIMATELY 184 NM
SOUTH-SOUTHWEST OF ANDERSEN AFB, HAS TRACKED NORTHWESTWARD AT 13
KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE 
IMAGERY DEPICTS A SLOWLY-CONSOLIDATING LOW-LEVEL CIRCULATION CENTER 
(LLCC) WITH IMPROVED CONVECTIVE BANDING OVER THE SOUTHERN SEMI-
CIRCLE. HOWEVER, A 031151Z METOP-B IMAGE DEPICTS AN ELONGATED LLCC 
WITH AN ILL-DEFINED CENTER AND CHAOTIC STRUCTURE, THEREFORE, THERE 
IS A MODERATE AMOUNT OF UNCERTAINTY IN THE EXACT INITIAL POSITION 
AND TRACK SPEED. ANIMATED WATER VAPOR IMAGERY AND CLOUD DRIFT WINDS 
INDICATE GOOD EQUATORWARD OUTFLOW, HOWEVER, POLEWARD OUTFLOW IS 
LIMITED DUE TO CONVERGENT FLOW ASSOCIATED WITH THE UPPER-LEVEL 
SUBTROPICAL RIDGE POSITIONED TO THE NORTH. THE INITIAL INTENSITY IS 
ASSESSED AT 30 KNOTS BASED ON RECENT ASCAT DATA AND T2.0 (30 KNOTS) 
DVORAK INTENSITY ESTIMATES FROM KNES AND PGTW. TD 08W IS CURRENTLY 
TRACKING WEST-NORTHWESTWARD ALONG THE LOW- TO MID-LEVEL SUBTROPICAL 
RIDGE (STR) ENTRENCHED NORTH OF THE SYSTEM.
3. FORECAST REASONING.
   A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS 
PROGNOSTIC REASONING MESSAGE.
   B. TD 08W IS FORECAST TO TRACK WEST-NORTHWESTWARD TO 
NORTHWESTWARD THROUGH TAU 72 ALONG THE SOUTHERN PERIPHERY OF THE 
STR. THE 03/00Z 500 MB ANALYSIS DEPICTS A STRONG STR ORIENTED EAST-
WEST, EXTENDING WESTWARD TO NEAR TAIWAN. DYNAMIC GUIDANCE IS 
CURRENTLY IN TIGHT AGREEMENT WITH A 140 NM SPREAD IN SOLUTIONS AT 
TAU 72. HOWEVER, GUIDANCE HAS BEEN FAIRLY ERRATIC AND, IN GENERAL, 
IS TRENDING FURTHER WEST OVER THE PAST TWELVE HOURS. DUE TO THE LACK 
OF A POLEWARD OUTFLOW MECHANISM, TD 08W IS FORECAST TO INTENSIFY 
SLOWLY THROUGH TAU 36 THEN AT A GREATER RATE OF INTENSIFICATION 
THROUGH TAU 72 AS POLEWARD OUTFLOW IMPROVES AND THE SYSTEM TRACKS 
OVER A REGION OF HIGH OCEAN HEAT CONTENT VALUES.
   C. IN THE EXTENDED TAUS, TD 08W IS EXPECTED TO TRACK POLEWARD 
ALONG THE WESTERN PERIPHERY OF THE STR, TOWARD A BREAK IN THE STR 
CREATED BY AN APPROACHING MIDLATITUDE SHORTWAVE TROUGH. WITH THE 
EXCEPTION OF GFDN WHICH IS SLOWER AND FURTHER WEST, THE DYNAMIC 
GUIDANCE IS IN GOOD (IMPROVED) AGREEMENT. TD 08W IS EXPECTED TO 
INTENSIFY TO A PEAK INTENSITY OF 105 KNOTS AT TAU 96 DUE 
TO IMPROVED POLEWARD OUTFLOW. OVERALL, THERE IS LOW CONFIDENCE IN 
THE FORECAST TRACK DUE TO UNCERTAINTY IN THE INITIAL POSITION AND 
TIMING OF THE RECURVE.//
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