WDPN31 PGTW 150300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 24W (SARIKA) WARNING NR 11//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TYPHOON (TY) 24W (SARIKA), LOCATED APPROXIMATELY 198 NM EAST OF
MANILA, PHILIPPINES, HAS TRACKED WESTWARD AT 08 KNOTS OVER THE
PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS A
DEEPENING CONVECTIVE STRUCTURE THAT HAS SHOWN INDICATIONS OF AN EYE
FORMING. A 142219Z CORIOLIS MICROWAVE IMAGE SHOWS FORMATIVE BANDING
IN ALL QUADRANTS WRAPPING TIGHTLY INTO A MICROWAVE EYE. THE CURRENT
POSITION IS BASED ON RADAR IMAGERY FROM THE PHILIPPINES AND IS
SUPPORTED BY THE SMALL MICROWAVE EYE IN THE CORIOLIS IMAGE. THE
INTENSITY HAS BEEN INCREASED TO 80 KNOTS BASED ON THE IMPROVED
STRUCTURE AND INCREASING DVORAK INTENSITY ESTIMATES TO T4.5 (77
KNOTS) FROM ALL AGENCIES. TY 24W IS TRACKING IN A VERY FAVORABLE
ENVIRONMENT WITH A POINT SOURCE ANTICYCLONE PROVIDING RADIAL OUTFLOW
AND LOW (5-10 KNOT) VERTICAL WIND SHEAR. SEA SURFACE TEMPERATURES
AND OCEAN HEAT CONTENT ARE ALSO VERY FAVORABLE. TY SARIKA IS MOVING
ON A WESTWARD TRACK UNDER THE INFLUENCE OF A SUB-TROPICAL RIDGE
(STR) TO THE NORTH.
3. FORECAST REASONING.
   A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING BULLETIN.
   B. TY SARIKA WILL CONTINUE TO TRACK WEST-NORTHWESTWARD ALONG THE
SOUTHERN PERIPHERY OF THE STEERING STR TO THE NORTH. VERY FAVORABLE
ENVIRONMENTAL CONDITIONS WILL SUPPORT INTENSIFICATION TO 95 KNOTS
OVER THE NEXT 12 HOURS JUST PRIOR TO LANDFALL OVER LUZON. THERE WILL
BE A SHORT WEAKENING PHASE AS THE CYCLONE TRACKS OVER THE RUGGED
LUZON TERRAIN BEFORE EMERGING OVER THE SOUTH CHINA SEA (SCS) NEAR
TAU 24. ENVIRONMENTAL CONDITIONS IN THE SCS WILL REMAIN FAVORABLE
WHICH WILL BEGIN A SECOND INTENSIFICATION PHASE. TY SARIKA WILL TURN
TO A MORE WESTWARD TRAJECTORY TOWARDS HAINAN AS THE STEERING STR
STRENGTHENS.
   C. IN THE EXTENDED FORECAST, TY SARIKA WILL TURN NORTHWESTWARD
TOWARDS A BREAK IN THE STEERING STR. THE SYSTEM WILL SKIRT THE
SOUTHERN PORTION OF HAINAN BEFORE MAKING LANDFALL NEAR HANOI,
VIETNAM. THE INTENSITY IN THE EXTENDED FORECAST BECOMES MORE COMPLEX
AS ENVIRONMENTAL CONDITIONS WOULD SUPPORT FURTHER INTENSIFICATION;
HOWEVER, INCREASED LAND INTERACTION WITH HAINAN WILL OFFSET THE
FAVORABLE ENVIRONMENT. THE INTENSITY AT LANDFALL OVER VIETNAM WILL
ULTIMATELY BE TIED TO THE TRACK OF THE TYPHOON AS IT PASSES HAINAN.
DYNAMIC MODEL GUIDANCE HAS COME INTO BETTER AGREEMENT, LENDING HIGH
CONFIDENCE TO THE JTWC FORECAST TRACK WHICH IS POSITIONED CLOSE TO
THE MULTI-MODEL CONSENSUS.//