WDPN33 PGTW 031500
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 19W (PARMA) WARNING NR 24// 
RMKS/
1. FOR METEOROLOGISTS. 
2. 12 HOUR SUMMARY AND ANALYSIS. 
    A. TYPHOON 19W (PARMA), LOCATED APPROXIMATELY 220 NM NORTH OF 
MANILA, PHILIPPINES, HAS TRACKED NORTHWESTWARD AT 06 KNOTS OVER 
THE PAST SIX HOURS. THE TYPHOON HAS MADE LANDFALL WITH EXTREME 
NORTHEASTERN LUZON, AND IS NOW LOCATED NEAR THE NORTH-CENTRAL 
COASTLINE. THE ONLY REPORTING OBSERVATION SITE IN NORTHERN LUZON 
(RPLI) HAD WINDS SUSTAINED AT 20 KNOTS (GUSTING TO 32 KNOTS) AS 
OF 1000Z. SEA LEVEL PRESSURE WAS ALSO REPORTED AT 993 MB. 
DVORAK VALUES FROM PGTW ESTIMATE THE INTENSITY AT 77 KNOTS.
3.   FORECAST REASONING 
    A. THE FORECAST REASONING HAS NOT CHANGED SIGNIFICANTLY SINCE 
THE PREVIOUS PROGNOSTIC REASONING BULLETIN.
    B. THE SYSTEM WILL EMERGE INTO THE LUZON STRAIT AS A WEAKENED 
SYSTEM, THOUGH GENERALLY FAVORABLE ENVIRONMENTAL CONDITIONS WILL 
FACILITATE FURTHER INTENSIFICATION. HOWEVER, INTENSIFICATION WILL BE 
LIMITED DUE TO UPWELLING OF COOLER WATER, WHICH IS TYPICAL OF SLOW-
MOVING SYSTEMS. THE SYSTEM WILL MORE OR LESS STALL IN THE LUZON
STRAIT FOR THE NEXT 36 - 48 HOURS UNTIL RIDGING IS ABLE TO BUILD BACK
IN FROM THE EAST. RIDGING IS EXPECTED TO RE-ESTABLISH ITSELF ONCE TY 
20W SUFFICIENTLY MOVES OUT TO THE NORTHEAST.
    C. A DEGREE OF DIRECT CYCLONE INTERACTION IS EXPECTED TO OCCUR 
WITH TY 20W, WHICH WILL BEND PARMA'S FORECAST TRACK SLIGHTLY 
EQUATORWARD AFTER TAU 48. BETWEEN TAU 96 AND 120, TY 20W WILL PUSH 
OUT TO THE NORTHEAST, REORIENTING THE MONSOON TROUGH SOUTHWEST TO 
NORTHEAST, AND ALLOWING RIDGING TO WORK BACK INTO THE SOUTHEAST OF 
THE SYSTEM. THESE CHANGES WILL ALSO ALLOW PARMA TO TRACK 
NORTHEASTWARD. INTENSITY GUIDANCE KEEPS PEAK INTENSITY BETWEEN 90 
AND 100 KNOTS, BUT A STRONGER SYSTEM IS NOT UNLIKELY AS IT MOVES 
INTO THE PHILIPPINE SEA. 
//
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