WDPN31 PGTW 240300
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 18W WARNING NR 22//
RMKS/
1. FOR METEOROLOGISTS.
2. 12 HOUR SUMMARY AND ANALYSIS.
   A. TYPHOON (TY) 18W (HAGUPIT) PEAKED IN INTENSITY SOMETIME AROUND
23/18Z AS IT APPROACHED THE SOUTHEAST CHINA COAST. DVORAK INTENSITY
ESTIMATES WERE 6.5 (127 KNOTS) AT THIS TIME. THE SYSTEM MADE LAND-
FALL AT APPROXIMATELY 23/2030Z, 45 NM SOUTHWEST OF YANGJIANG, CHINA,
WHICH REPORTED MAXIMUM SURFACE WINDS OF 360/54 KNOTS WITH SLP OF
976.2 MB. THE SYSTEM HAS SINCE WEAKENED SLIGHTLY WITH ANIMATED SAT-
ELLITE IMAGERY DEPICTING ASYMMETRIC DEEP CONVECTION WITH A 20 NM
CLOUD-FILLED EYE. HOWEVER, A 232223Z SSMIS IMAGE STILL INDICATES A
COMPLETE EYE-WALL STRADDLING THE COAST WITH DEEP CONVECTIVE BANDING
WRAPPING INTO THE SOUTHEAST QUADRANT. TY 18W HAS TRACKED GENERALLY
WEST-NORTHWESTWARD AT 18 KNOTS. THE MODELS HAVE REMAINED CONSISTENT
AND IN EXCELLENT AGREEMENT WITH THE CURRENT FORECAST. 
   B. TY 18W CONTINUES TO TRACK ALONG THE SOUTHERN PERIPHERY OF
THE MID-LEVEL SUBTROPICAL RIDGE. THE 23/12Z 500 MB ANALYSIS SHOWED
A EAST-WEST ORIENTED STR EXTENDING WEST-SOUTHWESTWARD INTO NORTHERN
THAILAND. ANIMATED WATER VAPOR IMAGERY SHOWS GOOD RADIAL OUTFLOW.
THE CURRENT POSITION IS BASED ON HIGH-CONFIDENCE POSITION FIXES OF
THE VISIBLE EYE AS WELL AS THE RECENT MICROWAVE IMAGE. THE CURRENT
INTENSITY IS BASED ON AN AVERAGE OF DVORAK ESTIMATES RANGING FROM
90 KNOTS TO 115 KNOTS FROM PGTW, KNES AND RJTD. 
3. FORECAST REASONING.  
   A. NO SIGNIFICANT CHANGES TO TRACK OR PHILOSOPHY BUT ADJUSTED
INITIAL INTENSITIES UP BASED ON PRE-LANDFALL INTENSIFICATION. 
   B. THE ORIENTATION OF THE STR WILL PRODUCE A WESTWARD TO WEST-
SOUTHWESTWARD TRACK INTO NORTHERN VIETNAM OVER THE NEXT 48 HOURS. 
THIS WILL ALLOW THE SYSTEM TO MAINTAIN TYPHOON INTENSITY UNTIL IT
MOVES INTO NORTHERN VIETNAM NEAR TAU 24, AT WHICH POINT THE SYSTEM
WILL BEGIN TO DISSIPATE QUICKLY. TY 18W IS FORECAST TO DISSIPATE
AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND BY TAU 48. THE REMNANTS
MAY TRACK EASTWARD BACK OVER WATER BUT ARE NOT EXPECTED TO RE-
DEVELOP DUE TO AN UNFAVORABLE ENVIRONMENT. THE MODEL TRACKERS ARE
IN VERY GOOD AGREEMENT WITH THIS FORECAST TRACK.
FORECAST TEAM: DELTA// 
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