WDPN33 PGTW 212100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 02W (SURIGAE) WARNING NR 034//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TYPHOON (TY) 02W (SURIGAE), LOCATED APPROXIMATELY 356 NM 
NORTHEAST OF MANILA, PHILIPPINES, HAS TRACKED NORTHWARD AT 05 KNOTS 
OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED (EIR) IMAGERY 
STILL SHOWS A VIGOROUS SYSTEM WITH A BROAD, 50NM EYE AND A CLOUD 
SHIELD THAT IS BEGINNING TO STRETCH TO THE NORTHEAST AS IT FEELS THE 
EFFECTS OF VIGOROUS UPPER LEVEL WESTERLIES. PGTW AND FMEE FIXES ARE 
IN GOOD AGREEMENT WITH DATA T NUMBERS ASSESSED AT T4.5 AND FINAL 
CURENT INTENSITY ESTIMATES CONSTRAINED TO T5.5 (102KTS). CLOUD TOPS 
ARE VISIBLY WARMING AND WATER VAPOR ANIMATION SHOWS A SHARPENING 
EDGE AS SUBSIDENCE ENCROACHES ON THE NORTHWEST QUANDRANT. A GFS 
CROSS SECTION OF THE STORM DEPICTS A SHARP DRY LINE OVER THE TAIWAN 
STRAIT. THE AXIS OF DEEP MOISTURE HAS NOW SHIFTED TO A SOUTHWEST 
THROUGH NORTHEAST BEARING, INDICATING THE BEGINNINGS OF A TRANSITION 
TO ASYMMETRY. TY SURIGAE IS TRACKING ALONG THE WESTERN PERIPHERY OF 
A SUBTROPICAL RIDGE (STR) AND HAS CROSSED A SIGNIFICANT CHECKPOINT 
DURING THE PAST SIX HOURS AS IT ROUNDED THE STR AXIS AND IS NOW 
CLEARLY BEGINNING TO APPROACH THE MID-LATITUDES. 
   A. THERE IS NO SIGNIFICANT CHANGE TO THE FORECAST PHILOSOPHY 
SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE.
   B. TY SURIGAE WILL CONTINUE TO THE NORTHEAST AND CONTINUE GAINING 
LATITUDE DURING THE NEXT 48 HOURS, WEAKENING AND STRETCHING AS IT 
DOES SO. TWO MID-LATITUDE TROUGHS WILL AFFECT THE SYSTEM IN THE NEAR 
TERM. THE FIRST WILL PASS NORTH OF TY SURIGAE AS IT TRACKS SOUTH OF 
OKINAWA. THE TROUGH WILL STRETCH BUT NOT PICK UP THE SYSTEM, AND AS 
THE TRAILING SHORT-WAVE RIDGE BUILDS IN BEHIND IT. AS THIS RIDGE 
BUILDS, IT WILL NUDGE THE SYSTEM TO THE SOUTH BETWEEN TAU 48 AND 72. 
TRACK GUIDANCE IS TIGHT THROUGH TAU 72 (NEAR THE 135TH MERIDIAN), 
THEN BEGINS TO SPREAD AND VARY IN ALONG-TRACK SPEEDS DURING THE 
PROCESS OF ABSORPTION INTO THE THICKNESS RIBBON (BAROCLINIC ZONE).  
STEADY DETERIORATION OF THE SYSTEM WILL THEN BEGIN. INTENSITY 
GUIDANCE ALSO CONSOLIDATED IN THE LATEST ITERATION, SHOWING A STEADY 
AND LINEAR DECLINE THROUGH THE FIRST 72 HOURS. THE INTENSITY 
FORECAST IS PLACED IN THE MIDDLE OF THE GUIDANCE PACKAGE. THERE 
IS GOOD CONFIDENCE IN BOTH TRACK AND INTENSITY FORECAST THROUGH THE 
FIRST 72 HOURS WHILE THE LACK OF RECENT SCATTEROMETRY AND THE 
PENDING EXPANSION OF THE WINDFIELDS BY THE UPPER LEVEL TROUGHS MAKE 
FOR CONSIDERABLY LESS CONFIDENCE IN THE WIND RADII. 
   C. BY TAU 96 A SECOND, DEEPER SHORT WAVE THAT IS CURRENTLY 
TRACKING OVER THE GOBI DESERT WILL PICK UP THE SYSTEM AND CAUSE TY 
SURIAGE TO BEGIN EXTRA-TROPICAL TRANSITION (ETT) IN EARNEST. MODEL 
GUIDANCE HAS CRYSTALLIZED REGARDING THE FORMATION OF AN EXTRA 
TROPICAL CYCLONE COMPLETING NEAR OR JUST AFTER TAU 120. THE 
DETERMINISTIC GFS SOLUTION, HOWEVER, CONTINUES TO DEPICT AN 
ALTERNATE SCENARIO WHERE VIGOROUS WESTERLIES DECAPITITATE THE SYSTEM 
AND LEAVE A WEAK, LOW LEVEL VORTEX MEANDERING BETWEEN THE 20TH AND 
25TH LATITUDE BETWEEN TAU 96 AND 120. A MORE STANDARD CASE OF 
ABSORPTION INTO THE BAROCLINIC ZONE AND TRANSITION TO A MID-LATITUDE 
LOW IS BECOMING MORE CONVINCING BASED ON THE MODEL GUIDANCE. PHASE 
BASED GUIDANCE IS UNANIMOUS AND DEPICTS TRANSITION TO A COLD CORE 
LOW WITH THE EXCEPTION OF GFS WHICH HOLDS THE SYSTEM AS A WARM CORE 
CYCLONE THROUGH DISSIPATION. BASED ON THE PREPONDERANCE OF GUIDANCE, 
THE JTWC FORECAST IS BASED ON THE ETT SCENARIO, ALBEIT WITH LOWER 
CONFIDENCE THAN DESIRED GIVEN THE RECENT OUTSTANDING PERFORMANCE OF 
THE GFS MODEL. THE HEARTENING NEWS IS THAT EVEN IF THE GFS SOLUTION 
DOES MANIFEST, THE LEFTOVER LOW LEVEL VORTEX WILL BE SO WEAK AND FAR 
FROM LAND AS TO BE INCONSEQUENTIAL. THE JTWC TRACK STAYS VERY TIGHT 
WITH CONSENSUS THROUGH TAU 96, THEN IS HEDGED TO THE SOUTH OF 
CONSENSUS IN THE LAST 24 HOURS, TOWARDS THE ECMWF AND JGSM TRACK 
GUIDANCE. THE INTENSITY FORECAST REMAINS IN THE MIDDLE OF THE MODEL 
GUIDANCE ENVELOPE THROUGHOUT THE FORECAST. A BRIEF BUMP IN INTENSITY 
WILL OCCUR AS IT FUSES WITH THE BAROCLINIC ZONE AND BECOMES A 
VIGOROUS STORM FORCE LOW WHILE TRACKING TO THE SOUTHEAST OF IWO TO.//
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