WDPN32 PGTW 230300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR SUPER TYPHOON 28W (LEKIMA) WARNING NR 
11//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   SUPER TYPHOON 28W (LEKIMA), LOCATED APPROXIMATELY 513 NM 
NORTHEAST OF ANDERSEN AFB, GUAM, HAS TRACKED WEST-NORTHWESTWARD AT 
17 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE 
IMAGERY (MSI) REVEALS STY 28W HAS BEEN QUICKLY TRACKING ALONG THE 
SOUTHERN PERIPHERY OF THE DEEP LAYERED SUBTROPICAL RIDGE (STR). THE 
INTENSITY HAS BEEN MAINTAINED AT 140 BASED ON STEADY DVORAKS FROM 
PGTW AND KNES. UPPER LEVEL ANALYSIS INDICATES A POINT SOURCE 
ANTICYCLONE IS PROVIDING VERY FAVORABLE DUAL CHANNEL OUTFLOW SUPPORT 
TO THE EAST AND SOUTHWEST AND IS CREATING A LOW VERTICAL WIND SHEAR 
(VWS) ENVIRONMENT OVER THE SYSTEM. SEA SURFACE TEMPERATURES (SSTS) 
IN THE VICINITY OF THE LOW LEVEL REMAIN VERY FAVORABLE (29 DEGREES 
CELSIUS) FOR MAINTAINING THE INTENSITY OF THE SYSTEM
3. FORECAST REASONING.
   A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY FROM THE 
PREVIOUS PROGNOSTIC REASONING MESSAGE.
   B. STY 28W IS EXPECTED TO TRACK TO THE NORTHWEST UNDER THE 
STEERING INFLUENCE OF THE STR THROUGH THE NEXT 36 HOURS. AFTER TAU 
36, A PRESSING MID-LATITUDE TROUGH WILL MOVE INTO THE AREA AND BEGIN 
TO MODIFY THE STR. THIS WILL CAUSE TY 28W TO INITIALLY TRACK TO THE 
NORTH AND THEN TO THE NORTHEAST IN A GENERAL RECURVE SCENARIO. 
FAVORABLE ENVIRONMENTAL FACTORS OF GOOD OUTFLOW, WARM SSTS, AND LOW 
VWS WILL ALLOW STY 28W TO MAINTAIN SUPPER TYPHOON STRENGTH OVER THE 
NEXT 24 HOURS. AFTER WHICH, DECREASING OCEAN PARAMETERS AND 
INCREASING VWS WILL START TO SLOWLY WEAKEN THE SYSTEM.
   C. AFTER TAU 72, STY 28W WILL ACCELERATE TO THE NORTHEAST AS IT 
BEGINS EXTRA-TROPICAL TRANSITION (ETT). FURTHER DECREASING 
ENVIRONMENTAL FACTORS WILL CONTINUE TO ERODE THE SYSTEM AS IT 
QUICKLY MOVES NORTHEASTWARD. ETT IS EXPECTED TO BE COMPLETE BY TAU 
96 WHILE THE SYSTEM BECOMES EMBEDDED IN THE BAROCLINIC ZONE. NUMERIC 
MODEL GUIDANCE HAS IMPROVED AND IS IN GOOD AGREEMENT THROUGH TAU 96. 
DUE TO THE TIGHT AGREEMENT IN THE NUMERIC MODELS, THERE IS A HIGH 
CONFIDENCE IN THE EARLY PORTION OF THE FORECAST. IN LATER TAUS MODEL 
GUIDANCE HAS IMPROVED FROM THE PREVIOUS FORECAST, BUT CONFIDENCE 
REMAINS LOW AS THIS IMPROVEMENT IS FAIRLY RECENT.//
NNNN