Tropical Storm LINGLING Advisory czw., 05.09.

MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 15W (LINGLING) WARNING NR 13//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TYPHOON (TY) 15W (LINGLING), LOCATED APPROXIMATELY 194 NM
SOUTHWEST OF KADENA AB, OKINAWA, JAPAN, HAS TRACKED NORTHWARD
AT 06 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE
IMAGERY SHOWS TIGHTLY-CURVED BANDS WRAPPED TIGHTER INTO THE
WELL-DEFINED 15NM EYE. THE INITIAL POSITION IS PLACED WITH HIGH
CONFIDENCE BASED ON THE EYE FEATURE OBSERVED IN A 042227Z SSMIS 37
GHZ MICROWAVE IMAGE WHICH IS CONSISTENT WITH THE CIRCULATION DEPICTED
IN A COMPOSITE RADAR LOOP FROM JMA AND A SURFACE OBSERVATION AT
MIYAKOJIMA (47927), LOCATED 40NM TO THE NORTH. THE INITIAL INTENSITY
OF 115 KTS IS BASED ON DVORAK INTENSITY ESTIMATES OF T6.0/115 KTS
FROM PGTW AND RCTP. UPPER-LEVEL ANALYSIS INDICATES A FAVORABLE
ENVIRONMENT WITH LOW TO MODERATE (15-20KT) VERTICAL WIND SHEAR (VWS)
OFFSET BY VIGOROUS EQUATORWARD OUTFLOW. ADDITIONALLY, THE SOUTHERLY
UPPER-LEVEL WINDS ARE IN PHASE WITH THE NORTHWARD MOTION OF THE
SYSTEM, DECREASING THE EFFECT OF VWS ON THE SYSTEM. SEA SURFACE
TEMPERATURES (SSTS) AT 28-29C REMAIN CONDUCIVE. TY 15W MAINTAINS A
NORTHWARD TRACK UNDER THE STEERING INFLUENCE OF THE SUBTROPICAL RIDGE
(STR) TO THE EAST.
3. FORECAST REASONING.
   A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE
PREVIOUS PROGNOSTIC REASONING MESSAGE.
   B. TY 15W WILL CONTINUE NORTHWARD UNDER THE STR. AFTER TAU 48, IT
WILL TRACK MORE NORTH-NORTHEASTWARD IN THE YELLOW SEA AS THE STR
RECEDES EASTWARD IN RESPONSE TO A MIDLATITUDE TROUGH APPROACHING FROM
THE NORTHWEST. THE OVERALL FAVORABLE ENVIRONMENT WILL PROMOTE A
PERIOD OF CONTINUED INTENSIFICATION TO A PEAK OF 120 KTS AT TAUS
12-24. AS THE SYSTEM ENTERS THE YELLOW SEA, INCREASING VWS AND
COOLING SSTS WILL BEGIN TO WEAKEN THE SYSTEM. IN THIS PORTION OF THE
JTWC TRACK, NUMERICAL MODELS ARE IN TIGHT AGREEMENT LENDING HIGH
CONFIDENCE.
   C. AFTER TAU 72, TY 15W IS EXPECTED TO MAKE LANDFALL AND INTERACT
WITH THE RUGGED TERRAIN OF CENTRAL NORTH KOREA. BY TAU 96, IT WILL
COMMENCE EXTRA-TROPICAL TRANSITION (ETT) AND ACCELERATE
NORTHEASTWARD. BY TAU 120, TY 15W WILL COMPLETE ETT AND CONTINUE TO
RAPIDLY WEAKEN AS THE SYSTEM ENCOUNTERS INCREASING VWS AND RUGGED
TERRAIN. NUMERICAL MODELS REMAIN IN GOOD AGREEMENT WITH GFS AS THE
NOTABLE RIGHT-OF-TRACK OUTLIER. DUE TO UNCERTAINTY IN TRACK SPEEDS
OVER RUGGED TERRAIN, THERE IS MODERATE CONFIDENCE IN THIS EXTENDED
PORTION OF THE JTWC FORECAST THAT IS LAID JUST LEFT OF MODEL
CONSENSUS TO OFFSET THE UNLIKELY GFS TRACK INTO THE STR.//
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