Tropical Storm KALMAEGI Advisory 11月19日

MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 27W (KALMAEGI) WARNING NR 025//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TYPHOON 27W (KALMAEGI), LOCATED APPROXIMATELY 289 NM NORTH-
NORTHEAST OF MANILA, PHILIPPINES, HAS TRACKED WEST-NORTHWESTWARD AT
06 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED (EIR)
SATELLITE IMAGERY REVEALS THAT THE SYSTEM IS HOLDING TOGETHER WITH A
16-22 NM RAGGED, OBLONG EYE AND SPIRAL BANDING. THE SYSTEM IS
LOOKING LESS ORGANIZED THAN SIX HOURS AGO AS THE EYE HAS BEEN
WOBBLING WITHIN THE LOW-LEVEL CIRCULATION AS IT FIGHTS INCREASING
VERTICAL WIND SHEAR. THERE IS GOOD CONFIDENCE IN THE INITIAL
POSITION BASED ON ANIMATED EIR IMAGERY AND AN 181719Z NOAA-20 ATMS
MICROWAVE IMAGE. THE INITIAL INTENSITY IS ASSESSED AT 75 KNOTS BASED
ON HEDGING ON THE LOWER END OF DVORAK INTENSITY ESTIMATES OF T4.5
(77 KNOTS) FROM RCTP AND T5.0 (90 KNOTS) FROM PGTW AND RJTD. UPPER-
LEVEL ANALYSIS INDICATES A MARGINALLY FAVORABLE ENVIRONMENT WITH
MODERATE TO STRONG (20 TO 30 KNOTS) VERTICAL WIND SHEAR OFFSET BY
ROBUST POLEWARD OUTFLOW. TY 27W IS TRACKING SLOWLY WEST-
NORTHWESTWARD AS THE SUBTROPICAL RIDGE (STR) POSITIONED TO THE EAST
BUILDS WESTWARD.
3. FORECAST REASONING.
   A. THERE IS NO SIGNIFICANT CHANGE TO THE FORECAST PHILOSOPHY FROM
THE PREVIOUS PROGNOSTIC REASONING MESSAGE.
   B. WITHIN THE NEXT 06-24 HOURS, TY 27W IS FORECAST TO GRADUALLY
TURN WEST-SOUTHWESTWARD AS IT ENCOUNTERS LOW-LEVEL NORTHEASTERLY
SURGE FLOW AND WEAKENS DUE TO INCREASING VERTICAL WIND SHEAR (25-35
KNOTS). TY 27W WILL WEAKEN RAPIDLY AFTER TAU 18 DUE TO INCREASED
FRICTIONAL EFFECTS AND STRONG VWS. NEAR TAU 24, THE SYSTEM WILL
TRACK OVER THE SOUTH CHINA SEA UNDER THE STEERING INFLUENCE OF THE
STR AND NORTHEAST SURGE FLOW WITH DISSIPATION ANTICIPATED BY TAU 72.
NUMERICAL MODEL GUIDANCE IS IN FAIR AGREEMENT LENDING MODERATE
CONFIDENCE TO THE JTWC FORECAST TRACK.//
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