Tropical Storm USAGI Advisory 11月18日

MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 33W (THIRTYTHREE)
WARNING NR 01//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TROPICAL DEPRESSION (TD) 33W (THIRTYTHREE), LOCATED APPROXIMATELY
512 NM EAST OF DAVAO CITY, PHILIPPINES, HAS TRACKED WESTWARD AT 15
KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE
IMAGERY AND A 180713Z NOAA-19 MHS 89GHZ MICROWAVE IMAGE DEPICT A
CONSOLIDATING SYSTEM WITH DEEP CONVECTIVE BANDING WRAPPING INTO THE
SOUTHWEST QUADRANT OF A PARTIALLY-EXPOSED, BROAD LOW-LEVEL
CIRCULATION CENTER (LLCC). OVERALL, THERE IS GOOD CONFIDENCE IN THE
CURRENT POSITION BASED ON THE AFOREMENTIONED IMAGERY AND SURFACE
OBSERVATIONS FROM KOROR (PTRO) SHOWING STEADY NORTHEASTERLY WINDS
GUSTING AS HIGH AS 32 KNOTS. THE CURRENT INTENSITY IS ASSESSED AT 25
KNOTS BASED ON DVORAK INTENSITY ESTIMATES OF T1.0 TO T1.5 (25 KNOTS)
FROM PGTW AND KNES. UPPER-LEVEL ANALYSIS INDICATES A MARGINALLY-
FAVORABLE ENVIRONMENT WITH MODERATE TO STRONG (15 TO 30 KNOTS)
EASTERLY VERTICAL WIND SHEAR OFFSET BY STRONG DIFFLUENCE ALOFT. TD
33W IS TRACKING WESTWARD UNDER THE STEERING INFLUENCE OF THE DEEP-
LAYERED SUBTROPICAL RIDGE (STR) POSITIONED TO THE NORTH.
3. FORECAST REASONING.
   A. THIS IS THE INITIAL PROGNOSTIC REASONING MESSAGE AND SETS THE
FORECAST PHILOSOPHY.
   B. TD 33W IS EXPECTED TO TRACK WESTWARD TO WEST-NORTHWESTWARD
THROUGH TAU 72 AS IT TRACKS ALONG THE WESTERN PERIPHERY OF THE
EASTERN STR. TD 33W SHOULD INTENSIFY STEADILY TO 55 KNOTS BY TAU 48
UNDER GENERALLY FAVORABLE CONDITIONS INCLUDING WARM SST (29-30C) AND
STRONG DIVERGENCE ALOFT. AFTER TAU 48, TD 33W WILL MAKE LANDFALL
OVER NORTHEAST MINDANAO, HOWEVER, ONLY A SLIGHT DECREASE IN
INTENSITY IS EXPECTED THROUGH TAU 72 DUE TO THE TRACK REMAINING OVER
WATER NORTH AND NORTHWEST OF MINDANAO. NUMERICAL MODEL GUIDANCE IS
IN FAIR AGREEMENT WITH A SPREAD OF 150NM IN SOLUTIONS AT TAU 72.
   C. AFTER TAU 72, TD 33W WILL CONTINUE TO TRACK WEST-NORTHWESTWARD
WHILE TRANSITIONING TO THE STEERING INFLUENCE OF THE WESTERN STR.
THERE IS INCREASING UNCERTAINTY WITH A SPREAD OF 260NM AT TAU 120,
HOWEVER, THE JTWC FORECAST TRACK FAVORS A FLATTER TRACK AND IS
POSITIONED ON THE SOUTHERN EDGE OF THE AIDS ENVELOPE CLOSER TO THE
ECMWF SOLUTION. TD 33W SHOULD REINTENSIFY TO A PEAK OF 60 KNOTS BY
TAU 120 UNDER MARGINALLY-FAVORABLE CONDITIONS. OVERALL, THERE IS
MODERATE CONFIDENCE IN THE JTWC FORECAST TRACK.//
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