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 03//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL DEPRESSION 33W (THIRTYTHREE), LOCATED APPROXIMATELY 841
NM EAST-SOUTHEAST OF MANILA, PHILIPPINES, HAS TRACKED
NORTHWESTWARD AT 07 KNOTS OVER THE PAST SIX HOURS. ANIMATED
ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS FLARING,
EXPANSIVE CENTRAL CONVECTION. A PARTIAL 181841Z SSMIS 91GHZ
IMAGE SHOWS THE LOW LEVEL CIRCULATION CENTER (LLCC) IS TO THE
EAST OF CONVECTION, WITH LOWER LEVEL BANDING WRAPPING INTO IT.
THE INITIAL POSITION IS BASED ON THE EIR LOOP AND AFOREMENTIONED
MICROWAVE IMAGE WITH LOW CONFIDENCE.  THE INITIAL INTENSITY IS
MAINTAINED AT 30 KTS BASED ON A 181241Z ASCAT PASS SHOWING A
BROAD AREA OF 30 KT WINDS IN THE SOUTHWESTERN QUADRANT OF THE
SYSTEM, ON THE HIGH END OF DVORAK CURRENT INTENSITY ESTIMATES
RANGING FROM T1.0 (25 KNOTS) TO T2.0 (30 KNOTS) FROM PGTW,
RJTD, AND KNES. UPPER-LEVEL ANALYSIS INDICATES A MARGINALLY-
FAVORABLE ENVIRONMENT WITH MODERATE TO STRONG (15 TO 25 KNOTS)
EASTERLY VERTICAL WIND SHEAR (VWS) THAT IS PUSHING THE
CONVECTION TO THE WEST OF THE LLCC OFFSET BY STRONG DIFFLUENCE
ALOFT THAT IS SUPPORTING THE FORMATIVE CENTRAL DENSE OVERCAST.
TD 33W IS TRACKING UNDER THE STEERING INFLUENCE OF THE DEEP-
LAYERED SUBTROPICAL RIDGE (STR) POSITIONED TO THE NORTH.
3. FORECAST REASONING.
   A.  THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE
PREVIOUS PROGNOSTIC REASONING MESSAGE.
   B. IN THE NEXT 72 HOURS, A MIDLATITUDE TROUGH WILL PASS OVER
NORTHEASTERN ASIA, LEADING TO A WEAKENING IN THE CENTER OF THE
STR, AND A RE-ORIENTING OF TWO LOBES OF THE STR TO EITHER SIDE.
TD 33W IS EXPECTED TO TRACK WESTWARD TO WEST-NORTHWESTWARD
THROUGH TAU 72 TOWARDS THE WEAKNESS IN THE STR. TD 33W SHOULD
INTENSIFY STEADILY TO 45 KNOTS BY TAU 48 AS WARM SEA SURFACE
TEMPERATURES (28-29 DEGREES CELSIUS) AND EXCELLENT OUTFLOW
COMPETE WITH MODERATE TO HIGH VWS. AROUND TAU 48, TD 33W WILL
MAKE LANDFALL OVER NORTHEAST MINDANAO. INTENSITY IS HELD THE
SAME BETWEEN TAU 48 TO 72 AS TD 33W TRACKS THROUGH THE SHALLOW,
WARM BODIES OF WATER BETWEEN THE PHILIPPINE ISLANDS INCLUDING
THE SULU SEA. NUMERICAL MODEL GUIDANCE IS IN FAIR AGREEMENT WITH
A SPREAD OF 205NM IN SOLUTIONS AT TAU 72.
   C. AFTER TAU 72, TD 33W WILL TRACK WESTWARD WHILE
TRANSITIONING TO THE STEERING INFLUENCE OF THE WESTERN STR,
WHICH WILL BUILD IN TO THE NORTH OF TD 33W. THE SPREAD BETWEEN
MODELS REMAINS 205NM AT TAU 120, WITH THE MOST VARIATION IN
NORTH TO SOUTH POSITIONING. THE JTWC FORECAST TRACK FAVORS A
FLATTER TRACK AND IS POSITIONED BETWEEN THE MULTI-MODEL
CONSENSUS AND THE ECMWF SOLUTION, WHICH IS TO THE SOUTH
OF CONSENSUS. NAVGEM IS THE NORTHERN OUTLIER AND PREDICTS A
POLEWARD TURN AT TAU 120. TD 33W SHOULD INTENSIFY TO A PEAK OF
55 KNOTS BY TAU 120 UNDER MARGINALLY FAVORABLE CONDITIONS IN THE
SOUTH CHINA SEA. OVERALL, THERE IS MODERATE CONFIDENCE IN THE
JTWC FORECAST TRACK.//
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