Tropical Storm THREE Advisory 3月15日

MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 03W (THREE)
WARNING NR 001//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TROPICAL DEPRESSION 03W (THREE), LOCATED APPROXIMATELY 324 NM
SOUTH OF NAVSTA GUAM, HAS TRACKED WESTWARD AT 10 KNOTS OVER THE PAST
SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI)
DEPICTS A PARTIALLY EXPOSED LOW LEVEL CIRCULATION CENTER (LLCC) WITH
DEEP CONVECTION PRIMARILY DISPLACED TO THE NORTH AND IN A DEEP
CONVECTIVE BAND TO THE EAST. ALTHOUGH AN OLDER 141206Z ASCAT PASS
SHOWED A WAVELIKE PATTERN WITH CYCLONIC TURNING AND STRONGER 25-30
KT WINDS ONLY TO THE NORTH AND NO RETURN FLOW, A 142049Z SSMIS 91GHZ
MICROWAVE IMAGE DEPICTS SHALLOW BANDING WRAPPING INTO THE LLCC FROM
THE SOUTHWEST. THE INITIAL POSITION IS BASED ON THE PARTIALLY
EXPOSED LLCC WITH HIGH CONFIDENCE. THE INITIAL INTENSITY IS
ASSESSED AT 25 KNOTS BASED ON THE APPARENT CLOSED CIRCULATION IN MSI
AND MICROWAVE IMAGERY, THE AFOREMENTIONED ASCAT PASS, AND
MULTIAGENCY DVORAK CURRENT INTENSITY ESTIMATES OF T1.0 (25 KTS).
ENVIRONMENTAL CONDITIONS ARE MARGINALLY FAVORABLE WITH MODERATE (15-
20 KT) SOUTHWESTERLY VERTICAL WIND SHEAR, GOOD POLEWARD OUTFLOW, AND
ADEQUATE SEA SURFACE TEMPERATURES (26 TO 28C). TD 02W IS CURRENTLY
TRACKING WESTWARD ALONG THE SOUTHEASTERN
PERIPHERY OF A DEEP LAYER SUBTROPICAL RIDGE (STR) POSITIONED
TO THE NORTH AND NORTHWEST.
3. FORECAST REASONING.
   A. THIS IS THE FIRST PROGNOSTIC REASONING MESSAGE AND SETS THE
FORECAST PHILOSOPHY.
   B. THROUGH TAU 72, TD 02W IS EXPECTED TO TRACK WESTWARD TO WEST-
SOUTHWESTWARD ALONG THE SOUTHERN PERIPHERY OF A DEEP-LAYERED STR TO
THE NORTH. A TROUGH APPROACHING FROM THE NORTHWEST IS WEAKENING THE
STR, ALLOWING FOR GOOD POLEWARD OUTFLOW. DUE TO THE MARGINAL VWS AND
SSTS, AND GOOD POLEWARD OUTFLOW, TD 03W IS FORECAST TO SLOWLY
INTENSIFY TO 30 KTS BY TAU 30. AFTER TAU 30, THE STR WILL BUILD BACK
IN TO THE NORTH OF TD 03W, LEADING TO DIMINISHING POLEWARD OUTFLOW
AND A MOSTLY WESTWARD TRACK. THOUGH MODELS ARE IN GOOD NORTH-SOUTH
AGREEMENT, ECMWF PREDICTS A FASTER ALONG-TRACK MOTION THAN DO THE
OTHER MODELS.
   C. AFTER TAU 72, SURFACE RIDGING BUILDING IN NEAR JAPAN WILL
RESULT IN COLD, DRY NORTHEASTERLY SURGE NEGATIVELY IMPACTING TD 03W.
IN ADDITION TO THE DRY AIR AND HIGHER VWS, LAND INTERACTION AS TD
03W CROSSES MINDANAO WILL LEAD TO FURTHER WEAKENING AND DISSIPATION
BY TAU 96. GIVEN THE POOR ORGANIZATION OF THE CIRCULATION, EARLIER
DISSIPATION INTO A TROPICAL WAVE VICE A TROPICAL CYCLONE IS
POSSIBLE. DUE TO THE DIFFERENCES IN ALONG-TRACK SPEED, THERE IS FAIR
CONFIDENCE IN THE JTWC TRACK FORECAST.//
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