Tropical Storm KALMAEGI Advisory mié, 13-11

MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 27W (TWENTYSEVEN)
WARNING NR 001//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TROPICAL DEPRESSION (TD) 27W (TWENTYSEVEN), LOCATED APPROXIMATELY
569 NM EAST-SOUTHEAST OF MANILA, PHILIPPINES, HAS TRACKED WESTWARD
AT 10 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED
SATELLITE IMAGERY SHOWS A SYSTEM WITH DEEP, FLARING, AND
DISORGANIZED CONVECTION THAT IS SHEARED APPROXIMATELY 30NM FROM AND
PARTLY EXPOSING AN ELONGATED AND RAGGED LOW LEVEL CIRCULATION (LLC).
THE INITIAL POSITION IS PLACED WITH FAIR CONFIDENCE ON THE PARTLY
EXPOSED LLC. THE INITIAL INTENSITY OF 25KTS IS BASED ON THE DVORAK
ESTIMATE OF T1.5/25KTS FROM PGTW AND IS CONSISTENT WITH RECENT ASCAT
PASSES. ANALYSES INDICATE A MARGINAL ENVIRONMENT WITH WARM (>30C)
SST AND STRONG WESTWARD OUTFLOW OFFSET BY A COLD DRY NORTHERLY SURGE
OVER THE PHILIPPINE SEA AND MODERATE TO STRONG (15-25KT) VERTICAL
WIND SHEAR ALOFT. THE CYCLONE IS TRACKING ALONG THE SOUTHERN
PERIPHERY OF A LOW REFLECTION OF THE SUBTROPICAL RIDGE (STR) TO THE
NORTH.
3. FORECAST REASONING.
   A. THIS IS THE FIRST PROGNOSTIC REASONING MESSAGE ON THIS SYSTEM
AND SETS THE FORECAST PHILOSOPHY.
   B. TD 27W WILL TRACK MORE NORTHWESTWARD AS IT GRADUALLY DEVELOPS
AND TRACKS MORE ALONG THE SOUTHWEST EDGE AND HIGHER REFLECTION OF
THE STR. THE MARGINAL ENVIRONMENT WILL FUEL A MODEST INTENSIFICATION
TO A PEAK OF 45KTS BY TAU 72 AS IT DRIFTS EAST OF LUZON.
   C. AFTER TAU 72, TD 27W WILL CONTINUE TRACKING NORTHWESTWARD,
ALBEIT AT A SLOWER PACE. INCREASING VWS AND NORTHERLY SURGE NEAR THE
SURFACE WILL BEGIN TO ERODE THE SYSTEM, REDUCING ITS FORWARD SPEED
AND ITS INTENSITY - DOWN TO 30KTS BY TAU 120. NUMERICAL MODELS ARE
IN BROAD AGREEMENT WITH THE DIRECTION OF TRACK; HOWEVER, THERE IS A
WIDE SPREAD IN THE MODEL ENVELOPE (OVER 640NM) WITH EEMN ON THE
EXTREME LEFT AND AFUM ON THE RIGHT MARGIN. THIS, PLUS THE
UNCERTAINTY IN THE STORM MOTION ASSOCIATED WITH A DEVELOPING
CYCLONE, LEND LOW CONFIDENCE IN THE JTWC FORECAST TRACK.//
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