
WDPN31 PGTW 252100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 05W (FIVE) WARNING
NR 02//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL DEPRESSION 05W (FIVE), LOCATED APPROXIMATELY 306 NM
SOUTH OF HONG KONG, HAS TRACKED WESTWARD AT 11 KNOTS OVER THE
PAST SIX HOURS. ANIMATED INFRARED (IR) IMAGERY DEPICTS AN AREA OF
FLARING CONVECTION WRAPPING INTO A LOW-LEVEL CIRCULATION CENTER
(LLCC). THE INITIAL POSITION IS BASED ON ANIMATED IR IMAGERY, SO
THERE IS SOME UNCERTAINTY. THE RELATIVELY DISORGANIZED CONVECTIVE
STRUCTURE AND SUBJECTIVE DVORAK ESTIMATES OF T1.5 FROM ALL AGENCIES
SUPPORT AN INTENSITY THAT REMAINS AT 25 KNOTS. THE QUICK DEVELOPMENT
IN THE LAST 12 HOURS SEEMS TO HAVE SLOWED AS THE CONVECTION REMAINS
DISORGANIZED AROUND THE LLCC. UPPER-LEVEL OUTFLOW IS RESTRICTED IN
THE NORTHERN AND EASTERN QUADRANTS, WITH 10-15 KNOTS OF
NORTHEASTERLY SHEAR DISPLACING THE CONVECTION TO THE SOUTHWEST OF
THE LLCC. TD 05W IS TRACKING WEST-NORTHWESTWARD ALONG THE PERIPHERY
OF A SUBTROPICAL RIDGE TO THE NORTH.
3. FORECAST REASONING.
A. THE GENERAL FORECAST PHILOSOPHY REMAINS THE SAME, BUT THE
TRACK HAS BEEN ADJUSTED WESTWARD DUE TO THE INTENSITY OF THE
SUBTROPICAL RIDGE TO THE NORTH OF THE SYSTEM.
B. TD 05W IS EXPECTED TO CONTINUE ON ITS WEST-NORTHWESTWARD TRACK
TOWARD HAINAN ISLAND. SSTS REMAIN WARM ALONG THE TRACK, BUT OCEAN
HEAT CONTENT DROPS OFF IN THE GULF OF TONKIN. LANDFALL IS EXPECTED
ON HAINAN ISLAND AROUND TAU 24 AT A PEAK INTENSITY OF 35 KTS,
FOLLOWED BY WEAKENING DUE TO LAND INTERACTION. LITTLE IF ANY
REINTENSIFICATION IS FORECAST ONCE TD 05W RE-EMERGES OVER WATER. A
SECOND LANDFALL IS EXPECTED BY TAU 48, WITH DISSIPATION BY TAU 72.
TRACK GUIDANCE FROM THE DYNAMICAL MODELS HAS SHIFTED WESTWARD, AND
THE OFFICIAL FORECAST LIES TO THE WEST OF CONSENSUS NEAR THE ECMWF
SOLUTION GIVEN THE INTENSITY AND ORIENTATION OF THE 700 MB RIDGE
CURRENTLY IN PLACE OVER SOUTHEAST CHINA. TOWARD THE END OF THE
FORECAST PERIOD, A GRADUAL TURN TOWARD THE NORTHWEST IS EXPECTED AS
THE RIDGE WEAKENS IN RESPONSE TO THE PASSAGE OF A MID-LATITUDE
TROUGH IN THE WESTERLIES. THERE IS HIGH CONFIDENCE IN THE FORECAST
TRACK.//
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