WDPN31 PGTW 260900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 05W (MIRINAE) WARNING
NR 04//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TROPICAL STORM (TS) 05W (MIRINAE), LOCATED APPROXIMATELY 132 NM
SOUTHEAST OF HAIKOU, CHINA, HAS TRACKED WEST-NORTHWESTWARD AT 12
KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE
IMAGERY DEPICTS A SLOWLY CONSOLIDATING LOW-LEVEL CIRCULATION CENTER
(LLCC) WITH DEEP CONVECTION BUILDING OVER THE CENTER AND IMPROVED
DEEP CONVECTIVE BANDING. A 260225Z ASCAT PARTIAL IMAGE SHOWS A BAND
OF 30-KNOT WINDS OVER THE EASTERN SEMI-CIRCLE OF THE LLCC, WHICH
ALONG WITH THE DVORAK ESTIMATES OF 30 TO 35 KNOTS, SUPPORTS THE
CURRENT INTENSITY ASSESSMENT OF 35 KNOTS. THE CURRENT POSITION IS
BOLSTERED BY A 260714Z SSMI IMAGE SHOWING A WELL-DEFINED CENTER
POSITIONED JUST UNDER THE NORTHERN EDGE OF THE DEEP CONVECTIVE BAND
WITH TIGHTLY-WRAPPED SHALLOW BANDING. ALTHOUGH THE SYSTEM HAS
CONSOLIDATED, THE LLCC REMAINS PARTIALLY EXPOSED OVER THE NORTHERN
PERIPHERY OF THE LLCC DUE TO MODERATE (20 KNOTS) NORTHEASTERLY
VERTICAL WIND SHEAR. TS 05W CONTINUES TO TRACK WEST-NORTHWESTWARD
ALONG THE PERIPHERY OF THE SUBTROPICAL RIDGE TO THE NORTH.
3. FORECAST REASONING.
   A. THE GENERAL FORECAST PHILOSOPHY REMAINS THE SAME.
   B. TS 05W IS EXPECTED TO TRACK WEST-NORTHWESTWARD THROUGH TAU 24
UNDER THE CONTINUED INFLUENCE OF THE LOW- TO MID-LEVEL SUBTROPICAL
RIDGE (STR) TO THE NORTH. AFTER TAU 24, THE SYSTEM SHOULD TRACK
INCREASINGLY POLEWARD TOWARD A WEAKNESS IN THE STR CREATED BY AN
APPROACHING MIDLATITUDE SHORTWAVE TROUGH. DYNAMIC GUIDANCE IS IN
TIGHT AGREEMENT THROUGH TAU 24 LENDING HIGH CONFIDENCE TO THE EARLY
PORTION OF THE FORECAST TRACK. AFTER TAU 24, THE DYNAMIC GUIDANCE
INDICATES INCREASING SPREAD DUE TO MINOR DIFFERENCES IN THE TIMING
AND DEGREE OF THE RE-CURVE PHASE OF THE FORECAST TRACK, THEREFORE
THERE IS INCREASING UNCERTAINTY IN THE EXACT TRACK OF THE SYSTEM. TS
05W IS EXPECTED TO INTENSIFY SLIGHTLY PRIOR TO MAKING LANDFALL OVER
HAINAN ISLAND WITH A PEAK INTENSITY OF 40 KNOTS EXPECTED NEAR TAU
12. TS 05W SHOULD WEAKEN AS IT TRACKS OVER HAINAN ISLAND WITH A
SLIGHT RE-INTENSIFICATION AS THE SYSTEM TRACKS OVER THE GULF OF
TONKIN NEAR TAU 24. FURTHER WEAKENING AND DISSIPATION IS FORECAST AS
THE SYSTEM MAKES LANDFALL OVER NORTHEAST VIETNAM AND TRACKS INLAND.
THE OFFICIAL FORECAST LIES NEAR THE CONSENSUS./=