Tropical Storm CHOI-WAN Advisory 06 Οκτ.

MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 23W (CHOI-WAN) WARNING
NR 14//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TROPICAL STORM (TS) 23W (CHOI-WAN), LOCATED APPROXIMATELY 149 NM
WEST-SOUTHWEST OF MINAMI TORI SHIMA, HAS TRACKED WEST-NORTHWESTWARD
AT 10 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED
(EIR) SATELLITE IMAGERY DEPICTS A SLOWLY CONSOLIDATING, BROAD LOW-
LEVEL CIRCULATION CENTER (LLCC) WITH IMPROVED CONVECTIVE BANDING. A
051526Z GPM 37GHZ IMAGE SHOWS MULTIPLE CONVECTIVE BANDS WRAPPING
INTO A BROAD BUT DEFINED LLCC. THE CURRENT POSITION IS BASED ON THE
EIR AND GPM IMAGERY WITH FAIR CONFIDENCE. THE INITIAL INTENSITY IS
ASSESSED AT 60 KNOTS, HEDGED SLIGHTLY HIGHER THAN THE DVORAK
INTENSITY ESTIMATES OF 55 KNOTS (T3.5) BASED ON THE CONVECTIVE
STRUCTURE. UPPER-LEVEL ANALYSIS SHOWS A FAVORABLE ENVIRONMENT WITH
RADIAL OUTFLOW AND LOW VERTICAL WIND SHEAR (VWS). ADDITIONALLY, WARM
SEA SURFACE TEMPERATURES (SSTS) ARE CONDUCIVE FOR FURTHER
DEVELOPMENT. TS 23W IS TRACKING ALONG THE SOUTHWESTERN PERIPHERY OF
A DEEP-LAYERED SUB-TROPICAL RIDGE (STR).
3. FORECAST REASONING.
   A. NO CHANGE TO FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC
REASONING MESSAGE.
   B. TS CHOI-WAN IS FORECAST TO ROUND THE SOUTHWESTERN PERIPHERY OF
THE STEERING STR AND TRACK ON A POLEWARD TRAJECTORY. FAVORABLE
ENVIRONMENTAL CONDITIONS WILL PERSIST FOR THE NEXT 24 TO 36 HOURS,
ALLOWING TS 23W TO REACH A PEAK INTENSITY OF 80 KNOTS BEFORE MOVING
INTO AN UNFAVORABLE ENVIRONMENT. NEAR TAU 24, THE STORM WILL BEGIN
EXTRA-TROPICAL TRANSITION (ETT) AS IT INTERACTS WITH THE BAROCLINIC
ZONE. AFTER TAU 36, TS 23W IS FORECAST TO WEAKEN AS IT ENCOUNTERS
STRONG VWS AND TRACKS OVER COOL SST (BELOW 26 CELSIUS). TS CHOI-WAN
WILL COMPLETE ETT AS IT GAINS FRONTAL CHARACTERISTICS BY TAU 48 BUT
WILL REMAIN A STRONG COLD-CORE LOW AS IT TRACKS NORTHWARD WITH
EXPANSIVE GALE-FORCE WINDS, WHICH SHOULD EXTEND AS FAR WEST AS THE
NORTHEAST COAST OF HONSHU. DYNAMIC MODEL GUIDANCE REMAINS IN VERY
TIGHT AGREEMENT THROUGHOUT THE FORECAST PERIOD, THEREFORE, THERE IS
HIGH CONFIDENCE IN THE JTWC TRACK FORECAST.//
NNNN
NNNN