Tropical Storm DANAS Advisory 05.10.

MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 23W (DANAS) WARNING NR
07//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TROPICAL STORM (TS) 23W (DANAS), LOCATED APPROXIMATELY 950 NM
EAST-SOUTHEAST OF KADENA AB, HAS TRACKED WEST-NORTHWESTWARD AT 15
KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE
IMAGERY INDICATES A CONSOLIDATING LOW-LEVEL CIRCULATION CENTER
(LLCC) WITH A DEVELOPING CENTRAL DENSE OVERCAST FEATURE. THE SYSTEM
HAS INTENSIFIED ABOUT 20 KNOTS OVER THE PAST 24 HOURS AND, AS
DEPICTED IN A 042207Z SSMIS IMAGE, HAS DEVELOPED TIGHTLY-CURVED
BANDING WHICH IS WRAPPING INTO A WELL-DEFINED CENTER. THEREFORE,
THERE IS GOOD CONFIDENCE IN THE INITIAL POSITION AND RECENT MOTION.
THE INITIAL INTENSITY IS ASSESSED AT 50 KNOTS AND IS BASED ON THE
HIGHER RANGE OF DVORAK INTENSITY ESTIMATES WHICH TOP OUT AT 55
KNOTS. THE INTENSITY ASSESSMENT IS ALSO SUPPORTED BY AUTOMATED
INTENSITY ESTIMATES RANGING FROM 50 TO 55 KNOTS. ANIMATED WATER
VAPOR IMAGERY INDICATES IMPROVED POLEWARD OUTFLOW INTO THE BROAD,
DEEPENING TUTT TO THE NORTHEAST. TS 23W IS TRACKING ALONG THE
SOUTHERN PERIPHERY OF A DEEP, STRONG SUBTROPICAL RIDGE (STR)
ENTRENCHED SOUTH OF JAPAN.
 3. FORECAST REASONING.
   A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
   B. TS 23W IS FORECAST TO REMAIN ON A WEST-NORTHWESTWARD TRACK
THROUGH TAU 48 UNDER THE STEERING INFLUENCE OF THE DEEP STR.
FAVORABLE SST ALONG THE FORECAST TRACK WITH IMPROVING UPPER-LEVEL
CONDITIONS WILL ALLOW FOR RAPID INTENSIFICATION THROUGH TAU 72.
DYNAMIC GUIDANCE IS IN TIGHT AGREEMENT THROUGH TAU 48 BUT DIVERGES
NEAR THE RE-CURVE POINT (JUST SOUTHEAST OF OKINAWA). ALL DYNAMIC
MODELS INDICATE A RE-CURVE SCENARIO BUT DIFFER ON THE THE TIMING OF
THE RE-CURVE. OVERALL, THERE IS LOW CONFIDENCE IN THE JTWC FORECAST
TRACK. TS 23W IS FORECAST TO PEAK AT 90 KNOTS NEAR OKINAWA; HOWEVER,
THERE IS POTENTIAL FOR FURTHER INTENSIFICATION.
   C.  IN THE EXTENDED TAUS, TS 23W IS FORECAST TO RE-CURVE
NORTHWARD AFTER PASSING OKINAWA AND BEGIN EXTRA-TROPICAL TRANSITION
(ETT). THE SYSTEM IS EXPECTED COMPLETE ETT AS IT ACCELERATES AND
TRACKS INTO THE SOUTHERN PORTION OF THE SEA OF JAPAN. TS 23W SHOULD
WEAKEN SIGNIFICANTLY AFTER TAU 72 AS IT ENCOUNTERS INCREASING
VERTICAL WIND SHEAR AND COOLER SST IN ADDITION TO INCREASED
INTERACTION WITH LAND. DUE TO THE UNCERTAINTY IN THE RE-CURVE POINT,
THERE IS LOW CONFIDENCE IN THE JTWC FORECAST TRACK.//
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