Tropical Storm SONGDA Advisory ma, 10-10

MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 23W (SONGDA) WARNING NR 08//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TYPHOON (TY) 23W (SONGDA), LOCATED APPROXIMATELY 278 NM EAST OF
IWO TO, HAS TRACKED NORTHWESTWARD AT 11 KNOTS OVER THE PAST SIX
HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS A RAPIDLY-
CONSOLIDATING LOW-LEVEL CIRCULATION CENTER (LLCC) WITH TIGHTLY-
CURVED DEEP CONVECTIVE BANDING WRAPPING INTO A DEFINED CENTER. A
092124Z SSMIS 91GHZ IMAGE SHOWS DEEP CONVECTIVE BANDING WRAPPING
TIGHTLY INTO A COMPACT CORE WITH A MICROWAVE EYE FEATURE, WHICH
SUPPORTS THE CURRENT POSITION WITH GOOD CONFIDENCE. ANIMATED WATER
VAPOR IMAGERY REVEALS NEAR-RADIAL OUTFLOW, WHICH IS FUELING THE
RAPID CONSOLIDATION. THE CURRENT INTENSITY IS ASSESSED AT 65 KNOTS
BASED ON DVORAK INTENSITY ESTIMATES OF T4.0 FROM ALL AGENCIES AND A
09/2041Z SATCON ESTIMATE OF 63 KNOTS. TY 23W IS TRACKING
NORTHWESTWARD ALONG THE SOUTHWEST PERIPHERY OF THE DEEP-LAYERED
SUBTROPICAL RIDGE (STR) POSITIONED TO THE NORTHEAST.
3. FORECAST REASONING.
   A.  NO SIGNIFICANT CHANGE TO THE FORECAST PHILOSOPHY FROM THE
PREVIOUS PROGNOSTIC REASONING MESSAGE.
   B. TY 23W IS FORECAST TO TRACK NORTHWESTWARD THROUGH TAU 12 THEN
RE-CURVE NORTHEASTWARD AND ACCELERATE AS IT ROUNDS THE WESTERN
PERIPHERY OF THE STR. TY SONGDA WILL CONTINUE TO INTENSIFY DUE TO
THE FAVORABLE RADIAL OUTFLOW AND IMPROVING POLEWARD OUTFLOW
ASSOCIATED WITH AN APPROACHING MIDLATITUDE SHORTWAVE TROUGH AND IS
EXPECTED TO REACH A PEAK INTENSITY OF 90 KNOTS BY TAU 36. AFTER TAU
48, TY SONGDA WILL BEGIN EXTRA-TROPICAL TRANSITION (ETT) AS IT
BEGINS TO INTERACT WITH THE MIDLATITUDE WESTERLIES AND THE
ASSOCIATED STRONG BAROCLINIC ZONE. THE SYSTEM IS EXPECTED TO WEAKEN
AS IT ENCOUNTERS INCREASING VERTICAL WIND SHEAR AND ACCELERATES
NORTHEASTWARD. TY 23W WILL COMPLETE ETT BY TAU 72 AS IT GAINS
FRONTAL CHARACTERISTICS AND BECOMES EMBEDDED WITHIN THE MIDLATITUDE
WESTERLY FLOW. NUMERICAL MODEL GUIDANCE REMAINS IN EXCELLENT
AGREEMENT, THEREFORE, THERE IS HIGH CONFIDENCE IN THE JTWC FORECAST
TRACK.//
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