MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 13W (SOUDELOR) WARNING
NR 03//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL STORM (TS) 13W (SOUDELOR), LOCATED APPROXIMATELY 261 NM
WEST- NORTHWEST OF ENEWETAK, HAS TRACKED WEST-NORTHWESTWARD AT 05
KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED IR IMAGERY SHOWS A
DEEP CDO FEATURE OBSCURING A LLCC WITH TIGHT BANDING WRAPPING INTO
THE CENTER. THE INITIAL POSITION IS BASED ON THE ABOVE IMAGERY AND
AN EDGE OF SWATH 301519Z AMSU-B IMAGE WITH LOW CONFIDENCE. THE
INITIAL INTENSITY OF 40 KNOTS IS BASED ON AN OVERALL ASSESSMENT OF
DVORAK ESTIMATES FROM PGTW, KNES, AND RJTD. UPPER-LEVEL ANALYSIS
INDICATES A FAVORABLE ENVIRONMENT WITH MODERATE VWS OFFSET BY GOOD
POLEWARD OUTFLOW DUE TO A TUTT CELL TO THE NORTH. THE CYCLONE IS
CURRENTLY TRACKING ALONG THE SOUTHERN PERIPHERY OF A DEEP-LAYERED
STR.
3. FORECAST REASONING.
A. THERE IS NO SIGNIFICANT CHANGE TO THE FORECAST PHILOSOPHY
FROM THE PREVIOUS PROGNOSTIC REASONING MESSAGE.
B. TS 13W IS FORECAST TO TRACK WEST-NORTHWESTWARD THROUGHOUT THE
FORECAST UNDER THE INFLUENCE OF THE STR. WHILE SOME SUBSIDENCE ON
THE NORTHEASTERN SIDE OF THE SYSTEM MAY INHIBIT RAPID DEVELOPMENT IN
THE SHORT TERM, EXPECT GRADUAL INCREASE IN INTENSITY THROUGH TAU 72
DUE TO GOOD POLEWARD OUTFLOW, DECREASING VWS, AND HIGH OHC THROUGH
THE NORTHERN MARIANAS ISLANDS.
C. IN THE EXTENDED TAUS, UPPER LEVEL CONDITIONS WILL CONTINUE TO
BE FAVORABLE, WITH A PEAK INTENSITY OF 125 KNOTS. WHILE SSTS WILL
REMAIN FAVORABLE AS THE SYSTEM TRACKS NORTH OF 20 DEGREES, OHC WILL
BECOME SLIGHTLY LESS FAVORABLE, WITH THE SYSTEM FLAT-LINING
INTENSITY. EXPECT A SLIGHTLY MORE POLEWARD COMPONENT TO THE TRACK AS
THE DEEP STR OVER CENTRAL HONSHU TRACKS SLIGHTLY TO THE EAST. WHILE
DYNAMIC MODEL GUIDANCE IS IN GOOD AGREEMENT, DUE TO THE LOW
CONFIDENCE IN THE INITIAL POSITION AND ITS AFFECT ON THE PERSISTENCE
OF THE TRACK, THERE IS LOW CONFIDENCE IN THE JTWC FORECAST TRACK.//
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