MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 02W (WUTIP) WARNING NR 05// RMKS// 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL STORM (TS) 02W (WUTIP), LOCATED APPROXIMATELY 742 NM SOUTHEAST OF ANDERSEN AFB, GUAM, HAS TRACKED WESTWARD AT 10 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS A PARTIALLY-EXPOSED LOW-LEVEL CIRCULATION CENTER (LLCC) POSITIONED OVER THE EASTERN EDGE OF AN AREA OF PERSISTENT CORE CONVECTION WITH FRAGMENTED DEEP CONVECTIVE BANDING OVER THE NORTHERN AND WESTERN PERIPHERIES. A 200545Z SSMIS 91GHZ COLOR COMPOSITE MICROWAVE IMAGE INDICATES SHALLOW BANDING WRAPPING INTO A DEFINED LLCC WITH A DEEP CONVECTIVE BAND OVER THE WESTERN SEMICIRCLE. OVERALL, THERE IS FAIR CONFIDENCE IN THE INITIAL POSITION BASED ON THE FORMATIVE STRUCTURE OF THE LLCC EVIDENT IN SATELLITE IMAGERY. THE INITIAL INTENSITY REMAINS ASSESSED AT 45 KNOTS BASED ON DVORAK INTENSITY ESTIMATES OF T3.0 (45 KNOTS) FROM ALL AGENCIES. UPPER- LEVEL CONDITIONS REMAIN FAVORABLE WITH STRONG DIFFLUENCE ALOFT, PARTICULARLY POLEWARD OUTFLOW, AND LOW TO MODERATE VERTICAL WIND SHEAR. ADDITIONALLY, SST VALUES (29C) AND HIGH OCEAN HEAT CONTENT VALUES REMAIN CONDUCIVE FOR FURTHER DEVELOPMENT. TS 02W IS TRACKING WESTWARD UNDER THE STEERING INFLUENCE OF THE LOW- TO MID-LEVEL SUBTROPICAL RIDGE POSITIONED TO THE NORTH. 3. FORECAST REASONING. A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. THIS FORECAST REMAINS HIGHLY CONSISTENT WITH THE PREVIOUS JTWC WARNING. B. THROUGH TAU 72, TS 02W IS EXPECTED TO TRACK WESTWARD TO WEST- NORTHWESTWARD ALONG THE SOUTHERN PERIPHERY OF A DEEP-LAYERED STR ENTRENCHED TO THE NORTH. DUE TO THE VERY FAVORABLE ENVIRONMENTAL CONDITIONS, THE SYSTEM IS FORECAST TO INTENSIFY RAPIDLY TO 105 KNOTS BY TAU 72. NUMERICAL MODEL GUIDANCE IS IN GOOD AGREEMENT WITH A SPREAD OF 125NM AT TAU 72. C. IN THE EXTENDED PERIOD, UNCERTAINTY INCREASES SIGNIFICANTLY WITH A BIFURCATION IN THE MODEL GUIDANCE. IN GENERAL, THE SPREAD HAS DECREASED OVER THE PAST DAY BUT REMAINS LARGE AT TAU 120 (340NM). GFS, GFS ENSEMBLE, AFUM, EGRR, JGSM AND NAVGEM INDICATE A RECURVE SCENARIO WEST OF GUAM, WHICH APPEARS UNLIKELY DUE TO THE LACK OF A DEEP SHORTWAVE TROUGH (ALTHOUGH THERE IS A WEAK MIDLATITUDE SHORTWAVE TROUGH PRESENT WELL TO THE NORTH, OVER AND EAST OF MAINLAND JAPAN). GFS AND NAVGEM CONTINUE TO ERRONEOUSLY DRIVE THE SYSTEM DIRECTLY INTO AND THROUGH A STRONG STR POSITIONED OVER GUAM. ECMWF REMAINS THE SOLE OUTLIER BUT PRESENTS A MORE REALISTIC, CONSISTENT SOLUTION WITH A STAIR-STEP PATTERN AFTER TAU 120 AND EVENTUAL TRACK TOWARD THE WEST. THE JTWC OFFICIAL FORECAST FAVORS A NON-RECURVE SCENARIO CLOSER TO THE ECMWF SOLUTION DUE TO THE LACK OF A MIDLATITUDE RECURVE MECHANISM (DEEP SHORTWAVE TROUGH AND ASSOCIATED FRONTAL SYSTEM), AND PRESENCE OF A STRONG STR. TS 02W IS FORECAST TO MAINTAIN INTENSITY AT 100 TO 105 KNOTS AS IT SKIRTS SOUTHWEST OF GUAM, AND MAY STILL PRODUCE GALE-FORCE SUSTAINED WINDS AND ISOLATED GUSTS NEAR 50 KNOTS OVER GUAM. OVERALL, CONFIDENCE REMAINS LOW DUE TO THE BIFURCATION IN THE NUMERICAL GUIDANCE.// NNNN NNNN