WDPN31 PGTW 140300 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 16W (SIXTEEN) WARNING NR 015// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 12.5N 163.2E INITIAL INTENSITY: 30 KTS GEOGRAPHIC REFERENCE: 1072 NM EAST OF ANDERSEN AFB MOVEMENT PAST 6 HOURS: WESTWARD AT 15 KTS SIGNIFICANT WAVE HEIGHT: 13 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS DEEP CONVECTION FLARING OVER A BROAD, PARTIALLY-EXPOSED, RAGGED LOW-LEVEL CIRCULATION (LLC), WHICH SUPPORTS THE INITIAL POSITION WITH MEDIUM CONFIDENCE. ALTHOUGH VERTICAL WIND SHEAR VALUES ARE LOW, DIFFLUENT UPPER-LEVEL EASTERLY FLOW OF 20-25 KNOTS OFFSET BY MODERATE POLEWARD OUTFLOW, ENHANCED BY A TUTT CELL TO THE NORTHWEST, AND DRY AIR ENTRAINMENT ARE HINDERING SUSTAINED CONVECTION AND LIMITING DEVELOPMENT. THE INITIAL INTENSITY OF 30 KTS IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON THE PGTW DVORAK ESTIMATE. INITIAL WIND RADII BASIS: NOT APPLICABLE (THERE ARE NO INITIAL WIND RADII). CURRENT STEERING MECHANISM: DEEP-LAYERED SUBTROPICAL RIDGE (STR) ENTRENCHED TO THE NORTH. AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T2.5 - 35 KTS KNES: T3.0 - 45 KTS CIMSS ADT: 41 KTS AT 132340Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY UNFAVORABLE VWS: 5-10 KTS SST: 29-30 CELSIUS OUTFLOW: MODERATE POLEWARD OTHER FACTORS: DRY AIR ENTRAINMENT ANALYSIS CONFIDENCE: INITIAL POSITION: MEDIUM INITIAL INTENSITY: MEDIUM INITIAL WIND RADII: NOT APPLICABLE 3. FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: TD 16W IS EXPECTED TO TRACK WESTWARD ALONG THE SOUTHERN PERIPHERY OF THE STR THROUGH TAU 72 THEN TURN WEST-NORTHWESTWARD THROUGH TAU 120 AS IT TRACKS ALONG THE SOUTHWEST PERIPHERY OF THE STR. TD 16W SHOULD EVENTUALLY BEGIN STRENGTHENING AFTER 36 TO 48 HOURS AS INDICATED IN THE BULK OF THE INTENSITY GUIDANCE WITH A MORE RAPID INTENSIFICATION TREND AFTER TAU 72 WITH A PEAK INTENSITY OF 70 KNOTS ANTICIPATED BY TAU 120. MODEL DISCUSSION: THERE IS SIGNIFICANT UNCERTAINTY (MEDIUM OVERALL) IN THE EXACT TRACK WITH A SPREAD OF 165NM AT TAU 72 NEAR GUAM. DUE TO THE BROAD NATURE OF THE LLC, THERE IS ADDITIONAL UNCERTAINTY IN THE INITIAL POSITION OF THIS BROAD LLC, WHICH COULD LEAD TO MINOR SHIFTS IN THE TRACK AS THE SYSTEM STRUGGLES TO CONSOLIDATE OVER THE NEXT TWO DAYS. INTENSITY GUIDANCE IS IN GOOD AGREEMENT THROUGH TAU 48 BUT DIVERGES AFTER TAU 48 WITH HWRF INDICATING A PEAK INTENSITY OF 110 KNOTS AT TAU 120 AND THE JTWC INDICATING A PEAK INTENSITY OF 70 KNOTS AT TAU 120. DUE TO THE MARGINALLY FAVORABLE CONDITIONS AND BROAD NATURE OF THE SYSTEM, THIS FORECAST IS SOMEWHAT CONSERVATIVE. OVERALL, THERE IS LOW CONFIDENCE IN THE INTENSITY FORECAST. FORECAST CONFIDENCE: TRACK 0 - 72 HR: MEDIUM TRACK 72-120 HR: MEDIUM INTENSITY 0 - 72 HR: LOW INTENSITY 72-120 HR: LOW// NNNN