WDPN31 PGTW 070900 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 03W (GUCHOL) WARNING NR 006// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 15.2N 133.8E INITIAL INTENSITY: 45 KTS GEOGRAPHIC REFERENCE: 757 NM SOUTH-SOUTHEAST OF KADENA AB MOVEMENT PAST 6 HOURS: NORTH-NORTHWESTWARD AT 07 KTS SIGNIFICANT WAVE HEIGHT: 18 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A GRADUALLY CONSOLIDATING CIRCULATION WITH CONVECTIVE BANDS STRUGGLING TO WRAP AROUND THE CORE OF THE SYSTEM. A 070402Z AMSR2 89GHZ MICROWAVE IMAGE REVEALS FRAGMENTED AND DISORGANIZED CORE CONVECTION WITH IMPROVING DEEP CONVECTION IN THE PERIPHERY. THE INITIAL POSITION IS PLACED WITH MEDIUM CONFIDENCE BASED ON MSI AND AMSR2 IMAGERY. THE INITIAL INTENSITY OF 45 KTS IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON THE PREPONDERANCE OF EVIDENCE INCLUDING: CIMSS ADT, CIMMS D-PRINT AND AGENCY DVORAK INTENSITY ESTIMATES ALL FALLING NEAR 45KTS. INITIAL WIND RADII BASIS: PERSISTENCE CURRENT STEERING MECHANISM: NEAR-EQUATORIAL RIDGE (NER) TO THE SOUTH AND A NARROW EXTENSION OF THE STR TO THE NORTH AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T2.5 - 35 KTS RJTD: T3.0 - 45 KTS KNES: T3.0 - 45 KTS CIMSS ADT: 43 KTS AT 070530Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE VWS: 0-5 KTS SST: 28-29 CELSIUS OUTFLOW: MODERATE EASTWARD OTHER FACTORS: DRY AIR MASS TO THE NORTH ANALYSIS CONFIDENCE: INITIAL POSITION: MEDIUM INITIAL INTENSITY: MEDIUM INITIAL WIND RADII: LOW 3. FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: TS 03W SEEMS TO HAVE RECENTLY REGAINED SOME FORWARD PROGRESS. AS THE NARROW EXTENSION OF THE STR TO NORTH IS BROKEN DOWN THROUGH TAU 36, 03W WILL CONTINUE TO TRACK NORTHWESTWARD IN A FAVORABLE ENVIRONMENT. LOW VERTICAL WIND SHEAR (VWS), WARM SSTS AND FAVORABLE UPPER LEVEL OUTFLOW PROVIDED BY A TROPICAL UPPER TROPOSPHERIC TROUGH (TUTT) IS FORECASTED TO INTENSIFY THE SYSTEM TO AROUND 85KTS. AFTER TAU 36, A SHORT WAVE TROUGH BREAKS DOWN THE AFOREMENTIONED BLOCKING RIDGE TO THE NORTH AND COMBINED WITH A REORIENTATION OF THE RIDGING TO THE SOUTH AND EAST, 03W WILL BEGIN TO RECURVE POLEWARD. IN THE EXTENDED TRACK, COOLING SSTS, INCREASING VWS AND DRY AIR ENTRAINMENT WILL GRADUALLY WEAKEN THE SYSTEM AS IT IS PROPELLED NORTHEASTWARD BY A PASSING TROUGH. BY TAU 120, NOW NORTH OF THE 26TH PARALLEL AND HAVING WEAKENED TO 70KTS, 03W WILL CONTINUE PICKING UP SPEED AND WEAKENING AS IT CONTINUES TO INTERACT WITH AND EVENTUALLY INTEGRATE INTO THE TROUGH. MODEL DISCUSSION: NUMERICAL MODELS ARE IN GOOD AGREEMENT WITH A TIGHT SPREAD IN MODEL OUTPUT THROUGH TAU 72, AFTER WHICH SLIGHT CROSS-TRACK DEVIATIONS EMERGE THROUGH TAU 120. FOR THIS REASON THE JTWC TRACK FORECAST IS PLACED INITIALLY WITH HIGH CONFIDENCE AND WITH MEDIUM CONFIDENCE THEREAFTER. RELIABLE MODEL INTENSITY GUIDANCE IS IN GOOD AGREEMENT WITH ALL MEMBERS AS WELL AS SEVERAL RI AIDS SHOWING A SHARP INCREASE THROUGH TAU 36. AFTER TAU 36, THERE IS A 15-20KT SPREAD IN MODEL OUTPUT THROUGH THE FORECAST PERIOD. FOR THIS REASON THE JTWC INTENSITY FORECAST IS PLACED CLOSE TO THE MULTI-MODEL CONSENSUS WITH OVERALL MEDIUM CONFIDENCE. FORECAST CONFIDENCE: TRACK 0 - 72 HR: HIGH TRACK 72-120 HR: MEDIUM INTENSITY 0 - 72 HR: MEDIUM INTENSITY 72-120 HR: MEDIUM// NNNN