02W set to reach Typhoon intensity within 36h slowly approaching the Marianas// TC 19S(FABIEN) slow weakening next 72h// 2009utc

JTWC IS ISSUING 6HOURLY WARNINGS AND 3HOURLY SATELLITE BULLETINS ON TD 02W. 12HOURLY WARNINGS AND 3HOURLY SATELLITE BULLETINS ARE ISSUED ON TC 19S(FABIEN).

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) INDICATES RAPID CONSOLIDATION AND CONVECTIVE ORGANIZATION HAS OCCURRED OVER THE PAST SEVERAL HOURS. NUMEROUS VERTICAL HOT TOWERS CAN BE OBSERVED ORBITING THE CONSOLIDATING LLCC OF 02W. A RECENT 200556Z SSMIS 91GHZ MICROWAVE IMAGE REVEALS IMPROVING YET STILL FRAGMENTED DEEP CONVECTIVE BANDING IN ALL QUADRANTS. THE INITIAL POSITION IS PLACED WITH MEDIUM CONFIDENCE BASED ON THE FULLY OBSCURED NATURE OF THE LLCC IN MSI AND SSMIS IMAGERY. THE INITIAL INTENSITY OF 30KTS IS ASSESSED WITH HIGH CONFIDENCE BASED ON A NEAR TOTAL CONSENSUS AMONGST AGENCY DVORAK INTENSITY ESTIMATES AND VARIOUS AUTOMATED INTENSITY ESTIMATES SUCH AS CIMSS SATCON AND ADT, ALL OF WHICH INDICATE 30KTS.SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) INDICATES RAPID CONSOLIDATION AND CONVECTIVE ORGANIZATION HAS OCCURRED OVER THE PAST SEVERAL HOURS. NUMEROUS VERTICAL HOT TOWERS CAN BE OBSERVED ORBITING THE CONSOLIDATING LLCC OF 02W. A RECENT 200556Z SSMIS 91GHZ MICROWAVE IMAGE REVEALS IMPROVING YET STILL FRAGMENTED DEEP CONVECTIVE BANDING IN ALL QUADRANTS. THE INITIAL POSITION IS PLACED WITH MEDIUM CONFIDENCE BASED ON THE FULLY OBSCURED NATURE OF THE LLCC IN MSI AND SSMIS IMAGERY. THE INITIAL INTENSITY OF 30KTS IS ASSESSED WITH HIGH CONFIDENCE BASED ON A NEAR TOTAL CONSENSUS AMONGST AGENCY DVORAK INTENSITY ESTIMATES AND VARIOUS AUTOMATED INTENSITY ESTIMATES SUCH AS CIMSS SATCON AND ADT, ALL OF WHICH INDICATE 30KTS.

FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: TD 02W IS FORECAST TO CONTINUE TRACKING GENERALLY NORTH-NORTHWESTWARD UNDER THE STEERING INFLUENCE OF THE STR TO THE NORTHEAST. CURRENTLY IN A FAVORABLE ENVIRONMENT CHARACTERIZED BY MODERATE VERTICAL WIND SHEAR WHICH IS MORE THAN COMPENSATED BY WARM SEA SURFACE TEMPERATURES (30C) AND BUILDING OUTFLOW ALOFT. OVER THE NEXT 24 HOURS, TD 02W HAS A SIGNIFICANT POTENTIAL TO RAPIDLY INTENSIFY AS POLEWARD OUTFLOW BUILDS AND CORE CONVECTION CONTINUES TO CONSOLIDATE. AFTER TAU 24, HAVING REACHED TROPICAL STORM STATUS, 02W WILL CONTINUE TRACKING NORTH-NORTHWESTWARD AND GRADUALLY INTENSIFYING UNTIL REACHING 85KTS NEAR TAU 72. AS THE SYSTEM PASSES JUST EAST OF GUAM, THE STR TO THE EAST IS FORECAST TO REORIENT AND BUILD FURTHER NORTHEASTWARD, THIS SHIFT WILL PUSH THE SYSTEM WEST-NORTHWESTWARD THROUGH THE FORECAST PERIOD. BY TAU 120, NOW CLEAR OF GUAM, 02W WILL CONTINUE TRACKING WEST-NORTHWESTWARD HAVING REACHED A PEAK INTENSITY OF 100KTS.

MODEL DISCUSSION: NUMERICAL MODELS ARE IN GOOD AGREEMENT THROUGH TAU 72 WITH A BULK OF THE GUIDANCE CLOSELY FOLLOWING THE JTWC FORECAST TRACK. AFUM, ECMWF ENSEMBLE AND HWRF ARE THE ONLY MEMBERS AT THIS TIME THAT BRING THE SYSTEM WEST OF GUAM. AFTER TAU 72, WITH THE EXCEPTION OF NVGM, ALL MEMBER GUIDANCE SHIFT THE TRACK WEST-NORTHWESTWARD THROUGH THE FORECAST PERIOD. WITH ALL MEMBERS SHOWING ONLY A 130NM CROSS TRACK SPREAD THROUGH TAU 96, THE JTWC FORECAST TRACK IS PLACED CLOSE TO THE MULTI-MODEL CONSENSUS WITH HIGH CONFIDENCE. RELIABLE MODEL INTENSITY GUIDANCE IS IN GOOD AGREEMENT WITH ALL MEMBERS AS WELL AS SEVERAL RAPID INTENSIFICATION (RI) AIDS SHOWING A STEEP INCREASE IN INTENSITY THROUGH TAU 48 AND A MORE GRADUAL INCREASE THROUGH THE FORECAST PERIOD. FOR THIS REASON THE JTWC FORECAST INTENSITY IS PLACED WITH OVERALL MEDIUM CONFIDENCE.

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS AN ELONGATED CIRCULATION WITH AN ASYMMETRIC CONVECTIVE COVER FULLY OBSCURING THE LOW LEVEL CIRCULATION CENTER (LLCC) BENEATH. A RECENT 200418Z ASCAT-B SCATTEROMERTY PASS REVEALS A SIMILARLY ASYMMETRIC WIND FIELD WITH 45-50 KNOT WINDS EXCLUSIVELY IN THE SOUTHWESTERN QUADRANT WHILE 25-30KT WINDS DOMINATE THE NORTHERN SEMICIRCLE. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON SCATTEROMERTY DATA AND MSI IMAGERY. THE INITIAL INTENSITY OF 50KTS IS ASSESSED WITH HIGH CONFIDENCE BASED PRIMARILY ON SCATTEROMETERY DATA THOUGH THE PREPONDERANCE OF INTENSITY ESTIMATES BOTH DVORAK AND CIMMS ALSO INDICATE 19S HAS MAINTAINED 50KTS.

FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: HAVING RECENTLY REACHED ITS APOGEE, TC 19S (FABIEN) IS FORECAST TO MAKE A POLEWARD SHIFT OVER THE NEXT 12 HOURS. DURING THIS TIME, AS VERTICAL WIND SHEAR (VWS) REMAINS LOW AND OUTFLOW REMAINS GENERALLY FAVORABLE, THE SYSTEM IS FORECAST TO MAINTAIN ITS INTENSITY. BY TAU 24, NOW TRACKING GENERALLY SOUTHWARD IN A POOR STEERING ENVIRONMENT, VWS AND VERTICAL TILTING INCREASES AND UPPER LEVEL OUTFLOW WEAKENS RESULTING IN GRADUAL WEAKENING. BY TAU 72, A BUILDING STR JUST EAST OF THE SYSTEM FORCES FABIEN WESTWARD UNTIL ITS EVENTUAL DISSIPATION BY 96.

MODEL DISCUSSION: NUMERICAL MODELS ARE IN GOOD AGREEMENT WITH ALL MEMBERS GENERALLY FOLLOWING THE JTWC FORECAST TREND THROUGH TAU 72. AFTER TAU 72, AS THE NEW STR TO THE EAST EXERTS STEERING INFLUENCE, AND MEMBER GUIDANCE FANS OUT CONSIDERABLY AS SOLUTIONS STRUGGLE TO ACCOUNT FOR THIS NEW ELEMENT. FOR THIS REASON THE JTWC TRACK FORECAST IS PLACED INITIALLY WITH MEDIUM CONFIDENCE AND EVENTUALLY WITH LOW CONFIDENCE. RELIABLE MODEL INTENSITY GUIDANCE IS IN GOOD AGREEMENT WITH A BULK OF THE MEMBERS STAGNATING THE SYSTEM THROUGH TAU 12 AFTER WHICH ALL MEMBERS WEAKEN THE SYSTEM THROUGH THE FORECAST PERIOD. FOR THIS REASON THE JTWC FORECAST INTENSITY IS PLACED WITH OVERALL MEDIUM CONFIDENCE.