TROPICAL DEPRESSION 26W INTENSIFYING

TROPICAL CYCLONE ADVISORY
NOV 22 2009

TROPICAL DEPRESSION 26W/PRE-NIDA

POSITION: 6.62N 148.89E

CURRENT INTENSITY: MAX: 25kt GUST: 35kt (46-65kph)
CURRENT PRESSURE: 1004MB
SURFACE WIND ANALYSIS: 26KT (48KPH) MSLP: 1004.8MB
ADVANCE DVORAK TECHNIQUES (ADT): 26KT(48KPH) MSLP: 1002.4MB
CENTRAL REGION TEMP: -47.05C (CURVE BAND)
CENTRAL CLOUD TEMP: -51.86C
FORECAST 12HRS: 35KT/65KPH

TROPICAL DEPRESSION (TD) 26W HAS GRADUALLY CONSOLIDATED OVER THE PAST 12 HOURS AS EVIDENCED BY ANIMATED MULTISPECTRAL IMAGERY. THE CURRENT POSITION AND INTENSITY ARE BASED ON THE ABOVE ANIMATION AND EXTRAPOLATED FROM A 2112OOZ QUIKSCAT PASS SHOWING 25-KNOT UNFLAGGED WINDS SOUTHEAST OF A WELL-DEFINED LOW LEVEL CIRCULATION CENTER. UPPER LEVEL ANALYSIS INDICATES THE SYSTEM IS SOUTHWEST OF THE RIDGE AXIS IN AN AREA OF MODERATE VERTICAL WIND SHEAR. TD 26W IS EMBEDDED IN THE MONSOON TROUGH IN A VERY WEAK STEERING PATTERN.

FORECAST REASONING.
A. THIS IS THE FIRST PROGNOSTIC REASONING BULLETIN AND ESTABLISHES THE FORECAST PHILOSOPHY FOR TD 26W.
B. TD 26W IS EXPECTED TO INITIALLY DRIFT SLOWLY TO THE NORTHEAST WITH THE GRADIENT LEVEL SOUTHWESTERLY FLOW. AFTER TAU 24, AS THE SYSTEM INTENSIFIES AND GAINS VERTICAL HEIGHT, A LOW TO MID-LEVEL SUBTROPICAL RIDGE TO THE NORTHEAST WILL BEGIN TO STEER THE SYSTEM TO THE NORTHWEST. AS THE STEERING MECHANISM SOLIDIFIES, TD 26W WILL INCREASE ITS FORWARD MOTION AND CONTINUE TO INTENSIFY TO A STRONG TROPICAL STORM BY TAU 72.
C. BEYOND TAU 72, AS THE CYCLONE APPROACHES THE UPPER LEVEL RIDGE AXIS, THE VERTICAL WIND SHEAR IS EXPECTED TO RELAX AND FURTHER ENHANCE DEVELOPMENT. ADDITIONALLY, ALONG-TRACK SEA SURFACE TEMPERATURES ARE WELL IN EXCESS OF 28 DEGREES CELSIUS, FURTHER AIDING INTENSIFICATION, EASILY EXCEEDING TYPHOON STRENGTH. THERE IS VERY MINIMAL NUMERIC GUIDANCE AVAILABLE AT THIS TIME AND THIS TRACK FORECAST IS IN THE GENERAL DIRECTION OF THE JTWC CONSENSUS.

TROPICAL DISTURBANCE 93W

JMA: MINIMAL DEPRESSION

POSITION:7.8N, 128.9E

CURRENT INTENSITY: MAX: 20kt GUST: 25kt (37-46kph)
CURRENT PRESSURE: 1007MB
SURFACE WIND ANALYSIS: 29KT (54KPH) MSLP: 1004.3MB
ADVANCE DVORAK TECHNIQUES (ADT): 0KT (KPH) MSLP: 0MB
CENTRAL REGION TEMP: 0C
CENTRAL CLOUD TEMP: 0C
FORECAST 12HRS: 25KT/46KPH

THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 6.7N 129.0E, IS NOW LOCATED NEAR 7.8N 128.9E, APPROXIMATELY 340 NM WEST OF PALAU. ANIMATED MULTISPECTRAL SATELLITE IMAGERY CONTINUES TO SHOW CONSOLIDATION OF DEEP CONVECTION NEAR A WELL-DEFINED LOW LEVEL CIRCULATION CENTER (LLCC). A 212327Z TRMM MICROWAVE IMAGE SHOWS MULTIPLE CONVECTIVE BANDS CONVERGING INTO THE SYSTEM CENTER WHILE THE INCREASINGLY SYMMETRIC LLCC IS EVIDENT IN A 220038Z ASCAT PASS. HOWEVER, THE LLCC HAS BEEN PARTIALLY-EXPOSED IN VISIBLE IMAGERY OVER THE LAST 6 TO 12 HOURS AS THE DEEP CONVECTION HAS BEEN SHEARED SLIGHTLY TO THE WEST. ADDITIONALY, THOUGH THE SYSTEM HAS SOME DIVERGENT FLOW ALOFT, IT CURRENTLY LACKS A GOOD OUTFLOW MECHANISM.

MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 17 TO 22 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1006 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS REMAINS FAIR.

JUST VOTE OR COMMENT FOR FEEDBACK