000 AXNT20 KNHC 011116 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT MON NOV 01 2010 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS OF SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST FROM THE EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED ON SATELLITE IMAGERY...METEOROLOGICAL ANALYSIS...WEATHER OBSERVATIONS...AND RADAR. BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1015 UTC. ...SPECIAL FEATURES... TROPICAL STORM TOMAS IS CENTERED NEAR 13.8N 67.7W AT 01/0900 UTC OR ABOUT 115 NM NE OF CURACAO MOVING W AT 12 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1003 MB. MAXIMUM SUSTAINED WIND SPEED IS 45 KT WITH GUSTS TO 55 KT. TOMAS CONTINUES ON A WESTWARD TRACK BUT IS EXPERIENCING MID-LEVEL SOUTHWESTERLY SHEAR...AND THEREFORE SCATTERED MODERATE TO STRONG CONVECTION REMAINS WELL EAST OF THE LOW-LEVEL CENTER OVER THE EASTERN CARIBBEAN SEA FROM 11N-15N BETWEEN 62W-66W. A GRADUAL WEAKENING TREND IS EXPECTED DUE TO THIS VERTICAL SHEAR...HOWEVER...THE SHEAR IS FORECAST TO RELAX BY LATE TUESDAY AND AN OPPORTUNITY FOR RESTRENGTHENING THEREAFTER EXISTS. SEE THE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT1/WTNT21 KNHC FOR MORE DETAILS. ...ITCZ... ITCZ AXIS IS ALONG 07N12W 05N20W 07N34W 06N43W 08N49W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS FROM 03N-08N BETWEEN 11W-16W. ONE SURFACE TROUGH IS EMBEDDED WITHIN THE ITCZ FROM 06N-14N ALONG 34W WITH SCATTERED SHOWERS FROM 09N-14N BETWEEN 31W-36W. ANOTHER SURFACE TROUGH IS ANALYZED FROM 06N51W TO 13N49W WITH SCATTERED MODERATE AND ISOLATED STRONG CONVECTION FROM 08N-13N BETWEEN 45W-52W. ...DISCUSSION... GULF OF MEXICO... A WEAK UPPER LEVEL LOW IS CENTERED OVER THE NE YUCATAN PENINSULA NEAR 21N87W BUT REMAINS EMBEDDED IN VERY DRY AIR. ELSEWHERE N OF 23N...MOSTLY WESTERLY ZONAL UPPER LEVEL FLOW IS NOTED ON WATER VAPOR IMAGERY AND ALSO EXHIBITS VERY DRY AIR ALOFT. THIS UPPER LEVEL PATTERN CONTINUES TO SUPPORT A SURFACE RIDGE THAT EXTENDS FROM THE W ATLC ALONG 28N WITH 15-20 KT SOUTHERLY WINDS OVER THE NW GULF N OF 24N W OF 94W. LOW-LEVEL CONVERGENCE OF THESE SOUTHERLY WINDS THIS MORNING IS PRODUCING ISOLATED SHOWERS WITHIN 30 NM OF A LINE FROM 27N96W TO THE LOUISIANA COAST NEAR CAMERON. ELSEWHERE...MOSTLY FAIR CONDITIONS AND CLEAR SKIES PERSIST ACROSS MUCH OF THE BASIN WITH ONLY A FEW ISOLATED SHOWERS NOTED ON DOPPLER RADAR IMAGERY OVER THE EXTREME SOUTHERN FLORIDA PENINSULA AND PORTION OF THE FLORIDA STRAITS. LOOKING AHEAD...AN AREA OF DEVELOPING LOW PRESSURE OVER NORTH TEXAS WILL INTRODUCE A COLD FRONT INTO THE NW GULF BY EARLY TUESDAY WITH STRONG NW TO N WINDS EXPECTED W OF THE FRONT. CARIBBEAN SEA... A LARGE AND VERY BROAD UPPER LEVEL ANTICYCLONIC CIRCULATION IS CENTERED OVER THE SE CARIBBEAN NEAR 12N65W. EMBEDDED BENEATH THIS FEATURE ALOFT IS TROPICAL STORM TOMAS WHICH CONTINUES TO IMPACT THE EASTERN CARIBBEAN. GOES-13 SHORTWAVE INFRARED SATELLITE IMAGERY INDICATES A TOTALLY EXPOSED LOW-LEVEL CIRCULATION WELL WEST OF THE MAIN DEEP CONVECTION ASSOCIATED WITH THE SYSTEM LOCATED FROM 11N-15N BETWEEN 62W-66W...INCLUDING SCATTERED SHOWERS OVER THE LESSER ANTILLES AND ADJACENT WATERS E OF 62W. FARTHER WEST...LOW-LEVEL CONVERGENCE OF EASTERLY TRADES AND MARGINAL MIDDLE TO UPPER LEVEL DIFFLUENCE ON THE WESTERN PERIPHERY OF THE UPPER LEVEL RIDGE IS PROVIDING FOR SCATTERED SHOWERS AND ISOLATED TSTMS OCCURRING FROM 09N-19N BETWEEN 75W-83W. OTHERWISE...THE REMAINDER OF THE BASIN IS EXPERIENCING MODERATE TO FRESH TRADES AND THIS GENERAL SURFACE WIND PATTERN IS EXPECTED TO PERSIST THROUGH TUESDAY OUTSIDE THE INFLUENCING DOMAIN OF TOMAS AS IT TRACKS WESTWARD TO NEAR 75W BY LATE WEDNESDAY. ATLANTIC OCEAN... WESTERLY ZONAL UPPER LEVEL FLOW IS ACROSS THE W ATLC W OF 55W AND WATER VAPOR IMAGERY INDICATES A RELATIVELY DRY AIRMASS ASSOCIATED WITH THIS UPPER LEVEL ENVIRONMENT. THIS SUPPORTS A 1021 MB SURFACE HIGH CENTERED NEAR 29N64W THAT EXTENDS A RIDGE AXIS WESTWARD ALONG 28N ACROSS THE FLORIDA PENINSULA AND INTO THE NE GULF OF MEXICO. AN UPPER LEVEL SHORTWAVE TROUGH DIPS INTO THE DISCUSSION ZONE NEAR 32N50W AND EXTENDS AN AXIS S-SW TO 26N52W THAT IS SUPPORTING A STATIONARY FRONT ANALYZED FROM 32N50W TO A 1016 MB LOW CENTERED NEAR 27N52W. SCATTERED SHOWERS AND ISOLATED TSTMS ARE LOCATED WITHIN 150 NM E OF THE FRONT N OF 26N. THE REMAINDER OF THE EASTERN ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1031 MB HIGH CENTERED EAST OF THE AZORES NEAR 37N23W. FARTHER SOUTH OVER THE TROPICAL EAST ATLC... A BROAD UPPER LEVEL TROUGH IS NOTED E OF 40W THAT IS PROVIDING MIDDLE TO UPPER LEVEL SUPPORT OF WIDELY SCATTERED SHOWERS FROM 13N-19N BETWEEN 19W-28W...WHICH INCLUDES THE CAPE VERDE ISLANDS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN