000 AXNT20 KNHC 011800 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1745 UTC. ...SPECIAL FEATURES... TROPICAL STORM TOMAS IS CENTERED NEAR 13.6N 68.7W AT 01/1500 UTC. THIS LOCATION IS ABOUT 90 MI...150 KM NNE OF CURACAO ABOUT 420 MI...675 KM SE OF PORT AU PRINCE HAITI. TOMAS IS MOVING W AT 12 KT. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 1005 MB. MAXIMUM SUSTAINED WIND SPEED IS 40 KT WITH GUSTS TO 50 KT. PLEASE READ THE LATEST NHC INTERMEDIATE PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS MIATCPAT1/WTNT31 KNHC AND THE FULL FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT1/WTNT21 KNHC FOR MORE DETAILS. TOMAS CONTINUES TO EXPERIENCE MID-LEVEL SOUTHWESTERLY SHEAR. HOWEVER...AN AREA OF SCATTERED STRONG CONVECTION HAS RECENTLY FORMED JUST TO THE NORTHEAST OF THE LOW-LEVEL CENTER FROM 13N TO 16N BETWEEN 66W AND 70W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS OVER THE SE QUADRANT OF THE SYSTEM FROM 10N TO 14N BETWEEN 62W AND 66W. A GRADUAL WEAKENING TREND IS EXPECTED OVER THE NEXT 24 HOURS DUE TO THIS VERTICAL SHEAR. HOWEVER...AFTER THAT TIME...THE SHEAR IS EXPECTED TO DECREASE AND THE OTHER ATMOSPHERIC AND OCEANIC PARAMETERS SHOULD SUPPORT STRENGTHENING. ...ITCZ... THE ITCZ IS ANALYZED FROM THE SOUTHERN COAST OF LIBERIA NEAR 5N9W WESTWARD ALONG 4N20W 5N30W 6N40W 9N50W. A SURFACE TROUGH IS EMERGING INTO THE TROPICAL ATLC FROM THE WEST AFRICAN COAST ANALYZED FROM 12N11W TO 4N13W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS E OF 20W FROM 2N TO 9N. A SECOND EMBEDDED SURFACE TROUGH IS ANALYZED ALONG 35W S OF 13N WITH NO ASSOCIATED DEEP CONVECTION. A THIRD AND MORE ENERGETIC SURFACE TROUGH IS ANALYZED FROM 13N49W TO 7N52W. THIS TROUGH IS STILL EMBEDDED IN THE ITCZ. HOWEVER...VISIBLE SATELLITE IMAGERY COMBINED WITH LOW LEVEL DERIVED WINDS INDICATE WEAK CYCLONIC CURVATURE ALONG THE TROUGH AXIS. SCATTERED MODERATE CONVECTION IS FROM 7N TO 12N BETWEEN 47W AND 55W. THIS AREA OF CONVECTION IS EXPECTED TO REACH THE ISLAND OF BARBADOS IN THE NEXT 48 HOURS. SCATTERED WEAK TO ISOLATED MODERATE CONVECTION IS ELSEWHERE FROM 6N TO 10N BETWEEN 42W AND 47W. SIMILAR CONVECTION IS WITHIN 50 NM ON EITHER SIDE OF THE ITCZ AXIS BETWEEN 23W AND 28W. ...DISCUSSION... GULF OF MEXICO... WATER VAPOR IMAGERY AND UPPER AIR SATELLITE DERIVED WINDS INDICATE A WEAK ELONGATED UPPER LEVEL LOW/TROUGH CENTERED FROM THE WESTERN YUCATAN PENINSULA TO THE SW GULF. HOWEVER...THIS FEATURE REMAINS EMBEDDED IN VERY DRY AND STABLE AIR. THE SAME PRODUCT DISPLAYS MOSTLY WESTERLY ZONAL UPPER LEVEL FLOW N OF 24N. UPPER LEVEL MODEL DATA INDICATES A 70 KT JET-STREAK DEVELOPING OVER THE FAR NW GULF...LIKELY RESPONSIBLE FOR AN LINE OF SCATTERED MODERATE TO HEAVY SHOWERS AND ISOLATED THUNDERSTORMS MOVING ALONG THE EASTERN TEXAS COAST AND WESTERN LOUISIANA COAST BETWEEN GALVESTON ISLAND TO MARSH ISLAND RESPECTIVELY. THIS UPPER LEVEL JET ENHANCES A SHORTWAVE THAT SUPPORTS A LOW PRESSURE SYSTEM OVER E TEXAS...EXPECTED TO INTRODUCE A COLD FRONT INTO THE NW GULF BY TUESDAY WITH STRONG NORTHERLY WINDS BEHIND THE FRONT. CARIBBEAN SEA... BROAD UPPER LEVEL ANTICYCLONIC CIRCULATION COVERS MOST OF THE CARIBBEAN...CENTERED OVER THE SE BASIN. EMBEDDED BENEATH THIS FEATURE ALOFT IS TROPICAL STORM TOMAS WHICH CONTINUES TO IMPACT THE EASTERN CARIBBEAN. SEE SPECIAL FEATURES ABOVE FOR MORE DETAILS. AN EXTENSION OF THE ITCZ IS OVER THE FAR SW BASIN ALONG 10N. THIS FEATURE ALONG WITH WEAK MID LEVEL TROUGHINESS ON THE WESTERN PERIPHERY OF THE UPPER LEVEL RIDGE IS PROVIDING FOR SCATTERED SHOWERS AND ISOLATED TSTMS OCCURRING FROM 09N-16N BETWEEN 75W-84W. OTHERWISE...THE REMAINDER OF THE BASIN IS EXPERIENCING MODERATE TO FRESH TRADES AND THIS GENERAL SURFACE WIND PATTERN IS EXPECTED TO PERSIST OVER THE NEXT 24 HOURS OUTSIDE THE INFLUENCING DOMAIN OF TOMAS. ATLANTIC OCEAN... WESTERLY ZONAL UPPER LEVEL FLOW IS ACROSS THE W ATLC W OF 50W AND WATER VAPOR IMAGERY INDICATES A RELATIVELY DRY AIRMASS ASSOCIATED WITH THIS UPPER LEVEL ENVIRONMENT. THIS SUPPORTS A 1021 MB SURFACE HIGH CENTERED NEAR 27N65W THAT IS PROVIDING FAIR WEATHER CONDITIONS W OF 51W. A WEAK STATIONARY FRONT IS ANALYZED FROM 32N49W TO 26N51W. THIS FRONT HAS LOST UPPER LEVEL SUPPORT AND IS EXPECTED TO DISSIPATE OVER THE NEXT 24 TO 36 HOURS. IN THE MEANTIME...SCATTERED SHOWERS ARE LOCATED WITHIN 200 NM E OF THE FRONT N OF 22N. THE REMAINDER OF THE EASTERN ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1030 MB HIGH CENTERED EAST OF THE AZORES NEAR 38N22W. 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 14N-18N BETWEEN 19W-26W...INCLUDING THE CAPE VERDE ISLANDS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ GARCIA