000 AXNT20 KNHC 041200 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT THU NOV 04 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 15.9N 76.0W AT 04/1200 UTC OR ABOUT 260 NM SW OF PORT AU PRINCE HAITI AND ABOUT 140 NM SSE OF KINGSTON JAMAICA MOVING NNW AT 6 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 998 MB. MAXIMUM SUSTAINED WIND SPEED IS 40 KT WITH GUSTS TO 50 KT. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS FROM 15N-18N BETWEEN 74W-76W. ISOLATED MODERATE CONVECTION IS ELSEWHERE SPREADING NORTHWARD OVER JAMAICA AND HISPANIOLA FROM 15N-19N BETWEEN 67W-78W. AS TOMAS TRACKS TOWARD THE WINDWARD PASSAGE AND HISPANIOLA...A SIGNIFICANT THREAT OF HEAVY RAINFALL... FLOODING...AND MUD SLIDES ARE POSSIBLE OVER HAITI AND THE DOMINICAN REPUBLIC DURING THE NEXT FEW DAYS. SEE 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. ...ITCZ... ITCZ AXIS IS ALONG 07N12W 09N25W 06N30W 08N45W 09N49W 10N60W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS WITHIN 240 NM S OF THE AXIS BETWEEN 10W-18W. A SURFACE TROUGH IS EMBEDDED WITHIN THE ITCZ FROM 05N30W TO 13N24W WITH ISOLATED MODERATE CONVECTION WITHIN 180 NM EITHER SIDE OF THE SURFACE TROUGH. ANOTHER SURFACE TROUGH STRETCHES FROM THE ITCZ REGION NEAR 10N47W TO A WEAKNESS WITHIN THE SUBTROPICAL RIDGE TO THE NORTH NEAR 22N45W. SCATTERED MODERATE CONVECTION IS MAINLY LOCATED EAST OF THE SURFACE TROUGH AXIS FROM 08N-19N BETWEEN 37W-48W. THIS AREA OF CONVECTION IS LIKELY ENHANCED EAST OF AN UPPER LEVEL TROUGH AXIS EXTENDING FROM 22N47W INTO THE DEEP TROPICAL ATLC NEAR 04N35W. ...DISCUSSION... GULF OF MEXICO... AN UPPER LEVEL SHORTWAVE TROUGH AXIS EXTENDS FROM MISSISSIPPI INTO THE NORTH-CENTRAL GULF NEAR 29N90W THEN SW TO CENTRAL MEXICO. THIS UPPER LEVEL TROUGHING SUPPORTS A COMPLEX AREA OF LOW PRESSURE FOCUSED ON A PAIR OF 1006 MB LOWS CENTERED AT 04/0900 UTC NEAR 30N86W AND 29N89W. WHILE A COLD FRONT EXTENDS FROM THE EASTERNMOST LOW OVER THE EASTERN GULF WATERS TO THE YUCATAN PENINSULA...THE AIRMASS HAS BECOME UNIFORM ENOUGH TO CONSIDER IT DISSIPATING...HOWEVER...LEFTOVER LOW-LEVEL CONVERGENCE AND PLENTY OF UPPER LEVEL DIFFLUENCE ARE GENERATING NUMEROUS SHOWERS AND ISOLATED TSTMS OVER A LARGE PORTION OF THE EASTERN GULF AND FLORIDA PENINSULA THIS MORNING. THE WESTERNMOST LOW...MORE CLOSELY ASSOCIATED WITH THE UPPER LEVEL LOW CENTER... HAS TRANSITIONED TO A FORMING COLD FRONT EXTENDING SW TO THE MEXICO COAST SOUTH OF BROWNSVILLE TEXAS NEAR 25N97W. STRONG NORTHERLY WINDS UP TO 30 KT ARE OBSERVED ON MANY OF THE BUOYS AND OIL PLATFORMS THIS MORNING WITH ISOLATED SHOWERS AND TSTMS OCCURRING N OF 25N BETWEEN 88W-94W. A STATIONARY FRONT IS ANALYZED BETWEEN THE LOWS AND NORTHEASTWARD OVER NORTHERN FLORIDA INTO THE W ATLC WATERS N OF 30N. AS THE UPPER LEVEL TROUGH AXIS SWINGS EASTWARD THROUGHOUT THE DAY ON THURSDAY... NORTHERLY WINDS TO GALE FORCE WILL SPREAD OVER THE WESTERN GULF W OF 92W AS THE COLD FRONT SWEEPS ACROSS THE CENTRAL GULF WATERS. CARIBBEAN SEA... A LARGE AND VERY BROAD UPPER LEVEL ANTICYCLONIC CIRCULATION IS CENTERED OVER THE CENTRAL CARIBBEAN NEAR 15N75W. EMBEDDED BENEATH THIS FEATURE ALOFT IS TROPICAL STORM TOMAS WHICH CONTINUES TO TRACK N-NW TOWARD THE WINDWARD PASSAGE AND EASTERN HISPANIOLA. SATELLITE IMAGERY INDICATES SCATTERED SHOWERS AND TSTMS ASSOCIATED WITH TOMAS ARE LOCATED FROM 15N-19N BETWEEN 67W-79W. TO THE SOUTH AND SOUTHWEST OF TOMAS...LOW-LEVEL GLOBAL MODEL FIELDS INDICATE THE PRESENCE OF A MONSOON TROUGH AXIS EXTENDING FROM SW OF TOMAS NEAR 13N78W TO COSTA RICA AND INTO THE E PACIFIC REGION. THIS MONSOONAL TROUGH AXIS ALONG WITH THE UPPER LEVEL DIFFLUENT ENVIRONMENT IN PLACE OVER THE CARIBBEAN IS GENERATING SCATTERED SHOWERS AND TSTMS FROM 08N-15N BETWEEN 68W-83W...INCLUDING INTERIOR PORTIONS OF PANAMA AND COSTA RICA. ATLANTIC OCEAN... AN UPPER LEVEL RIDGE EXTENDS NORTHWARD FROM THE CARIBBEAN SEA AND COVERS THE W ATLC W OF 55W. MOIST SW FLOW ALOFT IS LOCATED BETWEEN THE UPPER LEVEL ANTICYCLONE CENTERED IN THE CARIBBEAN AND A VIGOROUS UPPER LEVEL SHORTWAVE TROUGH LOCATED OVER THE NORTH-CENTRAL GULF OF MEXICO THAT IS PROVIDING A DIFFLUENT ENVIRONMENT GENERATING NUMEROUS SHOWERS AND ISOLATED TSTMS OVER THE FLORIDA PENINSULA AND W ATLC WATERS W OF 76W. A STATIONARY FRONT MEANDERS FROM A 1006 MB LOW CENTERED OFF THE NORTH CAROLINA COAST NEAR 35N75W TO THE FLORIDA COAST NEAR JACKSONVILLE. THE COMPLEX AREA OF LOW PRESSURE IN THE GULF IS FORECAST TO MOVE E-NE OVER THE NEXT 24 HOURS WITH A COLD FRONT EMERGING INTO THE W ATLC WATERS BY LATE THURSDAY WITH SOUTHERLY WINDS TO GALE FORCE EXPECTED N OF 29N WITHIN 180 NM E OF FRONT. FARTHER EAST...LINGERING LOW-LEVEL MOISTURE IS FOUND WITHIN SURFACE RIDGING ACROSS THE W ATLC AND POSSIBLE ISOLATED SHOWERS ARE FROM 21N-25N BETWEEN 50W-67W. A SURFACE TROUGH ALSO LOCATES ON THE EASTERN PERIPHERY OF THE SURFACE RIDGE FROM 31N46W TO 29N56W WITH ISOLATED SHOWERS WITHIN 90 NM EITHER SIDE OF THE BOUNDARY. OVER THE CENTRAL ATLC...A WEAKNESS WITHIN THE SUBTROPICAL RIDGE IS FOUND BETWEEN 36W AND 48W. A 1007 MB LOW CENTERED NORTH OF THE DISCUSSION AREA NEAR 35N39W EXTENDS A COLD FRONT TO 25N44W WITH SCATTERED SHOWERS AND ISOLATED TSTMS WITHIN 120 NM EAST OF THE FRONT. SOUTH OF THE COLD FRONT...A SURFACE TROUGH ANALYZED FROM 10N47W TO 22N45W IS ALSO CAPTURED WITHIN THE RIDGE WEAKNESS AND IS DISCUSSED FURTHER IN THE ITCZ SECTION. THE REMAINDER OF THE EASTERN ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1031 MB HIGH CENTERED OVER THE IBERIAN PENINSULA NEAR 42N05W. THE RIDGE AXIS EXTENDS FROM THE HIGH SW TO THE AZORES THEN TO NEAR 24N32W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN