000 AXNT20 KNHC 141744 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT TUE APR 14 2009 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 1715 UTC. ...THE ITCZ... THE ITCZ AXIS IS CENTERED ALONG 4N8W 4N12W...CROSSING THE EQUATOR ALONG 20W TO 1S30W INTO NORTHEASTERN BRAZIL NEAR 3S44W. A TROPICAL WAVE-LIKE FEATURE...ANALYZED AS A SFC TROUGH ALONG 13W S OF 7N...IS WITHIN THE ITCZ. A LARGE CLUSTER OF MODERATE TO STRONG CONVECTION IS ASSOCIATED WITH THIS SFC TROUGH COVERING THE AREA FROM 1N-5N BETWEEN 10W-15W. THE HOVMOLLER DIAGRAM SHOWS THE WESTWARD PROPAGATION OF THIS AREA OF CONVECTION WHILE THE SSMI-DERIVED TPW PRODUCT INDICATES A BULGE OF MOISTURE ASSOCIATED WITH THIS FEATURE. ELSEWHERE...SCATTERED MODERATE CONVECTION IS FROM THE EQUATOR TO 2N BETWEEN 7W-12W...AND FROM 0N-3N BETWEEN 14W-20W. SIMILAR CONVECTION IS ALSO FOUND WITHIN 100-130 NM N OF AXIS BETWEEN 24W-29W ...DISCUSSION... THE GULF OF MEXICO... A COLD FRONT IS CURRENTLY MOVING ACROSS THE GULF OF MEXICO. AS OF 1500 UTC...THE FRONT STRETCHES FROM NEAR APALACHICOLA IN NORTHERN FLORIDA ACROSS THE CENTRAL GULF TO 22N96W. A RECENT QSCAT PASS SHOWED NE WINDS OF 20-25 KT BEHIND THE FRONT. A LARGE AREA OF SHOWERS WITH EMBEDDED STRONG TSTMS IS AHEAD OF THE FRONT AFFECTING N-CENTRAL FLORIDA WHERE A COUPLE OF TORNADO WATCHES WERE ISSUED. THE FRONT WILL CONTINUE TO MOVE SE ACROSS THE REGION EXTENDING FROM THE FLORIDA BIG BEND TO THE YUCATAN PENINSULA THIS EVENING THEN STALL OVER THE SE GULF WED...WHEN IS EXPECTED TO REACH SOUTH FLORIDA...AND LIKELY DISSIPATE THU. HIGH PRESSURE WILL BUILD OVER GULF IN THE WAKE OF FRONT THROUGH SAT. WINDS WILL INCREASE ACROSS THE WESTERN GULF ON FRI DUE TO A TIGHT PRES GRADIENT BETWEEN A RIDGE OVER THE EASTERN CONUS AND LOWER PRES OVER MEXICO. MODEL GUIDANCE INDICATES SE WINDS OF 20 TO 25 KT IN THAT AREA. A PRE-FRONTAL TROUGH E OF THE COLD FRONT EXTENDS FROM 22N91W TO 17N93W. THE WEAK SFC LOW THAT WAS PREVIOUSLY ALONG THE TROUGH OVER THE SW GULF HAS DISSIPATED. SOUTH FLORIDA ALONG WITH THE SE GULF OF MEXICO HAS S-SW WINDS OF 15-20 KT WITH A FEW SHOWERS MOVING NWD UNDER THE PREVAILING WIND FLOW. IN THE UPPER LEVELS...A DEEP LAYERED TROUGH EXTENDING ACROSS THE CENTRAL U.S. INTO THE CENTRAL GULF OF MEXICO SUPPORTS THE AFOREMENTIONED COLD FRONT. SW FLOW AHEAD OF THIS TROUGH IS HELPING TO INDUCE THE CONVECTIVE ACTIVITY OVER CENTRAL FLORIDA. THE CARIBBEAN SEA... MODERATE TO FRESH TRADEWINDS ARE BLOWING ACROSS THE EAST AND CENTRAL CARIBBEAN. WINDS VEER TO THE SE OVER THE WESTERN CARIBBEAN DUE TO THE PRESENCE OF THE COLD FRONT ACROSS THE GULF OF MEXICO. NOAA BUOY 42056 IS REPORTING SUSTAINED WINDS OF 20 KT. SIMILAR WIND SPEEDS ARE NOTED OVER WESTERN CUBA. IN GENERAL...MOSTLY FAIR WEATHER PREVAILS ACROSS THE ENTIRE BASIN WITH THE TYPICAL LOW-TOPPED TRADE WINDS SHOWERS. THESE SCATTERED SHOWERS ARE MORE CONCENTRATED OVER THE E CARIBBEAN. IN THE UPPER LEVELS...A BROAD RIDGE WITH STRONG SUBSIDENCE COVERS MUCH OF THE AREA. STRONG W-SW FLOW AHEAD OF THE TROUGH OVER THE GULF OF MEXICO IS ADVECTING SOME MID/UPPER LEVEL MOISTURE OVER THE NW CARIBBEAN AND WESTERN CUBA INCLUDING ALSO THE SE GULF OF MEXICO. EXPECT LITTLE CHANGE OVER THE NEXT 24 HOURS. THE ATLANTIC OCEAN... A COLD FRONT ENTERS THE FORECAST AREA NEAR 32N37W THEN CONTINUES SW TO NEAR 25N60W. VIS SATELLITE IMAGERY REVEALS A NARROW BAND OF CLOUDS WITH ISOLATED SHOWERS ASSOCIATED WITH THE FRONT. THE REMAINDER OF THE REGION IS UNDER THE INFLUENCE OF HIGH PRES. A 1024 MB HIGH IS CENTERED JUST OVER BERMUDA WITH THE RIDGE ENVELOPING THE NORTHERN CARIBBEAN SEA...SOUTH FLORIDA AND THE BAHAMAS. A COLD FRONT PRESENTLY OVER THE SE U.S. AND THE GULF OF MEXICO WILL MOVE OFF THE GEORGIA COAST T0NIGHT AND EXTEND FROM 31N74W TO STRAITS OF FLORIDA MIDDAY WEDNESDAY. S TO SW WINDS 20 TO 30 KT ARE EXPECTED AHEAD OF THE FRONT OVER THE NW PORTION OF THE DISCUSSION AREA JUST N OF THE NW BAHAMAS EARLY WED. WINDS WILL SHIFT TO THE W AND THEN NW AFTER THE FRONTAL PASSAGE. A 1031 MB HIGH IS OVER THE E ATLANTIC JUST WEST OF THE AZORES. A RIDGE AXIS EXTENDS S FROM THIS HIGH INTO THE TROPICS TO NEAR 10N30W. IN THE UPPER LEVELS...A RIDGE/TROUGH/RIDGE PATTERN IS PRESENT WITH THE FIRST RIDGE OVER THE W ATLANTIC W OF 60W. AN UPPER LEVEL TROUGH IS OVER THE CENTRAL ATLANTIC EXTENDING FROM 30N40W TO NEAR BARBADOS IN THE WINDWARD ISLANDS. ANOTHER LARGE UPPER LEVEL RIDGE IS OVER THE E ATLANTIC ANCHORED ON A HIGH LOCATED SOUTH OF THE CAPE VERDE ISLANDS NEAR 8N26W. A JET-STREAM BRANCH WITH CORE WINDS OF 90-100 KT LIES BETWEEN THE ABOVE MENTIONED TROUGH OVER THE CENTRAL ATLC AND THE RIDGE. $$ GR