000 AXNT20 KNHC 251751 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT SUN MAR 25 2007 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHEASTERN SECTIONS OF SOUTH AMERICA...AND THE 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. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 6N9W 4N20W 2N35W 2N45W AND INTO NE BRAZIL NEAR 1S51W. FAIRLY LARGE CLUSTER OF NUMEROUS MODERATE/ISOLATED STRONG CONVECTION IS S OF THE AXIS FROM 4S-4N BETWEEN 10W-15W. THIS SEEMS TO BE MORE ASSOCIATED WITH A SECONDARY REGION OF TROUGHING/SPEED CONVERGENCE S OF THE MAIN ITCZ...AND MAY NEED TO BE ADDED TO THE 1800 UTC MAP. ISOLATED SHOWERS/TSTMS EXIST ELSEWHERE WITHIN 120 NM EITHER SIDE OF THE AXIS...EXCEPT FOR SCATTERED ACTIVITY NEAR THE BRAZIL COAST FROM 3S-5N BETWEEN 44W-53W. ...DISCUSSION... GULF OF MEXICO... SFC HIGH PRESSURE OVER THE SE U.S. CONTINUES TO EXTEND SW OVER THE GULF AND IS THE DRIVING FORCE IN TODAYS MARINE WEATHER. THE HIGH IS PRODUCING ABUNDANT MODERATE TO FRESH (11-21 KT ON THE BEAUFORT SCALE) E TO SE WINDS ACROSS THE BASIN. THESE WINDS HAVE LEVELED OFF THE SEAS IN THE 3-6 FT RANGE. WAVE SPECTRA ACROSS THE GULF ARE GENERALLY DOMINATED BY STEEP WIND WAVES WITH PEAK PERIODS MOSTLY IN THE IN THE 5-7 SEC BAND. LARGER AND STEEPER WAVES SHOULD BE ANTICIPATED IN THE STRAITS OF FLORIDA WITH THE ELY FLOW AGAINST THE OPPOSING GULF STREAM. VERY LITTLE SHOWER OR TSTM ACTIVITY NOTED ACROSS THE GULF THIS AFTERNOON...THOUGH MORE ACTIVITY IS NOTED OVER NRN MEXICO AND TX. THIS IS ASSOCIATED PRIMARILY WITH A FAIRLY SHARP MID TO UPPER LEVEL TROUGH EXTENDING SSW THROUGH ARIZONA/NEW MEXICO TO THE NE PACIFIC WITH AN EMBEDDED LOW CENTER NOTED IN THE CENTRAL GULF OF CALIFORNIA. UPPER DIFFLUENCE BETWEEN THE TROUGH AND THE DOMINATING UPPER RIDGE OVER THE GULF IS SUPPORTING THE SHOWER/TSTM ACTIVITY OVER MEX/TX. ASSOCIATED UPPER MOISTURE IS SPREADING INTO THE WRN GULF W OF 90W WITH WNW FLOW. SFC RIDGING WILL KEEP SIMILAR CONDITIONS ACROSS THE GULF INTO EARLY WEEK. THE MID TO UPPER TROUGH WILL MOVE THROUGH TX DURING MON AND TUE. MOST OF THE ASSOCIATED SHOWER/TSTM ACTIVITY IS EXPECTED TO STAY INLAND THOUGH SOME MAY SPILL INTO THE FAR NW GULF. CARIBBEAN... MOST ACTIVE WEATHER IN THE CARIBBEAN CONTINUES TO BE BETWEEN JAMAICA AND THE TURKS AND CAICOS ISLANDS. BROKEN TO OVERCAST MULTILAYERED CLOUDS WITH EMBEDDED SHOWERS ARE FROM 16N-24N BETWEEN 68W-78W. LIGHTNING DATA HAVE CONTINUED TO DEPICT ISOLATED TO SCATTERED TSTMS IN THIS VICINITY AS WELL. THE DRIVING WEATHER SUPPORT FOR THIS ACTIVITY IS A MID TO UPPER LOW BETWEEN JAMAICA AND CUBA NEAR 19N78W. THIS HAS A SFC REFLECTION AS A TROUGH EXTENDING THROUGH THE WINDWARD PASSAGE. GFS SUGGESTS THIS AREA WILL DRIFT SLOWLY E EARLY THIS WEEK...SO MARINE INTERESTS NEAR HISPANIOLA SHOULD ANTICIPATE SHOWER ACTIVITY WITH EMBEDDED TSTMS TO PERSIST OVER THE NEXT DAY OR SO. MUCH OF THE REMAINDER OF THE CARIB IS EXPERIENCING 10-20 KT TRADES EXCEPT A BIT STRONGER NE WINDS S OF CUBA...MAINLY N OF 18N AND W OF 78W WHERE A TIGHTER GRADIENT EXISTS. SIMILAR TRADE FLOW EXPECTED THROUGH EARLY WEEK. ATLANTIC... THE INTERACTION BETWEEN HIGH PRESSURE OVER THE SE U.S. AND A PAIR OF SFC TROUGHS IN THE WRN ATLC CONTINUE TO PRODUCE 15-25 KT NE WINDS NEAR THE BAHAMAS AND ATLC WATERS FROM 20N-29N W OF 65W. A REINFORCING COLD FRONT...CURRENTLY JUST S OF CAPE HATTERAS ASSOCIATED WITH A DEEPENING 1005 MB LOW NEAR 38N61W...WILL EXPAND THIS REGION OF HIGH NE WINDS IN THE WRN ATLC EARLY THIS WEEK. MODERATE TO STRONG...STEEP WIND WAVES/SWELL SHOULD ALSO BE ANTICIPATED IN THIS REGION. SEE OFFSHORE WATERS FORECAST UNDER AWIPS HEADER MIAOFFNT3 FOR MORE DETAILS. THE SFC TROUGHING IN THE WRN/CENTRAL ATLC AND CARIB IS PRODUCING SCATTERED SHOWER ACTIVITY OVER MUCH OF THE AREA FROM 19N-28N BETWEEN 47W-80W. THIS IS BEING ENHANCED BY A LARGE FETCH OF UPPER WSW FLOW THROUGH THE SAME AREA. THE REMAINDER OF THE E AND CENTRAL ATLC SFC PATTERN IS DOMINATED BY A 1029 MB HIGH SW OF THE AZORES NEAR 38N31W. THIS IS PRODUCING WIDESPREAD 15-20 KT TRADES AND FAIR WEATHER E OF 55W. UPPER FLOW IS HIGHLY ZONAL OVER THIS PORTION OF THE ATLC AS WELL. $$ WILLIS