000 AXNT20 KNHC 152356 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 705 PM EST THU JAN 15 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...THE ITCZ... THE ITCZ AXIS IS CENTERED ALONG 5N10W 2N20W...CROSSING THE EQUATOR ALONG 30W TO 1S40W INTO NORTHEASTERN BRAZIL NEAR 3S45W. ISOLATED MODERATE CONVECTION IS WITHIN 90 NM SOUTH OF AXIS BETWEEN 14W-17W. SIMILAR CONVECTION IS NEAR 4N20W...AND NEAR 5N18W. ...DISCUSSION... THE GULF OF MEXICO... STRONG COLD SURFACE HIGH PRESSURE SYSTEM OVER THE CENTRAL CONUS IS INVADING THE GULF OF MEXICO AND THE STATE OF FLORIDA. THIS SYSTEM WILL PRODUCE A NOTICEABLE INCREASE IN WINDS AND SEAS ACROSS THE GULF THIS EVENING TO LATE FRIDAY...AND WILL ALSO KEEP MAX AND MIN TEMPERATURES BELOW NORMAL ACROSS SOUTH FLORIDA THROUGH THE UPCOMING WEEKEND. MULTILAYERED CLOUDS WITH EMBEDDED SHOWERS COVER THE MAJORITY OF THE GULF WATERS. SWLY WINDS ALOFT CONTINUE TO TRANSPORT ABUNDANT MID/UPPER LEVEL MOISTURE FROM THE EPAC ACROSS SOUTH-CENTRAL MEXICO INTO THE GULF AND THE STATE OF FLORIDA. A 110-130 KT JETSTREAM CROSSES THE N GULF WATERS AND THE SE CONUS THEN CONTINUES INTO THE ATLANTIC OCEAN. THE NEXT COLD FRONT IS EXPECTED TO MOVE SE ACROSS THE GULF SUNDAY EVENING THROUGH MONDAY. THE CARIBBEAN SEA... A STATIONARY FRONT EXTENDS FROM CENTRAL CUBA TO THE GULF OF HONDURAS NEAR 16N88W. SCATTERED MODERATE CONVECTION IS NEAR THE TAIL END OF THE FRONT. THE STRONG HIGH PRES COVERING THE GULF OF MEXICO WILL BUILD NORTH OF THE FRONT TONIGHT AND FRIDAY WITH AN INCREASE IN WINDS OVER THE NW CARIBBEAN. MEANWHILE...THE FRONT IS FORECAST TO MOVE TO EAST CUBA TO GULF OF HONDURAS FRI NIGHT AND REMAIN NEARLY STATIONARY. ELSEWHERE...MODERATE TO STRONG TRADE WINDS ARE BLOWING ACROSS THE BASIN. SHALLOW MOISTURE EMBEDDED IN THE TRADE WIND FLOW IS MOVING WWD ACROSS THE BASIN...MORE CONCENTRATED SOUTH OF HISPANIOLA AND OVER PUERTO RICO AND THE VIRGIN ISLANDS. IN THE UPPER LEVELS...AN UPPER RIDGE ANCHORED BY A HIGH NEAR THE COAST OF COLOMBIA DOMINATES THE ENTIRE REGION. SW WINDS ON THE WESTERN PERIPHERY OF THIS HIGH ARE ADVECTING SIGNIFICANT MID/UPPER LEVEL MOISTURE ACROSS THE NW CARIBBEAN AND CUBA INTO THE BAHAMAS AND THE W ATLC. STRONG SUBSIDENCE AND THE ASSOCIATED DRY AIR MASS IS NOTED OVER THE REMAINDER OF THE CARIBBEAN SEA...PARTICULARLY E OF 75W. THE ATLANTIC OCEAN... A SURFACE TROUGH...REFLECTION OF AN UPPER-LEVEL LOW CENTERED NEAR 14N53W...IS ALONG 19N52W 15N56W 10N59W. MOISTURE ASSOCIATED WITH THIS SYSTEM IS ALREADY REACHING THE LESSER ANTILLES. THE GFS COMPUTER MODEL SUGGESTS THAT THIS SYSTEM WILL MOVE WWD UNDER THE TRADE WIND FLOW AFFECTING THE LESSER ANTILLES TONIGHT AND THEN THE US/UK VIRGIN ISLANDS AND PUERTO RICO FRI THROUGH SUNDAY PRODUCING A SIGNIFICANT INCREASE IN MOISTURE. THIS MAY ALLOW FOR AN INCREASE IN SHOWER ACTIVITY TO THOSE ISLANDS. ELSEWHERE...A STATIONARY FRONT ENTERS THE FORECAST AREA NEAR 31N65W THEN CONTINUES SW CROSSING THE CENTRAL BAHAMAS AND CENTRAL CUBA INTO THE NW CARIBBEAN. SCATTERED SHOWERS ARE ASSOCIATED WITH THE FRONTAL BOUNDARY. STRONG HIGH PRES IS BUILDING BEHIND THE FRONT OVER THE SE CONUS. THE REMAINDER OF THE ATLANTIC FORECAST REGION REMAINS UNDER THE INFLUENCE OF A SFC RIDGE ANCHORED BY A 1032 MB HIGH SITUATED SW OF THE AZORES NEAR 37N38W. A SWATH OF MODERATE TO STRONG TRADE WINDS IS ON THE SOUTHERN PERIPHERY OF THIS RIDGE MAINLY FROM 10N-22N EAST OF 50W. ALOFT...A RIDGE EXTENDS FROM THE CARIBBEAN SEA THROUGH HISPANIOLA AND PUERTO RICO INTO THE CENTRAL AND EASTERN ATLANTIC. SOUTH OF THE RIDGE...THE ABOVE MENTIONED UPPER-LEVEL LOW. AN UPPER-LEVEL TROUGH IS OVER WEST AFRICA AND THE EASTERN ATLC E OF 25W. $$ GR