000 AXNT20 KNHC 281146 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 705 AM EST MON JAN 28 2008 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHERN 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1100 UTC ...THE ITCZ... THE ITCZ AXIS IS CENTERED ALONG 5N10W 4N25W 2N35W EQ41W INTO NE BRAZIL NEAR 2S46W. SCATTERED SHOWERS AND ISOLATED TSTMS ARE WITHIN 70-100 NM EITHER SIDE OF AXIS MAINLY BETWEEN 20W-37W. WIDELY SCATTERED MODERATE CONVECTION IS ALONG THE EQUATOR BETWEEN 40W AND 49W. ...DISCUSSION... THE GULF OF MEXICO... HIGH PRES IS BUILDING ACROSS THE GULF WITH NLY WINDS AND COOLER TEMPERATURES. AS OF 09Z...A 1025 MB SFC HIGH IS LOCATED OVER SE LOUISIANA EXTENDING A RIDGE SW TO THE BAY OF CAMPECHE. THIS FEATURE ALSO COVERS FLORIDA AND WESTERN CUBA. THE LEADING EDGE OF THIS SFC HIGH IS A COLD FRONT THAT HAS PUSHED DOWN TO EASTERN CUBA AND THE NW CARIBBEAN. SCATTERED COLD AIR STRATOCUMULUS CLOUDS ARE MAINLY OVER THE EAST-CENTRAL GULF WHILE LOW LEVEL CLOUDS ARE POOLED AGAINST THE SIERRA MADRE MOUNTAINS. HIGH PRES WILL SLOWLY SLIDE SE AND WILL BE JUST EAST OF THE BAHAMAS TUE MORNING. SLY RETURN FLOW WILL DEVELOP ACROSS THE WESTERN GULF LATER TODAY AND TONIGHT AND THE NEXT COLD FRONT IS FORECAST TO MOVE OFF TEXAS COAST TUE EVENING. IN THE UPPER LEVELS...A RIDGE ALONG EASTERN MEXICO/TEXAS DOMINATES THE GULF GIVING THE AREA NWLY WIND FLOW. A SUBTROPICAL JET IS DRAWING ABUNDANT UPPER LEVEL MOISTURE FROM THE EPAC ACROSS NW MEXICO...TEXAS AND THE NW QUADRANT OF THE GULF. THE CARIBBEAN SEA... MAIN FEATURE IN THE CARIBBEAN SEA IS A COLD FRONT THAT TRAILS ACROSS EASTERN CUBA...THE CAYMAN ISLANDS AND THE NW CARIBBEAN. THE FRONT HAS DISSIPATED OVER THE YUCATAN PENINSULA AND THE BAY OF CAMPECHE AS HIGH PRES BUILDS IN. THIS FRONTAL SYSTEM IS PRODUCING SCATTERED TO BROKEN LOW LEVEL CLOUDS AND ISOLATED SHOWERS OVER CUBA AND THE CAYMAN ISLANDS. HOWEVER...THE FRONTAL BOUNDARY BECOMES MORE ACTIVE OVER THE W ATLC DUE TO A DIFFLUENT PATTERN ALOFT. ACCORDING TO THE GFS MODEL...THE FRONT WILL CONTINUE TO PUSH EWD AND WILL BE EXTENDED FROM HISPANIOLA TO HONDURAS THIS AFTERNOON WITH SCATTERED RAIN AND SHOWERS. THE SAME FRONT IS FORECAST TO AFFECT PUERTO RICO LATE TONIGHT THROUGH TUESDAY WITH AN INCREASE IN SHOWER ACTIVITY. THE TAIL END OF A WEAKENING FRONTAL BOUNDARY CONTINUES TO PRODUCE PATCHES OF LOW LEVEL CLOUDS AND ISOLATED SHOWERS OVER THE WINDWARD PASSAGE AND HISPANIOLA. THE REMAINDER OF THE CARIBBEAN SEA AND CENTRAL AMERICA HAS MODERATE TRADEWINDS. POCKETS OF LOW LEVEL CLOUDS WITH EMBEDDED SHOWERS DOT THE AREA MORE CONCENTRATED IN A BAND EXTENDING OVER THE EASTERN CARIBBEAN FROM THE NORTHERN LEEWARD ISLANDS TO ISLA MARGARITA OFFSHORE VENEZUELA. THIS BAND MAY PRODUCE LIGHT RAIN OVER THE UK/US VIRGIN ISLANDS TODAY. PATCHES OF LOW LEVEL CLOUDS ARE ALSO AFFECTING FROM WESTERN PANAMA TO NICARAGUA WHERE THE LOW LEVEL FLOW IS SLIGHTLY CONFLUENT. IN THE UPPER LEVELS...THE BASIN REMAINS UNDER THE INFLUENCE OF A SHORT-WAVE TROUGH OVER THE NW PORTION AND A MODEST MID/UPPER LEVEL RIDGE ELSEWHERE. WV IMAGERY SHOWS MODERATE TO STRONG SUBSIDENCE ACROSS THE ENTIRE REGION. THE ATLANTIC OCEAN... A COLD FRONT ENTERS THE FORECAST AREA NEAR 31N63W...THEN CONTINUES SW ACROSS THE SE BAHAMAS AND EASTERN CUBA INTO THE NW CARIBBEAN. SATELLITE IMAGERY AND LIGHTNING DATA SHOW SCATTERED SHOWERS AND TSTMS WITHIN 120 NM AHEAD OF THE FRONT AND NE OF THE SE BAHAMAS. SIMILAR CONVECTIVE ACTIVITY IS NOTED FROM 23N-26N BETWEEN 61W-65W. UPPER DIFFLUENCE BETWEEN THE DEEP LAYERED TROUGH THAT SUPPORTS THIS FRONT AND A RIDGE OVER THE CENTRAL ATLC IS ENHANCING ALL THIS ACTIVITY. COLD AIR STRATOCUMULUS CLOUDS ARE OBSERVED OVER THE W ATLC BEHIND THE FRONTAL ZONE. A 1013 MB SFC LOW IS NEAR 28N56W GENERATING SCATTERED SHOWERS AND TSTMS. A STATIONARY FRONT EXTENDS SW FROM THE LOW TO HISPANIOLA AND THE WINDWARD PASSAGE. A WARM FRONT ALSO EXTENDS E FROM THE LOW TO 28N50W. AT THIS POINT...A COLD FRONT CONTINUES NE TO BEYOND 31N38W. THE COLD FRONT OVER THE W ATLANTIC IS EXPECTED TO MERGE WITH THE STATIONARY FRONT OVER THE CENTRAL ATLANTIC AND MOVE TOWARD PUERTO RICO LATE TONIGHT. A SURFACE TROUGH CONTINUES TO LINGER OVER THE EASTERN ATLC AND LIES ALONG 28W/29W FROM 25N TO 32N. A QUIKSCAT PASS FROM AROUND 08Z SHOWS THE WIND SHIFT RELATED TO THE TROUGH. ALOFT...A TROUGH/RIDGE/TROUGH PATTERN DOMINATES THE REGION. A DIGGING UPPER-LEVEL TROUGH IS OVER THE WESTERN ATLC SUPPORTING THE PREVIOUSLY MENTIONED COLD FRONT. THE BASE OF THE TROUGH REACHES THE ISLAND OF GREAT INAGUA IN THE BAHAMAS. THE CENTRAL ATLC IS UNDER THE INFLUENCE OF AN UPPER RIDGE WHILE ANOTHER UPPER-LEVEL TROUGH PERSISTS OVER THE E ATLC WITH A CUT-OFF LOW NW OF THE MADEIRA ISLANDS NEAR 31N23W. UPPER LEVEL DIFFLUENCE E OF THE LOW CENTER IS PRODUCING A LARGE AREA OF CLOUDS WITH EMBEDDED SHOWERS OVER THE CANARY/MADEIRA ISLANDS. FURTHER SOUTH...A SWATH OF STRONG WLY UPPER LEVEL WINDS IS OVER THE TROPICAL ATLANTIC S OF 20N FROM THE NE CARIBBEAN TO W AFRICA CROSSING THE CAPE VERDE ISLANDS. $$ GR