000 AXNT20 KNHC 111030 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT TUE MAR 11 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 0945 UTC. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 5N7W 2N11W CROSSING THE EQUATOR NEAR 18W THEN ALONG 1S25W 1S39W TO 2S46W. CLUSTERS OF SCATTERED MODERATE/STRONG CONVECTION ARE FROM 3W-13W BETWEEN THE THE COAST OF SW AFRICA TO ACROSS THE EQUATOR. SCATTERED MODERATE CONVECTION IS WITHIN 75 NM OF 5N W OF 45W TO INLAND OVER SOUTH AMERICA. ...DISCUSSION... GULF OF MEXICO... SHORTWAVE UPPER TROUGH IS MOVING OVER THE LOWER MISSISSIPPI VALLEY WITH THE ACCOMPANYING COLD FRONT ENTERING THE GULF AT 11/0900 UTC THROUGH A 1018 MB LOW ALONG THE SE LOUISIANA COAST NEAR 30N89W THEN SW ALONG 25N94W INTO MEXICO S OF TAMPICO. THIS FRONT IS GENERATING SCATTERED SHOWERS/THUNDERSTORMS WITHIN 75 NM E OF THE FRONT N OF 24N WITH ISOLATED SHOWERS WITHIN 45 NM W OF THE REMAINDER OF THE FRONT. THE REMAINDER OF THE GULF IS DOMINATED BY A BROAD UPPER RIDGE ANCHORED BY AN UPPER HIGH IN THE CARIBBEAN AND IS GIVING THE AREA SW UPPER FLOW. A SURFACE RIDGE OVER THE FAR SE U.S. AND W ATLC CONTINUES TO WEAKEN BUT IS STILL PROVIDING RETURN FLOW OVER THE GULF E OF THE FRONT BANKING BROKEN/OVERCAST LOW CLOUDS WITH ISOLATED SHOWERS OVER THE REMAINDER OF THE AREA. COLD AIR STRATOCUMULUS CLOUDS ARE FILLING THE AREA W OF THE FRONT. A JETSTREAM WITH WINDS FROM 90 TO 115 KT IS OVER THE GULF N OF A LINE FROM BROWNSVILLE TEXAS ACROSS FLORIDA JUST S OF LAKE OKEECHOBEE. THE FRONT WILL CONTINUE TO TRANSVERSE THE GULF TODAY AND WEAKEN IN THE W ATLC ON WED. CARIBBEAN SEA... AN UPPER HIGH IS OVER THE W CARIBBEAN ANCHORED OVER THE AREA BETWEEN SE CUBA,,,HAITI...AND JAMAICA WHILE AN UPPER TROUGH FROM THE CENTRAL ATLC EXTENDS INTO THE E CARIBBEAN ACROSS THE WINDWARD ISLANDS TO THE ABC ISLANDS. MODERATE NE TO E TRADE WINDS DOMINATES THE ENTIRE CARIBBEAN AND ARE USHERING IN ISOLATED CLUSTERS OF SHOWERS ACROSS THE REGION. MODERATE/STRONG SUBSIDENCE AND DRY STABLE AIR DOMINATES THE CARIBBEAN. ATLANTIC OCEAN... THE SURFACE RIDGE OVER THE FAR SE U.S. CONTINUES TO BUILD OVER THE W ATLC W OF THE CENTRAL ATLC FRONT ANCHORED BY A SERIES OF WEAK HIGHS N OF THE REGION. A WEAK COLD FRONT IS IN THE CENTRAL ATLC ENTERING THE AREA NEAR 32N53W EXTENDING TO 26N64W WHERE IT BECOMES A SURFACE TROUGH ACROSS THE CENTRAL BAHAMAS NEAR 24N76W THROUGH THE FLORIDA STRAITS WHILE THE UPPER LEVEL SUPPORT REMAINS N OF THE REGION. OVERCAST LOW/MID CLOUDS WITH ISOLATED SHOWERS ARE WITHIN 150 NM W OF THE FRONT AND N OF THE SURFACE TROUGH TO 30N. AN UPPER RIDGE COVERS THE W ATLC EXTENDING FROM THE UPPER HIGH IN THE NW CARIBBEAN. AN UPPER TROUGH IS OVER THE REMAINDER OF THE E/CENTRAL ATLC EXTENDING FROM A WEAK UPPER LOW NEAR 33N40W SW ALONG 21N48W INTO THE E CARIBBEAN OVER THE N WINDWARD ISLANDS. A WEAK SURFACE TROUGH EXTENDS FROM 32N45W TO NEAR 27N48W BUT DUE TO THE STRONG SUBSIDENCE AND DRY STABLE AIR THAT DOMINATES THE CENTRAL ATLC THERE IS ONLY SCATTERED LOW CLOUDS PRESENT. A SECOND UPPER TROUGH EXTENDS OVER THE FAR E ATLC E OF 20N WITH AN UPPER LOW INLAND OVER W AFRICA. A SURFACE RIDGE COVERS THE E ATLC E OF 40W ANCHORED BY A 1026 MB HIGH BETWEEN THE AZORES AND THE MADEIRA ISLANDS. AN UPPER HIGH IS IN THE TROPICAL ATLC NEAR 11N30W AMPLIFYING NORTHWARD AND COVERS THE TROPICAL ATLC WITH A JETSTREAM OF WINDS FROM 90 TO 115 KT ALONG THE NW PERIPHERY WITHIN 150 NM OF LINE FROM 17N45W TO NEAR 28N27W. $$ WALLACE