000 AXNT20 KNHC 110453 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0345 UTC. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 7N10W 2N18W CROSSING THE EQUATOR NEAR 26W THEN ALONG 1S39W TO 2S46W. CLUSTERS OF SCATTERED MODERATE/STRONG CONVECTION ARE FROM THE PRIME MERIDIAN TO 12W BETWEEN THE EQUATOR AND 5N. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE WITHIN 180 NM N OF THE AXIS FROM 16W-28W AND FROM 1N-6N W OF 45W TO INLAND OVER SOUTH AMERICA. ...DISCUSSION... GULF OF MEXICO... SHORTWAVE UPPER TROUGH IS OVER E TEXAS AND MOVING TOWARD THE MISSISSIPPI VALLEY WITH THE ACCOMPANYING COLD FRONT ENTERING THE GULF AT 11/0300 UTC OVER CENTRAL LOUISIANA NEAR VERMILION BAY TO 25N97W THEN INTO MEXICO S OF LAGUNA MADRE WITH THE WESTERN EXTENSION OF THE FRONT SLIDING FASTER DOWN THE E SLOPES OF THE SIERRA MADRE MOUNTAINS. THIS FRONT IS GENERATING SCATTERED SHOWERS/THUNDERSTORMS WITHIN 75 NM E 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 ANCHORED OVER THE FAR E U.S. AND W ATLC IS PROVIDING RETURN FLOW OVER THE GULF E OF THE FRONT BANKING BROKEN/OVERCAST LOW CLOUDS WITH ISOLATED SHOWERS OVER THE REMAINDER OF THE AREA WITH THE EXCEPTION OF CLEARING SKIES W OF THE FRONT. A JETSTREAM WITH WINDS FROM 90 TO 115 KT IS OVER THE GULF N OF A LINE FROM JUST N OF TAMPICO MEXICO ACROSS FLORIDA S OF LAKE OKEECHOBEE. THE FRONT WILL TRANSVERSE THE GULF TODAY AND WEAKEN IN THE W ATLC ON WED. CARIBBEAN SEA... AN UPPER HIGH IS OVER THE W CARIBBEAN ANCHORED NEAR THE SE COAST OF CUBA WHILE AN UPPER TROUGH FROM THE CENTRAL ATLC EXTENDS INTO THE E CARIBBEAN ACROSS THE N 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. STRONG SUBSIDENCE AND DRY STABLE AIR DOMINATES THE CARIBBEAN EXCEPT IN THE FAR NW AREA WHERE THE REMNANTS OF A FRONTAL BOUNDARY ARE GENERATING ISOLATED SHOWERS FROM FAR W CUBA THROUGH THE YUCATAN CHANNEL. ATLANTIC OCEAN... A WEAK COLD FRONT REMAINS IN THE W/CENTRAL ATLC ENTERING THE AREA E OF BERMUDA NEAR 32N58W EXTENDING TO 26N70W WHERE IT WEAKENS FURTHER ACROSS THE CENTRAL BAHAMAS NEAR 24N75W TO OVER CENTRAL CUBA TO NEAR HAVANA 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. THE SURFACE RIDGE OVER THE FAR E U.S. IS BUILDING OVER THE W ATLC W OF THE FRONT ANCHORED BY A 1026 MB HIGH OFF THE GEORGIA COAST NEAR 32N75W AND A 1028 MB HIGH N OF THE REGION. 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 CENTRAL ATLC EXTENDING FROM A WEAK UPPER LOW NEAR 32N42W SW ALONG 23N48W INTO THE E CARIBBEAN OVER THE N WINDWARD ISLANDS. A WEAK SURFACE TROUGH EXTENDS FROM 30N46W TO NEAR 21N51W 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 S OF THE CANARY ISLANDS AND AN UPPER LOW INLAND OVER W AFRICA. A SURFACE RIDGE COVERS THE E ATLC E OF 40W ANCHORED BY A 1026 MB HIGH S OF THE AZORES. AN UPPER HIGH IS IN THE TROPICAL ATLC NEAR 11N28W AMPLIFYING NORTHWARD AND COVERS THE TROPICAL ATLC WITH A JETSTREAM OF WINDS FROM 90 TO 110 KT ALONG THE NW PERIPHERY WITHIN 150 NM OF LINE FROM 18N46W TO NEAR 28N30W. $$ WALLACE