000 AXNT20 KNHC 231736 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT WED MAR 23 2011 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTION 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...ITCZ... ITCZ AXIS IS ANALYZED ALONG 7N11W 3N25W 2N36W CROSSING THE EQUATOR AND INTO SOUTH AMERICA NEAR 48W. SCATTERED MODERATE/ STRONG CONVECTION IS WITHIN 120 NM S AND 90 NM N OF THE ITCZ BETWEEN 13W-19W AND WITHIN 45 NM OF 2N BETWEEN 41W-44W. SMALL CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE WITHIN 60 NM OF 1N BETWEEN 19W-23W AND WITHIN 60 NM N OF THE ITCZ BETWEEN 32W-36W. ...DISCUSSION... GULF OF MEXICO... BROAD UPPER RIDGE COVERS THE GULF OF MEXICO ANCHORED OVER W CUBA WITH THE AXIS EXTENDING OVER NE FLORIDA AND ALONG THE CONUS EASTERN SEABOARD. STRONG SUBSIDENCE AND DRY STABLE AIR ALOFT DOMINATE THE GULF WATERS. THE SURFACE RIDGE COVERING THE GULF REMAINS ANCHORED BY A 1019 MB HIGH IN THE W ATLC GIVING THE GULF CLEAR SKIES AND FAIR WEATHER THIS AFTERNOON. THE SURFACE RIDGE WILL REMAIN ACROSS THE N GULF THROUGH LATE THU THEN A COLD FRONT WILL MOVE ACROSS THE N GULF COAST. CARIBBEAN SEA... THE UPPER RIDGE OVER THE GULF OF MEXICO COVERS MOST OF THE CARIBBEAN GIVING THE AREA NE TO E WINDS ALOFT WITH STRONG SUBSIDENCE AND DRY STABLE AIR ALOFT W OF A LINE FROM GUADELOUPE ISLANDS IN THE LEEWARD ISLANDS TO CENTRAL NICARAGUA. A LARGE UPPER RIDGE ANCHORED OVER THE DEEP TROPICS COVERS THE SE CARIBBEAN. THE TIGHT PRESSURE GRADIENT OVER THE CARIBBEAN IS BEING GENERATED BETWEEN THE SURFACE RIDGE OVER THE GULF OF MEXICO AND THE W INTO CENTRAL ATLC AND THE LOWER PRESSURE OVER THE TROPICS TO PRODUCE MODERATE TO STRONG NE TO E TRADE WINDS ACROSS THE BASIN WITH THE STRONGEST WINDS ALONG THE COAST OF COLOMBIA. THE UPPER RIDGE ANCHORED OVER THE TROPICS IS DRAWING TROPICAL MOISTURE ACROSS SOUTH AMERICA INTO THE SE CARIBBEAN AND ACROSS THE WINDWARD ISLANDS GENERATING SCATTERED TO NUMEROUS SHOWERS OVER THE SE CARIBBEAN SE OF A LINE FROM MARTINIQUE TO CURACAO ISLAND. ISOLATED LOW LEVEL MOISTURE REMAINS ACROSS THE REMAINDER OF THE CARIBBEAN GENERATING PATCHES OF ISOLATED SHOWERS USHERED IN ON THE TRADE WINDS MAINLY N OF 15N W OF 73W AND OVER THE SW CARIBBEAN INLAND AND WITHIN 90 NM ALONG THE COAST FROM 13N IN NICARAGUA TO 80W IN PANAMA. SURFACE RIDGE OVER THE GULF OF MEXICO AND W ATLC WILL MOVE SE AND WEAKEN THROUGH FRI. ATLANTIC OCEAN... A BROAD SURFACE RIDGE DOMINATES THE W AND CENTRAL ATLC INTO THE GULF OF MEXICO ANCHORED BY A 1019 MB HIGH NEAR 26N73W AND A 1023 MB HIGH IN THE CENTRAL ATLC NEAR 30N40W. BROAD UPPER TROUGH COVERS THE W ATLC N OF 20N W OF 45W SUPPORTING A FRONT THAT IS N OF THE DISCUSSION AREA WITH A SURFACE TROUGH EXTENDING JUST INTO THE REGION ALONG 31N57W 30N63W TO 31N68W. SCATTERED SHOWERS ARE WITHIN 60/75 NM SE OF THE SURFACE TROUGH. THE BROAD UPPER RIDGE ANCHORED OVER THE TROPICS EXTENDS N ALONG 32W TO NEAR 28N WHILE A SECOND UPPER TROUGH IS JUST TO THE N BETWEEN 22W-33W SUPPORTING A COLD FRONT THAT ENTERS THE REGION NEAR 32N27W ALONG 28N28W TO A 1016 MB SURFACE LOW NEAR 24N35W AND A SURFACE TROUGH EXTENDING S ALONG 20N37W TO 16N45W. ISOLATED SHOWERS ARE WITHIN WITHIN 60/75 NM E OF THE COLD FRONT. SURFACE RIDGE WILL SHIFT E AS A WEAK FRONT MOVES INTO THE FAR W ATLC LATE THU/EARLY FRI MOVING INTO THE CENTRAL ATLC BY SAT. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW