000 AXNT20 KNHC 270520 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT TUE MAR 27 2007 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHEASTERN 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. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 8N12W 2N20W ALONG THE EQUATOR FROM 31W-43W THEN S OF THE EQUATOR INTO SOUTH AMERICA NEAR 1S48W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE WITHIN 120/150 NM OF THE AXIS E OF 15W TO INLAND OVER AFRICA. CLUSTERS OF SIMILAR CONVECTION ARE FROM 4N TO S OF THE EQUATOR FROM 28W-48W. ...DISCUSSION... GULF OF MEXICO... UPPER LEVEL LOW IS MOVING OVER W TEXAS WITH THE UPPER TROUGH MOVING INTO THE W GULF N OF 23N W OF 95W GENERATING A SQUALL LINE CURRENTLY INLAND ALONG THE TEXAS COAST. NARROWING HIGH AMPLIFIED UPPER RIDGE EXTENDS FROM THE E PACIFIC REGION ACROSS S MEXICO AND THE E BAY OF CAMPECHE OVER THE CENTRAL GULF TO OVER THE FAR E US CONTINUING TO ADVECT TROPICAL MOISTURE OVER MEXICO AND INTO THE CENTRAL GULF GENERATING ISOLATED SHOWERS/ THUNDERSTORMS MAINLY N OF 26N FROM 90W-95W. MODERATE/STRONG EASTERLY SURFACE WINDS FROM THE W ATLC ACROSS THE GULF CONTINUE TO BRING IN LOW LEVEL WIDELY ISOLATED SHOWERS OVER S FLORIDA...THE FLORIDA KEYS AND THROUGH THE STRAITS OF FLORIDA E OF 84W. SURFACE RIDGE CONTINUES TO EXTEND FROM THE NW ATLC OVER MUCH OF THE GULF. CARIBBEAN... UPPER RIDGE IN THE GULF OF MEXICO EXTENDS OVER THE FAR NW CARIBBEAN W OF 82W. UPPER LEVEL TROUGH FROM THE W ATLC EXTENDS THROUGH THE WINDWARD PASSAGE TO AN UPPER LOW JUST E OF JAMAICA NEAR 18N75W CONTINUING S TO NEAR 14N77W BRINGING STRONG SUBSIDENCE AND DRY AIR INTO THE NW CARIBBEAN W OF 75W. A SURFACE REFLECTION IN THE FORM OF A SURFACE TROUGH EXTENDS FROM 13N73W THROUGH THE MONA PASSAGE TO 20N67W ENHANCING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS N OF 14N FROM 66W-75W INCLUDING HISPANIOLA AND PUERTO RICO WITH SOME ISOLATED SHOWERS OVER E CUBA AND JAMAICA. REMAINDER OF THE CARIBBEAN IS UNDER A BROAD UPPER RIDGE THAT IS ANCHORED IN THE TROPICAL ATLC GIVING THE AREA SW UPPER FLOW AND ADVECTING TROPICAL MOISTURE WITH SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS S OF 14N E OF 74W TO OVER THE WINDWARD ISLANDS. STRONG EASTERLY WINDS ARE N OF 15N W OF 75W WHILE THE REMAINDER OF THE CARIBBEAN IS UNDER LIGHT/MODERATE SURFACE WINDS. ATLANTIC... UPPER RIDGE IN THE GULF OF MEXICO EXTENDS OVER THE FAR W ATLC W OF 77W. DEEP LAYERED TROUGH IS MOVING S OVER THE W ATLC N OF 25N FROM 45W-77W WITH THE ASSOCIATED COLD FRONT ENTERING THE REGION NEAR 32N47W EXTENDING WESTWARD ALONG 27N54W TO NEAR 27N73W. MODERATE/STRONG SUBSIDENCE AND DRY UPPER AIR REMAIN W OF 72W WITH COLD AIR STRATOCUMULUS CLOUDS NW OF FRONT. A PREFRONTAL SURFACE TROUGH EXTENDS FROM 28N52W TO 21N58W WITH SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 200 NM E OF THE FRONT N OF 26N. THE UPPER TROUGH OVER THE SW ATLC EXTENDS FROM 25N70W S ACROSS THE S BAHAMA ISLANDS INTO THE CARIBBEAN THROUGH THE WINDWARD PASSAGE TO THE UPPER LOW E OF JAMAICA. THE UPPER TROUGH IS GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS S OF 21N FROM 65W-74W. AN UPPER TROUGH IS OVER THE E ATLC N OF 20N E OF 34W TO THE COAST OF AFRICA. BROAD SURFACE RIDGE DOMINATES THE E ATLC E OF THE COLD FRONT ANCHORED BY A 1032 MB HIGH S OF THE AZORES. AN E/W UPPER RIDGE COVERS THE FAR E TROPICAL ATLC EXTENDING FROM OVER AFRICA ALONG 8W TO 25W AND A SECOND ANCHORED BY AN UPPER HIGH NEAR 5N40W. AS A RESULT...THE REMAINDER OF THE ATLC REMAINS RATHER TRANQUIL WITH FAIR WEATHER CLOUDS. LAST VISIBLE IMAGES SHOW AN AREA OF AFRICAN DUST EXTENDING FROM 8N-21N TO THE CAPE VERDE ISLANDS. $$ PAW