000 AXNT20 KNHC 131119 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 705 AM EST MON MAR 13 2006 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...WEATHER OBSERVATIONS... RADAR...AND METEOROLOGICAL ANALYSIS. BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1045 UTC. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 5N9W 4N15W 5N26W EQ40W 2N47W INTO SOUTH AMERICA NEAR 2N51W. CLUSTERS OF SCATTERED MODERATE/ ISOLATED STRONG CONVECTION ARE FROM THE EQUATOR TO 7N E OF 20W TO ACROSS THE PRIME MERIDIAN. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE WITHIN 150 NM OF THE AXIS FROM 37W-50W. ...DISCUSSION... GULF OF MEXICO... STRONG UPPER RIDGE DOMINATES THE GULF EXTENDING FROM AN UPPER HIGH IN THE BAY OF CAMPECHE NEAR 19N94W NE TO OVER THE E US. AS A RESULT...THE CORE OF THE STRONGEST WESTERLIES AND ASSOCIATED DYNAMICS REMAIN N OF THE AREA MOVING ACROSS THE UPPER MISSISSIPPI VALLEY. AT THE SURFACE...THE COMBINATION OF BROAD LOW PRESSURE OVER THE CENTRAL US AND A 1027 MB HIGH JUST SW OF BERMUDA IS CREATING MODERATE/STRONG SE FLOW ACROSS THE ENTIRE GULF. THIS PATTERN IS CREATING AN ALMOST SUMMER-LIKE AIRMASS IN THE LOWER LEVELS WITH DEWPOINTS IN THE UPPER 60S TO 70S ACROSS THE REGION. THE BROAD LOW PRESSURE AND ASSOCIATED DEEP LAYERED TROUGH IS MOVING TOWARD THE GULF ARRIVING LATE TODAY INTO TUE MORNING GENERATING SHOWERS AND THUNDERSTORMS THAT WILL MOVE RAPIDLY ACROSS THE GULF INTO THE W ATLC DURING THE DAY WED. IN THE MEANTIME...MOSTLY CLEAR SKIES PREVAIL ACROSS THE GULF WITH THE EXCEPTION OF HIGH CLOUDS OVER THE NW GULF STREAMING FROM THE E PACIFIC ACROSS MEXICO. CARIBBEAN SEA... BROAD UPPER RIDGE OVER THE TROPICAL ATLC IS GIVING THE S CARIBBEAN UPPER WESTERLY FLOW S OF 15N. THE UPPER HIGH IN THE S GULF IS GIVING THE NW CARIBBEAN UPPER EASTERLY FLOW AND A UPPER LOW IN THE W ATLC DIPS OVER THE NE CARIBBEAN E OF 75W. STRONG SUBSIDENCE AND DRY UPPER AIR DOMINATE THE ENTIRE CARIBBEAN. TROPICAL MOISTURE IS MOVING ACROSS THE E CARIBBEAN GENERATING ISOLATED SHOWERS S OF 17N W OF 70W TO OVER THE LESSER ANTILLES. THE REMAINDER OF THE AREA IS UNDER GENERALLY CLEAR SKIES WITH MODERATE/STRONG EASTERLY TRADE WINDS. LITTLE CHANGE IS EXPECTED FOR THE AREA WITH SOME WEAKENING OF THE TRADES LATE MON INTO TUE DUE TO A FRONTAL PASSAGE IN THE GULF INTO W ATLC...THEN RETURNING ON WED. ATLANTIC OCEAN... A CUT-OFF UPPER LOW IS IN THE SW ATLC NEAR 25N62W COVERING THE AREA FROM 17N-31N BETWEEN 50W-78W INCLUDING THE N CARIBBEAN ISLANDS AND THE BAHAMAS. MODERATE/STRONG SUBSIDENCE AND DRY UPPER AIR COVER THE W ATLC W OF 40W. AT THE SURFACE...A 1027 MB HIGH IS LOCATED SW OF BERMUDA NEAR 31N67W WITH A RIDGE COVERING THE AREA W OF 40W INTO THE GULF OF MEXICO. LOW LEVEL MOISTURE REMAINS OVER THE SW ATLC FROM 18N-28N W OF 60W TO OVER THE BAHAMAS INCLUDING THE N CARIBBEAN ISLANDS PROVIDING ISOLATED SHOWERS TO THE ISLANDS. A DEEP LAYERED TROUGH IS OVER THE CENTRAL ATLC N OF 23N FROM 35W-50W WITH THE ASSOCIATED COLD FRONT ENTERING THE AREA NEAR 32N41W EXTENDING WSW TO 29N53W. BROKEN/OVERCAST LOW CLOUDS WITH ISOLATED SHOWERS ARE WELL SE OF THE FRONT WITHIN 120 NM OF LINE FROM 21N60W 25N37W TO BEYOND 32N33W. THE AIR BEHIND THIS FRONT IS VERY DRY AT ALL LEVELS. A VERY BROAD UPPER HIGH IS LOCATED OVER THE TROPICS NEAR 7N38W COVERING THE E ATLC S OF 23N...THE ENTIRE TROPICAL ATLC...AND THE S CARIBBEAN S OF 15N. N OF 23N E OF 35W ARE AN UPPER RIDGE AND TROUGH WITH NO SURFACE REFLECTION. MODERATE/STRONG SUBSIDENCE ALSO COVERS THE E ATLC LEAVING THE ITCZ AXIS AND ASSOCIATED CONVECTION S OF 7N. GENERALLY TRANQUIL WEATHER PREVAILS OVER THE FAR E ATLC WHERE THE LATEST VISIBLE SATELLITE IMAGERY SHOWS A STRONG SAHARAN AIR LAYER OUTBREAK COVERING THE AREA SE OF A LINE FROM 26N26W TO 10N40W...LEAVING THAT AREA VIRTUALLY CLOUD FREE. $$ WALLACE