000 AXNT20 KNHC 130544 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0345 UTC. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 6N10W 5N14W 4N23W EQ38W INTO SOUTH AMERICA NEAR 3N51W. SCATTERED MODERATE/STRONG CONVECTION IS WITHIN 60 NM OF THE AXIS FROM 14W-20W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM THE EQUATOR TO THE ITCZ AXIS BETWEEN 7W-20W. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE WITHIN 150 NM OF THE AXIS FROM 35W-50W. ...DISCUSSION... GULF OF MEXICO... STRONG UPPER RIDGE DOMINATES THE GULF EXTENDING FROM AN UPPER HIGH IN THE BAY OF CAMPECHE NEAR 19N93W NE TO OVER THE E US. AS A RESULT...THE CORE OF THE STRONGEST WESTERLIES AND ASSOCIATED DYNAMICS/LIFT REMAIN N OF THE AREA OVER THE UPPER MISSISSIPPI VALLEY. AT THE SURFACE...THE COMBINATION OF BROAD LOW PRESSURE OVER THE CENTRAL US AND A 1028 MB HIGH JUST W 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 70S ACROSS THE REGION. THE BROAD LOW PRESSURE AND ASSOCIATED DEEP LAYERED TROUGH WILL MOVE INTO THE GULF LATE MON/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. REMNANTS OF A RECENT FRONT IN THE CENTRAL ATLC HAS LEFT LOW LEVEL MOISTURE MOVING ACROSS THE E CARIBBEAN GENERATING ISOLATED SHOWERS FROM 13N-18N BETWEEN THE LEEWARD ISLANDS AND 70W. 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 W ATLC...THEN RETURNING ON WED. ATLANTIC OCEAN... A CUT-OFF UPPER LOW IS IN THE SW ATLC NEAR 23N68W COVERING THE AREA FROM THE N CARIBBEAN ISLANDS TO BERMUDA BETWEEN 56W AND FLORIDA. MODERATE SUBSIDENCE AND DRY UPPER AIR COVER THE W ATLC W OF 68W. AT THE SURFACE...A 1028 MB HIGH IS LOCATED W OF BERMUDA NEAR 32N67W WITH A RIDGE COVERING THE AREA W OF 50W INTO THE GULF OF MEXICO. LOW LEVEL MOISTURE FROM A RECENT FRONT REMAINS OVER THE SW ATLC FROM N OF HISPANIOLA TO OVER THE BAHAMAS PROVIDING ISOLATED SHOWERS TO THE ISLANDS. A DEEP LAYERED TROUGH IS OVER THE CENTRAL ATLC N OF 25N FROM 38W-55W WITH THE ASSOCIATED COLD FRONT ENTERING THE AREA NEAR 32N44W EXTENDING WSW TO 29N57W. BROKEN/OVERCAST LOW CLOUDS WITH ISOLATED SHOWERS ARE SE OF THE FRONT WITHIN 250 NM OF LINE FROM 24N57W 26N44W TO BEYOND 32N34W. THE AIR BEHIND THIS FRONT IS VERY DRY AT ALL LEVELS. A VERY BROAD UPPER HIGH IS LOCATED OVER THE TROPICS NEAR 4N35W COVERING THE E ATLC S OF 25N...THE ENTIRE TROPICAL ATLC...AND THE S CARIBBEAN S OF 15N. 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 YESTERDAY VISIBLE SATELLITE IMAGERY SHOWS A STRONG SAHARAN AIR LAYER OUTBREAK THAT NOW COVERS THE AREA SE OF A LINE FROM 30N30W TO 10N50W...LEAVING THAT AREA VIRTUALLY CLOUD FREE. $$ WALLACE