000 AXNT20 KNHC 032336 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT SAT MAY 03 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2245 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 21W/22W S OF 9N MOVING W 10 KT. WAVE WAS READJUSTED SLIGHTLY DUE TO THE SLOWER SPEED. WAVE HAS A WELL DEFINED BUT BROAD LOW AMPLITUDE INVERTED-V SIGNATURE AND NO ASSOCIATED SHOWERS/CONVECTION. ...THE ITCZ... THE ITCZ AXIS IS CENTERED ALONG 1N2W 2N13W 5N18W THEN 3N23W 2N32W INTO NE BRAZIL NEAR 2N52W. SCATTERED MODERATE/STRONG CONVECTION IS WITHIN 45 NM BOTH SIDES OF THE ITCZ AXIS FROM 25W-28W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 6N TO S OF THE EQUATOR E OF 16W ACROSS THE PRIME MERIDIAN AND FROM 7N TO S OF THE EQUATOR W OF 45W TO INLAND OVER SOUTH AMERICA. ...DISCUSSION... GULF OF MEXICO... DEEP LAYERED TROUGH IS CENTERED OVER THE MISSISSIPPI VALLEY WITH THE UPPER TROUGH JUST CLIPPING THE N GULF COAST AND THE ASSOCIATED COLD FRONT ENTERING THE REGION ACROSS LOUISIANA NEAR VERMILION BAY EXTENDING SW OVER S TEXAS JUST N OF BROWNSVILLE. A SQUALL LINE OF HEAVY SHOWERS/NUMEROUS THUNDERSTORMS IS TO THE SE OF THE ACTUAL FRONT WITHIN 60 NM OF LINE FROM 27N91W 27N88W TO OVER THE FLORIDA PANHANDLE NEAR PANAMA CITY. BROAD UPPER RIDGE COVERS THE REMAINDER OF THE GULF INTO THE W CARIBBEAN ANCHORED IN THE E PACIFIC REGION. STRONG SUBSIDENCE AND A DRY STABLE AIR ARE OVER THE SE GULF WITH A SIMILAR AIR MASS BEHIND THE FRONTAL BOUNDARY OVER THE N GULF COAST STATES. HOWEVER...UPPER LEVEL MOISTURE IS BEING DRAWN ACROSS MEXICO AND S TEXAS DUE TO THE BROAD UPPER RIDGE MENTIONED ABOVE. OTHER THAN THE ACTIVITY ASSOCIATED WITH THE FRONT/SQUALL LINE...THE GULF REMAINS RATHER CLEAR THIS EVENING. CARIBBEAN SEA... BROAD UPPER RIDGE COVERS W CARIBBEAN WITH A SECOND UPPER RIDGE OVER THE E CARIBBEAN EXTENDING FROM THE W TROPICAL ATLC. THE UPPER TROUGH OVER THE W/CENTRAL ATLC DIPS OVER THE N/CENTRAL CARIBBEAN N OF 16N FROM THE VIRGIN ISLANDS TO W CUBA. A LINGERING COLD FRONT ASSOCIATED WITH THE UPPER TROUGH EXTENDS TO THE VIRGIN/N LEEWARD ISLANDS AND PRODUCING AN AREA OF SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS FROM 14N-18N E OF 69W ACROSS THE LEEWARD AND VIRGIN ISLANDS. OTHERWISE...A WEAK PRESSURE GRADIENT REMAINS ACROSS THE AREA PROVIDING FAIR WEATHER AND CLEAR SKIES WITH SOME SCATTERED FAST MOVING CIRRUS CLOUDS MOVING ACROSS THE AREA. ATLANTIC OCEAN... NARROW UPPER RIDGE EXTENDS FROM CENTRAL CUBA NEAR SANTA CLARA NE ALONG THE E COAST OF THE US. A BROAD UPPER TROUGH COVERS THE REMAINDER OF THE W ATLC AND THE CENTRAL ATLC DIPPING S INTO THE N CARIBBEAN WITH THE ASSOCIATED FRONTAL BOUNDARY MAINLY N OF THE REGION. A LINGERING DISSIPATING COLD FRONT ENTERS THE REGION NEAR 32N38W ALONG 22N51W TO THE VIRGIN/N LEEWARD ISLANDS NEAR 18N62W. SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ARE WITHIN 120 NM OF LINE FROM 23N46W TO 30N33W AND WITHIN 150 NM OF LINE FROM 22N54W TO ACROSS THE THE LEEWARD ISLANDS INTO THE NE CARIBBEAN NEAR 17N62W. BROAD UPPER RIDGE COVERS THE E ATLC WITH A RIDGE AXIS EXTENDING FROM 16N37W TO 32N28W. AN UPPER LEVEL TROUGH IS IN THE TROPICAL ATLC EXTENDING FROM 11N25W TO 4N28W PRECEDING THE TROPICAL WAVE. A SURFACE RIDGE COVERS THE W ATLC ANCHORED BY A 1023 MB HIGH NEAR 31N70W WITH A SECOND SURFACE RIDGE OVER THE E ATLC ANCHORED BY A 1019 MB HIGH NEAR 25N27W. MAINLY CLEAR SKIES AND FAIR WEATHER CONTINUES IN THE REGIONS OF THE SURFACE RIDGES. $$ WALLACE