000 AXNT20 KNHC 070546 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT WED MAY 07 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0445 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 50W S OF 8N MOVING W NEAR 20 KT. WAVE CONTINUITY WOULD PLACE THE WAVE CLOSER TO 55W. WAVE IS WEAK AND IS MOVING OVER SOUTH AMERICA WHICH WILL WEAKEN IT FURTHER. PRECIPITABLE WATER AND MIMIC-TPW SHOWS THE WAVE NEAR 54W AT 07/000 UTC. HOWEVER THERE IS NO SHOWERS OR CONVECTION ASSOCIATED WITH THIS WAVE. ...ITCZ... ITCZ AXIS IS ALONG 9N12W 6N20W 2N28W 1N33W INTO SOUTH AMERICA NEAR 1N51W. SCATTERED MODERATE/STRONG CONVECTION IS FROM 3N TO S OF THE EQUATOR BETWEEN 26W-30W WITH CLUSTERS OF SIMILAR CONVECTION WITHIN 60 NM OF THE ITCZ AXIS FROM 33W-38W AND S OF 3N W OF 44W TO INLAND OVER SOUTH AMERICA. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 5N TO S OF THE EQUATOR BETWEEN 19W-22W. ...DISCUSSION... GULF OF MEXICO... BROAD UPPER RIDGE COVERS THE GULF WITH THE AXIS EXTENDING FROM THE W BAY OF CAMPECHE TO OVER THE SE US AND THE MISSISSIPPI VALLEY. MODERATE SUBSIDENCE AND DRY AIR DOMINATES THE AREA RESULTING IN CLEAR SKIES OVER THE GULF TONIGHT. A WEAK 1017 MB HIGH IS CENTERED ALONG THE COAST OF SE LOUISIANA AND WILL SHIFT E ACROSS FLORIDA LATER TODAY AS THE RIDGE BUILDS OVER THE W ATLC AND ENCOMPASSES THE GULF. STRONG SOUTHERLY SURFACE WINDS ARE OVER THE W GULF DUE TO THE RETURN FLOW AROUND THE SURFACE RIDGE AND WILL CONTINUE THROUGH WED NIGHT. BROAD UPPER TROUGH OVER THE W ATLC EXTENDS TO COVER FLORIDA AND THE FAR E GULF AND DIPS S INTO THE NW CARIBBEAN. CARIBBEAN SEA... BROAD UPPER TROUGH IN THE W ATLC DIPS S OVER THE NW CARIBBEAN N OF 18N FROM THE W CUBA TO OVER HISPANIOLA. BROAD UPPER RIDGE COVERS THE THE REMAINDER OF THE CARIBBEAN ANCHORED IN THE W TROPICAL ATLC WITH THE AXIS EXTENDING W ACROSS VENEZUELA AND COLOMBIA TO NICARAGUA. MODERATE/STRONG SUBSIDENCE AND DRY STABLE AIR DOMINATES THE CARIBBEAN. HOWEVER REMNANTS OF AFTERNOON THUNDERSTORMS OVER HAITI...CUBA...AND JAMAICA ARE PRODUCING ISOLATED SHOWERS ALONG THEIR IMMEDIATE COASTLINES. MODERATE TO STRONG E TRADE WINDS COVER MOST OF THE CARIBBEAN WITH THE STRONGEST WINDS ALONG THE COAST OF COLOMBIA. THESE TRADE WINDS ARE ALSO GENERATING A SMALL AREA OF ISOLATED SHOWERS FROM 14N-18N BETWEEN 78W-86W. OTHERWISE THE AREA REMAINS RATHER CLEAR TONIGHT. ATLANTIC OCEAN... BROAD UPPER TROUGH COVERS THE W ATLC W OF 55W DIPPING S INTO THE NW CARIBBEAN AND THE FAR E GULF OF MEXICO. AN INTENSE SHORTWAVE IS EMBEDDED WITHIN THIS FLOW EXTENDING ALONG 67W N OF 25N. AT 07/0300 UTC...A COLD FRONT ENTERS THE REGION OVER BERMUDA SW TO 28N72W WHERE IT CONTINUES AS A STATIONARY BOUNDARY TO A WEAK 1015 MB LOW OFF THE FLORIDA COAST NEAR 27N79W WITH A SURFACE TROUGH EXTENDING S ALONG THE SE COAST OF FLORIDA TO THE N COAST OF CUBA NEAR HAVANA. A SECOND SURFACE TROUGH ALSO EXTENDS FROM 27N70W TO OVER THE TURKS AND CAICOS NEAR 21N74W. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS AS INDICATED BY LIGHTENING DATA ARE TO THE E WITHIN 150 NM OF LINE FROM 25N68W TO BEYOND 32N63W. THE REMAINDER OF THE ATLC IS DOMINATE BY A DEEP LAYERED RIDGE WITH THE UPPER RIDGE ANCHORED OVER THE CAPE VERDE ISLANDS AND THE SURFACE RIDGE ANCHORED BY A 1025 MB HIGH NEAR 33N42W. A WEAK UPPER TROUGH IS EMBEDDED IN THE W TROPICAL ATLC EXTENDING FROM 10N46W TO 4N49W. LAST VISIBLE SATELLITE IMAGERY AND SAHARAN AIR LAYER TRACKER FROM CIMSS INDICATES THE THAT AFRICAN DUST COVERS MOST OF THE TROPICAL ATLC S OF 22N E OF 50W. $$ WALLACE