000 AXNT20 KNHC 092351 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT FRI MAY 09 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 2315 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 37/38W S OF 8N MOVING W AT 15 KT. LATESTS VIS SAT IMAGERY FOR THE DAY REVEALED WEAK CYCLONIC TURNING ALONG THE WAVE AXIS NEAR 6N WHERE THERE ARE SOME SHOWER/TSTM ACTIVITY. THE MIMIC-TPW PRODUCT FROM CIMSS ALSO SHOWS THE PRESENCE OF THIS WAVE WITH A PRONOUNCED BULGE OF MOISTURE ON EITHER SIDE OF THE WAVE AXIS. ACCORDING TO THE COMPUTER MODELS...THIS TROPICAL WAVE WILL ENTER THE CARIBBEAN SEA ON TUE. ...ITCZ... ITCZ AXIS IS ALONG 5N9W 2N20W 4N35W THEN ALONG 2N39W CROSSING THE EQUATOR NEAR 45W INTO NE BRAZIL NEAR 2S50W. SCATTERED MODERATE TO STRONG CONVECTION IS FROM 2N-5N BETWEEN 9W-15W. SIMILAR CONVECTION IS OVER NE BRAZIL NEAR THE ITCZ AXIS. WIDELY SCATTERED MODERATE CONVECTION IS WITHIN 120-140 NM N OF AXIS BETWEEN 27W-32W. ...DISCUSSION... GULF OF MEXICO... BROAD UPPER LEVEL RIDGE ANCHORED ON A HIGH ACROSS THE CENTRAL MEXICAN PLATEAU REMAINS IN CONTROL OF THE ENTIRE GULF PRODUCING MODERATE TO STRONG SUBSIDENCE OVER THE BAY OF CAMPECHE AND SOUTHERN MEXICO...INCLUDING ALSO THE YUCATAN PENINSULA. ABUNDANT UPPER LEVEL MOISTURE IS BEING TRANSPORTED FROM THE EPAC ACROSS N MEXICO AND THE NORTHERN GULF WATERS BY SWLY AND THEN WLY UPPER-LEVEL WINDS AROUND THE PERIPHERY OF THE RIDGE. AT THE SURFACE...A RIDGE ALSO DOMINATES THE REGION GIVING THE AREA SOUTHERLY 10-15 KT SURFACE WINDS AND MOSTLY FAIR WEATHER. THE RIDGE WILL BEGIN TO SHIFT E SAT NIGHT IN ADVANCE OF A COLD FRONT MOVING INTO NW WATERS EARLY SUN MORNING. CARIBBEAN SEA... UPPER LEVEL ANTICYCLONIC FLOW OVER THE GULF OF MEXICO EXTENDS ACROSS WEST-CENTRAL CUBA AND THE NW CARIBBEAN. AN ELONGATED UPPER LEVEL TROUGH REMAINS OVER THE BASIN EXTENDING FROM THE S BAHAMAS THROUGH THE WINDWARD PASSAGE TO NEAR CABO GRACIAS A DIOS NICARAGUA. THE REMAINDER OF THE CARIBBEAN SEA IS UNDER THE INFLUENCE OF A BOARD UPPER LEVEL RIDGE ANCHORED IN THE TROPICAL ATLC OFF THE COAST OF NE BRAZIL. UPPER LEVEL MOISTURE IS BEING DRAWN ACROSS THE S AND E CARIBBEAN SEA BY STRONG SWLY WINDS BETWEEN THE AFOREMENTIONED UPPER LEVEL TROUGH AND THE RIDGE OFF THE COAST OF BRAZIL. A BAND OF TRANSVERSE HIGH CLOUDS EXTENDS FROM NEAR 14N80W ALL THE WAY NE TO BEYOND THE LEEWARD ISLANDS. FAIRLY STRONG TRADEWINDS COVER MOST OF THE REGION WITH THE STRONGEST WINDS JUST OFFSHORE THE COAST OF COLOMBIA. AN EARLIER QUIKSCAT PASS SHOWED ELY WINDS OF 20 TO 30 KT. MODERATE TO STRONG CONVECTION IS OVER WEST PANAMA AND COSTA RICA DUE TO THE CLOSE PROXIMITY OF THE ITCZ AND A DIFFLUENT PATTERN ALOFT. CONVECTION HAS ALSO FIRED UP OVER CENTRAL AND EASTERN CUBA WITH LIGHTNING DATA SHOWING NUMEROUS TSTMS. THIS ACTIVITY HAS DEVELOPED ALONG THE SEA BREEZE FRONT AIDED BY UPPER DIFFLUENCE. MODERATE SUBSIDENCE/DRY AIR DOMINATES THE NW CARIBBEAN BRINGING FAIR WEATHER TO THAT AREA. ATLANTIC OCEAN... A 1023 MB SURFACE HIGH IS CENTERED NEAR 28N58W. THIS HIGH ENVELOPS THE BAHAMAS...FLORIDA AND THE EASTERN GULF OF MEXICO. ANOTHER 1023 MB HIGH PRESSURE CENTER NEAR 34N24W EXTENDS A RIDGE OVER THE E ATLC. PATCHES OF LOW CLOUDS AND NELY WINDS ARE FOUND UNDER THIS RIDGE. THE STRONGEST WINDS...UP TO 25 KT ARE NEAR THE WEST COAST OF AFRICA DUE THE TIGHT PRES GRADIENT BETWEEN THE SFC HIGH AND LOWER PRES OVER AFRICA. ALOFT...BROAD UPPER TROUGH REMAINS OVER THE W-CENTRAL ATLC DIPPING S INTO THE CARIBBEAN SEA THROUGH THE WINDWARD PASSAGE. THE ASSOCIATED COLD FRONT ENTERS THE AREA NEAR 31N37W THEN CONTINUES SW TO 25N51W. AT THIS POINT...THE FRONT BECOMES STATIONARY TO 25N60W. BROKEN MAINLY LOW CLOUDS ARE ASSOCIATED WITH THE FRONTAL BOUNDARY WITH ISOLATED TSTMS NEAR THE TAIL END OF THE FRONT. MOSTLY ZONAL FLOW COVERS THE REMAINDER OF THE FORECAST REGION WITH ANOTHER UPPER LEVEL TROUGH CLIPPING THE E ATLC BETWEEN 25W AND 35W. AN UPPER RIDGE EXTENDS NWD ALONG 22/23W FROM AN UPPER HIGH LOCATED SE OF THE CAPE VERDE ISLANDS NEAR 9N18W. $$ GR