000 AXNT20 KNHC 252342 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT SUN MAY 25 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... A TROPICAL WAVE IS ALONG 25W SOUTH OF 13N MOVING WEST 10-15 KT. THE MIMIC-TPW PRODUCT CLEARLY INDICATES A BULGE OF MOISTURE RELATED TO THE WAVE AXIS. HOWEVER...DEEP CONVECTION HAS DIMINISHED CONSIDERABLY COMPARED WITH 24 HOURS AGO. SATELLITE IMAGERY ONLY SHOWS ISOLATED MODERATE SHOWERS NEAR THE WAVE AXIS. A TROPICAL WAVE IS ALONG 43W SOUTH OF 13N MOVING WEST 10-15 KT. AN INVERTED-V PATTERN IS APPARENT ON SATELLITE IMAGERY WITH SATELLITE DERIVED WINDS SHOWING VERY WELL THE WIND SHIFT ASSOCIATED WITH THE WAVE. ISOLATED MODERATE TO STRONG CONVECTION IS WITHIN 80-100 NM EITHER SIDE OF THE WAVE AXIS FROM 5N-11N A TROPICAL WAVE IS ALONG 68W SOUTH OF 15N MOVING WEST 10-15 KT. SFC OBSERVATIONS REVEAL THAT THE WAVE AXIS IS BETWEEN BONAIRE AND CURACAO. THE WAVE IS HELPING TO INDUCE SCATTERED MODERATE TO ISOLATED STRONG CONVECTION OVER WESTERN VENEZUELA. THE TROPICAL WAVE THAT WAS PREVIOUSLY OVER THE YUCATAN PENINSULA IS NO LONGER DISCERNIBLE BASED ON SATELLITE PICTURES AND SFC OBSERVATIONS. INSTEAD...A SFC TROUGH IS ANALYZED ON THE 21Z MAP OVER THE BAY OF CAMPECHE. AN EARLIER ASCAT PASS AND THE PRESSURE FIELD SHOW THE PRESENCE OF THIS TROUGH. ..THE ITCZ... THE ITCZ AXIS IS CENTERED ALONG 10N14W 7N23W 3N30W 2N41W EQ50W. CLUSTERS OF MODERATE TO STRONG CONVECTION ARE MOVING WWD ACROSS LIBERIA AND SIERRA LEONE. SIMILAR CONVECTION IS ALSO FOUND FROM 4N-8N EAST OF 20W TO THE AFRICAN COAST...AND NEAR 4N9W. ...DISCUSSION... THE GULF OF MEXICO... A 1021 MB HIGH CENTERED OVER THE MIDDLE ATLANTIC STATES EXTENDS A RIDGE OVER THE SE CONUS AND THE GULF OF MEXICO WITH A DRIER AND MORE STABLE AIR MASS MOVING IN. LIGHT TO MODERATE NE TO E WINDS AREA SEEN OVER THE EASTERN HALF OF THE GULF WHILE SLIGHTLY STRONGER E TO SE WINDS ARE BLOWING OVER THE WESTERN HALF OF THE GULF. ALOFT...AN UPPER-LEVEL RIDGE ANCHORED BY AN UPPER HIGH OVER CENTRAL MEXICO DOMINATES MOST OF THE GULF GIVING THE AREA MODERATE TO STRONG SUBSIDENCE AND MOSTLY CLEAR SKIES. CONVECTION HAS FLARED UP AGAIN EARLY THIS EVENING OVER PARTS OF GUATEMALA AND THE STATE OF CHIAPAS IN MEXICO. LIGHTNING DATA REVEALS SCATTERED TO NUMEROUS TSTMS EMBEDDED IN THIS AREA. UPPER DIFFLUENCE IS HELPING TO INDUCE THIS STRONG CONVECTIVE ACTIVITY. THE CARIBBEAN SEA... THE TAIL END OF A COLD FRONT IS OVER EASTERN CUBA GENERATING SOME SHOWER AND TSTM ACTIVITY. THE FRONT IS EXPECTED TO MOVE SLOWLY SE KEEPING A MOIST AND UNSTABLE ATMOSPHERE OVER EASTERN CUBA...JAMAICA...HISPANIOLA AND THE SE BAHAMAS DURING THE NEXT 24 HOURS. DUE TO THE PRESENCE OF THIS FRONT...A WEAK PRES PATTERN AND LIGHT TO MODERATE TRADE WINDS DOMINATES THE BASIN. A DEEP-LAYERED TROUGH EXTENDING OVER THE W ATLC SUPPORTS THIS FRONT WITH THE BASE OF THE TROUGH REACHING CENTRAL CUBA. ZONAL FLOW PREDOMINATES OVER THE CARIBBEAN SEA. LOW-TOPPED TRADE WIND SHOWERS ARE EVIDENT ON SATELLITE PHOTOS OVER THE EASTERN CARIBBEAN...MORE CONCENTRATED SOUTH OF PUERTO RICO. DEBRIS MOISTURE FROM CONVECTION OVER INTERIOR CENTRAL AMERICA IS ADVECTED OVER THE SW CARIBBEAN. SHOWERS AND TSTMS HAVE DEVELOPED ALONG THE SOUTH COAST OF WEST-CENTRAL CUBA UNDER A PREVAILING NLY FLOW. THE ATLANTIC OCEAN... A COLD FRONT STRETCHES FROM A 1009 MB LOW NEAR 31N60W TO EASTERN CUBA. A WIDE BAND OF MULTILAYERED CLOUDS WITH EMBEDDED SHOWERS AND SCATTERED TSTMS IS ASSOCIATED WITH THE FRONT. HIGH PRE OVER THE MIDDLE ATLC STATES IS BUILDING OVER THE W ATLC BEHIND THE FRONTAL SYSTEM. THE REMAINDER OF THE ATLC DISCUSSION AREA REMAINS RATHER TRANQUIL COURTESY OF A 1029 MB SFC HIGH LOCATED JUST WEST OF THE AZORES. FAIR WEATHER CUMULUS CLOUDS CONTINUE TO FLOW ACROSS THE REGION AROUND THE PERIPHERY OF THE RIDGE. ALOFT...A TROUGH/RIDGE/TROUGH PATTERN COVERS THE AREA. THE FIRST TROUGH IS OVER THE W ATLC SUPPORTING THE PREVIOUSLY MENTIONED COLD FRONT. A CLOSED UPPER-LEVEL LOW IS NEAR 30N34W WITH THE SECOND UPPER TROUGH EXTENDING SOUTH TO THE TROPICS NEAR 10N40W. ISOLATED TO SCATTERED SHOWERS ARE ASSOCIATED WITH THE UPPER-LOW. AN UPPER RIDGE DOMINATES THE REMAINDER OF THE E ATLC AND W AFRICA. UPPER DIFFLUENCE ASSOCIATED WITH THIS RIDGE IS ENHANCING CONVECTION OVER W AFRICA. $$ GR