000 AXNT20 KNHC 241740 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT SAT MAY 24 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...TROPICAL WAVES... A TROPICAL WAVE IS ALONG 30W/31W S OF 13N MOVING W AT 10 KT. THE MIMIC TOTAL PRECIPITABLE WATER PRODUCT CLEARLY INDICATES A BULGE OF MOISTURE ASSOCIATED WITH THIS WAVE. LOW-LEVEL TURNING ALONG WITH A WEAK INVERTED-V SIGNATURE IS APPARENT ON VISIBLE SATELLITE IMAGERY. MODERATE CONVECTION IS WITHIN 200NM OF THE WAVE AXIS N OF 7N. A TROPICAL WAVE IS ALONG 62W S OF 13N MOVING W 10 KT. UPPER AIR TIME-SECTION ANALYSIS FROM TRINIDAD AND TOBAGO INDICATE THAT THE WAVE PASSED OVER THE ISLAND DURING THE LAST 12 HOURS. SFC OBS ALONG THE SOUTHERNMOST WINDWARD ISLANDS DEPICT THE EXPECTED NE-SE WIND SHIFT BEHIND THE AXIS. CONVECTIVE ACTIVITY ASSOCIATED WITH THE WAVE IS MAINLY INLAND OVER VENEZUELA. A TROPICAL WAVE IS ALONG 85W/86W S OF 17N. THE NORTHERN PART OF THE WAVE AXIS ENTERS THE NE CARIBBEAN OVER CENTRAL HONDURAS. THE WAVE IS MOVING VERY SLOWLY WESTWARD. MID-LEVEL ROTATION IS EVIDENT ON SATELLITE IMAGERY...HOWEVER...THIS ROTATION HAS YET TO REACH THE SURFACE. UPPER LEVEL NELY FLOW HAS SHEARED MOST OF THE CONVECTION OUT AHEAD OF THE WAVE IN THE E PACIFIC. ..THE ITCZ... ITCZ AXIS IS CENTERED ALONG 7N12W 3N20W 3N29W ALONG THE EQUATOR BETWEEN 26W-41W AND INTO NE BRAZIL NEAR 2S46W. SCATTERED MODERATE TO STRONG CONVECTION IS WITHIN 100NM EITHER SIDE OF THE AXIS BETWEEN 17W-24W..AND FROM 6N-9N BETWEEN 19W-22W. SCATTERED MODERATE CONVECTION IS BETWEEN THE AXIS AND THE NE COAST OF BRAZIL W OF 37W. ...DISCUSSION... GULF OF MEXICO... A WEAK PRESSURE PATTERN IS PRODUCING LIGHT TO MODERATE SE WIND FLOW ACROSS THE GULF THIS AFTERNOON. A FRONTAL BOUNDARY IS EXPECTED TO MOVE ACROSS THE SE CONUS AND ENTER THE NE GULF LATE TONIGHT/EARLY SUN. WINDS IN THE FAR NE GULF WILL SHIFT N 15KT FOLLOWING THE FRONTAL PASSAGE. STRONG SUBSIDENCE UNDER AN UPPER RIDGE OVER THE CENTRAL AND W GULF IS MAINTAINING MOSTLY CLEAR SKIES THROUGHOUT THE REGION. CARIBBEAN SEA... LIGHT TO MODERATE EASTERLY TRADE WINDS CONTINUE TO DOMINATE THE WEATHER PATTERN IN THE CARIBBEAN. WESTWARD MOVING LOW-TOPPED TRADE WIND SHOWERS N OF 14N ARE EVIDENT ON SAN JUAN DOPPLER RADAR AND VISIBLE SATELLITE IMAGERY. DIVERGENCE AROUND AN UPPER LEVEL HIGH OVER JAMAICA IS SUPPORTING MODERATE CONVECTION BETWEEN EASTERN CUBA...HAITI...AND JAMAICA. A BAND OF LOW-LEVEL CLOUDS AND POSSIBLE SHOWERS HAS DEVELOPED IN THE SW CARIBBEAN FROM THE COAST OF COLOMBIA TO THE COAST OF NICARAGUA S OF 12N DUE TO LOW-LEVEL WIND SPEED CONVERGENCE. SIGNIFICANT DEEP CONVECTION IS LIMITED IN THE CARIBBEAN DUE TO THE PRESENCE OF A VERY DRY AND STABLE AIR MASS AROUND AN UPPER HIGH PRES. ATLANTIC OCEAN... NUMEROUS SHOWERS AND THUNDERSTORMS...AS INDICATED BY SATELLITE IMAGERY AND LIGHTNING DATA...HAVE MOVED OFF THE SE CONUS AND INTO THE W ATLC IN ADVANCE OF AN APPROACHING LOW PRESSURE SYSTEM. AS OF 16Z...THE CONVECTIVE ACTIVITY REMAINED N OF 27N...HOWEVER IT IS RAPIDLY MOVING TOWARD THE SOUTHEAST. THE SFC LOW PRES AND ASSOCIATED COLD FRONT IS EXPECTED TO ENTER THE NORTHERN PORTION OF THE DISCUSSION AREA LATER TONIGHT. FARTHER EAST...A SFC TROUGH...REMNANTS OF A FRONTAL BOUNDARY...EXTENDS FROM 31N55W ALONG 28N62W TO 28N68W. A BAND OF MULTILAYERED CLOUDS... SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ARE WITHIN 60 NM OF THE TROUGH. UPPER LEVEL DIVERGENCE ALONG THE LEADING EDGE OF AN UPPER TROUGH HAS SPAWNED AN AREA OF SCATTERED SHOWERS FROM 21N-28N BETWEEN 30W-37W. THE REMAINDER OF THE ATLC IS RATHER TRANQUIL DUE TO A STRONG HIGH PRESSURE RIDGE ANCHORED BY A 1028 NM SFC HIGH SW OF THE AZORES. FAIR WEATHER CUMULUS CLOUDS CONTINUE TO FLOW ACROSS THE REGION AROUND THE PERIPHERY OF THE RIDGE. $$ WADDINGTON