000 AXNT20 KNHC 270505 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT TUE MAY 27 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 0415 UTC. ...TROPICAL WAVES... TROPICAL WAVE WAS RELOCATED ALONG 29W S OF 8N BASED ON SATELLITE IMAGERY AND MODEL MOISTURE FIELDS MOVING W NEAR 10 KT. WAVE IS WEAK AND ILL-DEFINED WITH ANY CONVECTION EMBEDDED WITHIN THE ITCZ. TROPICAL WAVE IS ALONG 55W S OF 22N MOVING W 15-20 KT. WELL DEFINED HIGH AMPLITUDE WAVE APPROACHING THE LESSER ANTILLES ON THE WEST SIDE OF AN UPPER TROUGH. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 90 NM OF LINE FROM 10N51W TO 14N55W. TROPICAL WAVE WAS RELOCATED ALONG 70W/71W S OF 18N BASED ON MODEL MOISTURE FIELDS AND SURFACE OBSERVATIONS. SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ARE S OF 13N TO INLAND OVER SOUTH AMERICA BETWEEN THE ABC ISLANDS AND 73W. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 7N9W 5N15W 7N25W 3N36W 6N51W AND ACROSS THE SW CARIBBEAN 10N74W 12N79W ACROSS COSTA RICA NEAR 10N85W INTO THE E PACIFIC REGION. SCATTERED/NUMEROUS STRONG CONVECTION IS WITHIN 60 NM OF LINE FROM 6N29W TO 5N33W. SCATTERED MODERATE/STRONG CONVECTION IS WITHIN 45/60 NM OF LINE FROM 3N12W TO 4N17W AND WITHIN 45 NM OF LINE FROM 9N17W TO 6N28W. SCATTERED MODERATE/ISOLATED STRONG IS FROM 2N TO THE EQUATOR E OF 5W TO THE PRIME MERIDIAN. ...DISCUSSION... GULF OF MEXICO... UPPER LEVEL RIDGE COVERS THE W GULF ANCHORED OVER CENTRAL MEXICO WITH AN UPPER TROUGH COVERING THE E GULF EXTENDING FROM THE W ATLC. THIS COMBINED IS GIVING MOST OF THE GULF NORTHERLY UPPER FLOW. WEAK SURFACE RIDGE EXTENDS INTO THE NE GULF FROM THE W ATLC WITH A EQUALLY WEAK SURFACE TROUGH OFF THE W FLORIDA COAST GENERATING ISOLATED SHOWERS N OF 27N BETWEEN 83W-85W. MODERATE/ STRONG EASTERLY SURFACE FLOW IS PRODUCING SCATTERED SHOWERS OVER THE SE GULF S OF 26N E OF 85W ACROSS S FLORIDA AND THROUGH THE FLORIDA STRAITS. OTHERWISE THE REMAINDER OF THE GULF IS RATHER CLEAR TONIGHT. CARIBBEAN SEA... BROAD UPPER LEVEL TROUGH EXTENDS FROM THE W ATLC COVERING THE CARIBBEAN W OF 66W WHILE AN UPPER RIDGE EXTENDS OVER THE FAR E CARIBBEAN INTO THE W/CENTRAL ATLC. THE ASSOCIATED STATIONARY FRONT ENTERS THE CARIBBEAN THROUGH THE WINDWARD PASSAGE TO THE NW COAST OF JAMAICA WHERE IS DISSIPATES TO THE CAYMAN ISLANDS. THIS IS GENERATING CLUSTERS OF SCATTERED SHOWERS/THUNDERSTORMS OVER A BROAD AREA N OF 17N BETWEEN 69W-84W WITH THE HIGHEST CONCENTRATION WITHIN 120 NM OF THE FRONT. THE WESTERN UPPER FLOW ACROSS THE S CARIBBEAN IS DRAWING UPPER LEVEL MOISTURE ACROSS CENTRAL AMERICA INTO THE CARIBBEAN AND COUPLED WITH THE ITCZ AXIS IN THE SW CARIBBEAN IS PRODUCING AN AREA OF DENSE CLOUDINESS WITH SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS S OF 14N FROM THE ABC ISLANDS TO OVER CENTRAL AMERICA. EMBEDDED WITHIN THIS AREA IS A MID LEVEL LOW CENTERED NEAR 12N79W BUT AS OF YET NO INDICATION OF IT AT THE SURFACE. ATLANTIC... BROAD UPPER LEVEL TROUGH COVERS THE W ATLC W OF 61W INTO THE E GULF OF MEXICO AND THE CARIBBEAN WITH THE ASSOCIATED STATIONARY FRONT ENTERING THE REGION NEAR 32N58W ALONG 29N61W 23N70W INTO THE CARIBBEAN THROUGH THE WINDWARD PASSAGE. CLUSTERS OF SCATTERED SHOWERS/THUNDERSTORMS ARE WITHIN 200 NM OF THE FRONT WITH THE HIGHEST CONCENTRATION S OF 23N TO OVER THE GREATER ANTILLES. A SURFACE RIDGE IS BEGINNING TO BUILD BEHIND THE FRONT INTO THE NE GULF OF MEXICO. NARROW UPPER RIDGE EXTENDS FROM NE VENZUELA ACROSS THE LESSER ANTILLES OVER THE CENTRAL ATLC TO BEYOND 32N52W. LARGE UPPER LOW IS IN THE E/CENTRAL ATLC CENTERED NEAR 29N36W WITH AN UPPER TROUGH EXTENDING INTO THE TROPICAL ATLC TO NEAR 13N47W ENHANCING THE ACTIVITY AND AMPLITUDE OF THE TROPICAL WAVE ALONG 55W. AN UPPER TROUGH IS OVER THE NE ATLC E OF 20W TO OVER THE CANARY ISLANDS. A WEAK SURFACE TROUGH IS IN THE E/CENTRAL ATLC EXTENDING SE/NW FROM 22N27W ALONG 25N34W TO 28N41W WITH ISOLATED SHOWERS WITHIN 90 NM OF THE TROUGH AXIS. OTHERWISE THE ATLC IS DOMINATED BY A SURFACE RIDGE N OF 15N E OF THE STATIONARY FRONT ANCHORED BY A 1029 MB HIGH N OF THE REGION AND SW OF THE AZORES. $$ WALLACE