000 AXNT20 KNHC 211152 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT TUE MAY 21 2013 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS OF SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST FROM THE EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL ANALYSIS. BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1015 UTC. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 8N38W TO EQ40W MOVING W AT 10-15 KT. WAVE COINCIDES WITH A LOW AMPLITUDE MOISTURE MAXIMUM ON THE TOTAL PRECIPITABLE WATER IMAGERY WITH CURVATURE EVIDENT ON THE 700 MB STREAMLINES AND SATELLITE DERIVED WINDS. WAVE ALSO DISRUPTS THE ITCZ. TROPICAL WAVE EXTENDS FROM 15N63W TO INLAND OVER SOUTH AMERICA TO NEAR 8N65W MOVING W NEAR 5 KT. WAVE COINCIDES WITH A WEAK MOISTURE MAXIMUM ON THE TOTAL PRECIPITABLE WATER IMAGERY THAT CONTINUES TO SHIFT NORTHWARD OVER THE E CARIBBEAN WITH A WEAK CURVATURE ON THE 700 MB STREAMLINES. SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS DOT THE W TROPICAL ATLC/E CARIBBEAN FROM 10N-18N BETWEEN 58W-66W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL ATLC NEAR 11N15W CONTINUING ALONG 5N21W TO 3N26W WHERE THE ITCZ BEGINS AND CONTINUES ALONG 4N34W TO 2N38W. SCATTERED MODERATE/ STRONG CONVECTION IS WITHIN 60 NM OF LINE FROM 4N6W TO 5N12W. CLUSTERS OF SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ARE OFF THE COAST OF SW AFRICA FROM 3N-9N E OF 17W TO THE PRIME MERIDIAN. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE FROM 2N- 5N BETWEEN 19W-30W. CLUSTERS OF ISOLATED MODERATE CONVECTION ARE FROM 2N-6N BETWEEN 30W-38W AND FROM 2N TO THE EQUATOR BETWEEN 41W-46W. ...DISCUSSION... GULF OF MEXICO... A SHORTWAVE UPPER TROUGH EXTENDS FROM SE GEORGIA OVER THE FLORIDA PENINSULA TO NEAR 24N80W IN THE STRAITS OF FLORIDA. A BROAD UPPER RIDGE AXIS EXTENDS OVER THE W GULF ACROSS S MEXICO NEAR VERACRUZ TO OVER THE SE CONUS NEAR THE LOUISIANA/TEXAS BORDER COVERING THE REMAINDER OF THE GULF. A SURFACE RIDGE EXTENDS FROM THE W ATLC ACROSS CENTRAL FLORIDA TO OVER THE E GULF WITH SOUTHERLY RETURN FLOW COVERING THE REMAINDER OF THE GULF. WATER VAPOR IMAGERY INDICATES MOSTLY STRONG SUBSIDENCE AND DRY STABLE AIR ALOFT DOMINATING THE GULF THIS MORNING...THUS CLEAR SKIES FOR ALL BUT THE FAR W GULF WHERE LOW LEVEL CLOUDS ARE N OF 23N W OF 94W. MODEL GUIDANCE CONTINUES TO SHOW HIGH MOISTURE AND PRECIPITATION POTENTIAL OVER THE FAR E GULF AND OVER THE FLORIDA PENINSULA THROUGH EARLY WED BEFORE THE UPPER TROUGH IS EXPECTED TO MOVE E OF FLORIDA. A COLD FRONT MAY MOVE INTO THE NE GULF FRI THEN DRIFT S THROUGH SAT. CARIBBEAN SEA... AN UPPER RIDGE AXIS EXTENDS ALONG THE N COAST OF SOUTH AMERICA GIVING THE CARIBBEAN S OF 17N SW FLOW ALOFT. THE AREA N OF 17N IS UNDER NEAR ZONAL WESTERLY FLOW ALOFT. THE UPPER FLOW IS DRAWING TROPICAL MOISTURE ALOFT OVER THE S CARIBBEAN AND COUPLED WITH THE MONSOON TROUGH THAT EXTENDS FROM COLOMBIA NEAR 10N75W ALONG 11N80W TO ACROSS COSTA RICA NEAR 10N84W ARE GENERATING SCATTERED SHOWERS/THUNDERSTORMS S OF 12N BETWEEN 74W-84W. CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS CONTINUE OVER PORTIONS OF E CUBA AND FROM 16N-20N BETWEEN 74W-80W. THE E CARIBBEAN IS COVERED IN THE TROPICAL WAVE SECTION ABOVE. SURFACE RIDGE OVER THE W ATLC WILL MAINTAIN MODERATE TO FRESH TRADE WINDS OVER THE REGION WITH STRONGER WINDS AT TIMES OFF THE COAST OF COLOMBIA AND IN THE GULF OF HONDURAS THROUGH MID WEEK. HISPANIOLA... SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE WITHIN 60 NM ALONG THE S COAST OF THE DOMINICAN REPUBLIC BETWEEN BAHIA DE YUMA TO BAHIA DE OCOA. MODEL GUIDANCE INDICATES A SIMILAR PATTERN WILL PERSIST TODAY WITH THE MOST LIKELY PRECIPITATION TO BE DURING THE AFTERNOON AND EARLY EVENING HOURS ACROSS THE ISLAND WHEN PEAK DAYTIME HEATING AND INSTABILITY OCCUR. ANY AREAS THAT RECEIVE MEASURABLE AMOUNTS OF RAINFALL WILL LIKELY BE PRONE TO LOCALIZED FLOODING. MOISTURE FROM A TROPICAL WAVE MAY INCREASE ACTIVITY OVER THE ISLAND TONIGHT INTO WED. ATLANTIC OCEAN... A SHORTWAVE UPPER TROUGH OVER THE FLORIDA PENINSULA TO NEAR 24N80W IN THE STRAITS OF FLORIDA AND IS AMPLIFYING AN UPPER RIDGE OVER THE FAR W ATLC THAT EXTENDS FROM THE TURKS AND CAICOS NEAR 21N72W TO BEYOND 32N77W AND IS ENHANCING THE SCATTERED SHOWERS/ISOLATED THUNDERSTORMS FROM 24N-32N W OF 78W TO THE FLORIDA COAST. A SURFACE RIDGE EXTENDS FROM A 1024 MB HIGH NEAR 33N62W ACROSS CENTRAL FLORIDA INTO THE GULF OF MEXICO. CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE WITHIN 75 NM ALONG THE N COAST OF CUBA E OF 79W. A BROAD UPPER TROUGH COVERS THE REMAINDER OF THE W ATLC INTO THE CENTRAL ATLC SUPPORTING A COLD FRONT THAT ENTERS THE REGION NEAR 32N47W TO 28N54W WHERE IT DISSIPATES TO 27N60W. SCATTERED SHOWERS ARE WITHIN 90 NM E OF THE FRONT N OF 29N. A WEAK SURFACE TROUGH IS TO THE SE EXTENDING FROM 29N48W THROUGH AN EQUALLY WEAK 1019 MB SURFACE LOW NEAR 27N48W TO 25N49W. THIS FEATURE IS NOT PRODUCING ANY SIGNIFICANT WEATHER. A BROAD SURFACE RIDGE COVERS THE E ATLC ANCHORED BY A 1035 MB HIGH N OF THE AZORES. A COLD FRONT MAY MOVE INTO THE NW PORTION FRI SLOWLY MOVING E ACROSS THE WATERS N OF 27N THROUGH SAT. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW