000 AXNT20 KNHC 211753 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT WED MAY 21 2014 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...TROPICAL WAVE... VISIBLE SATELLITE IMAGERY SHOWS A TROPICAL WAVE MOVING OUT OF AFRICA THIS MORNING. THE UPPER-AIR TIME SECTION FROM DAKAR AND THE TPW ANIMATION BOTH INDICATE A BULGE OF MOISTURE ALONG THE COAST OF AFRICA THAT COINCIDES WITH THE WAVE AXIS. BASED ON THIS DATA...A TROPICAL WAVE IS ADDED TO THE 1200 UTC ANALYSIS/SURFACE MAP EXTENDING FROM 15N17W TO 10N18W. THIS SYSTEM WILL MOVE WESTWARD AT 10-15 KT. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH IS ANALYZED ACROSS AFRICA INTO THE TROPICAL ATLC NEAR 6N10W ALONG 4N12W TO 3N15W WHERE THE ITCZ BEGINS AND CONTINUES S OF THE EQUATOR NEAR 22W. CLUSTERS OF SCATTERED MODERATE TO ISOLATED STRONG CONVECTION ARE N OF THE EQUATOR TO INLAND OVER W AFRICA BETWEEN THE PRIME MERIDIAN AND 10W...AND FROM 1N TO 6N BETWEEN 10W AND 20W. ISOLATED MODERATE CONVECTION IS N OF THE EQUATOR TO 2.5N W OF 40W. ...DISCUSSION... GULF OF MEXICO... A 1024 MB HIGH PRES LOCATED OVER THE NE GULF NEAR 29N84W EXTENDS A RIDGE WESTWARD TOWARD TEXAS DOMINATING THE ENTIRE GULF WATERS WITH MOSTLY FAIR WEATHER. SOUTH OF RIDGE...AN EARLIER ASCAT PASS INDICATED A BROAD AREA OF 20 TO 25 KT WINDS OVER THE STRAITS OF FLORIDA OFF THE NW COAST OF CUBA. W OF THE RIDGE...SOUTHERLY RETURN FLOW HAS ESTABLISHED OVER THE WESTERN GULF. THE HIGH IS FORECAST TO MOVE TOWARD THE MOUTH OF THE MISSISSIPPI RIVER THROUGH THU WITH LITTLE CHANGE IN THE WEATHER PATTERN ACROSS THE REGION OVER THE NEXT 24 HOURS. A WEAK SURFACE TROUGH IS ANALYZED FROM 28N86W TO 25N86.5W AND WILL DISSIPATE LATER TODAY OR TONIGHT. ALOFT...AN UPPER RIDGE EXTENDS FROM THE E PACIFIC REGION ACROSS THE BAY OF CAMPECHE AND THE CENTRAL GULF TO BEYOND LOUISIANA GIVING MOST OF THE GULF NW FLOW IN THE UPPER-LEVELS. MODERATE TO STRONG MID/UPPER LEVEL SUBSIDENCE AND IMPLIED DRY AIR MASS IS NOTED ON WATER VAPOR IMAGERY ACROSS MOST OF THE GULF REGION. CARIBBEAN SEA... A MID/UPPER LEVEL TROUGH EXTENDS ACROSS CENTRAL CUBA AND THE NW CARIBBEAN. A WESTERLY UPPER JET REMAINS SE OF THE TROUGH AND IS HELPING TO INDUCE CONVECTION ACROSS THE CARIBBEAN SEA AND PARTS OF THE GREATER ANTILLES...PARTICULARLY ACROSS EASTERN CUBA... JAMAICA AND HISPANIOLA. VISIBLE SATELLITE IMAGERY REVEALS A BAND OF MULTILAYERED CLOUDS EXTENDING FROM NE HONDURAS ALL THE WAY NE ACROSS JAMAICA AND THE WINDWARD PASSAGE INTO THE ATLC WATERS. COMPUTER MODELS SHOW A GRADUAL AMPLIFICATION OF THE MID/UPPER LEVEL TROUGH ACROSS THE CENTRAL CARIBBEAN. AS A RESULT...IT WILL CONTINUE TO SUPPORT THE DEVELOPMENT OF SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ACROSS E CUBA...JAMAICA...HISPANIOLA AND PUERTO RICO MAINLY DURING THE AFTERNOON AND EARLY EVENING HOURS. A CLUSTER OF MODERATE TO ISOLATED STRONG CONVECTION IS NOTED OVER THE SW CARIBBEAN MAINLY S OF 11N E OF 80W LIKELY ASSOCIATED WITH THE MONSOON TROUGH. PATCHES OF LOW LEVEL CLOUDS EMBEDDED IN THE TRADE WIND FLOW ARE CROSSING THE LEEWARD ISLANDS PRODUCING ISOLATED TO SCATTERED PASSING SHOWERS. HIGH PRESSURE NORTH OF THE AREA WILL MAINTAIN FRESH TO STRONG TRADEWINDS IN THE CENTRAL CARIBBEAN OFF NE COLOMBIA AND NW VENEZUELA WITH MODERATE TO FRESH TRADES ELSEWHERE THROUGH SUNDAY. ...HISPANIOLA... THE ABOVE MENTIONED MID/UPPER LEVEL TROUGH WILL COMBINE WITH DAYTIME HEATING...A MOIST SOUTHEASTERLY FLOW AND LOCAL EFFECTS TO INDUCE THE DEVELOPMENT OF SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ACROSS PARTS OF THE ISLAND MAINLY DURING THE AFTERNOON AND EARLY EVENING HOURS THROUGH AT LEAST FRI. ATLANTIC OCEAN... A 1024 MB HIGH PRES LOCATED NEAR 32N74W EXTENDS A RIDGE ACROSS THE W ATLC. LIGHT TO MODERATE NE-E FLOW ON THE S PERIPHERY OF THE RIDGE IS TRANSPORTING SOME CLOUDINESS ACROSS THE BAHAMAS INTO CUBA. THE RIDGE IS BUILDING BEHIND A STATIONARY FRONT THAT ENTERS THE FORECAST REGION NEAR 31N56W THEN CONTINUES SW TO NEAR 27N64W WHERE IT BEGINS TO DISSIPATE. A NARROW LINE OF CLOUDINESS IS RELATED TO THE FRONT. THE HIGH IS FORECAST TO MOVE TO A POSITION NEAR 30N61W IN ABOUT 24 HOURS. A SECOND SURFACE RIDGE COVERS THE REMAINDER OF THE ATLC ANCHORED BY A HIGH LOCATED WELL N OF THE REGION. A SURFACE TROUGH...REFLECTION OF THE PREVIOUSLY MENTIONED MID/UPPER LEVEL TROUGH EXTENDS FROM 23N70W TO HAITI NEAR 18.5N72W. SURFACE DATA ALONG WITH A RECENT ASCAT PASS SHOW THE WIND SHIFT ASSOCIATED WITH THE TROUGH AXIS. A WEAK TROUGH RUNS FROM 08N27W TO 2N29W. A FEW SHOWERS ARE ASSOCIATED WITH THE TROUGH FORECAST TO DISSIPATE LATER TODAY OR TONIGHT. ALOFT... BROAD UPPER TROUGH EXTENDS FROM NEAR BERMUDA TO CENTRAL CUBA. A WESTERLY UPPER JET IS SE OF THE TROUGH AXIS PRODUCING A BAND OF MULTILAYERED CLOUDS THAT EXTEND FROM THE WINDWARD PASSAGE ALL THE WAY NE TO BEYOND 31N50W. TRANSVERSE HIGH CLOUDS ARE ALSO NOTED IN ASSOCIATION WITH THE STRONG UPPER-LEVEL WINDS. ANOTHER UPPER LEVEL TROUGH IS OVER THE E ATLC EXTENDING FROM 31N28W TO NEAR 10N42W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ GR