000 AXNT20 KNHC 151737 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT TUE JUL 15 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 1800 UTC. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 07N47W TO 16N44W MOVING W AT 15 KT. THE WAVE COINCIDES WITH A BROAD AND WEAK 700 MB TROUGH BETWEEN 42W-50W. NO SIGNIFICANT DEEP CONVECTION IS NOTED WITH THE WAVE AT THIS TIME. TROPICAL WAVE EXTENDS FROM 12N73W TO 19N72W MOVING W AT 15 KT. THIS TROPICAL WAVE IS IN A FAIRLY DRY AIRMASS AT THE BASE OF AN UPPER TROUGH PIVOTING THROUGH EASTERN CUBA. MODEST CONVECTION IS NOTED IN THE AREA BETWEEN HAITI...JAMAICA AND EASTERN CUBA BUT OTHERWISE NO SIGNIFICANT WEATHER IS ASSOCIATED WITH THE TROPICAL WAVE OR UPPER TROUGH. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 14N16W TO 09N30W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 09N30W TO 06N55W. SCATTERED MODERATE CONVECTION IS NOTED WITHIN 180 NM N OF THE ITCZ AXIS BETWEEN 35W AND 42W. ...DISCUSSION... GULF OF MEXICO... ISOLATED CLUSTERS OF CONVECTION ARE NOTED THIS MORNING WITHIN 60 NM OF THE COASTLINE FROM THE MOUTH OF THE MISSISSIPPI RIVER EASTWARD TO SW FLORIDA. SCATTERED CONVECTION HAD BEEN ACTIVE FARTHER OUT INTO THE SOUTH CENTRAL PORTIONS OF THE GULF OF MEXICO EARLIER THIS MORNING IN THE UNSTABLE AIR OVER THE NORTHERN EXTENT OF THE LOOP CURRENT. THE CONVECTION OVER THE EASTERN GULF IS BEING ENHANCED TO SOME DEGREE BY A MID TO UPPER LEVEL TROUGH DIGGING INTO LOWER MISSISSIPPI VALLEY. OTHERWISE A SURFACE RIDGE EXTENDS FROM SW FLORIDA TO 1018 MB HIGH PRESSURE CENTERED NEAR TAMPICO. BUOY DATA INDICATED MODERATE TO FRESH BREEZES NORTH OF THE RIDGE AXIS ACROSS THE NORTHERN GULF OF MEXICO WITH GENERALLY LIGHT TO MODERATE FLOW ELSEWHERE. A TROPICAL WAVE THAT WAS IN THE FAR SW GULF PREVIOUSLY HAS PUSHED WESTWARD THROUGH SOUTHERN MEXICO. A COLD FRONT RELATED TO THE UPPER TROUGH WILL SWEEP ACROSS THE NE WATERS THROUGH MID WEEK. CARIBBEAN SEA... DEEP LAYER MOISTURE REMAINS BELOW AVERAGE ACROSS MUCH OF THE CARIBBEAN BASIN N OF 14N. DRIER AND SUBSIDENT W TO NW FLOW ALOFT PERSISTS ON THE SOUTHERN PERIPHERY OF AN UPPER CYCLONE CENTERED NORTH OF THE AREA. FRESH TO STRONG TRADE WINDS ARE NOTED ACROSS MAINLY THE SOUTH CENTRAL CARIBBEAN...SOUTH OF STRONG RIDGING N OF THE AREA IN THE NW ATLANTIC. THIS TRADE WIND CONVERGENCE IS SUPPORTING AREAS OF SHOWERS AND THUNDERSTORMS OVER THE FAR SW CARIBBEAN ALONG THE COASTS OF COSTA RICA AND WESTERN PANAMA. THE A WEAK TROPICAL WAVE IS MOVING WESTWARD ACROSS THE CENTRAL CARIBBEAN BETWEEN HAITI AND NE COLOMBIA...ON THE SOUTHERN PERIPHERY OF AN UPPER TROUGH DIGGING ACROSS EASTERN CUBA AND THE WINDWARD PASSAGE. MODERATE TO FRESH EAST WINDS ARE ALSO NOTED OVER THE GULF OF HONDURAS AS RIDGING BUILDS IN BEHIND A TROPICAL WAVE THAT IS EXITING TO THE WEST THROUGH SOUTHERN MEXICO. ...HISPANIOLA... AN UPPER TROUGH IS APPROACHING HISPANIOLA FROM THE NW. THIS IS SUPPORTING CONVECTION ON THE WESTERN TIP OF THE NORTHERN PENINSULA OF HAITI. PRECIPITABLE WATER VALUES APPEAR SOMEWHAT LOWER THAN USUAL AS NOTED TPW IMAGERY AND THIS MAY BE A LIMITING FACTOR FOR WIDESPREAD CONVECTION. HOWEVER THE INTERACTION OF THE UPPER TROUGH AND DAYTIME HEATING WILL LIKELY ALLOW FOR ADDITIONAL SHOWERS AND THUNDERSTORMS TO FORM ACROSS THE ISLAND THROUGH THIS AFTERNOON...PARTICULARLY OVER THE MOUNTAINS. ATLANTIC OCEAN... AN UPPER LEVEL CYCLONE IS CENTERED NEAR 28N72W TO THE NE OF THE BAHAMAS. SCATTERED SHOWERS AND THUNDERSTORMS PERSIST ON THE PERIPHERY OF THIS UPPER CYCLONE...MAINLY IN THE MORE UNSTABLE AIRMASS ALONG THE GULF STREAM. A LARGE AREA OF SHOWERS AND THUNDERSTORMS IS ALSO NOTED TO THE EAST OF THE UPPER CYCLONE WITHIN 120 NM OF 27N65W. BUOY 41019 IS STATIONED IN THE MIDDLE OF THIS AREA OF CONVECTION...AND EARLIER REPORTS SHOWED PEAK WINDS TO 27 KT NEAR THUNDERSTORMS WITH SEAS TO 6 FT. FARTHER EAST...THE AIRMASS REMAINS RELATIVELY DRY N OF 15N AND EAST OF 60W. A TROPICAL WAVE IS LOCATED BETWEEN 42W AND 47W S OF 20N IN AN AREA OF LOWER TO MID LEVEL TROUGHING AS NOTED IN GOES DERIVED WINDS AND MODEL INITIALIZATIONS. ENHANCED TRADE WINDS CONVERGENCE TO THE EAST OF THE TROPICAL WAVE IS SUPPORTING AREAS OF CONVECTION WITHIN 180 NM N OF THE ITCZ. OTHERWISE...THE CENTRAL AND EASTERN ATLC ARE UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1028 MB HIGH CENTERED NEAR 34N51W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ CHRISTENSEN