000 AXNT20 KNHC 300603 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT MON JUN 30 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2345 UTC. ...SPECIAL FEATURES... SURFACE OBSERVATIONS AND SATELLITE DATA SHOW THE LOW PRESSURE SYSTEM LOCATED ABOUT 160 NM E OF DAYTONA BEACH FLORIDA IS SLOWLY BECOMING BETTER ORGANIZED WHILE DRIFTING SOUTH. ALTHOUGH UPPER LEVEL WINDS ARE ONLY MARGINALLY FAVORABLE FOR DEVELOPMENT...A TROPICAL DEPRESSION COULD FORM DURING THE NEXT DAY OR TWO. THE LOW IS CURRENTLY GENERATING SCATTERED MODERATE CONVECTION WITHIN 150 NM IN S QUADRANT. CONVECTION IS LIMITED ELSEWHERE AROUND THE SYSTEM. FOR ADDITIONAL INFORMATION REFER TO THE ATLC TROPICAL WEATHER OUTLOOK UNDER AWIPS/WMO HEADERS MIATWOAT/ABNT20 KNHC. ...TROPICAL WAVES... TROPICAL WAVE APPROACHING THE WINDWARD ISLANDS WITH AXIS EXTENDING FROM 17N57W TO 8N59W MOVING WNW AT 20 TO 25 KT. THIS WAVE WAS RELOCATED WELL WEST OF PREVIOUS POSITION BASED ON TPW SHOWING MOISTURE CRESTING EAST OF THE WINDWARDS. SAHARAN AIR LAYER HAS HINDERED PREVIOUS CONVECTIVE ACTIVITY. SCATTERED MODERATE CONVECTION FROM 9N TO 14N BETWEEN 58W AND 62W. TROPICAL WAVE IN THE EASTERN CARIBBEAN WITH AXIS EXTENDING FROM 17N67W TO THE N COAST OF VENEZUELA AT 68W. THE WAVE MOVING W AT 20 KT. MINIMAL CONVECTION ASSOCIATED WITH WAVE. TROPICAL WAVE IN THE WESTERN CARIBBEAN WITH AXIS EXTENDING FROM 20N85W TO THE N COAST OF HONDURAS AT 86W MOVING W AT 15-20 KT. MOST CONVECTION ASSOCIATED WITH WAVE IS OVER HONDURAS. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE COAST OF GUINEA NEAR 15N17W TO 6N35W. THE ITCZ BEGINS NEAR 6N35W AND CONTINUES TO 6N54W. SCATTERED MODERATE ISOLATED STRONG CONVECTION WITHIN 180 NM S OF THE AXIS BETWEEN 22W AND 32W...AND WITHIN 60-90 NM EITHER SIDE OF THE AXIS BETWEEN 32W AND 40W. ...DISCUSSION... ...THE GULF OF MEXICO... A MID-LEVEL CYCLONIC CIRCULATION BETWEEN TEXAS/LOUISIANA IS DRIFTING WESTWARD BENEATH A BUILDING MID TO UPPER LEVEL RIDGE. ANOTHER SMALL MID-LEVEL CYCLONE WAS CENTERED NEAR 23N86W. AT THE SURFACE...A RIDGE DOMINATED THE GULF AND WAS ANCHORED BY A 1020 MB HIGH JUST S OF PANAMA CITY FLORIDA. VARIABLE WINDS WERE IN THE 5 TO 10 KNOT RANGE NEAR THE HIGH AND OVER MOST OF THE GULF E OF 93W. WINDS WERE MORE SOUTHEASTERLY OVER THE WESTERN GULF...INCREASING TO 15 TO 20 KT ALONG THE TEXAS COAST AND ELSEWHERE W OF 93W. FAIR SKIES PREVAIL OVER MOST OF THE GULF. ...THE CARIBBEAN SEA... TWO TROPICAL WAVES ARE MOVING ACROSS THE CARIBBEAN OVER THE EAST- CENTRAL PORTION S OF PUERTO RICO AND OVER THE GULF OF HONDURAS INTO CENTRAL AMERICA. SSMI TPW IMAGERY SHOW MODERATE MOIST CONDITIONS SOUTH OF 16N WHILE A TONGUE OF VERY DRY SAHARAN AIR MOVES WESTWARD OVER THE NORTHERN CARIBBEAN AND THE GREATER ANTILLES. THIS DRY AIR IS SUPPORTING MOSTLY FAIR BUT HAZY CONDITIONS IN THIS REGION OF THE CARIBBEAN. OVER THE MOIST REGION...STRONG DEEP LAYER ENVIRONMENTAL WIND SHEAR HINDERS THE DEVELOPMENT OF CONVECTION. AT THE UPPER LEVELS...A CYCLONIC CIRCULATION IS OFF THE FAR NW TIP OF CUBA WHILE A BROAD EAST TO WEST ELONGATED RIDGE COVERS THE REMAINDER OF THE BASIN S OF 17N. AN UPPER-LEVEL LOW N OF PUERTO RICO IS GENERATING DIFFLUENCE OVER THE FAR NE CARIBBEAN WHICH IS SUPPORTING SCATTERED SHOWERS OVER THE NORTHERN LEEWARD ISLANDS. THE PRESSURE GRADIENT BETWEEN THE ATLANTIC RIDGE AND THE MONSOON TROUGH IS MAINTAINING 20-25 KT TRADES IN THE CENTRAL CARIBBEAN AND 10-20 KT WINDS IN BOTH THE WESTERN AND EASTERN CARIBBEAN. THE WAVE OVER THE WESTERN CARIBBEAN WILL MOVE INLAND OVER CENTRAL AMERICA TONIGHT AND MON AND IS EXPECTED TO MERGE WITH AN AREA OF LOW PRESSURE IN THE EPAC WATERS TOMORROW MORNING. THE WAVE OVER THE E CARIBBEAN WILL CONTINUE TO MOVE W TOWARD THE WESTERN BASIN WHILE A NEW TROPICAL WAVE ENTERS THE E CARIBBEAN ON MON. ...HISPANIOLA... DRY SAHARAN AIRMASS CONTINUES TO MOVE ACROSS THE GREATER ANTILLES AND ADJACENT WATERS...THUS SUPPORTING FAIR BUT HAZY WEATHER CONDITIONS. THE 1200 UTC SANTO DOMINGO RAOB INDICATED PRECIPITABLE WATER VALUES OF ONLY 1.26 INCHES AND A STRONG CAPPING INVERSION AT 850 MB. DESPITE THE OVERALL SUPPRESSED ENVIRONMENT...ISOLATED THUNDERSTORMS ERUPTED OVER THE HIGHER TERRAIN OF EASTERN HAITI AND CENTRAL DOMINICAN REPUBLIC. THE CONTINUED PRESENCE OF THE SAHARAN AIR LAYER IN THE AREA OVER THE NEXT COUPLE OF DAYS SHOULD RESULT IN DELAYED DEVELOPMENT OF AFTERNOON CONVECTION WITH GENERALLY LESS COVERAGE THAN IS TYPICALLY EXPECTED. ...THE ATLANTIC OCEAN... AN UPPER LEVEL ANTICYCLONE OVER NORTH-CENTRAL FLORIDA DOMINATED THE FLOW OVER THE ATLANTIC W OF 72W. THE AREA OF LOW PRESSURE BEING MONITORED OFF THE FLORIDA EAST COAST WAS SITUATED IN NORTHERLY FLOW ALOFT AT THE PERIPHERY OF THE ANTICYCLONE. AN SHARP MID TO UPPER LEVEL TROUGH WAS DIGGING SOUTHWARD OVER THE ATLC N OF 26N BETWEEN 65W AND 72W. THIS TROUGH SUPPORTED A SURFACE TROUGH EXTENDING FROM 31N61W TO 26N66W. SCATTERED SHOWERS AND ISOLATED TSTMS WERE NOTED E OF THE SURFACE TROUGH N OF 27N BETWEEN 55W AND 61W. ANOTHER UPPER TROUGH EXTENDED FROM A CYCLONIC CIRCULATION NEAR 30N45W THROUGH 22N65W TO THE NW CARIBBEAN. IN BETWEEN THE TWO LOW PRESSURE AREAS...A 1021 MB HIGH SLOWLY DRIFTING S IS NEAR 27N70W. ELSEWHERE OVER THE ATLANTIC...A BROAD SURFACE RIDGE ANCHORED BY A 1029 MB HIGH NEAR 33N41W EXTENDED A RIDGE TO 16N AND SUPPORTS GENERALLY FAIR WEATHER CONDITIONS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ COBB