000 AXNT20 KNHC 201739 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT FRI JUN 20 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 WAVES... A TROPICAL WAVE HAS MOVED OUT OF AFRICA AND EXTENDS FROM 15N17W TO 6N16W. THE HOVMOLLER DIAGRAM CLEARLY INDICATES THE WESTWARD PROPAGATION OF THE WAVE ACROSS AFRICA INTO THE TROPICAL ATLC OCEAN. SCATTERED MODERATE CONVECTION IS NOTED WHERE THE WAVE MEETS THE MONSOON TROUGH. THE WAVE WILL CONTINUE TO MOVE WESTWARD AT ABOUT 15 KT. THE TROPICAL WAVE PREVIOUSLY LOCATED ALONG 32W IS RELOCATED FARTHER EAST BASED ON VISIBLE SATELLITE IMAGERY AND A PAIR OF SURFACE OBSERVATIONS. THE WAVE CURRENTLY EXTENDS FROM 11N27W TO 5N28W. A CYCLONIC TURNING IS NOTED ALONG THE WAVE AXIS NEAR 7N28W. IN ADDITION...THE 1110 UTC ASCAT PASS INDICATES SOME WIND SHIFT IN ASSOCIATION WITH THIS FEATURE. THE WAVE WILL CONTINUE TO MOVE WESTWARD AT ABOUT 15 KT. A TROPICAL WAVE IS CURRENTLY MOVING ACROSS THE EASTERN CARIBBEAN AND EXTENDS FROM WESTERN PUERTO RICO TO NORTH-CENTRAL VENEZUELA NEAR 8N67W. THE SAN JUAN DOPPLER RADAR SHOWS SOME SHOWER ACTIVITY MOVING MAINLY ACROSS THE EAST PART OF THE INLAND IN A SE WIND FLOW BEHIND THE WAVE AXIS. MODERATE CONVECTION IS ALSO NOTED NEAR THE SOUTHERN END OF THE WAVE AXIS OVER VENEZUELA... PARTICULARLY N OF 8N BETWEEN 66W AND 70W. THE WAVE IS ACCOMPANIED BY A SURGE OF MOISTURE AS SEEN IN THE TOTAL PRECIPITABLE WATER IMAGERY. THE WAVE IS FORECAST TO MOVE ACROSS HISPANIOLA TONIGHT INTO SATURDAY. THIS SHOULD PROMOTE SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS. A TROPICAL WAVE IS MOVING ACROSS SE MEXICO AND EXTENDS FROM 19N93W TO 12N95W. THE WAVE IS GENERATING SOME SHOWER ACTIVITY IN THE GULF OF TEHUANTEPEC AND COINCIDES WITH A BULGE A MOISTURE AS OBSERVED IN THE TOTAL PRECIPITABLE WATER ANIMATION. FOR FURTHER INFORMATION ABOUT THIS WAVE PLEASE SEE THE TROPICAL WEATHER DISCUSSION FOR THE EPAC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH ENTERS THE ATLANTIC ALONG THE COAST OF GUINEA NEAR 9N14W THEN CONTINUES TO 07N26W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 06N30W TO 02N40W TO 1N50W AT THE COAST OF BRAZIL. SCATTERED MODERATE CONVECTION IS FROM 5N-9N BETWEEN 12W-25W. SIMILAR CONVECTION IS ALSO NOTED WITHIN 150 NM N OF AXIS BETWEEN 30W-33W. ...DISCUSSION... GULF OF MEXICO... A MOSTLY DRY AND STABLE ATMOSPHERE CONTINUES TO DOMINATE THE GULF REGION UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A HIGH PRES OF 1020 MB LOCATED OVER THE SE CONUS. VISIBLE SATELLITE IMAGERY SUGGESTS THE PRESENCE OF SAHARAN DUST OVER THE GULF WATERS MAINLY S OF 25N CREATING HAZY CONDITIONS. IN ADDITION... THE 1200 UTC VERACRUZ SOUNDING ALSO SHOWS THE INVERSION ASSOCIATED WITH THE DUST. A TROPICAL WAVE IS MOVING ACROSS THE FAR SOUTHERN BAY OF CAMPECHE AND SE MEXICO. ALOFT...CONDITIONS HAVE CHANGED LITTLE OVER THE PAST 24 HOURS. AN UPPER LEVEL NORTHERLY FLOW IS ACROSS MOST OF THE GULF REGION BETWEEN A MIDDLE TO UPPER LEVEL TROUGH OVER FLORIDA AND WESTERN CUBA AND AN UPPER LEVEL RIDGE WITH AXIS ALONG THE COASTS OF MEXICO AND TEXAS. WATER VAPOR IMAGERY INDICATES MOST OF THIS NORTHERLY FLOW ALOFT REMAINS RELATIVELY DRY AND STABLE...PARTICULARLY BETWEEN 87W AND 94W. WEAK RIDGING SHOULD MEANDER TO NEAR THE CENTRAL GULF DURING THE NEXT TWO DAYS AND GENERALLY DRY CONDITIONS WILL PREVAIL. THIS SYSTEM WILL ALSO MAINTAIN GENERALLY LIGHT TO MODERATE WINDS AND SLIGHT SEAS THROUGH THE WEEKEND. CARIBBEAN SEA... WATER VAPOR IMAGERY INDICATES AN UPPER LEVEL TROUGH OVER THE NW CARIBBEAN WITH AXIS EXTENDING FROM WESTERN CUBA AND THE ISLE OF YOUTH TO THE GULF OF HONDURAS INTO NORTHERN CENTRAL AMERICA. A RIDGE DOMINATES THE REMAINDER OF THE BASIN. ABUNDANT MID TO UPPER LEVEL MOISTURE IS AHEAD OF THE TROUGH AXIS COVERING THE MAJORITY OF THE CARIBBEAN SEA. VISIBLE SATELLITE IMAGERY SHOWS A 300 NM WIDE BAND OF MULTILAYERED CLOUDS WITH SPORADIC CONVECTION EXTENDING FROM HONDURAS AND NICARAGUA ALL THE WAY NE TO OVER EASTERN CUBA AND THE BAHAMAS. A TROPICAL WAVE IS MOVING ACROSS THE EASTERN CARIBBEAN. PLEASE SEE TROPICAL WAVE SECTION FOR DETAILS. ISOLATED TO SCATTERED MODERATE CONVECTION IS OBSERVED OVER THE SW CARIBBEAN LIKELY ASSOCIATED WITH THE PROXIMITY OF THE MONSOON TROUGH OVER PARTS OF PANAMA AND COSTA RICA. A DIFFLUENT PATTERN ALOFT IS ALSO HELPING TO INDUCE THIS CONVECTIVE ACTIVITY. PRES GRADIENT BETWEEN A RIDGE N OF AREA AND THE COLOMBIAN/PANAMANIAN LOW WILL CONTINUE TO SUPPORT FRESH TO STRONG TRADE WINDS ACROSS THE CENTRAL CARIBBEAN. FRESH TO LOCALLY STRONG WINDS CONTINUE TO BLOW ACROSS THE GULF HONDURAS MAINLY AT NIGHT. ...HISPANIOLA... A TROPICAL WAVE OVER THE MONA PASSAGE THIS AFTERNOON WILL BRING AN INCREASE IN SHOWER AND THUNDERSTORM ACTIVITY TONIGHT AND SATURDAY...ENHANCING THE DIURNAL LATE AFTERNOON-EARLY EVENING MAXIMUM IN CONVECTION. MOISTURE IS ALREADY ON INCREASE ACROSS THE ISLAND. ATLANTIC OCEAN... A WEAK AREA OF LOW PRES HAS DEVELOPED JUST OUT NE FLORIDA OR ABOUT 80 MILES E-NE OF DAYTONA BEACH. A SWIRL OF LOW CLOUDS IS ASSOCIATED THE LOW CENTER AND IS TOTALLY EXPOSED TO THE NORTH OF SMALL AREA OF SHOWERS AND TSTMS. SURFACE PRES ARE RELATIVELY HIGH IN THE REGION. CONDITIONS ARE EXPECTED TO REMAIN UNFAVORABLE FOR TROPICAL CYCLONE DEVELOPMENT WHILE THE DISTURBANCE ACCELERATES NORTHEASTWARD. THE LATEST NHC WEATHER OUTLOOK GIVES THIS LOW PRES AREA A LOW CHANCE OF DEVELOPING INTO A TROPICAL CYCLONE DURING THE NEXT 48 HOURS. A WEAK HIGH PRES OF 1021 MB IS CENTERED NEAR 28N71W. THIS FEATURE WILL DISSIPATE IN ABOUT 24 HOURS. OTHERWISE...A SURFACE RIDGE DOMINATES THE REMAINDER OF THE CENTRAL AND EAST ATLC WITH A PAIR OF 1024 MB HIGH PRES CENTERS LOCATED NEAR 27N44W AND NEAR 28N32W. THESE FEATURES WILL REMAIN NEARLY STATIONARY OVER THE NEXT 24 HOURS. MODERATE TO FRESH TRADE WINDS ARE SEEN ON THE SOUTHERN PERIPHERY OF THE RIDGE. ALOFT...WATER VAPOR IMAGERY CONTINUES TO SHOW AN UPPER LEVEL TROUGH OVER THE FLORIDA PENINSULA AND WESTERN CUBA. SW FLOW AHEAD OF THE TROUGH IS ADVECTING MID/UPPER LEVEL MOISTURE ACROSS EAST AND CENTRAL CUBA INTO THE BAHAMAS. TO THE EAST...ANOTHER UPPER LEVEL LOW IS CENTERED NEAR 27.5N57W. A TROUGH EXTENDS FROM THE LOW CENTER TO NEAR 21N60W. ANOTHER AREA OF MULTILAYERED CLOUDS WITH EMBEDDED SHOWERS IS NOTED AHEAD OF THE TROUGH COVERING THE AREA FROM 17N-25N BETWEEN 54W-60W. MOSTLY FAIR WEATHER PREVAILS ACROSS THE REMAINDER OF THE ATLC N OF THE ITCZ/MONSOON TROUGH. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ GR