000 AXNT20 KNHC 171043 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT THU JUL 17 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1015 UTC. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 11N17W TO 19N18W MOVING W AT 10-15 KT. A FAIRLY IMPRESSIVE AMOUNT OF CONVECTION IS ASSOCIATED WITH THE WAVE THAT HAS MOVED OFF THE COAST OF WEST AFRICA THIS MORNING IN AN AREA OF MAXIMUM LOW-LEVEL MOISTURE CONVERGENCE TO THE SOUTH AND EAST OF THE WAVE AXIS. SCATTERED MODERATE AND STRONG CONVECTION IS FROM 06N-14N BETWEEN 12W-19W. TROPICAL WAVE EXTENDS FROM 05N39W TO 13N37W MOVING W AT 15 KT. THE WAVE COINCIDES WITH WEAK 700 MB TROUGHING BETWEEN 34W-42W... AND A BROAD AREA OF 850 MB RELATIVE VORTICITY FOCUSED ALONG THE WAVE AXIS NEAR 09N. ISOLATED MODERATE CONVECTION IS FROM 05N-10N BETWEEN 36W-43W. TROPICAL WAVE EXTENDS FROM 07N52W TO 12N50W MOVING W AT 15 KT. THE WAVE APPEARS AS PART OF A GREATER 700 MB TROUGH BETWEEN 50W- 60W...OF WHICH THE WEAKER 700 MB TROUGH IS S OF 12N ALONG 51W. SCATTERED MODERATE CONVECTION IS FROM 08N-10N BETWEEN 50W-57W. TROPICAL WAVE EXTENDS FROM 13N56W TO 20N53W MOVING W AT 10-15 KT. SIMILAR TO THE WAVE SE OF THIS WAVE...THE WAVE LIES WITHIN A BROAD 700 MB TROUGH ALOFT BETWEEN 50W-60W. IT IS LIKELY ENERGY FROM BOTH THESE WAVE WILL MERGE OVER THE NEXT SEVERAL DAYS. NO SIGNIFICANT DEEP CONVECTION IS ASSOCIATED WITH THE WAVE AT THIS TIME. TROPICAL WAVE EXTENDS FROM 10N87W TO 19N87W MOVING W AT 10-15 KT. THE WAVE CONTINUES TO MOVE ON THE SOUTHWESTERN PERIPHERY OF A MID-LEVEL RIDGE CENTERED OVER CUBA AND THE YUCATAN CHANNEL REGION WITH MOST OF THE LOW-LEVEL ENERGY FOCUSED OVER CENTRAL AMERICA AND AREAS OF THE EAST PACIFIC SOUTH OF NICARAGUA. NO SIGNIFICANT DEEP CONVECTION IS NOTED WITH THE WAVE AT THIS TIME. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE COAST OF AFRICA NEAR 12N16W TO 10N26W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 10N26W TO 10N33W TO 06N42W TO 06N55W. ASIDE FROM CONVECTION ASSOCIATED WITH THE PREVIOUSLY MENTIONED TROPICAL WAVES... ISOLATED MODERATE CONVECTION IS FROM 06N-12N BETWEEN 20W-28W. ...DISCUSSION... GULF OF MEXICO... A LONGWAVE MIDDLE TO UPPER LEVEL TROUGH COVERS MUCH OF THE EASTERN CONUS WITH A TROUGH AXIS DIPPING SOUTHWARD OVER PORTIONS OF THE NE GULF AND NORTHERN FLORIDA. THE TROUGHING SUPPORTS A COLD FRONT EXTENDING FROM THE FLORIDA PANHANDLE NEAR 31N84W W-SW TO THE MISSISSIPPI RIVER DELTA REGION NEAR 29N89W. FROM THERE THE FRONT BECOMES STATIONARY ACROSS COASTAL LOUISIANA TO THE TEXAS AND LOUISIANA BORDER. IN ADDITION...A PRE-FRONTAL SURFACE TROUGH IS ANALYZED FROM NEAR JACKSONVILLE FLORIDA SW TO 28N88W IN THE NE GULF WATERS. WHILE THERE IS RELATIVELY DRY CONDITIONS ALONG THE FRONT...A FEW ISOLATED SHOWERS AND TSTMS ARE OCCURRING SOUTH OF THE PRE-FRONTAL TROUGH FROM 26N-29N EAST OF 87W. OTHER ISOLATED SHOWERS ARE OCCURRING FROM 25N-27N EAST OF 84W. OTHERWISE...A SURFACE RIDGE AXIS EXTENDS FROM ACROSS CUBA ALONG 22N INTO THE CENTRAL GULF THEN SW TO A 1017 MB HIGH ANCHORED ALONG THE MEXICO COAST NEAR 20N97W. MOSTLY CLOUDY SKIES PREVAIL IN ASSOCIATION WITH THE SURFACE RIDGE WHICH IS FORECAST TO SHIFT EASTWARD THROUGH EARLY FRIDAY. BY FRIDAY...SOUTHERLY RETURN FLOW WILL HAVE ESTABLISHED ITSELF ACROSS THE WESTERN GULF AS AN AREA OF LOW PRESSURE DEVELOPS ACROSS THE INTERMOUNTAIN WEST. CARIBBEAN SEA... NORTHWESTERLY FLOW ALOFT PREVAILS OVER THE WESTERN CARIBBEAN W OF 77W THIS MORNING PROVIDING MOSTLY STABLE CONDITIONS IN THE UPPER LEVELS OF THE ATMOSPHERE. HOWEVER...A PORTION OF UPPER LEVEL TROUGHING EXTENDS FROM THE SW NORTH ATLC OVER CUBA AND THE WINDWARD PASSAGE REGION GENERATING AN AREA OF ISOLATED SHOWERS AND TSTMS N OF 18N BETWEEN 73W-87W. FARTHER EAST...A BROAD UPPER LEVEL TROUGH IS OVER THE CENTRAL CARIBBEAN BETWEEN 70W-77W THAT REMAINS FAIRLY STABLE WITH WATER VAPOR IMAGERY INDICATING DRY AIR ALOFT. WEST-SOUTHWESTERLY FLOW ALOFT RESUMES E OF 70W ON THE SOUTHERN PERIPHERY OF THE UPPER LEVEL TROUGH WITH MOSTLY CLEAR SKIES PREVAILING THIS MORNING ACROSS PUERTO RICO...THE US/UK VIRGIN ISLANDS...AND THE REMAINDER OF THE LESSER ANTILLES. MODERATE TO FRESH TRADES ARE EXPECTED TO PERSIST THROUGH SATURDAY. ...HISPANIOLA... CURRENTLY CONDITIONS REMAIN FAIRLY TRANQUIL WITH ONLY A FEW MIDDLE TO UPPER LEVEL CONVECTIVE DEBRIS CLOUDS ON SATELLITE IMAGERY THIS MORNING. UPPER LEVEL TROUGHING LIES TO THE WEST OF THE ISLAND GENERATING SCATTERED SHOWERS AND TSTMS ACROSS EASTERN CUBA AND THE WINDWARD PASSAGE REGION...HOWEVER MUCH OF THIS ACTIVITY SHOULD REMAIN OFFSHORE THROUGH THE MORNING HOURS. GIVEN LITTLE MOVEMENT OF THE UPPER LEVEL LOW AND ASSOCIATED TROUGH TO THE NORTH OVER THE SW NORTH ATLC...AN UPPER LEVEL DIFFLUENT ENVIRONMENT REMAINS ACROSS HISPANIOLA AND SCATTERED SHOWERS AND TSTMS ARE EXPECTED THURSDAY AFTERNOON AND EVENING WITH PEAK DAYTIME HEATING AND INSTABILITY. ATLANTIC OCEAN... A LONGWAVE MIDDLE TO UPPER LEVEL TROUGH IS NOTED ON WATER VAPOR IMAGERY OVER THE EASTERN CONUS THAT SUPPORTS A 1012 MB LOW CENTERED ACROSS COASTAL GEORGIA NEAR 32N81W. THE FRONTAL BOUNDARY ASSOCIATED WITH THE LOW REMAINS OFFSHORE OF THE CAROLINAS AND INLAND ACROSS SOUTHERN GEORGIA AND THE FLORIDA PANHANDLE...WITH MOSTLY SOUTHWESTERLY WINDS ALOFT AND AT THE SURFACE ADVECTING MOISTURE AND CLOUDINESS NORTHWARD. SCATTERED SHOWERS AND TSTMS ARE OCCURRING EAST OF THE FRONT N OF 27N BETWEEN 74W-80W. FARTHER SOUTH...MOISTURE ON THE WESTERN PERIPHERY OF AN ELONGATED UPPER LEVEL LOW CENTERED NEAR 26N72W IS GENERATING SCATTERED SHOWERS AND TSTMS FROM 18N-27N BETWEEN 72W-79W. ON THE EASTERN PERIPHERY OF THE UPPER LEVEL LOW... SCATTERED SHOWERS AND TSTMS ARE OCCURRING FROM 23N-30N BETWEEN 66W-72W. FARTHER EAST...THE REMAINDER OF THE CENTRAL AND EASTERN ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1030 MB HIGH CENTERED NEAR 36N52W. THE ONLY WEAKNESS WITHIN THE RIDGE IS LOCATED ON THE EASTERN PERIPHERY AS A DISSIPATING COLD FRONT ENTERS THE DISCUSSION AREA NEAR 32N30W AND EXTENDS SW TO 28N42W. ISOLATED SHOWERS ARE OCCURRING WITHIN 60 NM EITHER SIDE OF THE FRONT. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN