000 AXNT20 KNHC 121250 CCA TWDAT TROPICAL WEATHER DISCUSSION...COR NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT FRI JUL 12 2013 ...CORRECTION IN ORDER TO ELIMINATE THE SPECIAL FEATURES SECTION AND TO CORRECT THE REFERENCE MEDIUM CHANCE TO LOW CHANCE OF DEVELOPMENT INTO A TROPICAL CYCLONE...NOW IN THE ATLANTIC OCEAN SECTION 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 10N33W TO 19N31W MOVING W AT 5-10 KT. THE WAVE REMAINS EMBEDDED WITHIN THE ITCZ AXIS AND COINCIDES WITH A GLOBAL MODEL INDICATED 700 MB TROUGH AND ASSOCIATED VORTICITY MAXIMUM IN THE VICINITY OF 15N32W. TOTAL PRECIPITABLE WATER IMAGERY SHOWS A RELATIVE MOISTURE MAXIMUM FROM 09N-20N BETWEEN 27W-37W. SIGNIFICANT DEEP CONVECTION LACKS...HOWEVER ISOLATED SHOWERS ARE OCCURRING FROM 08N-20N BETWEEN 26W-37W. TROPICAL WAVE EXTENDS FROM 14N81W TO 21N81W MOVING W AT 10-15 KT. THE WAVE...THE SOUTHERN EXTENT OF ENERGY ASSOCIATED WITH THE REMNANTS OF CHANTAL...CONTINUES WESTWARD WHILE PARTIAL ENERGY HAS FRACTURED TO THE NORTH AS A SURFACE TROUGH AND NO DEFINED LOW-LEVEL CIRCULATION CENTER. PLENTY OF LOW-LEVEL MOISTURE CONVERGENCE AND MID-LEVEL VORTICITY ARE AIDING IN GENERATING ISOLATED MODERATE CONVECTION FROM 15N-21N BETWEEN 76W-81W... INCLUDING CUBA...JAMAICA...AND THE CAYMAN ISLANDS. THE WAVE IS EXPECTED TO TRACK ACROSS THE NW CARIBBEAN SEA AND PORTIONS OF CENTRAL AMERICA OVER THE WEEKEND. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 09N13W TO 08N24W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 08N24W TO 12N32W TO 06N54W. SCATTERED MODERATE CONVECTION IS FROM 07N-11N BETWEEN 13W-22W. ISOLATED MODERATE CONVECTION IS WITHIN 120 NM EITHER SIDE OF THE ITCZ AXIS BETWEEN 38W-56W. ...DISCUSSION... GULF OF MEXICO... WATER VAPOR IMAGERY INDICATES EAST-NORTHEASTERLY UPPER LEVEL FLOW NORTH OF A BROAD TROUGH AXIS EXTENDING FROM AN UPPER LEVEL LOW CENTERED OVER THE FLORIDA STRAITS NEAR 23N80W TO OVER EAST- CENTRAL MEXICO NEAR 22N100W. MOSTLY DRY AND STABLE AIR ALOFT IS NOTED OVER A NARROW EAST-WEST SECTION OF THE CENTRAL GULF THIS MORNING FROM 23N-27N AS A SURFACE RIDGE ANCHORED BY A 1016 MB HIGH CENTERED NEAR 26N92W LIES BENEATH PROVIDING FOR OVERALL TRANQUIL CONDITIONS. THE SURFACE RIDGING HAS WEAKENED ITS INFLUENCE OVER THE NORTHERN GULF COAST WITH ISOLATED SHOWERS AND TSTMS OCCURRING N OF 27N THIS MORNING DUE TO A MID-LEVEL SHORTWAVE TROUGH MOVING OVER PORTIONS OF THE SE CONUS AND NE GULF. ANOTHER WEAKNESS IN THE SURFACE RIDGE IS NOTED ACROSS THE FLORIDA STRAITS AS THE SPECIAL FEATURE...REMNANTS OF CHANTAL... BEGIN TO IMPACT THE SOUTHERN FLORIDA PENINSULA AND ADJACENT COASTAL WATERS SURROUNDING THE FLORIDA KEYS. ACROSS PORTIONS OF THE SW GULF...WITHIN MOSTLY WESTERLY FLOW ALOFT ON THE SOUTHERN PERIPHERY OF THE UPPER LEVEL TROUGH AXIS...MIDDLE TO UPPER LEVEL MOISTURE INCREASES WITH ISOLATED SHOWERS OCCURRING S OF 23N. LOOKING AHEAD...SURFACE RIDGING IS EXPECTED TO REMAIN IN PLACE ACROSS THE BASIN THROUGH EARLY NEXT WEEK WITH GENERALLY E-SE WINDS PERSISTING. CARIBBEAN SEA... THE PRIMARY FOCUS FOR THE CARIBBEAN REMAINS ON THE SOUTHERN EXTENT OF ENERGY...REMNANT ENERGY OF CHANTAL...MOVING WESTWARD AS A TROPICAL WAVE ALONG 81W IN THE WESTERN CARIBBEAN. THE TROPICAL WAVE CONTINUES GENERATING WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS FROM 16N-22N BETWEEN 76W-81W...INCLUDING PORTIONS OF CUBA...JAMAICA...AND THE CAYMAN ISLANDS THIS MORNING. THE WAVE IS EXPECTED TO DRIFT WESTWARD OVER THE WEEKEND BRINGING INCREASED CHANCES OF PRECIPITATION TO THE NW CARIBBEAN AND PORTIONS OF CENTRAL AMERICA. OTHERWISE...THE MONSOON TROUGH AXIS EXTENDS ALONG 10N IN THE SW CARIBBEAN AND IS GENERATING A FEW ISOLATED SHOWERS AND TSTMS S OF 14N BETWEEN 80W-85W. THE REMAINDER OF THE CENTRAL AND EASTERN CARIBBEAN HAS RESUMED AN OVERALL QUIET PATTERN WITH WATER VAPOR IMAGERY INDICATING DRY AIR AND SUBSIDENCE ALOFT...ALONG WITH LIGHT NORTHEAST TO EAST TRADES. THE TRADES ARE FORECAST TO INCREASE GRADUALLY BETWEEN 65W-80W BY EARLY TUESDAY DUE TO AN INCREASE PRESSURE GRADIENT BETWEEN A CENTRAL ATLC RIDGE AND LOWER PRESSURE ACROSS THE SW CARIBBEAN AND NORTHERN SOUTH AMERICA. HISPANIOLA... CURRENTLY...MOST OF THE REMNANTS OF CHANTAL HAVE SHIFTED NW OF THE ISLAND WITH ONLY A FEW ISOLATED SHOWERS OCCURRING OVER FAR NW PORTIONS OF THE ISLAND THIS MORNING. SURFACE RIDGING TO THE NORTH AND EAST WILL CONTINUE TO BUILD WESTWARD OVER THE NEXT 24 TO 36 HOURS AS CONDITIONS ACROSS HISPANIOLA ARE EXPECTED TO IMPROVE LATE FRIDAY INTO EARLY SATURDAY. THEREAFTER...TRADES WILL RESUME ACROSS THE REGION WITH THE MORE TYPICAL AFTERNOON SCATTERED SHOWERS AND TSTMS OCCURRING ACROSS THE ISLAND DURING THE WEEKEND INTO EARLY NEXT WEEK. ATLANTIC OCEAN... A SURFACE TROUGH...THE REMNANTS OF CHANTAL...IS ANALYZED FROM THE FLORIDA STRAITS NEAR 23N80W TO 27N78W. SUPPORTED ALOFT BY AN UPPER LEVEL LOW CENTERED OVER THE FLORIDA STRAITS NEAR 23N80W... THE ENTIRE SYNOPTIC SYSTEM IS GENERATING SCATTERED MODERATE CONVECTION ACROSS THE SW NORTH ATLC S OF 27N W OF 72W. WHILE THE AREAL COVERAGE OF CONVECTION REMAINS RELATIVELY LARGE DUE TO MAXIMUM UPPER LEVEL DIFFLUENCE COVERING THE REGION... ORGANIZATION LACKS DUE TO AN INCREASED AMOUNT OF UPPER LEVEL WIND SHEAR. THE SURFACE TROUGH IS FORECAST TO DRIFT NORTHWARD OVER THE NEXT 36 TO 48 HOURS WITH A LOW CHANCE OF BECOMING A TROPICAL CYCLONE. AN UPPER LEVEL LOW IS CENTERED OVER THE FLORIDA STRAITS NEAR 24N80W THAT IS PROVIDING SUPPORT FOR THE CONVECTION ASSOCIATED WITH THE SPECIAL FEATURES SURFACE TROUGH...THE REMNANTS OF CHANTAL...THIS MORNING ACROSS THE EASTERN FLORIDA STRAITS... BAHAMAS...AND ADJACENT COASTAL WATERS EAST OF THE BAHAMAS. SCATTERED SHOWERS AND TSTMS ARE OCCURRING S OF 28N W OF 71W. THIS FEATURE IS EXPECTED TO SLIP NORTHWARD OVER THE NEXT 24 TO 36 HOURS AROUND THE WESTERN PERIPHERY OF SURFACE RIDGING ACROSS THE REMAINDER OF THE SW NORTH ATLC. THE RIDGE IS ANCHORED BY A 1022 MB HIGH CENTERED NE OF BERMUDA NEAR 34N63W. FARTHER EAST...AN UPPER LEVEL LOW IS CENTERED NEAR 30N60W THAT REMAINS AT THE SOUTHWESTERN EXTENT OF A STATIONARY FRONT ANALYZED FROM 32N43W TO 31N50W TO 28N55W. MOISTURE ASSOCIATED WITH THE UPPER LEVEL LOW AND A WEAK SURFACE TROUGH ANALYZED FROM 20N54W TO 30N56W ARE GENERATING ISOLATED SHOWERS AND TSTMS FROM 27N-33N BETWEEN 53W-62W. GLOBAL MODELS INDICATE THIS UPPER LEVEL FEATURE AND ASSOCIATED SURFACE TROUGHING WILL DRIFT WESTWARD ACROSS THE SW NORTH ATLC OVER THE COMING DAYS. FINALLY...THE EASTERN ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1020 MB HIGH CENTERED NEAR 31N35W. A SAHARAN AIR LAYERS CONTINUES TO BE THE OVERALL DOMINATE FEATURE PROVIDING FAIRLY STABLE CONDITIONS N OF 18N E OF 50W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN