000 AXNT20 KNHC 041934 CCA TWDAT TROPICAL WEATHER DISCUSSION...CORRECTION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT FRI JUL 04 2014 CORRECTED FOR ISSUE TIME 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 1745 UTC. ...SPECIAL FEATURES... HURRICANE ARTHUR IS CENTERED NEAR 38.5N 72.4W AT 04/1800 UTC OR ABOUT 110 NM ESE OF ATLANTIC CITY NEW JERSEY MOVING NE AT 23 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 977 MB. MAXIMUM SUSTAINED WINDS ARE NOW DOWN TO 80 KT WITH GUSTS TO 100 KT. THE EYE OF ARTHUR IS SWEEPING RAPIDLY NORTHEASTWARD WELL OFF THE MID ATLANTIC COAST. STRONG CONVECTION IS LOCATED WITHIN A 120 NM RADIUS FROM THE STORM CENTER IN THE NORTHERN SEMICIRCLE AND 90 NM IN THE S SEMICIRCLE. ALTHOUGH THE CENTER OF ARTHUR IS WELL SOUTH OF THE AREA...STEADY HEAVY RAINS ARE RAPIDLY OVERSPREADING LONG ISLAND AND NEW ENGLAND. SEE LATEST INTERMEDIATE PUBLIC ADVISORY UNDER AWIPS/WMO HEADER MIATCPAT1/WTNT31 KNHC AND THE FULL FORECAST/ADVISORY UNDER AWIPS/WMO HEADER MIATCMAT1/WTNT21 KNHC FOR MORE DETAILS. ...TROPICAL WAVES... A TROPICAL WAVE OFF THE AFRICAN COAST EXTENDS FROM 20N22W TO 09N24W AND IS MOVING W AT 20 KT. A STRONG SAHARAN AIR LAYER SIGNAL IS NOTED ON METEOSAT-9 IMAGERY TO THE WEST AND NORTH OF THE WAVE. NO SIGNIFICANT CONVECTION IS ASSOCIATED WITH THE WAVE. A TROPICAL WAVE EXTENDING FROM 20N50W TO 15N51W TO 10N49W IS MOVING W AT 15-20 KT AND IS EASILY IDENTIFIABLE ON RECENT VISIBLE SATELLITE IMAGERY. THERE IS NO SIGNIFICANT DEEP CONVECTION OCCURRING AT THIS TIME WITH THE WAVE DUE TO THE WAVE BEING EMBEDDED WITHIN A STRONG SAHARAN AIR LAYER. A TROPICAL WAVE EXTENDS FROM 19N72W TO 12N74W AND IS MOVING W AT 15-20 KT. THE WAVE HAS FRACTURED WITH THE A SURFACE TROUGH N OF THE GREATER ANTILLES FROM 24N69W TO 20N72W. THE WAVE IS CURRENTLY MOVING BENEATH A BROAD ELONGATED UPPER LEVEL LOW CENTERED NEAR HISPANIOLA. DUE TO THE RELATIVELY UNFAVORABLE ENVIRONMENT OF UPPER LEVEL WIND SHEAR IMPACTING THE WAVE...NO SIGNIFICANT CONVECTION IS ASSOCIATED WITH THE WAVE AT THIS TIME. A TROPICAL WAVE EXTENDS FROM 21N90W TO 10N92W AND IS MOVING W-NW AT 15 KT. RIDGING ALOFT IS IN THE VICINITY OF THE WAVE. SCATTERED STRONG CONVECTION IS LOCATED WITHIN 90 NM OF THE GULF OF TEHUANTEPEC IN THE E PACIFIC. A TROPICAL WAVE EXTENDS FROM 22N100W TO 11N99W AND IS MOVING W AT 10-15 KT. THE WAVE IS MOVING OVER THE HIGH TERRAIN OF MEXICO AND WILL ONLY BE DISCERNIBLE IN THE EAST PACIFIC. THUS THE WAVE WILL NO LONGER BE CARRIED OVER MEXICO ON THE 1800 UTC ANALYSIS. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 16N16W TO 09N35W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 09N35W TO THE COATS OF SOUTH AMERICA NEAR 05N52W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS LOCATED S OF THE MONSOON TROUGH WITHIN 75-90 NM EITHER SIDE OF A LINE FROM 07N15W TO 07N26W. ...DISCUSSION... GULF OF MEXICO... A WEAKENING MIDDLE/UPPER LEVEL CYCLONIC CIRCULATION IS POSITIONED OVER THE NW GULF NEAR 27.5N94.5W AND IS NEARLY STATIONARY. BROAD RIDGING ALOFT COVERS MOST OF THE SOUTHERN HALF OF THE GULF. OVER THE NE GULF SATELLITE DERIVED WINDS INDICATE SOUTHWESTERLY WINDS WITH SPEEDS IN THE 15 TO 20 KT RANGE. AT THE SURFACE A TROUGH EXTENDS FROM FLORIDA BIG BEND TO 27N89W. A STATIONARY FRONT IS LOCATED ACROSS THE FLORIDA PANHANDLE INTO SE LOUISIANA. SCATTERED SHOWERS AND TSTMS ARE LOCATED OVER THE WESTERN TWO-THIRDS OF THE BAY OF CAMPECHE...AND WITHIN 45 NM EITHER SIDE OF THE SURFACE TROUGH NOTED ABOVE. CARIBBEAN SEA... UPPER LEVEL ANTICYCLONIC FLOW PREVAILS OVER THE CARIBBEAN W OF 80W AND E OF 65W...WITH A FAIRLY AMPLIFIED MID-TO UPPER LEVEL TROUGH IN BETWEEN. THE TROUGH EXTENDS FROM A CYCLONIC CIRCULATION LOCATED OVER HAITI TO A BASE NEAR 12N77W. RESULTING SOUTHERLY WINDS ALOFT ARE LOCATED OVER THE EASTERN THIRD OF THE CARIBBEAN. AT THE SURFACE MODERATE EASTERLY TRADE WIND FLOW WAS NOTED IN GENERALLY FAIR SKIES. SCATTERED TSTMS WERE ERUPTING OVER OROGRAPHICALLY FAVORED AREAS IN HISPANIOLA...CUBA AND CENTRAL AMERICA. ...HISPANIOLA... SCATTERED TSTMS WERE DEVELOPING OVER THE INTERIOR OF HAITI AND THE DOMINICAN REPUBLIC. THE 1200 UTC SOUNDING FROM SANTO DOMINGO INDICATED A MORE MOIST ATMOSPHERE THAN THE PREVIOUS SEVERAL DAYS WITH PRECIPITABLE WATER VALUES OF 1.83 INCHES...CLOSER TO NORMAL VALUES. GIVEN THE EARLY DEVELOPMENT OF TSTMS...THE POTENTIAL IS FOR MORE COVERAGE OF THUNDERSTORMS LATER THIS AFTERNOON THAN NOTED PREVIOUSLY. ADDITIONALLY THE PRESENCE OF THE UPPER LOW IN THE AREA IS PROVIDING ENOUGH INSTABILITY WITH LIFTED INDICES OF - 6C AND CAPE VALUES OF 2968 J/KG NOTED IN THE SOUNDING AS WELL. ATLANTIC OCEAN... UPPER LEVEL RIDGING NOTED OVER THE WESTERN ATLANTIC W OF 75W. A MID-TO UPPER LEVEL TROUGH AXIS EXTENDS THROUGH 32N58W TO HISPANIOLA WITH CYCLONIC FLOW LOCATED UP TO 10 TO 15 DEGREES EITHER SIDE OF THE AXIS. THE TROUGH AND CYCLONIC CIRCULATION WERE MOVING W AND IMPINGING UPON THE RIDGE. FURTHER E...BROAD UPPER LEVEL RIDGING COVERED THE CENTRAL ATLANTIC FROM 10N TO 30N BETWEEN 38W AND 62W. WATER VAPOR IMAGERY INDICATES STRONG SUBSIDENCE ASSOCIATED WITH THIS FEATURE. MOVING DOWNSTREAM A WELL-DEFINED MIDDLE/UPPER LEVEL CYCLONIC CIRCULATION IS CENTERED NEAR 30N30W AND IS MOVING S AT 10 KT. LIGHT TO MODERATE EASTERLY WINDS ALOFT COVER THE DEEP TROPICS. AT THE SURFACE A TROUGH IS LOCATED THROUGH 31N55W TO 25N62W. SCATTERED LOW TOPPED SHOWERS ARE LOCATED ABOUT 60 NM EITHER SIDE OF THE TROUGH. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ COBB