000 AXNT20 KNHC 071747 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT SUN JUL 07 2013 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. ...SPECIAL FEATURES... TROPICAL WAVE EXTENDS FROM A 1010 MB LOW CENTERED NEAR 09N41W TO 15N40W MOVING W AT 20-25 KT. WHILE MOST OF THE WAVE AXIS ITSELF REMAINS EMBEDDED WITHIN SAHARAN DUST AND DOES NOT EXHIBIT ANY CONVECTION...THE LOW CENTER LOCATED ON THE SOUTHERN EXTENT OF THE WAVE AXIS REMAINS EMBEDDED WITHIN THE ITCZ AND EXHIBITS A RELATIVELY SMALL AREAL COVERAGE CYCLONIC SPIN ON SATELLITE IMAGERY THAT WAS CAPTURED ON AN EARLIER MORNING ASCAT PASS AROUND 07/1250 UTC. SCATTERED MODERATE CONVECTION IS OCCURRING FROM 06N-10N BETWEEN 42W-46W. THIS SYSTEM HAS A HIGH CHANCE OF TROPICAL CYCLONE DEVELOPMENT WITHIN THE NEXT 48 HOURS. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 14N72W TO 22N66W MOVING W-NW AT 15 KT. THE WAVE COINCIDES WITH A BROAD GLOBAL MODEL INDICATED 700 MB TROUGH PROGRESSING ACROSS PORTIONS OF THE NORTH-CENTRAL CARIBBEAN SEA AND SW NORTH ATLC WHICH IS EXPECTED TO DRIFT W-NW ON THE SOUTHERN PERIPHERY OF A SW NORTH ATLC RIDGE ANCHORED OFF THE COAST OF THE CAROLINAS. THE WAVE ALSO REMAINS ON THE HEELS OF A MIDDLE TO UPPER LEVEL LOW CENTERED NORTH OF HISPANIOLA NEAR 24N72W THAT CONTINUES TO DRAW MOISTURE AND A PORTION OF THE WAVE TO THE NW. ISOLATED MODERATE CONVECTION IS OCCURRING WITHIN 90 NM EITHER SIDE OF THE AXIS...INCLUDING ACROSS PORTIONS OF HISPANIOLA. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 11N15W TO 09N22W TO 10N30W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 10N30W TO 11N35W TO A 1010 MB LOW CENTERED NEAR 09N41W TO 03N51W. SCATTERED MODERATE CONVECTION IS FROM 05N-13N BETWEEN 15W-26W. ...DISCUSSION... GULF OF MEXICO... A MIDDLE TO UPPER LEVEL TROUGH AXIS EXTENDS FROM THE LOWER MISSISSIPPI RIVER VALLEY SOUTHWEST TO NE MEXICO. THIS MIDDLE TO UPPER LEVEL TROUGHING SUPPORTS A LARGE AREA OF DIFFLUENCE ACROSS THE WESTERN AND NORTH-CENTRAL GULF GENERATING SCATTERED SHOWERS AND TSTMS WEST OF A LINE FROM THE FLORIDA PANHANDLE NEAR 30N87W TO SOUTHERN MEXICO COAST NEAR COATZACOALCOS. ELSEWHERE...OVER PORTIONS OF THE EASTERN GULF...WATER VAPOR IMAGERY INDICATES THAT DRIER AIR ALOFT CONTINUES TO GRADUALLY DRIFT WESTWARD AS MIDDLE TO UPPER LEVEL RIDGING BUILDS IN ACROSS THE BASIN. AS A RESULT...SURFACE RIDGING ANCHORED ACROSS A LARGE PART OF THE SW NORTH ATLC IS ALSO BUILDING IN ACROSS THE FLORIDA PENINSULA AND EASTERN GULF THIS AFTERNOON PROVIDING MOSTLY FAIR CONDITIONS WITH ONLY FAST MOVING ISOLATED SHOWERS NOTED ON SATELLITE AND MOSAIC RADAR IMAGERY. WITH THIS OVERALL PATTERN IN PLACE...EAST- SOUTHEAST WINDS ARE FORECAST TO PREVAIL THROUGH THURSDAY. CARIBBEAN SEA... WATER VAPOR IMAGERY INDICATES AN UPPER LEVEL TROUGH AXIS EXTENDS FROM A SW NORTH ATLC UPPER LEVEL LOW CENTERED NEAR 24N72W WEST- SOUTHWEST TO OVER HONDURAS NEAR 16N86W. MOSTLY DRY AIR ALOFT IS ASSOCIATED WITH THIS TROUGH AXIS...HOWEVER MOISTURE INCREASES W OF 84W WITH A FEW ISOLATED SHOWERS OCCURRING ACROSS THE NW CARIBBEAN AND YUCATAN PENINSULA. OTHERWISE...FARTHER SOUTH AND EAST...DIFFLUENT SOUTHERLY UPPER LEVEL FLOW DOMINATES ACROSS THE SW CARIBBEAN WITH SCATTERED SHOWERS AND TSTMS OCCURRING S OF 13N BETWEEN 77W-85W...INCLUDING INLAND PORTIONS OF PANAMA...COSTA RICA...AND SE NICARAGUA. MUCH OF THE FOCUS FOR THIS CONVECTION IS ALSO WITHIN CLOSE PROXIMITY TO THE MONSOON TROUGH AXIS ALONG 09N/10N. FINALLY...THE NORTH-CENTRAL CARIBBEAN IS UNDER THE INFLUENCE OF A TROPICAL WAVE EXTENDING FROM THE SW NORTH ATLC NEAR 22N66W ACROSS EASTERN HISPANIOLA TO 14N72W. COINCIDING WITH MID-LEVEL CYCLONIC FLOW AND TRAILING AN UPPER LEVEL LOW CENTERED NORTH OF THE BASIN NEAR 23N72W...THE TROPICAL WAVE IS GENERATING ISOLATED SHOWERS AND TSTMS N OF 16N BETWEEN 68W-75W...INCLUDING MUCH OF HISPANIOLA. HISPANIOLA... CURRENTLY A TROPICAL WAVE IS PROGRESSING ACROSS THE ISLAND BRINGING WITH IT WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS. AN UPPER LEVEL LOW IS CENTERED NORTH OF HISPANIOLA NEAR 24N72W WHICH CONTINUES TO DRAW MOISTURE AND THE TROPICAL WAVE WESTWARD. THE DYNAMICS ASSOCIATED WITH THE UPPER LEVEL LOW AND INTERACTION WITH THE TROPICAL WAVE WILL KEEP PRECIPITATION CHANCES HIGH OVER THE ISLAND THROUGH THIS EVENING INTO THE OVERNIGHT HOURS. AS THE WAVE PASSES OVER THE NEXT 24 TO 36 HOURS...WIDELY SCATTERED SHOWERS AND TSTMS ARE EXPECTED THROUGH MONDAY. ATLANTIC OCEAN... A MIDDLE TO UPPER LEVEL ANTICYCLONIC CIRCULATION IS CENTERED OFF THE COAST OF THE CAROLINA NEAR 34N74W THAT SUPPORTS A 1024 MB HIGH CENTERED NEAR 34N72W. OVERALL THESE SYNOPTIC FEATURES ARE PROVIDING MUCH OF THE SW NORTH ATLC WITH RELATIVELY TRANQUIL CONDITIONS N OF 29N...HOWEVER S OF 29N A MIDDLE TO UPPER LEVEL LOW IS CENTERED NEAR 24N72W WITH A SURFACE TROUGH ANALYZED FROM 22N76W TO 27N75W. ASIDE FROM THE IMMEDIATE ISOLATED SHOWERS ASSOCIATED WITH THE UPPER LEVEL LOW OCCURRING FROM 21N-28N BETWEEN 69W-76W...ISOLATED SHOWERS CONTINUE TO ADVECT ACROSS THE BAHAMAS AND INLAND ACROSS PORTIONS OF THE FLORIDA PENINSULA AND FLORIDA STRAITS. A TROPICAL WAVE EXTENDING NORTHEAST FROM EASTERN HISPANIOLA TO 22N66W IS ALSO PROVIDING PORTIONS OF THE SW NORTH ATLC WITH ISOLATED SHOWERS AND TSTMS N OF 18N BETWEEN 56W-71W. OTHERWISE...THE LAST AREA OF SIGNIFICANT WEATHER IS NOTED ACROSS THE CENTRAL ATLC AS A MID-LEVEL SHORTWAVE TROUGH PROGRESSES EASTWARD IN THE VICINITY OF 32N41W. THIS TROUGHING SUPPORTS A DISSIPATING STATIONARY FRONT ANALYZED FROM 32N41W W- SW TO 28N50W TO 27N62W. ISOLATED SHOWERS AND TSTMS ARE OCCURRING WITHIN 90 NM EITHER SIDE OF THE BOUNDARY AND FROM 27N-31N BETWEEN 38W-44W. THE REMAINDER OF THE EASTERN ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1024 MB HIGH CENTERED SOUTH OF THE AZORES NEAR 34N29W. THE RIDGE AXIS EXTENDS FROM THE HIGH SW TO 20N50W. A LARGE PORTION OF THE EASTERN AND CENTRAL ATLC ARE ALSO INFLUENCED BY A SAHARAN AIR LAYER...SUSPENDED DUST...N OF 12N E OF 50W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN