000 AXNT20 KNHC 110556 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT SAT JUL 11 2015 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 07N38W TO 16N38W MOVING W AT 10-15 KT. THE WAVE COINCIDES WITH A RELATIVELY BROAD 700 MB GLOBAL MODEL INDICATED TROUGH BETWEEN 33W-44W. IN ADDITION...A MAXIMUM IN 850 MB RELATIVE VORTICITY IS NOTED IN GUIDANCE ALONG THE WAVE AXIS NEAR 12N. NO SIGNIFICANT CONVECTION IS NOTED ON SATELLITE IMAGERY DUE LARGELY TO SAHARAN DUST THAT COVERS A LARGE AREA OF THE TROPICAL ATLC. TROPICAL WAVE EXTENDS FROM 10N63W TO 18N63W MOVING W AT 15 KT. THE WAVE COINCIDES WITH A SUBTLE 700 MB SHORTWAVE TROUGH AND A MAXIMUM OF 850 MB RELATIVE VORTICITY CENTERED IN THE VICINITY OF 16N62W. NO SIGNIFICANT CONVECTION IS NOTED ON SATELLITE IMAGERY AT THIS TIME. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 21N17W TO 13N23W TO 11N31W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 11N31W TO 09N48W TO 11N61W. ...DISCUSSION... GULF OF MEXICO... UPPER LEVEL RIDGING IS NOTED ON WATER VAPOR IMAGERY OVER THE SW GULF WATERS AND SOUTHERN MEXICO S OF 25N W OF 88W. MIDDLE TO UPPER LEVEL DIFFLUENCE ASSOCIATED WITH THE RIDGING IS GENERATING AN AREA OF SCATTERED SHOWERS AND TSTMS ACROSS THE SW GULF AND SOUTHERN MEXICO S OF 21N BETWEEN 90W-98W. OTHERWISE...THE REMAINDER OF THE BASIN IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1020 MB HIGH CENTERED IN THE NE GULF WATERS NEAR 29N85W. GENERALLY LIGHT TO MODERATE EAST-SOUTHEAST WINDS PREVAIL AND ARE EXPECTED TO PERSIST THROUGH SATURDAY AS THE HIGH DRIFTS SLOWLY WESTWARD TO THE NW GULF BY SUNDAY. CARIBBEAN SEA... NORTHWESTERLY FLOW ALOFT BECOMES MORE WESTERLY E OF 80W AS AN OVERALL STABLE ENVIRONMENT EXISTS OVER MUCH OF THE BASIN THIS EVENING WITH THIS SYNOPTIC SETUP. THIS FLOW LIES ON THE SOUTHERN PERIPHERY OF A BROAD AND ELONGATED UPPER LEVEL LOW CENTERED OVER THE WINDWARD PASSAGE NEAR 21N74W. WHILE MOSTLY CLEAR SKIES PREVAIL...THE UPPER LEVEL LOW IS GENERATING A FEW ISOLATED SHOWERS AND TSTMS ACROSS PORTIONS OF HISPANIOLA AND THE CARIBBEAN APPROACHES TO THE WINDWARD PASSAGE. SCATTERED SHOWERS AND TSTMS ARE ALSO OCCURRING S OF 12N W OF 75W...INCLUDING PANAMA...COSTA RICA...AND NICARAGUA DUE TO CLOSE PROXIMITY OF THE MONSOON TROUGH AXIS ALONG 08N/09N. A TROPICAL WAVE IS ALONG 63W AND IS INTRODUCING A GRADUAL INCREASE IN CLOUDINESS AND POSSIBLE ISOLATED SHOWERS ACROSS THE WINDWARD ISLAND S OF 15N. FINALLY...THE PRIMARY IMPACT FOR THE CARIBBEAN REMAINS THE FRESH TO STRONG TRADES OCCURRING S OF 16N BETWEEN 68W-80W. THE PRESSURE GRADIENT IS EXPECTED TO RELAX SOMEWHAT BY LATE MONDAY. ...HISPANIOLA... AN ELONGATED UPPER LEVEL LOW IS CENTERED N OF THE WINDWARD PASSAGE NEAR 21N74W PROVIDING AMPLE LIFTING DYNAMICS TO GENERATE A FEW ISOLATED SHOWERS AND TSTMS OCCURRING ACROSS WESTERN PORTIONS OF THE ISLAND THIS EVENING...INCLUDING THE SOUTHWESTERN ADJACENT COASTAL WATERS. THIS ACTIVITY IS EXPECTED TO CONTINUE ON A DIMINISHING TREND BY THE LATE MORNING HOURS. WITH THE UPPER LEVEL LOW SLOW TO MOVE ON SATURDAY...WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS ARE POSSIBLE DURING THE LATE AFTERNOON AND EARLY EVENING HOURS. ATLANTIC OCEAN... AN UPPER LEVEL LOW IS CENTERED NORTH OF THE WINDWARD PASSAGE NEAR 21N74W SUPPORTING WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS ACROSS PORTIONS OF THE SW NORTH ATLC FROM 20N-27N BETWEEN 66W-76W. OTHERWISE...THE REMAINDER OF THE SW NORTH ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1021 MB HIGH CENTERED NEAR 29N75W. FARTHER EAST...THE CENTRAL AND EASTERN ATLC IS DOMINATED BY A INFLUENCE OF ANOTHER SURFACE RIDGE ANCHORED BY A NEARLY STATIONARY 1029 MB HIGH CENTERED SE OF THE AZORES NEAR 36N25W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN