000 AXNT20 KNHC 120558 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT SUN JUL 12 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 09N29W TO 17N28W MOVING W AT 15 KT. THE WAVE COINCIDES WITH A 700 MB TROUGH BETWEEN 24W-34W AND A MAXIMUM IN 850 MB RELATIVE VORTICITY ALONG THE WAVE AXIS NEAR 14N. NO SIGNIFICANT CONVECTION IS NOTED ON SATELLITE IMAGERY DUE TO SAHARAN DUST THAT COVERS A LARGE PORTION OF THE TROPICAL NORTH ATLC. TROPICAL WAVE EXTENDS FROM 07N45W TO 16N45W MOVING W AT 15 KT. THE WAVE COINCIDES WITH A RELATIVELY BROAD 700 MB GLOBAL MODEL INDICATED TROUGH BETWEEN 42W-53W. IN ADDITION...A MAXIMUM IN 850 MB RELATIVE VORTICITY IS NOTED IN GUIDANCE ALONG THE WAVE AXIS NEAR 11N. NO SIGNIFICANT CONVECTION IS NOTED ON SATELLITE IMAGERY DUE LARGELY TO SAHARAN DUST THAT COVERS A LARGE AREA OF THE TROPICAL NORTH ATLC. TROPICAL WAVE EXTENDS FROM 11N72W TO 19N71W MOVING W AT 15 KT. THE WAVE COINCIDES WITH A SUBTLE 700 MB SHORTWAVE TROUGH AS PART OF A LARGER MID-LEVEL TROUGH ASSOCIATED WITH AN UPPER LEVEL LOW CENTERED OVER EASTERN CUBA. AS THE WAVE MOVES WEST AND COMES UNDER THE INFLUENCE OF THE DYNAMICS OF THE UPPER LEVEL LOW... SCATTERED MODERATE CONVECTION REMAINS ACROSS A LARGE AREA FROM 15N-22N BETWEEN 63W-75W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 14N17W TO 10N22W TO 10N27W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 10N30W TO 08N45W TO 06N54W. SCATTERED MODERATE CONVECTION IS FROM 04N-06N BETWEEN 21W-27W AND FROM 05N-08N BETWEEN 38W-42W. ...DISCUSSION... GULF OF MEXICO... A MIDDLE TO UPPER LEVEL RIDGE CENTERED OVER WEST TEXAS NEAR 32N102W CONTINUES TO BUILD IN OVER THE SE CONUS AND MUCH OF THE NORTHERN TWO-THIRDS OF THE GULF BASIN THIS EVENING. WATER VAPOR IMAGERY INDICATES MUCH OF THE NORTHEASTERLY FLOW ON THE SOUTHEASTERN PERIPHERY OF THE RIDGE ALOFT IS RELATIVELY DRY PROVIDING FOR AN OVERALL STABLE ENVIRONMENT AND QUIET CONDITIONS AT THE SURFACE FOR THE OVERNIGHT PERIOD. A FEW EARLIER ISOLATED SHOWERS AND TSTMS THAT FORMED ACROSS INTERIOR PORTIONS OF THE FLORIDA PENINSULA CONTINUE TO DIMINISH ACROSS THE FAR EASTERN WATERS AS A 1020 MB HIGH REMAINS ANCHORED NEAR 28N88W WHICH IS SLOWLY DRIFTING WESTWARD. GENTLE TO MODERATE ANTICYCLONIC WINDS ARE EXPECTED TO PERSIST THROUGH MONDAY INTO EARLY TUESDAY. CARIBBEAN SEA... NORTHWESTERLY FLOW ALOFT BECOMES MORE WESTERLY E OF 78W AS AN OVERALL STABLE ENVIRONMENT EXISTS OVER THE NW CARIBBEAN. THE WESTERLY FLOW LIES ON THE SOUTHERN PERIPHERY OF A VERY BROAD UPPER LEVEL LOW CENTERED OVER EASTERN CUBA. STRONG MIDDLE TO UPPER LEVEL DYNAMICS ASSOCIATED WITH THE LOW AND THE PRESENCE OF A TROPICAL WAVE ALONG 72W PROVIDING AMPLE LOW-LEVEL CONVERGENCE ARE GENERATING A LARGE AREA OF SCATTERED SHOWERS AND TSTMS ACROSS PORTIONS OF THE EASTERN AND CENTRAL CARIBBEAN FROM 13N- 22N BETWEEN 65W-75W. MOISTURE FROM CONVECTION OCCURRING S OF 12N BETWEEN 75W-83W ACROSS THE SW CARIBBEAN AND PANAMA IS ALSO BEING ADVECTED INTO THE UPPER LEVEL LOW. WHILE THE UPPER LEVELS REMAIN FAIRLY DYNAMIC AND ACTIVE THROUGH THE OVERNIGHT INTO SUNDAY... MODERATE TO FRESH TRADES PREVAIL WITH ONLY A SMALL AREA OF OCCASIONAL STRONG POSSIBLE WITHIN CLOSE PROXIMITY TO THE COAST OF COLOMBIA. THESE TRADES ARE EXPECTED TO PERSIST THROUGH TUESDAY. ...HISPANIOLA... A BROAD UPPER LEVEL LOW IS CENTERED OVER EASTERN CUBA PLACING THE ISLAND UNDER MAXIMUM MOIST SOUTHWESTERLY FLOW ALOFT THIS EVENING. GIVEN THE MIDDLE TO UPPER LEVEL DIFFLUENCE AND PRESENCE OF A TROPICAL WAVE ALONG 72W...SCATTERED SHOWERS AND TSTMS ARE OCCURRING ACROSS MUCH OF THE ISLAND THIS EVENING AND THIS ACTIVITY IS EXPECTED TO PERSIST THROUGHOUT THE DAY ON SUNDAY. THE UPPER LEVEL LOW IS FORECAST TO MOVE SLOWLY WEST-NORTHWEST LEAVING HISPANIOLA WITHIN THE AREA OF MAXIMUM DIFFLUENCE ALOFT THROUGH EARLY MONDAY RESULTING IN CONTINUED CONVECTION AND THE POSSIBILITY OF LOCALIZED FLOODING AND POSSIBLE MUDSLIDES. ATLANTIC OCEAN... AN UPPER LEVEL LOW IS CENTERED OVER EASTERN CUBA NEAR 20N76W SUPPORTING A BROAD AREA OF SCATTERED SHOWERS AND TSTMS ACROSS PORTIONS OF THE SW NORTH ATLC FROM 19N-23N BETWEEN 62W-75W. ISOLATED SHOWERS AND TSTMS ARE ELSEWHERE FROM 22N-28N BETWEEN 67W-80W. OTHERWISE...THE REMAINDER OF THE SW NORTH ATLC IS UNDER THE INFLUENCE OF A WEAK SURFACE RIDGE ANCHORED BY A 1019 MB HIGH CENTERED NEAR 30N74W. ALONG THE DISCUSSION AREA BORDER...A PAIR OF MID-LEVEL SHORTWAVE TROUGHS ARE NOTED ON WATER VAPOR IMAGERY...ONE NEAR 32N60W AND ANOTHER MOVING OFF THE CAROLINA COASTLINE NEAR 35N75W. BOTH SHORTWAVE SUPPORT LOW PRESSURE AREAS TO THE NORTH OF 32N...WITH A STATIONARY FRONT ANALYZED FROM 33N63W TO 33N72W. LOW-LEVEL MOISTURE CONTINUES TO POOL ALONG AND TO THE SOUTH OF THE STATIONARY FRONT GENERATING ISOLATED SHOWERS N OF 29N BETWEEN 57W-70W. FINALLY...THE CENTRAL AND EASTERN ATLC ARE DOMINATED BY AN INFLUENCE OF A SURFACE RIDGE ANCHORED BY A NEARLY STATIONARY 1028 MB HIGH CENTERED SE OF THE AZORES NEAR 37N24W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN