000 AXNT20 KNHC 301138 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT FRI AUG 30 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1015 UTC. ...SPECIAL FEATURES... A TROPICAL WAVE STILL IS MOVING THROUGH AFRICA...FROM MAURITANIA TO SENEGAL AND GUINEA-BISSAU. THE 30/0600 UTC POSITION REMAINS ALONG 15W/16W BASED ON THE LONG-TERM SATELLITE IMAGERY AND A LOW PRESSURE CENTER THAT IS NEAR 14N ALONG THE TROPICAL WAVE. CONVECTIVE PRECIPITATION...NUMEROUS STRONG FROM 9N TO 11N BETWEEN 14W AND 17W. ENVIRONMENTAL CONDITIONS APPEAR CONDUCIVE FOR DEVELOPMENT...AND THIS SYSTEM HAS THE POTENTIAL TO BECOME A TROPICAL DEPRESSION DURING THE NEXT COUPLE OF DAYS WHEN THE LOW MOVES BETWEEN THE WEST COAST OF AFRICA AND THE CAPE VERDE ISLANDS. AFTER THAT TIME...CONDITIONS ARE EXPECTED TO BECOME A LESS CONDUCIVE FOR DEVELOPMENT AS THE DISTURBANCE MOVES TOWARD THE WEST-NORTHWEST OVER THE EASTERN ATLANTIC. THE SYSTEM HAS A MEDIUM CHANCE OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS AND HIGH CHANCE OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 5 DAYS. WHETHER THIS SYSTEM BECOMES A TROPICAL CYCLONE OR NOT...IT WILL LIKELY BRING CLOUDINESS AND THUNDERSTORMS TO PORTIONS OF THE CAPE VERDE ISLANDS IN THE NEXT 2 OR 3 DAYS. ...TROPICAL WAVES... AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 48W/49W TO THE SOUTH OF 20N MOVING WESTWARD 10 TO 15 KNOTS. CONVECTIVE PRECIPITATION... SCATTERED MODERATE TO ISOLATED STRONG FROM 14N TO 20N BETWEEN 42W AND 50W. RAINSHOWERS ARE POSSIBLE ELSEWHERE FROM 4N TO 22N BETWEEN 40W AND 55W. THIS WAVE IS FORECAST TO MOVE WESTWARD... INTO A REGION WHERE THE UPPER LEVEL WINDS ARE NOT FAVORABLE FOR DEVELOPMENT. THIS SYSTEM HAS A LOW CHANCE OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS...AND A LOW CHANCE OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 5 DAYS. AN ATLANTIC OCEAN SURFACE TROUGH IS ALONG 61W TO THE SOUTH OF 19N. CONVECTIVE PRECIPITATION...ISOLATED MODERATE FROM 10N TO 20N BETWEEN 59W AND 63W...FROM THE ATLANTIC OCEAN INTO THE CARIBBEAN SEA. AN ATLANTIC OCEAN-TO-CARIBBEAN SEA TROPICAL WAVE CURVES ALONG 25N62W...TO 20N66W...CUTTING ACROSS CENTRAL PUERTO RICO...TO THE COAST OF VENEZUELA ALONG 67W. IT IS MOVING WESTWARD 15 TO 20 KNOTS. THE WAVE IS MOVING THROUGH THE AREA OF AN ALREADY- EXISTING MIDDLE LEVEL TO UPPER LEVEL TROUGH. THE TROUGH EXTENDS FROM A 27N57W CYCLONIC CIRCULATION CENTER...TO 24N60W 22N66W... ACROSS PUERTO RICO...TO 16N65W IN THE CARIBBEAN SEA. A SECONDARY SURGE OF ENERGY INTO AN ALREADY-EXISTING TROUGH IS ALONG 32N66W 30N70W 27N72W. CONVECTIVE PRECIPITATION...SCATTERED MODERATE TO ISOLATED STRONG FROM 20N TO 25N BETWEEN 57W AND 68W...AND TO THE NORTH OF 27N BETWEEN 60W AND 80W. RAINSHOWERS ARE POSSIBLE ELSEWHERE TO THE WEST AND NORTHWEST OF THE LINE THAT PASSES THROUGH 32N52W TO 25N55W TO 18N62W IN THE ATLANTIC OCEAN. RAINSHOWERS ARE POSSIBLE IN THE CARIBBEAN SEA TO THE NORTH OF 16N BETWEEN 64W AND 80W. AN INLAND TROPICAL WAVE HAS MOVED AWAY FROM THE ISTHMUS OF TEHUANTEPEC OF SOUTHERN MEXICO. IT IS NOW AN EASTERN PACIFIC OCEAN FEATURE. CONVECTIVE PRECIPITATION...ISOLATED MODERATE IN THE SOUTHWESTERN CORNER OF THE GULF OF MEXICO TO THE SOUTH OF 20N AND IN THE ISTHMUS OF TEHUANTEPEC. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH PASSES THROUGH THE COASTAL SENEGAL NEAR 12N17W TO 9N30W 7N40W AND 7N48W. CONVECTIVE PRECIPITATION... NUMEROUS STRONG FROM 10N TO 11N BETWEEN 26W AND 28W. SCATTERED MODERATE TO ISOLATED STRONG FROM 11N TO 15N BETWEEN 32W AND 40W...AND FROM 3N TO 6N BETWEEN 28W AND 40W. ISOLATED MODERATE FROM 4N TO 13N BETWEEN 43W AND 60W. ...DISCUSSION... THE GULF OF MEXICO... A MIDDLE LEVEL TO UPPER LEVEL CYCLONIC CIRCULATION CENTER IS IN THE SOUTHERNMOST PART OF FLORIDA/THE FLORIDA KEYS/THE FLORIDA STRAITS. THIS CYCLONIC CENTER HAS BEEN IN THIS GENERAL AREA FOR THE LAST FEW DAYS. CYCLONIC WIND FLOW COVERS THE GULF OF MEXICO...FLORIDA...THE FLORIDA STRAITS...THE BAHAMAS...THE ATLANTIC OCEAN...CUBA...AND THE NORTHWESTERN PART OF THE CARIBBEAN SEA FROM 21N TO 29N BETWEEN 76W AND 90W. CONVECTIVE PRECIPITATION...SCATTERED TO NUMEROUS STRONG IN THE FLORIDA STRAITS ALONG THE COAST OF CUBA BETWEEN 78W AND 81W. RAINSHOWERS ARE POSSIBLE ELSEWHERE IN THE GULF OF MEXICO TO THE SOUTH OF 28N TO THE EAST OF 84W TOWARD THE BAHAMAS. A SECOND MIDDLE LEVEL TO UPPER LEVEL CYCLONIC CIRCULATION CENTER IS INLAND IN THE SOUTHWESTERN SECTIONS OF MEXICO NEAR 21N105W. CYCLONIC WIND FLOW COVERS MEXICO AND THE GULF OF MEXICO TO THE SOUTH OF 28N TO THE WEST OF 93W. WEAK SURFACE TO LOW LEVEL CYCLONIC WIND FLOW COVERS THE AREA FROM 22N TO 28N BETWEEN 87W AND 96W. A SURFACE TROUGH CURVES ALONG 28N93W 25N93W 24N95W. RAINSHOWERS ARE POSSIBLE IN THIS AREA ALSO. COMPARATIVELY DRIER AIR IN SUBSIDENCE SHOWS UP IN WATER VAPOR IMAGERY TO THE NORTH OF 22N TO THE WEST OF 84W. FOR THE OFFSHORE OIL PLATFORM SITES THAT ARE TO THE NORTH OF 27N TO THE WEST OF 88W... LOW LEVEL CLOUD CEILINGS ARE AT THE FOLLOWING ICAO STATIONS... KMZG...KBBF...LOW TO MIDDLE LEVEL AT KBQX AND AT KGVX...KCRH. ICAO STATION KEMK IS REPORTING A VISIBILITY OF LESS THAN ONE MILE WITH HAZE. FAIR SKIES/CLEAR SKIES AT OR LOWER THAN 12000 FEET ARE BEING REPORTED ELSEWHERE ACROSS THE AREA. BROKEN LOW LEVEL TO MIDDLE LEVEL CLOUDS COVER TEXAS FROM THE HOUSTON METROPOLITAN AREA SOUTHWARD TO THE COAST. BROKEN MIDDLE LEVEL CLOUDS ARE IN TALLAHASSEE FLORIDA...AND IN PUNTA GORDA. FAIR SKIES/CLEAR SKIES AT OR LOWER THAN 12000 FEET ARE BEING REPORTED ELSEWHERE IN THE COASTAL STATIONS OF THE U.S.A. GULF COAST STATES. THE CARIBBEAN SEA... A MIDDLE LEVEL TO UPPER LEVEL INVERTED TROUGH IS ALONG 16N76W TO 13N78W TO 11N78W. CYCLONIC WIND FLOW IS TO THE SOUTH OF 17N BETWEEN 73W AND 82W. THE TROUGH IS SURROUNDED BY COMPARATIVELY DRIER AIR IN SUBSIDENCE AS SEEN ON WATER VAPOR IMAGERY. A MIDDLE LEVEL TO UPPER LEVEL TROUGH CUTS ACROSS THE AREA THAT RUNS FROM FROM PUERTO RICO TO HISPANIOLA. BROAD MIDDLE LEVEL TO UPPER LEVEL ANTICYCLONIC WIND FLOW COVERS THE CARIBBEAN SEA TO THE WEST OF THE WINDWARD PASSAGE. CONVECTIVE PRECIPITATION...SCATTERED MODERATE TO ISOLATED STRONG IN THE CARIBBEAN SEA TO THE NORTH OF 16N TO THE WEST OF THE WINDWARD PASSAGE. THE MONSOON TROUGH IS ALONG 9N74W IN COLOMBIA...BEYOND 8N84W IN THE EASTERN PACIFIC OCEAN. CONVECTIVE PRECIPITATION...SCATTERED TO NUMEROUS STRONG IN COLOMBIA AND IN THE SOUTHWESTERN CORNER OF THE CARIBBEAN SEA TO THE SOUTH OF 11N TO THE WEST OF 75W. PLEASE READ THE HIGH SEAS FORECAST...MIAHSFAT2...AND THE OFFSHORE FORECAST...MIAOFFNT3...FOR MORE DETAILS ABOUT THE NORTHEAST TO EAST WINDS 20 TO 25 KNOTS AND SEA HEIGHTS LOWER THAN 8 FEET TO THE SOUTH OF 13N BETWEEN 67W AND 73W. HISPANIOLA... AN ATLANTIC OCEAN-TO-CARIBBEAN SEA TROPICAL WAVE CURVES ALONG 25N62W...TO 20N66W...CUTTING ACROSS CENTRAL PUERTO RICO...TO THE COAST OF VENEZUELA ALONG 67W. IT IS MOVING WESTWARD 15 TO 20 KNOTS. THE WAVE IS MOVING THROUGH THE AREA OF AN ALREADY- EXISTING MIDDLE LEVEL TO UPPER LEVEL TROUGH. THE TROUGH EXTENDS FROM A 27N57W CYCLONIC CIRCULATION CENTER...TO 24N60W 22N66W... ACROSS PUERTO RICO...TO 16N65W IN THE CARIBBEAN SEA. RAINSHOWERS ARE POSSIBLE IN THE CARIBBEAN SEA TO THE NORTH OF 16N BETWEEN 64W AND 80W. THE GFS FORECASTS FOR 700 MB AND 500 MB...SHOW THAT ANTICYCLONIC WIND FLOW WILL BE MOVING ACROSS HISPANIOLA FOR THE NEXT 48 HOURS...WITH AN EAST-TO-WEST ORIENTED RIDGE. THE GFS FORECAST FOR 250 MB SHOWS THAT A RIDGE WILL COVER HISPANIOLA FOR THE FIRST 24 HOURS OF THE FORECAST PERIOD. A TROUGH WILL REPLACE THE RIDGE FOR THE REST OF THE FORECAST PERIOD. THE ATLANTIC OCEAN... A MIDDLE LEVEL TO UPPER LEVEL CYCLONIC CIRCULATION CENTER IS NEAR 28N35W. CYCLONIC WIND FLOW COVERS THE AREA FROM 23N TO 33N BETWEEN 28W AND 44W. A SURFACE TROUGH IS ALONG 33N38W 29N39W 26N41W. RAINSHOWERS ARE POSSIBLE TO THE NORTH OF 26N BETWEEN 34W AND 42W. A 1023 MB HIGH PRESSURE CENTER IS NEAR 33N45W. SURFACE ANTICYCLONIC WIND FLOW IS TO THE NORTH OF 25N BETWEEN THE 33N38W 26N41W SURFACE TROUGH AND 60W. PLEASE READ THE HIGH SEAS FORECAST...MIAHSFAT2...FOR DETAILS ABOUT THE TROPICAL WAVE THAT IS ALONG 48W FROM 12N TO 21N. EXPECT WINDS 20 KNOTS OR LESS AND SEA HEIGHTS TO 8 FEET FROM 16N TO 19N BETWEEN 45W AND 50W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ MT