000 AXNT20 KNHC 291138 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT THU AUG 29 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. ...TROPICAL WAVES... AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 21N45W 16N44W 11N43W. CONVECTIVE PRECIPITATION...SCATTERED MODERATE TO ISOLATED STRONG FROM 13N TO 18N BETWEEN 37W AND 45W. DEVELOPMENT...IF ANY...WILL BE SLOW TO OCCUR DURING THE NEXT COUPLE OF DAYS WHILE THE WAVE MOVES WESTWARD AT ABOUT 15 MPH AND APPROACHES THE LESSER ANTILLES. AFTER THAT TIME...UPPER-LEVEL WINDS COULD INHIBIT FURTHER 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 TROPICAL WAVE IS ALONG 23N59W 17N58W...TO A 1013 MB LOW PRESSURE CENTER THAT IS NEAR 13N56W. CONVECTIVE PRECIPITATION...SCATTERED MODERATE TO STRONG FROM 12N TO 14N BETWEEN 54W AND 58W...AND FROM 19N TO 22N BETWEEN 55W AND 62W. A BAHAMAS-TO-CUBA-TO JAMAICA SURFACE TROUGH IS ALONG 24N77W... 20N78W 15N78W. CONVECTIVE PRECIPITATION...NUMEROUS STRONG IN THE BAHAMAS WITHIN A 30 NM RADIUS OF 24N76W. ISOLATED MODERATE IN THE WINDWARD PASSAGE. AN INLAND TROPICAL WAVE IS MOVING THROUGH THE EASTERN SECTIONS OF THE ISTHMUS OF TEHUANTEPEC OF SOUTHERN MEXICO. MIDDLE LEVEL TO UPPER LEVEL CYCLONIC WIND FLOW COVERS THE SOUTHWESTERN CORNER OF THE GULF OF MEXICO. CONVECTIVE PRECIPITATION...SCATTERED STRONG TO THE SOUTH OF 21N BETWEEN 93W AND 96W INCLUDING ACROSS THE ISTHMUS OF TEHUANTEPEC OF SOUTHERN MEXICO INTO THE EASTERN PACIFIC OCEAN. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH PASSES THROUGH THE COASTAL AREAS OF GUINEA- BISSAU NEAR 12N16W TO 10N18W...TO A 1013 MB LOW PRESSURE CENTER THAT IS NEAR 8N22W...TO 9N31W AND 8N44W. CONVECTIVE PRECIPITATION...NUMEROUS STRONG FROM 6N TO 10N BETWEEN 24W AND 28W. ISOLATED MODERATE ELSEWHERE TO THE SOUTH OF 10N TO THE EAST OF 60W. ...DISCUSSION... THE GULF OF MEXICO... A MIDDLE LEVEL TO UPPER LEVEL CYCLONIC CIRCULATION CENTER IS NEAR 25N81W IN THE FLORIDA STRAITS. CYCLONIC WIND FLOW COVERS THE GULF OF MEXICO...FLORIDA...THE FLORIDA STRAITS...THE BAHAMAS...AND THE ATLANTIC OCEAN FROM 22N TO 29N BETWEEN 76W AND 86W. A SURFACE TROUGH CUTS ACROSS SOUTHEASTERN FLORIDA FROM LAKE OKEECHOBEE TO CUBA NEAR 23N81W. UPPER LEVEL SOUTHWESTERLY TO WESTERLY WIND FLOW IS CUTTING ACROSS THE SOUTHEASTERN GULF OF MEXICO AND THE FLORIDA STRAITS FROM THE NORTHWESTERN CARIBBEAN SEA. CONVECTIVE PRECIPITATION...SCATTERED MODERATE TO ISOLATED STRONG IN THE BAHAMAS FROM 24N TO 27N BETWEEN 76W AND 79W. A SECOND MIDDLE LEVEL TO UPPER LEVEL CYCLONIC CIRCULATION CENTER IS NEAR 22N97W IN THE SOUTHWESTERN CORNER OF THE GULF OF MEXICO. A SURFACE TROUGH IS IN THE SOUTHWESTERN CORNER OF THE GULF OF MEXICO...96W/97W FROM 23N TO 26N. CYCLONIC WIND FLOW THAT IS MOVING AROUND THE 22N97W CENTER COVERS THE AREAS THAT ARE FROM 16N TO 28N BETWEEN 90W AND 105W IN THE GULF OF MEXICO AND INTERIOR MEXICO. CONVECTIVE PRECIPITATION... RAINSHOWERS ARE POSSIBLE ELSEWHERE TO THE SOUTH OF 27N TO THE WEST OF 90W IN THE GULF OF MEXICO. A SURFACE TROUGH IS ALONG 89W/90W FROM 23N TO 29N. CONVECTIVE PRECIPITATION...RAINSHOWERS ARE POSSIBLE FROM 23N TO 29N BETWEEN 87W AND 92W. 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...KMYT...KDLP...KCRH...KHQI...KGVX WITH A MIDDLE LEVEL CEILING ALSO. MIDDLE LEVEL CLOUD CEILINGS ARE FOUND AT THE STATIONS...KBQX AND KBBF. 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. MIDDLE LEVEL AND HIGH LEVEL CLOUDS ARE REPORTED FROM PALACIOS TO THE HOUSTON METROPOLITAN AREA. BROKEN MIDDLE LEVEL CLOUDS ARE IN PARTS OF THE FAR WESTERN FLORIDA PANHANDLE. MIDDLE LEVEL AND HIGH LEVEL CLOUD CEILINGS ARE IN THE TAMPA METROPOLITAN AREA. 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. PLEASE READ THE HIGH SEAS FORECAST...MIAHSFAT2...AND THE OFFSHORE FORECAST...MIAOFFNT4...FOR SOUTHEAST WINDS 20 TO 25 KNOTS AND SEA HEIGHTS LOWER THAN 8 FEET TO THE SOUTH OF 20N TO THE EAST OF 92.5W FOR THE NEXT SIX HOURS OR SO. THE CARIBBEAN SEA... A MIDDLE LEVEL TO UPPER LEVEL INVERTED TROUGH IS ALONG 70W TO THE SOUTH OF HISPANIOLA. CYCLONIC WIND FLOW IS TO THE SOUTH OF 18N BETWEEN 67W AND 72W. THE TROUGH IS SURROUNDED BY COMPARATIVELY DRIER AIR IN SUBSIDENCE AS SEEN ON WATER VAPOR IMAGERY. UPPER LEVEL NORTHWESTERLY WIND FLOW REACHES HISPANIOLA FROM THE ATLANTIC OCEAN TO THE NORTH. BROAD MIDDLE LEVEL TO UPPER LEVEL ANTICYCLONIC WIND FLOW COVERS THE CARIBBEAN SEA TO THE WEST OF THE WINDWARD PASSAGE. SCATTERED MODERATE TO ISOLATED IN THE COASTAL WATERS OF HONDURAS TO BELIZE. ISOLATED MODERATE ELSEWHERE TO THE NORTH OF 15N TO THE WEST OF 80W. THE MONSOON TROUGH IS ALONG 9N BETWEEN 73W IN COLOMBIA BEYOND 84W IN COSTA RICA. CONVECTIVE PRECIPITATION...NUMEROUS STRONG IN COLOMBIA AND PANAMA AND COASTAL WATERS FROM 4N TO 10N BETWEEN 75W AND 80W...AND TO THE SOUTH OF 12N BETWEEN 80W AND THE COAST IN THE SOUTHWESTERN CORNER OF THE CARIBBEAN SEA. PLEASE READ THE HIGH SEAS FORECAST...MIAHSFAT2...AND THE OFFSHORE FORECAST...MIAOFFNT3...FOR MORE DETAILS ABOUT THE EAST TO SOUTHEAST WINDS 20 TO 25 KNOTS AND SEA HEIGHTS TO 8 FEET FROM 11N TO 13N BETWEEN 71W AND 75W. EXPECT ALSO EAST WINDS 20 TO 25 KNOTS AND SEA HEIGHTS LOWER THAN 8 FEET FROM 15N TO 17.5N BETWEEN 71W AND 74W. HISPANIOLA... A MIDDLE LEVEL TO UPPER LEVEL INVERTED TROUGH IS ALONG 72W TO THE SOUTH OF HISPANIOLA. CYCLONIC WIND FLOW IS TO THE SOUTH OF 18N BETWEEN 68W AND 74W. THE TROUGH IS SURROUNDED BY COMPARATIVELY DRIER AIR IN SUBSIDENCE AS SEEN ON WATER VAPOR IMAGERY. UPPER LEVEL NORTHWESTERLY WIND FLOW REACHES HISPANIOLA FROM THE ATLANTIC OCEAN TO THE NORTH. BROAD SURFACE LOW PRESSURE COVERS THE AREA THAT IS TO THE SOUTH OF CUBA...ACROSS THE WINDWARD CHANNEL...AND EASTWARD TO HISPANIOLA. A BAHAMAS-TO-CUBA-TO JAMAICA SURFACE TROUGH IS ALONG 24N77W...20N78W 15N78W. CONVECTIVE PRECIPITATION...ISOLATED MODERATE IN THE WINDWARD PASSAGE. THE GFS FORECASTS FOR 700 MB...500 MB...AND 250 MB SHOW THAT ANTICYCLONIC WIND FLOW WILL BE MOVING ACROSS HISPANIOLA FOR THE NEXT 48 HOURS...WITH AN EAST-TO-WEST ORIENTED RIDGE. THE ATLANTIC OCEAN... A MIDDLE LEVEL TO UPPER LEVEL TROUGH PASSES THROUGH 32N65W TO 28N68W 25N74W. CONVECTIVE PRECIPITATION...SCATTERED MODERATE TO ISOLATED STRONG TO THE NORTH OF 25N BETWEEN 55W AND 73W. A MIDDLE LEVEL TO UPPER LEVEL TROUGH EXTENDS FROM A 31N37W CYCLONIC CIRCULATION CENTER TO 26N41W 20N50W. A SURFACE TROUGH PASSES THROUGH 32N36W TO 28N38W. CONVECTIVE PRECIPITATION... SCATTERED MODERATE TO THE NORTH OF 29N BETWEEN 34W AND 38W. A SURFACE RIDGE PASSES THROUGH A 1024 MB HIGH PRESSURE CENTER THAT IS NEAR 33N44W...THROUGH 31N50W 30N55W 29N64W 27N70W. BROAD SURFACE ANTICYCLONIC WIND FLOW IS TO THE NORTH OF 22N TO THE EAST OF 70W...EXCEPT FOR THE 32N36W 28N38W SURFACE TROUGH. PLEASE READ THE HIGH SEAS FORECAST...MIAHSFAT2...FOR DETAILS ABOUT THE 24 HOUR FORECAST FOR NORTHEAST TO EAST WINDS 20 TO 25 KNOTS AND SEA HEIGHTS TO 8 FEET FROM 17N TO 20N BETWEEN 44W AND 50W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ MT