000 AXNT20 KNHC 221131 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT SUN SEP 22 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 25W/26W TO THE SOUTH OF 20N MOVING WESTWARD 10 TO 15 KNOTS. THE POSITION WAS HELD MORE TO THE EAST BASED ON THE LONG-TERM SATELLITE IMAGERY. CONVECTIVE PRECIPITATION...NUMEROUS STRONG FROM 12N TO 17N BETWEEN 26W AND 28W. SCATTERED STRONG FROM 10N TO 12N BETWEEN 28W AND 31W. AN ATLANTIC OCEAN SURFACE TROUGH IS ALONG 20N38W 13N36W. CONVECTIVE PRECIPITATION...ISOLATED MODERATE WITHIN 30 NM ON EITHER SIDE OF 12N34W 15N35W 19N38W. SCATTERED MODERATE TO ISOLATED STRONG FROM 18N TO 19N BETWEEN 32W AND 35W. AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 22N41W 15N43W 9N43W MOVING WESTWARD 10 TO 15 KNOTS. A MIDDLE LEVEL TO UPPER LEVEL TROUGH PASSES THROUGH 32N18W TO 26N20W TO 24N29W 21N34W 16N37W AND 11N40W. CONVECTIVE PRECIPITATION...RAINSHOWERS ARE POSSIBLE FROM 10N TO 20N BETWEEN 40W AND 50W. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH PASSES THROUGH THE COASTAL AREAS OF GAMBIA/ FROM 13N TO 14N BETWEEN 16W AND 17W...TO 12N20W 10N25W 12N29W 9N35W 9N39W 8N42W. THE ITCZ CONTINUES FROM 8N42W TO 5N49W AND 5N53W NEAR THE COAST OF FRENCH GUIANA. CONVECTIVE PRECIPITATION...SCATTERED MODERATE TO STRONG FROM 4N TO 12N TO THE EAST OF 44W...AND FROM 5N TO 10N BETWEEN 43W AND 60W. ...DISCUSSION... FROM THE WESTERN ATLANTIC OCEAN...ACROSS THE BAHAMAS AND CUBA...INTO THE NORTHWESTERN CORNER OF THE CARIBBEAN SEA... A MIDDLE LEVEL TO UPPER LEVEL TROUGH PASSES THROUGH 32N69W TO 27N70W...ACROSS THE BAHAMAS AND SOUTHEASTERN CUBA...TO 18N80W IN THE NORTHWESTERN PART OF THE CARIBBEAN SEA. A SURFACE TROUGH IS ALONG 31N74W 27N75W TO 24N77W IN THE BAHAMAS. CONVECTIVE PRECIPITATION...SCATTERED TO NUMEROUS STRONG IN THE CARIBBEAN SEA WITHIN A 60 NM RADIUS OF 17.5N81W...AND BETWEEN JAMAICA AND SOUTHEASTERN CUBA BETWEEN 77W AND 78W. RAINSHOWERS ARE POSSIBLE ELSEWHERE IN THE ATLANTIC OCEAN TO THE WEST OF 68W...AND IN THE CARIBBEAN SEA TO THE NORTHWEST OF THE LINE THAT PASSES THROUGH THE WINDWARD PASSAGE...TO 16N77W...TO 15N83W ALONG THE BORDER OF EASTERN HONDURAS/NORTHEASTERN NICARAGUA. THE GULF OF MEXICO... A DEEP LAYER TROUGH IS MOVING EASTWARD...FROM THE U.S.A. EAST COAST...THROUGH MISSISSIPPI AND LOUISIANA...INTO CENTRAL AND EAST CENTRAL TEXAS. THE TROUGH SUPPORTS A COLD FRONT THAT PASSES THROUGH THE WESTERN PART OF THE FLORIDA PANHANDLE...EXTREME SOUTHEASTERN LOUISIANA...TO A GULF OF MEXICO 1003 MB LOW PRESSURE CENTER THAT IS NEAR 26N95W...TO 20N95W AND 18N97W. CONVECTIVE PRECIPITATION...SCATTERED TO NUMEROUS STRONG FROM 26N TO 28N BETWEEN 91W AND 95W. SCATTERED MODERATE TO ISOLATED STRONG FROM 22N TO 24N BETWEEN 92W AND 96W. SCATTERED MODERATE TO THE NORTH OF 27N TO THE EAST OF 90W. SCATTERED STRONG IS INLAND IN MEXICO FROM 17N TO 21N. FOR THE OFFSHORE OIL PLATFORM SITES THAT ARE TO THE NORTH OF 27N TO THE WEST OF 88W... MULTILAYERED CLOUD CEILINGS COVER THE AREA. VISIBILITIES OF 3 MILES OR LOWER WITH FOG ARE REPORTED AT THE FOLLOWING ICAO STATIONS...KATP...KEIR...KSPR...KIPN. FAIR SKIES/CLEAR SKIES AT OR LOWER THAN 12000 FEET ARE BEING REPORTED ELSEWHERE ACROSS THE REST OF THE AREA. THE SKIES ARE CLEARING IN TEXAS...WITH SOME REMAINING LOW CLOUD CEILINGS IN THE DEEP SOUTH. CLEARING SKIES CONTINUE INTO THE MIDDLE TEXAS GULF COAST. LOW CLOUD CEILINGS CONTINUE FROM THE AREA THAT IS JUST TO THE EAST AND NORTHEAST OF THE MIDDLE TEXAS GULF COAST...TO THE HOUSTON METROPOLITAN AREA...TO THE UPPER TEXAS GULF COAST. LOW CLOUD CEILINGS COVER THE LOUISIANA GULF COASTAL PLAINS. MULTILAYERED CLOUD CEILINGS AND CONVECTIVE PRECIPITATION SURROUND LAKE PONTCHARTRAIN IN LOUISIANA. LOW LEVEL AND MIDDLE LEVEL CLOUD CEILINGS ARE PRESENT IN SOUTHERN MISSISSIPPI...AND IN COASTAL ALABAMA...WITH POSSIBLE RAIN. MULTILAYERED CLOUD CEILINGS WITH PRECIPITATION COVER FLORIDA TO THE WEST OF PERRY. MULTILAYERED CLOUD CEILINGS COVER FLORIDA FROM BROOKSVILLE WITH LIGHT RAIN...TO THE TAMPA METROPOLITAN AREA. PLEASE READ THE HIGH SEAS FORECAST...MIAHSFAT2...AND THE OFFSHORE FORECAST...MIAOFFNT4...FOR MORE DETAILS ABOUT THE COLD FRONT FROM MOBILE ALABAMA TO THE 1003 MB LOW PRESSURE CENTER THAT IS NEAR 26N95W TO 19N96W. EXPECT NORTH TO NORTHEAST WINDS 20 TO 25 KNOT AND SEA HEIGHTS TO 8 FEET TO THE NORTH OF 23N TO THE WEST OF THE FRONT. HISPANIOLA... UPPER LEVEL SOUTHWESTERLY WIND FLOW SPANS THE AREA. THIS WIND FLOW IS RELATED TO THE ATLANTIC OCEAN-TO-NORTHWESTERN CARIBBEAN SEA MIDDLE LEVEL TO UPPER LEVEL TROUGH. THE SURFACE PRESSURE PATTERN IS WEAK. THE GFS FORECAST FOR 700 MB AND FOR 500 MB SHOWS THAT ANTICYCLONIC WIND FLOW WILL COVER THE AREA...DUE TO AN EAST-TO- WEST ORIENTED RIDGE THAT WILL ENCOMPASS THE AREA FOR THE 48 HOUR FORECAST PERIOD. THE GFS FORECAST FOR 250 MB SHOWS THAT A NORTHEAST-TO-SOUTHWEST ORIENTED TROUGH WILL MOVE ACROSS THE AREA...AND REMAIN ACROSS THE AREA FOR THE 48 HOUR FORECAST PERIOD. THE REST OF THE CARIBBEAN SEA... AN UPPER LEVEL TROUGH PASSES THROUGH THE MONA PASSAGE...TO 15N69W...TOWARD NORTHWESTERN VENEZUELA. AN UPPER LEVEL RIDGE IS TO THE EAST OF THE TROUGH...ALONG 19N62W 13N60W. THE MONSOON TROUGH EXTENDS FROM COLOMBIA NEAR 9N74W...TO 9N80W IN PANAMA...ACROSS PANAMA...THROUGH EASTERN COSTA RICA...TO 12N86W IN NICARAGUA. CONVECTIVE PRECIPITATION...NUMEROUS STRONG IN COLOMBIA AND NEAR THE COLOMBIA/PANAMA BORDER FROM 5N TO 9N BETWEEN 74W AND 79W...AND IN THE EASTERN PACIFIC OCEAN AND COASTAL WATERS/COASTAL PLAINS OF CENTRAL AMERICA FROM 8N TO 11N BETWEEN 83W AND 90W. PLEASE READ THE HIGH SEAS FORECAST...MIAHSFAT2...AND THE OFFSHORE FORECAST...MIAOFFNT3...FOR MORE DETAILS ABOUT THE 24 HOUR FORECAST FOR EAST WINDS 20 TO 25 KNOTS AND SEA HEIGHTS TO 8 FEET FROM 11N TO 14N BETWEEN 68W AND 74W. THE REST OF THE ATLANTIC OCEAN... A MIDDLE LEVEL TO UPPER LEVEL CYCLONIC CIRCULATION CENTER IS IN THE ATLANTIC OCEAN NEAR 18N52W. CYCLONIC WIND FLOW COVERS THE AREA FROM 12N TO 25N BETWEEN 46W AND 60W. AN ATLANTIC OCEAN SURFACE TROUGH IS ALONG 57W/58W FROM 10N TO 19N. CONVECTIVE PRECIPITATION...ISOLATED MODERATE FROM 9N TO 14N BETWEEN 52W AND 55W...AND FROM 15N TO 16N BETWEEN 60W AND 61W. A MIDDLE LEVEL TO UPPER LEVEL TROUGH PASSES THROUGH 33N33W TO 30N40W. AN UPPER LEVEL RIDGE IS ALONG 32N56W 27N54W...TO THE WEST OF THE TROUGH. THE TROUGH SUPPORTS A COLD FRONT THAT PASSES THROUGH 32N32W TO 28N40W 27N46W AND 28N51W. A WARM FRONT CONTINUES FROM 28N51W TO 30N59W...TO A 1006 MB LOW PRESSURE CENTER THAT IS NEAR 30N62W. A SURFACE TROUGH CONTINUES FROM 30N62W TO 26N62W AND 22N64W. CONVECTIVE PRECIPITATION... SCATTERED STRONG WITHIN 30 NM TO 45 NM ON EITHER SIDE OF 32N56W 28N57W 24N58W. ISOLATED MODERATE ELSEWHERE FROM 20N TO 24N BETWEEN 58W AND 70W. A SURFACE RIDGE PASSES THROUGH THE MADEIRA ISLANDS...TO A 1020 MB HIGH PRESSURE CENTER THAT IS NEAR 29N22W...TO 26N31W AND 25N41W. PLEASE READ THE HIGH SEAS FORECAST...MIAHSFAT2...FOR MORE DETAILS ABOUT THE 1006 MB LOW PRESSURE CENTER THAT IS NEAR 30N62W. EXPECT 20 TO 25 KNOTS AND SEA HEIGHTS TO 10 FEET WITHIN 180 NM OF THE CENTER IN THE NORTHEASTERN SEMICIRCLE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ MT