000 AXNT20 KNHC 181804 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT FRI OCT 18 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...TROPICAL WAVES... AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 18W/19W TO THE SOUTH OF 19N MOVING WESTWARD 10 TO 15 KNOTS. CONVECTIVE PRECIPITATION... NUMEROUS STRONG FROM 11N TO 14N BETWEEN 19W AND 24W. PART OF THE PRECIPITATION IS RELATED TO THE ITCZ ALSO. AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 49W/50W TO THE SOUTH OF 15N. THE WAVE IS MOVING WESTWARD 10 TO 15 KNOTS. CONVECTIVE PRECIPITATION...SCATTERED STRONG FROM 8N TO 13N BETWEEN 46W AND 51W. A WEAKENING ATLANTIC OCEAN TROPICAL WAVE IS ALONG 21N61W 13N60W. THE WAVE IS MOVING WESTWARD 10 TO 15 KNOTS. IT IS NOT EASY TO RELATE ANY DEEP CONVECTIVE PRECIPITATION TO THIS TROPICAL WAVE. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH PASSES THROUGH COASTAL SENEGAL AND GUINEA- BISSAU TO 11N18W. THE ITCZ CONTINUES FROM 10N21W 8N30W 8N40W 8N43W. CONVECTIVE PRECIPITATION...NUMEROUS STRONG FROM 11N TO 14N BETWEEN 19W AND 24W. PART OF THE PRECIPITATION IS RELATED TO THE ITCZ ALSO. SCATTERED MODERATE TO ISOLATED STRONG FROM 5N TO 7N BETWEEN 17W AND 20W...AND ELSEWHERE FROM 5N TO 13N BETWEEN 30W AND 60W. ...DISCUSSION... FROM THE GULF OF MEXICO...INTO THE ATLANTIC OCEAN...AND INCLUDING IN THE NORTHWESTERN CORNER OF THE CARIBBEAN SEA... UPPER LEVEL ANTICYCLONIC WIND FLOW COVERS THE GULF OF MEXICO... THE ATLANTIC OCEAN TO THE WEST OF 70W...AND THE CARIBBEAN SEA TO THE NORTH OF 16N TO THE WEST OF THE WINDWARD PASSAGE. THE MEAN ANTICYCLONIC CIRCULATION CENTER IS IN THE FLORIDA STRAITS. COMPARATIVELY DRIER AIR IN SUBSIDENCE...AS SEEN IN WATER VAPOR IMAGERY...COVERS THE MOST OF THE AREA. THE ONLY EXCEPTION IS TO THE NORTHWEST OF THE LINE THAT RUNS FROM THE WESTERN FLORIDA PANHANDLE TO 22N97W ALONG THE MEXICO GULF COAST. BROKEN TO OVERCAST MULTILAYERED CLOUDS AND ISOLATED MODERATE CONVECTIVE PRECIPITATION ARE TO THE NORTHWEST OF THE LINE. A STATIONARY FRONT PASSES THROUGH FLORIDA JUST TO THE WEST OF APALACHEE BAY...TO THE NORTH CENTRAL GULF OF MEXICO NEAR 27N90W...TO 26N96W...INTO THE SOUTHWESTERN CORNER OF THE GULF OF MEXICO NEAR 19N96W. A 1016 MB HIGH PRESSURE CENTER IS NEAR 25N88W. SURFACE ANTICYCLONIC WIND FLOW COVERS THE GULF OF MEXICO...AROUND THE 1016 MB HIGH CENTER...BETWEEN FLORIDA AND THE STATIONARY FRONT. FOR THE OFFSHORE OIL PLATFORM SITES THAT ARE TO THE NORTH OF 27N TO THE WEST OF 88W... LOW CLOUD CEILINGS AND FOG AND VISIBILITIES LESS THAN THREE MILES ARE OBSERVED AT THE STATIONS THAT ARE TO THE WEST OF 94W. LOW CLOUD CEILINGS...AND SOME MIDDLE LEVEL CLOUD CEILINGS...COVER MANY OF THE REST OF THE ICAO STATIONS/PLATFORM SITES. FAIR SKIES COVER THE DEEP SOUTH OF TEXAS. MULTILAYERED CLOUD CEILINGS AND PRECIPITATION COVER THE REST OF THE TEXAS COASTAL PLAINS. LOW CLOUD CEILINGS COVER SOUTHEASTERN COASTAL LOUISIANA. MULTILAYERED CLOUD CEILINGS ARE AROUND THE SOUTHERN SIDE OF LAKE PONTCHARTRAIN. MULTILAYERED CLOUD CEILINGS AND PRECIPITATION COVER THE FLORIDA PANHANDLE TO THE WEST OF PERRY...WITH THE STATIONARY FRONT. PLEASE READ THE HIGH SEAS FORECAST...MIAHSFAT2...AND THE OFFSHORE FORECAST...MIAOFFNT4...FOR MORE DETAILS ABOUT THE 30- HOUR FORECAST COLD FRONT 30N85W 22N92W 18N94W. EXPECT NORTH TO NORTHEAST WINDS 20 TO 25 KNOTS AND SEA HEIGHTS TO 8 FEET TO THE WEST OF THE FRONT TO THE NORTH OF 22N. FROM THE WESTERN ATLANTIC OCEAN INTO THE CARIBBEAN SEA... INCLUDING ACROSS HISPANIOLA... A MIDDLE LEVEL TO UPPER LEVEL TROUGH PASSES THROUGH THE WESTERN ATLANTIC OCEAN NEAR 32N62W..TO 26N65W...ACROSS HISPANIOLA...TO 16N76W IN THE CARIBBEAN SEA...ACROSS NORTHERN NICARAGUA...AND THROUGH SOUTHERN HONDURAS...AND BEYOND EL SALVADOR. A SURFACE TROUGH IS IN THE ATLANTIC OCEAN ALONG 30N69W...TO A 1012 MB LOW PRESSURE CENTER THAT IS NEAR 28N71W...CROSSING THE BAHAMAS/TURKS AND CAICOS ISLANDS NEAR 22N73W...INTO THE WINDWARD PASSAGE. CONVECTIVE PRECIPITATION...IN THE CARIBBEAN SEA...BROKEN TO OVERCAST MULTILAYERED CLOUDS AND WIDELY SCATTERED TO SCATTERED MODERATE TO ISOLATED STRONG FROM 12N TO 18N BETWEEN 63W AND 73W. CONVECTIVE PRECIPITATION IN THE ATLANTIC OCEAN...SCATTERED MODERATE TO ISOLATED STRONG FROM 21N TO 25N BETWEEN 69W AND 71W...AND FROM 20N TO 29N BETWEEN 60W AND 63W. THE GFS FORECAST FOR 700 MB SHOWS THAT ANTICYCLONIC WIND FLOW... FROM AN EAST-TO-WEST ORIENTED RIDGE...WILL COVER THE AREA FOR MOST OF THE FIRST 24 HOURS OF THE FORECAST PERIOD. AN INVERTED TROUGH AND/OR CYCLONIC WIND FLOW FROM AN INVERTED TROUGH...WILL COVER THE AREA FOR THE REST OF THE 48 HOUR FORECAST PERIOD. THE GFS FORECASTS FOR 500 MB AND FOR 250 MB SHOW THAT CYCLONIC WIND FLOW FROM THE CURRENT ATLANTIC OCEAN-TO-CARIBBEAN SEA TROUGH WILL COVER THE AREA FOR THE NEXT 48 HOURS OR SO. THE REST OF THE CARIBBEAN SEA... THE 24-HOUR RAINFALL TOTAL IN INCHES FOR THE PERIOD ENDING AT 18/1200 UTC...ACCORDING TO THE PAN AMERICAN TEMPERATURE AND PRECIPITATION TABLES... MIATPTPAN...IS 0.96 IN GUADELOUPE. THE MONSOON TROUGH IS ALONG 9N BETWEEN 74W IN COLOMBIA AND BEYOND 85W INTO THE EASTERN PACIFIC OCEAN. CONVECTIVE PRECIPITATION...WIDELY SCATTERED TO SCATTERED MODERATE TO ISOLATED STRONG WITHIN 30 NM TO 60 NM ON EITHER SIDE OF 9N77W 10N80W 12N84W 14N84W. THE REST OF THE ATLANTIC OCEAN... A WEAKENING MIDDLE LEVEL TO UPPER LEVEL CYCLONIC CIRCULATION CENTER IS NEAR 24N53W. THE ASSOCIATED TROUGH FROM 24 HOURS AGO ALSO APPEARS TO HAVE DISSIPATED. A SURFACE TROUGH IS ALONG 55W FROM 18N TO 24N. A SECOND SURFACE TROUGH IS ALONG 19N52W 14N54W. CONVECTIVE PRECIPITATION...NUMEROUS STRONG FROM 20N TO 22N BETWEEN 46W AND 48W. WIDELY SCATTERED TO SCATTERED MODERATE TO ISOLATED STRONG ELSEWHERE FROM 19N TO 29N BETWEEN 44W AND 56W. A FAR EASTERN ATLANTIC OCEAN MIDDLE LEVEL TO UPPER LEVEL TROUGH SUPPORTS A COLD FRONT THAT PASSES THROUGH 32N18W NEAR THE MADEIRA ARCHIPELAGO...TO 28N23W AND 27N30W. BROKEN TO OVERCAST MULTILAYERED CLOUDS AND ISOLATED MODERATE CONVECTIVE PRECIPITATION ARE WITHIN 60 NM TO 120 NM ON EITHER SIDE OF THE LINE THAT PASSES THROUGH 32N12W 28N16W 25N22W 25N30W. A 1023 MB HIGH PRESSURE CENTER IS NEAR 33N44W. A 1018 MB HIGH PRESSURE CENTER IS NEAR 30N57W. SURFACE ANTICYCLONIC WIND FLOW COVERS THE ATLANTIC OCEAN TO THE NORTH OF 25N BETWEEN 33W AND 65W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ MT