000 AXNT20 KNHC 260552 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT WED SEP 26 2012 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 VALID THROUGH 0515 UTC. ...SPECIAL FEATURE... THE CENTER OF TROPICAL STORM NADINE AT 26/0300 UTC IS NEAR 31.2N 30.46W. NADINE IS ABOUT 445 NM/820 KM TO THE SOUTH-SOUTHWEST OF THE AZORES. NADINE IS MOVING SOUTH- SOUTHWESTWARD 4 KNOTS. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 997 MB. THE MAXIMUM SUSTAINED WIND SPEEDS ARE 40 KNOTS WITH GUSTS TO 50 KNOTS. TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 160 NM IN THE NORTHWESTERN QUADRANT...AND TO 100 NM ELSEWHERE AROUND THE CENTER OF NADINE. PLEASE READ THE FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT4/WTNT24 KNHC...AND THE PUBLIC ADVISORY...MIATCPAT4/WTNT34 KNHC...FOR MORE DETAILS. CONVECTIVE PRECIPITATION...SCATTERED MODERATE TO STRONG WITHIN A 30 NM RADIUS OF 31N29W. ...TROPICAL WAVE... A CARIBBEAN SEA TROPICAL WAVE IS ALONG 18N69W 15N72W...TO 11N73W IN NORTHEASTERN COLOMBIA. THE WAVE IS MOVING WESTWARD 15 KNOTS DURING THE LAST 24 HOURS. THE TROPICAL WAVE IS JUST TO THE EAST OF AN UPPER LEVEL TROUGH THAT PASSES THROUGH... CENTRAL HISPANIOLA TO A 14N75W CYCLONIC CIRCULATION CENTER TO THE GULF OF URABA OF COLOMBIA. RAINSHOWERS ARE POSSIBLE WITHIN 60 NM ON EITHER SIDE OF THE TROPICAL WAVE. IT IS NOT EASY TO FIND PRECIPITATION THAT ONLY ACCOMPANIES THE WAVE. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH PASSES THROUGH COASTAL SENEGAL NEAR 14N17W TO 11N20W 8N30W 8N37W. THE ITCZ CONTINUES FROM 8N37W TO 10N48W AND 11N53W. CONVECTIVE PRECIPITATION...WIDELY SCATTERED MODERATE TO ISOLATED STRONG FROM 10N TO 18N TO THE EAST OF 27W...FROM 3N TO 10N TO THE EAST OF 17W...AND WITHIN 120 NM ON EITHER SIDE OF 4N23W 7N33W 13N44W...RAINSHOWERS ARE POSSIBLE ELSEWHERE FROM 3N TO 13N BETWEEN 22W AND 50W. ...DISCUSSION... THE GULF OF MEXICO... A MIDDLE LEVEL TO UPPER LEVEL TROUGH CUTS THROUGH THE NORTHEASTERN FLORIDA...TO 25N88W IN THE GULF OF MEXICO... TO 21N91W IN THE SOUTHWESTERN CORNER OF THE AREA. COMPARATIVELY DRIER AIR IN SUBSIDENCE IS TO THE NORTHWEST AND WEST OF THE LINE THAT PASSES THROUGH 30N80W IN THE ATLANTIC OCEAN...TO 26N86W... TO 24N88W TO 21N95W TO 19N96W. BROKEN TO OVERCAST MULTILAYERED CLOUDS AND POSSIBLE RAINSHOWERS ARE TO THE EAST OF THE AREA OF COMPARATIVELY DRIER AIR. A SURFACE RIDGE PASSES THROUGH SOUTHEASTERN ALABAMA TO 27N94W IN THE NORTHWESTERN CORNER OF THE AREA...TO COASTAL MEXICO NEAR 23N98W...TO SOUTHERN MEXICO NEAR 19N96W. THE CARIBBEAN SEA... AN UPPER LEVEL TROUGH PASSES THROUGH...CENTRAL HISPANIOLA TO A 14N75W CYCLONIC CIRCULATION CENTER TO THE GULF OF URABA OF COLOMBIA. A TROPICAL WAVE IS JUST TO THE EAST OF THE UPPER LEVEL SYSTEM...ALONG 18N69W 15N72W...TO 11N73W IN NORTHEASTERN COLOMBIA. BROKEN TO OVERCAST MULTILAYERED CLOUDS AND POSSIBLE RAINSHOWERS ARE FROM THE COLOMBIA COASTAL WATERS TO 22N IN THE ATLANTIC OCEAN BETWEEN 66W AND 75W. RAINSHOWERS ARE POSSIBLE TO THE NORTH OF 13N TO THE WEST OF 76W IN SURFACE EASTERLY WIND FLOW AND POSSIBLE LINES OF SURFACE CONFLUENT WIND FLOW. SCATTERED MODERATE TO ISOLATED STRONG CONVECTIVE PRECIPITATION IS TO THE NORTHWEST OF THE LINE THAT EXTENDS FROM 16N84W AT THE COAST OF EASTERN HONDURAS TO THE CUBA COAST NEAR 22N80W. THIS PRECIPITATION IS RELATED TO THE UPPER LEVEL DIFFLUENT WIND FLOW FROM THE GULF OF MEXICO MIDDLE TO UPPER LEVEL TROUGH. PASSES THROUGH THE MONSOON TROUGH IS ALONG 8N77W IN PANAMA...BEYOND WESTERN PANAMA...AND BEYOND 10N85W IN NORTHWESTERN COSTA RICA. NO SIGNIFICANT DEEP CONVECTIVE PRECIPITATION IS IN THE SOUTHWESTERN CORNER OF THE CARIBBEAN SEA AT THIS MOMENT. PLEASE READ THE HIGH SEAS FORECASTS...MIAHSFAT2...AND THE OFFSHORE FORECAST...MIAOFFNT3...FOR DETAILS ABOUT 20 TO 25 KNOT WINDS AND 10 FOOT SEA HEIGHTS FROM 12N TO 16N BETWEEN 70W AND 80W FOR AT LEAST THE FIRST 30 HOURS OF THE FORECAST PERIOD. THE ATLANTIC OCEAN... A STATIONARY FRONT PASSES THROUGH THE ATLANTIC OCEAN JUST TO THE EAST OF BERMUDA...TO 29N60W...ACROSS ELEUTHERA ISLAND AND NEW PROVIDENCE ISLAND AND ANDROS ISLAND IN THE BAHAMAS... TO 23N82W IN THE FLORIDA STRAITS. BROKEN TO OVERCAST MULTILAYERED CLOUDS AND POSSIBLE CONVECTIVE PRECIPITATION ARE WITHIN 120 TO 240 NM ON EITHER SIDE OF THE LINE THAT PASSES THROUGH 34N68W TO 27N76W...TO 24N84W IN THE SOUTHEASTERN CORNER OF THE GULF OF MEXICO. AN UPPER LEVEL CYCLONIC CIRCULATION CENTER IS NEAR 30N44W. CYCLONIC WIND FLOW COVERS THE ATLANTIC OCEAN TO THE NORTH OF 23N BETWEEN 40W AND 57W. A SEPARATE CYCLONIC CIRCULATION CENTER IS NEAR 23N57W. CYCLONIC WIND FLOW THAT IS MOVING AROUND THIS CENTER COVERS THE ATLANTIC OCEAN FROM 18N TO 25N BETWEEN 50W AND 65W. A SURFACE TROUGH IS ALONG 23N50W 19N52W. CONVECTIVE PRECIPITATION...SCATTERED MODERATE TO STRONG FROM 20N TO 22N BETWEEN 49W AND 51W...ISOLATED MODERATE FROM 20N TO 24N BETWEEN 52W AND 58W. A MIDDLE LEVEL TO UPPER LEVEL TROUGH EXTENDS FROM A 25N36W CYCLONIC CIRCULATION CENTER TO 20N38W AND 15N45W. COMPARATIVELY DRIER AIR IN SUBSIDENCE IS WITHIN 120 NM ON EITHER SIDE OF THE LINE THAT STARTS NEAR 30N20W 25N27W 18N38W...AND TO THE NORTH OF 30N BETWEEN 10W AND 21W. ISOLATED MODERATE CONVECTIVE PRECIPITATION IS FROM 24N TO 25N BETWEEN 37W AND 40W... AND ALONG 21N BETWEEN 40W AND 41W. A SURFACE TROUGH IS ALONG 17N56W 12N58W. RAINSHOWERS ARE POSSIBLE WITHIN 30 TO 60 NM ON EITHER SIDE OF THE TROUGH. A SURFACE RIDGE IS ALONG 28N20W 22N27W...TO A 1018 MB HIGH PRESSURE CENTER THAT IS NEAR 22N35W. A SECOND RIDGE PASSES THROUGH 32N55W TO 21N64W. PLEASE READ THE HIGH SEAS FORECASTS...MIAHSFAT2... FOR DETAILS ABOUT TROPICAL STORM NADINE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ MT