000 AXNT20 KNHC 211204 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 705 AM EST WED NOV 21 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1115 UTC. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH PASSES THROUGH COASTAL SIERRA LEONE NEAR 9N13W 6N19W. THE ITCZ CONTINUES FROM 6N19W TO 5N27W 5N35W 6N43W...5N52W IN THE FRENCH GUIANA COASTAL WATERS. A SURFACE TROUGH IS ALONG 42W/43W FROM 2N TO 10N. THE TROUGH SHOWS UP WELL IN THE SHORTWAVE INFRARED SATELLITE IMAGERY AND THE LATEST SCATTEROMETER WIND DATA. CONVECTIVE PRECIPITATION...WIDELY SCATTERED TO SCATTERED MODERATE TO ISOLATED STRONG TO THE NORTH AND NORTHEAST OF 3N5W 3N12W 8N20W 10N20W...TO THE AFRICA COAST ALONG 10N...SCATTERED MODERATE TO ISOLATED STRONG FROM 4N TO 6N BETWEEN 34W AND 39W AND FROM 8N TO 10N BETWEEN 33W AND 37W... ISOLATED MODERATE ELSEWHERE FROM 3N TO 10N TO THE EAST OF 40W. ISOLATED MODERATE CONVECTIVE PRECIPITATION IS FROM 5N TO 10N BETWEEN 41W AND 46W WITH THE 42W/43W SURFACE TROUGH. ...DISCUSSION... THE GULF OF MEXICO... A DEEP LAYER TROUGH IS MOVING THROUGH THE U.S.A....BETWEEN THE EAST COAST AND 100W. A SURFACE TROUGH IS STILL WELL TO THE NORTH OF THE U.S.A. GULF COAST STATES. THE TROUGH STRETCHES FROM KENTUCKY AND TENNESSEE...TO ARKANSAS AND NORTHEASTERN TEXAS. THE 99W UPPER LEVEL RIDGE FROM 20/1100 UTC HAS FLATTENED OUT CONSIDERABLY. MIDDLE LEVEL TO UPPER LEVEL WESTERLY WIND FLOW COVERS THE GULF OF MEXICO. AN UPPER LEVEL RIDGE THAT IS IN MEXICO HAS MUCH MORE OF A WELL-DEFINED NORTHWESTERLY-TO- SOUTHEASTERLY ANGLE TO IT. A SURFACE TROUGH IS ALONG 24N95W 20N94W 19N91W. BROKEN TO OVERCAST LOW TO MIDDLE LEVEL CLOUDS AND POSSIBLE PRECIPITATION ARE TO THE SOUTH OF 25N TO THE WEST OF 90W. A SURFACE RIDGE CURVES THROUGH LOUISIANA TO THE DEEP SOUTH OF TEXAS...TO A COASTAL MEXICO NEAR 22N99W...INTO THE ISTHMUS OF TEHUANTEPEC OF SOUTHERN MEXICO...ACROSS GUATEMALA AND HONDURAS...INTO SOUTH CENTRAL NICARAGUA. A SURGE OF NORTHERLY WIND FLOW...FROM THE SURFACE TO THE LOW LEVELS...IS MARKED BY LOW CLOUDS THAT ARE MOVING FROM THE EASTERN GULF OF MEXICO INTO THE NORTHWESTERN CARIBBEAN SEA. A WEAKENING FRONTAL BOUNDARY WAS ANALYZED ON THE SURFACE MAP ANALYSIS 24 HOURS AGO. THE CLOUDS COVER THE WESTERN ATLANTIC OCEAN...THE GULF OF MEXICO...AND THE NORTHWESTERN CARIBBEAN SEA TO THE NORTH OF 18N BETWEEN 78W AND 87W. GALE-FORCE WINDS ARE BLOWING IN THE GULF OF TEHUANTEPEC. PLEASE READ THE EASTERN PACIFIC OCEAN HIGH SEAS FORECAST...MIAHSFEP2...FOR MORE DETAILS. THE CARIBBEAN SEA... BROAD UPPER LEVEL SOUTHWESTERLY WIND FLOW COVERS THE AREA THAT IS TO THE EAST OF THE LINE THAT RUNS FROM CUBA NEAR 21N79W TO THE COAST OF EASTERN HONDURAS NEAR 16N85W. BROAD MIDDLE LEVEL TO UPPER LEVEL ANTICYCLONIC WIND FLOW COVERS THE REST OF THE CARIBBEAN SEA...TO THE NORTHWEST OF THE 21N79W 16N85W LINE. BROAD MIDDLE LEVEL TO UPPER LEVEL ANTICYCLONIC WIND FLOW COVERS THE CARIBBEAN SEA THAT IS TO THE EAST OF 70W. A SURFACE TROUGH IS ALONG 19N65W...JUST TO THE EAST OF PUERTO RICO...15N67W...TO COASTAL VENEZUELA NEAR 11N69W. ISOLATED MODERATE TO LOCALLY STRONG CONVECTIVE PRECIPITATION IS WITHIN 60 NM ON EITHER SIDE OF 13N70W 15N67W 19N63W. THE MONSOON TROUGH IS ALONG 8N74W IN COLOMBIA...PASSING THROUGH 7N81W IN PANAMA...BEYOND SOUTHERN COSTA RICA...INTO THE EASTERN PACIFIC OCEAN. CONVECTIVE PRECIPITATION...SCATTERED MODERATE TO STRONG FROM 11N TO 14N BETWEEN 80W AND 84W IN THE WATERS TO THE EAST OF NICARAGUA...NUMEROUS STRONG IN THE EASTERN PACIFIC OCEAN FROM 5N TO 10N BETWEEN 76W IN COLOMBIA AND 85W IN COSTA RICA AND ITS COASTAL WATERS IN THE EASTERN PACIFIC OCEAN. THE UPPER LEVEL SOUTHWESTERLY WIND FLOW THAT IS IN THE AREA IS SHEARING THE CLOUD TOPS OF THIS AREA OF PRECIPITATION. BROKEN TO OVERCAST MIDDLE LEVEL AND HIGH LEVEL CLOUDS ARE ELSEWHERE TO THE SOUTH OF 18N BETWEEN 71W AND 84W. PLEASE READ THE OFFSHORE FORECAST...MIAHSFAT2...AND THE OFFSHORE FORECAST...MIAOFFNT3...FOR MORE DETAILS ABOUT THE 20 TO 25 KNOT WINDS AND 8 FOOT SEA HEIGHTS FROM 11N TO 15N TO THE WEST OF 81W. THE REST OF THE ATLANTIC OCEAN... A MIDDLE LEVEL TO UPPER LEVEL TROUGH PASSES THROUGH 32N58W TO 27N54W. THE TROUGH DISAPPEARS SOMEWHAT IN THE MIDDLE LEVEL TO UPPER LEVEL WESTERLY-TO-SOUTHWESTERLY WIND FLOW THAT COVERS THE ATLANTIC OCEAN TO THE WEST OF THE TROUGH...BASICALLY EVERYWHERE TO THE NORTH OF 20N TO THE WEST OF 60W. THE TROUGH SUPPORTS A COLD FRONT THAT PASSES THROUGH 32N56W TO 29N60W AND 21N68W. ONE SURFACE TROUGH IS ALONG 24N62W 20N66W. A SECOND SURFACE TROUGH IS ALONG 29N66W 27N72W 28N76W. A DISSIPATING COLD FRONT PASSES THROUGH 32N61W 30N71W 30N76W. ISOLATED MODERATE CONVECTIVE PRECIPITATION IS WITHIN 60 TO 90 NM ON EITHER SIDE OF 20N63W 24N59W 28N55W. WIDELY SCATTERED MODERATE TO ISOLATED STRONG CONVECTIVE PRECIPITATION IS TO THE NORTH OF 27N BETWEEN 40W AND 52W. RAINSHOWERS ARE POSSIBLE ELSEWHERE TO THE NORTH OF 21N TO THE WEST OF 64W. A MIDDLE LEVEL TO UPPER LEVEL TROUGH EXTENDS FROM A CYCLONIC CIRCULATION CENTER THAT IS NEAR 18N39W TO 9N48W AND 6N50W A SURFACE TROUGH IS ALONG 50W/51W FROM 13N TO 22N. THE TROUGH IS BECOMING WEAKER WITH TIME GRADUALLY. BROKEN TO OVERCAST MULTILAYERED CONVECTIVE DEBRIS CLOUDS AND POSSIBLE REMAINING PRECIPITATION FROM 10N TO 20N BETWEEN 30W AND 40W. A DEEP LAYER EASTERN ATLANTIC OCEAN TROUGH SUPPORTS A COLD FRONT THAT PASSES THROUGH 32N15W TO 31N17W. A DISSIPATING COLD FRONT IS ALONG 31N17W 28N30W 31N39W. A 1021 MB HIGH PRESSURE CENTER IS NEAR 26N25W. BROAD SURFACE ANTICYCLONIC WIND FLOW COVERS THE AREA FROM 9N TO THE DISSIPATING 31N17W 28N30W 31N39W COLD FRONT...BETWEEN AFRICA AND 45W. PLEASE READ THE HIGH SEAS FORECAST...MIAHSFAT2...FOR MORE DETAILS ABOUT 20 TO 25 KNOT WINDS AND 8 TO 12 FOOT SEAS WITH THE 31N57W 23N67W COLD FRONT...20 KNOT WINDS AND 8 TO 12 FOOT SEA HEIGHTS TO THE NORTH OF THE LINE FROM 27N50W TO 24N42W 23N38W 27N35W...20 TO 25 KNOT WINDS AND 12 FOOT SEA HEIGHTS WITH A DEVELOPING COLD FRONT FROM 31N65W TO 31N77W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ MT