000 AXNT20 KNHC 171805 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT WED APR 17 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. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH PASSES THROUGH COASTAL SIERRA LEONE NEAR 8N13W TO 6N16W 4N20W. THE ITCZ CONTINUES FROM 4N20W TO 3N28W. CONVECTIVE PRECIPITATION... ISOLATED MODERATE TO LOCALLY STRONG TO THE SOUTH OF 7N TO THE EAST OF 40W. ...DISCUSSION... THE GULF OF MEXICO... A MIDDLE LEVEL TO UPPER LEVEL RIDGE EXTENDS FROM THE YUCATAN CHANNEL TO 26N85W AND BEYOND 30N85W. HIGH CLOUDS COVER THE GULF OF MEXICO TO THE EAST OF 92W. THE LOW CLOUD CEILINGS THAT WERE IN THE DEEP SOUTH OF TEXAS DURING THE MORNING HOURS OF TODAY HAVE STARTED TO CLEAR UP A BIT...NOW REPORTING SCATTERED LOW CLOUDS FOR THE MOMENT. LOW CLOUD CEILINGS COVER THE TEXAS COASTAL PLAINS FROM AT LEAST FALFURRIAS TEXAS THAT IS INLAND...TO THE BEAUMONT-PORT ARTHUR AREA. THE OIL PLATFORM STATION...ICAO KGVX...ALSO IS REPORTING A LOW CLOUD CEILING. THE ICAO STATION KBBF IS REPORTING FAIR SKIES...WITH THE LOW CLOUDS CLEARING UP DURING THE LAST FEW HOURS. LOW CLOUD CEILINGS COVER THE LOUISIANA COASTAL PLAINS. THE STENNIS INTERNATIONAL AIRPORT IS REPORTING A MIDDLE LEVEL CLOUD CEILING. LOW CLOUD CEILINGS ARE ALONG THE MISSISSIPPI GULF COAST. THE SKY CONDITIONS FOR THE FLORIDA PANHANDLE CONSIST OF A MIXTURE OF SCATTERED TO BROKEN MULTILAYERED CLOUDS. FAIR SKIES COVER FLORIDA FROM THE FLORIDA BIG BEND TO BROOKSVILLE. LOW CLOUD CEILINGS ARE REPORTED AT BROOKSVILLE AND THE VANDENBERG AIRPORT NEAR TAMPA. SCATTERED LOW CLOUDS COVER THE REST OF THE FLORIDA COASTAL PLAINS TO THE FLORIDA KEYS. FOR THE OFFSHORE OIL PLATFORM SITES THAT ARE TO THE NORTH OF 27N TO THE WEST OF 88W... VISIBILITIES OF 3 MILES OR LOWER ARE AT THE ICAO STATIONS...KHQI...KEIR...KGUL...AND KMYT. A LOW CLOUD CEILING IS AT THE ICAO STATION KGVX. PLEASE READ THE HIGH SEAS FORECAST...MIAHSFAT2... AND THE OFFSHORE FORECAST...MIAOFFNT4...FOR THE 12-HOUR FORECAST OF SOUTHEASTERLY 20 TO 25 KNOT WINDS AND 8 FOOT SEA HEIGHTS TO THE NORTH OF 21.5N TO THE WEST OF 93W. THE CARIBBEAN SEA... A MIDDLE LEVEL TO UPPER LEVEL RIDGE EXTENDS FROM NORTHERN COLOMBIA NEAR 7N74W...TO 10N77W TO THE NORTH OF THE PANAMA COAST...TO CENTRAL HONDURAS... TO 17N87W...TOWARD THE NORTHWESTERN CORNER OF THE CARIBBEAN SEA...AND THE YUCATAN CHANNEL. THE NORTHERN PART OF THE RIDGE IS BECOMING IN PHASE WITH THE GULF OF MEXICO RIDGE. BROAD MIDDLE LEVEL TO UPPER LEVEL NORTHWESTERLY WIND FLOW COVERS MOST OF THE CARIBBEAN SEA... TO THE SOUTH OF 15N83W 15N77W 13N69W. THE AREA THAT IS TO THE SOUTH OF THE 15N83W 13N69W LINE IS COVERED BY THE ANTICYCLONIC WIND FLOW THAT ACCOMPANIES THE COLOMBIA-TO-CENTRAL HONDURAS RIDGE. THE NORTHWESTERLY WIND FLOW IS FLOWING TOWARD THE BASE OF AN ATLANTIC OCEAN TROUGH THAT REACHES ITS BASE NEAR 10N56W. RAINSHOWERS ARE POSSIBLE IN THE CARIBBEAN SEA AND IN THE ATLANTIC OCEAN FROM 13N TO 20N BETWEEN 50W AND 68W...AND ALSO IN THE ATLANTIC OCEAN FROM 20N TO 27N BETWEEN 50W AND 70W. THE ANTICYCLONIC WIND FLOW HAS BEEN PUSHING HIGH CLOUDS FROM SOUTH AMERICA AND CENTRAL AMERICA INTO THE CARIBBEAN SEA...TO THE SOUTH OF 14N. THE TOTAL PRECIPITATION AMOUNTS...FOR THE 24-HOUR TIME PERIOD ENDING AT 17/1200 UTC...ARE 1.45 INCHES FOR SAN JUAN PUERTO RICO... 1.13 INCHES FOR ST. THOMAS IN THE U.S. VIRGIN ISLANDS...0.44 OF AN INCH FOR GUADELOUPE...AND 0.13 OF AN INCH IN TRINIDAD. THESE DATA ARE ACCORDING TO THE PAN AMERICAN TEMPERTATURE AND PRECIPITATION TABLE...MIATPTPAN. THE MONSOON TROUGH IS ALONG 7N74W IN COLOMBIA... BEYOND 6N87W IN THE EASTERN PACIFIC OCEAN. CONVECTIVE PRECIPITATION...SCATTERED TO NUMEROUS STRONG WITHIN A 30 NM RADIUS OF 8N76W IN COLOMBIA...WITHIN A 60 NM RADIUS OF 7N77W NEAR THE COLOMBIA COAST... FROM 3N TO 7N BETWEEN 80W AND 85W. PLEASE READ THE HIGH SEAS FORECAST...MIAHSFAT2... AND THE OFFSHORE FORECAST...MIAOFFNT3...FOR MORE DETAILS ABOUT THE NORTHEAST TO EAST 20 TO 25 KNOT WINDS AND SEA HEIGHTS REACHING 9 FEET FROM 10.5N TO 14N BETWEEN 70W AND 77W. ALSO EXPECT EAST 20 TO 25 KNOT WINDS AND SEA HEIGHTS REACHING 8 FEET TO THE SOUTH OF 18N TO THE WEST OF 85W INCLUDING IN THE GULF OF HONDURAS. THE ATLANTIC OCEAN... A MIDDLE LEVEL TO UPPER LEVEL TROUGH PASSES THROUGH 32N48W TO 28N53W 24N58W AND 21N61W. A SECOND MIDDLE LEVEL TO UPPER LEVEL TROUGH IS ALONG 25N43W 19N47W 14N53W 10N56W. THE 32N48W 21N61W TROUGH IS EMBEDDED IN THE LARGER-SCALE WIND FLOW THAT ALSO INCLUDES THE 19N47W 10N56W TROUGH. A STATIONARY FRONT PASSES THROUGH 33N33W TO 32N36W... TO A 1021 MB LOW PRESSURE CENTER THAT IS NEAR 32N39W. A COLD FRONT TRAILS FROM THE LOW PRESSURE CENTER TO 28N47W. A DISSIPATING STATIONARY FRONT CONTINUES FROM 28N47W TO 27N55W AND 31N62W TO A 31N66W TRIPLE POINT. A DISSIPATING COLD FRONT EXTENDS FROM THE TRIPLE POINT TO 29N67W AND 26N69W. A DISSIPATING OCCLUDED FRONT CONTINUES FROM THE TRIPLE POINT TO A 1019 MB LOW PRESSURE CENTER THAT IS NEAR 30N69W. A SECOND 1019 MB LOW PRESSURE CENTER IS NEAR 30N75W. A SURFACE TROUGH EXTENDS FROM THE 30N75W LOW CENTER TO 29N74W 26N76W AND 26N79W OFF THE SOUTHEASTERN FLORIDA COAST. RAINSHOWERS ARE POSSIBLE TO THE NORTH OF 26N BETWEEN 66W AND THE COAST OF THE SOUTHEASTERN U.S.A. THE TOTAL PRECIPITATION FOR FREEPORT IN THE BAHAMAS FOR THE 24-HOUR TIME PERIOD ENDING AT 17/1200 UTC IS 1.58 INCHES...ACCORDING TO THE PAN AMERICAN TEMPERTATURE AND PRECIPITATION TABLE...MIATPTPAN. A MIDDLE LEVEL TO UPPER LEVEL TROUGH PASSES THROUGH 15W/16W...TO THE NORTH OF 24W...ALONG THE COASTS OF THE WESTERN SAHARA AND MOROCCO. A SURFACE RIDGE PASSES THROUGH 32N20W... TO A 1024 MB HIGH PRESSURE CENTER THAT IS NEAR 28N33W...TO 25N45W 25N58W AND 27N62W. PLEASE READ THE HIGH SEAS FORECAST...MIAHSFAT2... FOR MORE DETAILS ABOUT...N OF LINE FROM 31N59W TO 23N35W WINDS 20 KT OR LESS. SEAS TO 9 FT IN N TO NE SWELL...EXCEPT 9 TO 10 FT IN NE SWELL N OF 29N BETWEEN 46W AND 53W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ MT