000 AXNT20 KNHC 111057 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT SUN OCT 11 2009 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...METEOROLOGICAL ANALYSIS...WEATHER OBSERVATIONS...AND RADAR. BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1015 UTC. ...TROPICAL WAVES... AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 38W/39W TO THE SOUTH OF 16N. IT HAS BEEN DRIFTING WESTWARD DURING THE LAST 24 HOURS. IT APPEARS THAT ITS WESTWARD PROGRESSION IS BEING BLOCKED BY A MIDDLE LEVEL TROUGH THAT IS ALONG 19N33W 14N45W 10N57W. A CARIBBEAN SEA TROPICAL WAVE IS ALONG 73W/74W TO THE SOUTH OF 16N MOVING WESTWARD 10 TO 15 KT. SHOWERS AND POSSIBLE THUNDERSTORMS FROM 12N TO 15N BETWEEN 75W AND 78W. A TROPICAL WAVE IS ALONG 92W/93W TO THE SOUTH OF 19N MOVING TOWARD THE ISTHMUS OF TEHUANTEPEC 10 TO 15 KT. IT IS NOT EASY TO RELATE ANY PRECIPITATION DIRECTLY JUST TO THIS WAVE. AN UPPER LEVEL TROUGH IS ON TOP OF THIS AREA AT THE SAME TIME. ...THE ITCZ... FROM 9N13W TO 8N20W TO 12N37W TO 12N42W TO NORTHERN GUYANA AND EASTERN VENEZUELA NEAR 7N61W. NUMEROUS STRONG SHOWERS AND THUNDERSTORMS ARE FROM 9N TO 10N BETWEEN 45W AND 48W. ISOLATED MODERATE SHOWERS AND POSSIBLE THUNDERSTORMS ARE WITHIN 300 NM TO 400 NM TO THE NORTH OF 4N9W 5N20W 6N30W 10N39W...AND ELSEWHERE FROM 4N TO 13N BETWEEN 40W AND 57W. ...DISCUSSION... THE GULF OF MEXICO... THE UPPER LEVEL ATMOSPHERIC SUPPORT FOR THE CURRENT STATIONARY FRONT IS PRETTY MUCH NON-EXISTENT. MUCH OF THE UPPER LEVEL FLOW APPEARS TO BE ANTICYCLONIC RIGHT ON TOP OF THE FRONT. A COMPLETELY SEPARATE UPPER LEVEL TROUGH RUNS FROM ONE CYCLONIC CIRCULATION CENTER THAT IS ALONG THE NORTHERN COAST OF THE ISTHMUS OF TEHUANTEPEC OF MEXICO AND A SECOND CYCLONIC CENTER THAT IS NEAR 12N97W...THAT IS ABOUT 280 NM TO THE SOUTH-SOUTHWEST OF THE GULF OF TEHUANTEPEC. WARMING CLOUD TOP TEMPERATURES AND DISSIPATING CONVECTIVE PRECIPITATION ARE OCCURRING ALONG THE MEXICO COAST FROM 17N TO 21N BETWEEN 95W AND 97W. THE STATIONARY FRONT RUNS FROM THE FLORIDA BIG BEND TO THE NORTH CENTRAL GULF WATERS TO COASTAL MEXICO NEAR 20N97W...AND CURVING NORTHWESTWARD BEYOND THE TEXAS BIG BEND. SHOWERS AND POSSIBLE THUNDERSTORMS ARE WITHIN 180 NM TO THE NORTHWEST OF 28N87W 25N93W 22N97W. THE CARIBBEAN SEA... THE LINE OF UPPER LEVEL DIFFLUENT FLOW THAT SEPARATES THE GULF OF MEXICO CYCLONIC FLOW AND THE UPPER LEVEL ANTICYCLONIC FLOW THAT COVERS THE WESTERN CARIBBEAN SEA IS MORE OR LESS ALONG 86W/87W. ANTICYCLONIC FLOW GOES FROM CENTRAL AMERICA TO 80W. A MASS OF DRY AIR IN SUBSIDENCE IS ROLLING ACROSS THE CARIBBEAN SEA FROM EAST-TO-WEST BETWEEN 60W AND 80W...PRESSING UP AGAINST THE ANTICYCLONIC FLOW FROM CENTRAL AMERICA. THE ONLY SIGNIFICANT DEEP CONVECTIVE PRECIPITATION THAT IS SURVIVING THE DRY AIR IS THE SHOWER/THUNDERSTORM ACTIVITY FROM THE 73W/74W TROPICAL WAVE. THE ATLANTIC OCEAN... THE REMNANT OF HENRI IS A 1013 MB LOW PRESSURE CENTER THAT IS NEAR 20N71W. SHOWERS AND THUNDERSTORMS ARE ALONG THE NORTHERN COAST OF HAITI WITH THE REMNANT OF HENRI. UPPER LEVEL ANTICYCLONIC FLOW AND DRY AIR IN SUBSIDENCE COVER THE AREA TO THE NORTH OF 20N TO THE WEST OF 50W. EVEN MORE UPPER LEVEL ANTICYCLONIC FLOW CONTINUES TO THE NORTH OF 20N BETWEEN 40W AND 50W...AS SOME OF THIS FLOW HEADS TOWARD THE TROUGH THAT PASSES THROUGH 32N36W 24N37W TO 20N39W. THIS TROUGH SUPPORTS THE STATIONARY FRONT THAT PASSES THROUGH 32N38W TO 25N41W. A SURFACE TROUGH CONTINUES FROM 25N41W TO 20N50W AND 21N62W. ISOLATED MODERATE SHOWERS ARE STAYING ALIVE IN THE DRY AIR FROM 19N TO 20N BETWEEN 57W AND 65W. SHOWERS AND ISOLATED STRONG THUNDERSTORMS COVER THE AREA FROM 23N TO 32N BETWEEN 28W AND 35W...NEAR A SURFACE TROUGH THAT IS WITHIN 300 NM TO 360 NM TO THE EAST OF THE TROUGH TO THE NORTH OF 20N. $$ MT