000 AXNT20 KNHC 110558 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0315 UTC FOR GOES-12 IMAGERY...AND THROUGH 0530 UTC FOR METEOSAT-8 IMAGERY. ...TROPICAL WAVES... AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 17N37W 14N39W 9N40W MOVING WEST 10 KT OR LESS. THIS WAVE HAS BEEN SLOWING DOWN IN SPEED 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 TO THE SOUTH OF 16N MOVING WESTWARD 10 TO 15 KT. SHOWERS AND POSSIBLE THUNDERSTORMS FROM 13N TO 15N BETWEEN 73W AND 75W. A TROPICAL WAVE IS MOVING ACROSS SOUTHEASTERN MEXICO BETWEEN THE SOUTHWESTERN YUCATAN PENINSULA AND THE ISTHMUS OF TEHUANTEPEC... MOVING WESTWARD 10 TO 15 KT. IT IS NOT EASY TO RELATE ANY PRECIPITATION DIRECTLY JUST TO THIS WAVE. ...THE ITCZ... FROM 9N13W TO 8N20W TO 12N37W TO 12N42W TO THE NORTHERN COAST OF SURINAME TO 7N63W IN EASTERN VENEZUELA. NUMEROUS STRONG SHOWERS AND THUNDERSTORMS ARE FROM 12N TO 13N BETWEEN 29W AND 31W... WITHIN A 30 NM RADIUS OF 10N43W...9N48W...AND 8N50W. WARMING CLOUD TOP TEMPERATURES AND WEAKENING BUT POSSIBLY LINGERING PRECIPITATION FROM 10N TO 12N BETWEEN 41W AND 43W. SHOWERS ARE POSSIBLE WITHIN 180 NM ON EITHER SIDE OF 7N12W 7N23W 12N31W... AND WITHIN 60 NM ON EITHER SIDE OF 13N38W 10N45W 6N56W. ...DISCUSSION... THE GULF OF MEXICO... THE UPPER LEVEL ATMOSPHERIC SUPPORT FOR THE CURRENT STATIONARY FRONT IS PRETTY MUCH NON-EXISTENT. SOME OF THE FLOW IN THE NORTH CENTRAL GULF WATERS IS SOUTHWESTERLY. SOME OF THE FLOW IN THE CENTRAL GULF WATERS IS ANTICYCLONIC. AN UPPER LEVEL TROUGH RUNS FROM ONE CYCLONIC CIRCULATION CENTER IS NEAR THE BAY OF CAMPECHE BETWEEN THE SOUTHWESTERN PART OF THE YUCATAN PENINSULA AND THE ISTHMUS OF TEHUANTEPEC...AND A SECOND CYCLONIC CENTER THAT IS NEAR 13N96W...THAT IS ABOUT 200 NM TO THE SOUTH-SOUTHWEST OF THE GULF OF TEHUANTEPEC. STRONG SHOWERS AND THUNDERSTORMS ARE IN THE GULF AND ISTHMUS OF TEHUANTEPEC. THE STATIONARY FRONT PASSES THROUGH THE FLORIDA PANHANDLE TO THE NORTH CENTRAL GULF WATERS...TO 26N95W...AND TO COASTAL MEXICO NEAR 20N97W. DISORGANIZED ISOLATED MODERATE TO STRONG SHOWERS AND POSSIBLE THUNDERSTORMS ARE FROM 21N TO 26N BETWEEN 95W AND 97W. 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 JAMAICA ALONG 77W. A MASS OF DRY AIR IN SUBSIDENCE IS ROLLING ACROSS THE CARIBBEAN SEA FROM EAST-TO-WEST BETWEEN 60W AND 77W. THE ONLY SIGNIFICANT DEEP CONVECTIVE PRECIPITATION THAT IS SURVIVING THE DRY AIR IS THE SHOWER/THUNDERSTORM ACTIVITY FROM 13N TO 15N BETWEEN 73W AND 75W THAT ACCOMPANIES THE 73W TROPICAL WAVE. THE ATLANTIC OCEAN... THE REMNANT OF HENRI IS A 1013 MB LOW PRESSURE CENTER THAT IS NEAR 20N70W. THE LITTLE BIT OF PRECIPITATION THAT WAS ACCOMPANYING THE REMNANT OF HENRI HAS BEEN OVERWHELMED BY THE DRY AIR IN SUBSIDENCE THAT SURROUNDS IT. 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 32N38W 23N39W TO 19N42W. THIS TROUGH SUPPORTS THE STATIONARY FRONT THAT PASSES THROUGH 32N37W TO 25N40W AND 22N50W. A SURFACE TROUGH CONTINUES FROM 22N50W TO 21N55W AND 21N62W. ISOLATED MODERATE SHOWERS ARE STAYING ALIVE IN THE DRY AIR FROM 19N TO 21N BETWEEN 50W AND 63W. SHOWERS AND ISOLATED STRONG THUNDERSTORMS COVER THE AREA FROM 23N TO 32N BETWEEN 28W AND 40W. $$ MT