000 AXNT20 KNHC 172339 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT SUN OCT 17 2010 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...THE ITCZ... 9N23W 7N29W 7N35W...8N40W 7N45W 8N54W. STRONG RAINSHOWERS AND THUNDERSTORMS ARE FROM 6N TO 8N BETWEEN 20W AND 22W...AND FROM 9N TO 10N BETWEEN 22W AND 24W. ISOLATED MODERATE RAINSHOWERS ARE ELSEWHERE FROM 2N TO 10N BETWEEN 13W AND 22W. ONE SURFACE TROUGH IS ALONG 19N18W 14N20W 9N21W. ISOLATED MODERATE RAINSHOWERS AND LOCALLY STRONG RAINSHOWERS COVER THE WATERS FROM 10N TO 22N BETWEEN THE AFRICA COAST AND 22W. A SECOND SURFACE TROUGH IS ALONG 14N26W 10N28W. ISOLATED MODERATE RAINSHOWERS ARE FROM 10N TO 13N BETWEEN 24W AND 30W. A THIRD SURFACE TROUGH IS ALONG 15N35W...TO A 1009 MB LOW PRESSURE CENTER THAT IS NEAR 11N37W...TO 7N38W. STRONG RAINSHOWERS AND THUNDERSTORMS ARE FROM 5N TO 9N BETWEEN 31W AND 43W. IT IS NOT EASY TO DETERMINE IF THE PRECIPITATION IS MORE RELATED TO THE ITCZ OR TO THE 15N35W 7N38W SURFACE TROUGH. ...DISCUSSION... THE GULF OF MEXICO... THE MIDDLE LEVEL TO UPPER LEVEL TROUGH THAT WAS ALONG 110W ABOUT 24 HOURS AGO NOW IS ALONG 102W/103W...STILL IN MEXICO. UPPER LEVEL SOUTHWESTERLY WIND FLOW EXITS MEXICO...AND CROSSES 90W. THE FLOW EVENTUALLY BECOMES WESTERLY AS IT HEADS TOWARD FLORIDA AND CROSSES FLORIDA...HEADING INTO THE ATLANTIC OCEAN. DRY AIR IN SUBSIDENCE COVERS MEXICO TO THE EAST OF 109W AND MOST OF THE GULF OF MEXICO. UPPER LEVEL MOISTURE HUGS THE TEXAS COAST AND MOST OF THE LOUISIANA COAST FROM WEST TO EAST. BROAD SURFACE ANTICYCLONIC FLOW COVERS THE AREA. THE CARIBBEAN SEA... SURFACE-TO-LOW LEVEL CYCLONIC FLOW COVERS THE WESTERN CARIBBEAN SEA TO THE WEST OF 74W. A SURFACE TROUGH IS ALONG 17N76W TO A 1009 MB LOW PRESSURE CENTER THAT IS NEAR 12N78W...TO THE COSTA RICA/PANAMA BORDER...AND EVENTUALLY INTO THE EASTERN PACIFIC OCEAN NEAR 9N89W. STRONG RAINSHOWERS AND THUNDERSTORMS ARE FROM 11N TO 13N BETWEEN 81W AND 82W. SCATTERED MODERATE RAINSHOWERS AND ISOLATED STRONG THUNDERSTORMS COVER THE AREA FROM NICARAGUA NEAR 13N TO 20N BETWEEN 81W AND 85W. BROAD SURFACE-TO-LOW LEVEL CYCLONIC FLOW AND STRONG RAINSHOWERS AND THUNDERSTORMS COVER COLOMBIA FROM 5 TO THE COAST BETWEEN 73W AND 77W. AN UPPER LEVEL CYCLONIC CIRCULATION CENTER IS NEARLY ON TOP OF WESTERN GUADELOUPE. THE CYCLONIC FLOW THAT IS MOVING AROUND THE CENTER COVERS PARTS OF COASTAL VENEZUELA...THE CARIBBEAN SEA...AND THE ATLANTIC OCEAN FROM 8N TO 21N BETWEEN 55W AND 68W. RAINSHOWERS ARE POSSIBLE WITHIN THE AREA OF CYCLONIC FLOW. STRONG PRECIPITATION IS IN NORTHWESTERN VENEZUELA IN UPPER LEVEL DIFFLUENT FLOW...JUST AWAY FROM THE CYCLONIC FLOW THAT IS MOVING AROUND THE GUADELOUPE CYCLONIC CENTER. THE PRECIPITATION IN WESTERN PUERTO RICO HAS BEEN SHEARED BY THE UPPER LEVEL FLOW. RAINSHOWERS AND POSSIBLE THUNDERSTORMS ARE TO THE SOUTH OF 17N BETWEEN 77W AND 86W. COMPARATIVELY DRIER AIR IN SUBSIDENCE IS PUSHING UP AGAINST THE HIGH LEVEL MOISTURE ALONG 73W/74W. THE RAINSHOWERS AND THUNDERSTORMS THAT ARE IN EASTERN CUBA ARE RELATED TO THE STATIONARY FRONT THAT CROSSES THE ACKLINS AND CROOKED ISLAND IN THE BAHAMAS. THE PRECIPITATION THAT IS OCCURRING IN HISPANIOLA AND IN WESTERN JAMAICA IS RELATED TO DIFFLUENT FLOW IN BETWEEN THE WESTERN CARIBBEAN SEA TROUGH AND THE ATLANTIC OCEAN TROUGH THAT SUPPORTS THE ATLANTIC OCEAN COLD FRONT AND THE BAHAMAS STATIONARY FRONT. THE ATLANTIC OCEAN... BROAD CYCLONIC FLOW IS TO THE NORTH AND NORTHWEST OF 22N78W 26N60W BEYOND 32N46W. THIS CYCLONIC FLOW IS RELATED TO A DEEP LAYER ATLANTIC OCEAN TROUGH THAT IS TO THE NORTH OF THE AREA. THE TROUGH THAT IS TO THE NORTH OF THE AREA SUPPORTS A COLD FRONT THAT PASSES THROUGH 32N48W TO 24N60W TO 23N70W. THE FRONT BECOMES STATIONARY AND CONTINUES FROM 23N70W...TO THE ACKLINS AND CROOKED ISLAND IN THE BAHAMAS...TO THE CUBA COAST NEAR 22N77W. RAINSHOWERS AND THUNDERSTORMS ARE WITHIN 30 NM ON EITHER SIDE OF 27N50W BEYOND 32N44W...AND 26N55W 23N64W 22N71W 21N76W. AN UPPER LEVEL TROUGH PASSES THROUGH 32N27W TO 18N29W 12N39W. A SURFACE TROUGH PASSES THROUGH 32N29W TO 25N35W TO 21N47W. ISOLATED MODERATE RAINSHOWERS AND POSSIBLE THUNDERSTORMS ARE WITHIN 30 NM ON EITHER SIDE OF 32N25W 27N30W...AND WITHIN 60 NM ON EITHER SIDE OF 27N30W 24N31W 21N41W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ MT