000 AXNT20 KNHC 290612 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT TUE APR 29 2008 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHERN SECTIONS OF SOUTH AMERICA...AND THE 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 0545 UTC. ...THE ITCZ... 4N8W 4N10W 2N20W 1N30W...CROSSING THE EQUATOR AT 36W...INTO NORTHEASTERN BRAZIL NEAR 4S46W. STRONG SHOWERS AND THUNDERSTORMS ARE FROM 4N TO 5N BETWEEN 20W AND 25W. ISOLATED MODERATE SHOWERS AND LOCALLY STRONG THUNDERSTORMS ARE SOUTH OF 4N4W 5N10W 8N13W 5N30W 4N51W. ...DISCUSSION... THE GULF OF MEXICO... WHAT APPEARS TO BE THE BASE OF A DEEP LAYER TROUGH REACHES NORTHERN AREAS OF SOUTH CAROLINA/GEORGIA/ALABAMA. A POSSIBLE BRANCH OF THIS TROUGH EVENTUALLY CONTINUES IN THE NORTHWESTERN CORNER OF THE GULF OF MEXICO NEAR 29N91W TO 25N97W IN COASTAL NORTHEASTERN MEXICO JUST SOUTH OF TEXAS. UPPER LEVEL SOUTHWESTERLY WIND FLOW AND MIDDLE TO HIGH LEVEL CLOUDS ARE IN THE SOUTHWESTERLY FLOW. MIDDLE TO UPPER LEVEL DRY AIR/ SUBSIDENCE IS NORTHWEST OF A LINE THROUGH 30N86W IN THE FLORIDA PANHANDLE TO 26N90W TO 23N98W IN COASTAL MEXICO. A COLD FRONT IS BEING SUPPORTED BY THE DEEP LAYER TROUGH. THE TROUGH PASSES THROUGH SOUTH CENTRAL GEORGIA TO FLORIDA NEAR 29N83W...INTO THE EASTERN GULF OF MEXICO NEAR 26N85W TO 23N90W AND TO THE ISTHMUS OF TEHUANTEPEC IN MEXICO NEAR 18N94W. ISOLATED MODERATE SHOWERS ARE IN THE ATLANTIC OCEAN WITHIN 10 NM TO 15 NM ON EITHER SIDE OF THE LINE THROUGH 31N77W TO 28N79W. CLOUDS AND POSSIBLE PRECIPITATION ARE WITHIN 120 NM TO 180 NM ON EITHER SIDE OF THE LINE THROUGH 30N80W 26N87W 20N96W. THE CARIBBEAN SEA... AN UPPER LEVEL RIDGE PASSES THROUGH 10N60W TO NORTHERN COASTAL VENEZUELA AND COLOMBIA...CURVING TO 13N80W...AND NORTHWESTWARD INTO THE YUCATAN CHANNEL. HIGH LEVEL CLOUDS ARE CURVING ANTICYCLONICALLY FROM THE SOUTHERN CARIBBEAN SEA NORTHWARD AS FAR AS JAMAICA...AND THEN STAYING SOUTH OF 17N70W AND 15N60W. THE BASE OF AN ATLANTIC OCEAN-TO-CARIBBEAN SEA MIDDLE TO UPPER LEVEL TROUGH REACHES 15N60W. BROAD MIDDLE TO UPPER LEVEL NORTHWESTERLY WIND FLOW COVERS THE REST OF THE AREA...A RESULT OF THE COMBINATION OF THE ANTICYCLONIC WIND FLOW FROM THE EAST- TO-WEST RIDGE IN NORTHERN SOUTH AMERICA AND THE CYCLONIC FLOW ON THE WESTERN SIDE OF THE TROUGH WHOSE BASE REACHES 15N60W. STRONG SHOWERS AND THUNDERSTORMS IN COLOMBIA NORTH OF 9N ABOUT SIX HOURS EARLIER HAVE DISSIPATED. ISOLATED MODERATE SHOWERS ARE IN THE SOUTHWESTERN CARIBBEAN WATERS FROM 10N TO 13N BETWEEN 80W AND 82W...NEAR JAMAICA FROM 16N TO 18N BETWEEN 75W AND 78W. THE ATLANTIC OCEAN... AN UPPER LEVEL RIDGE ALONG 20N69W 25N70W BEYOND 32N69W IS IN BETWEEN THE SOUTHEASTERN U.S.A.-TO-GULF OF MEXICO DEEP LAYER TROUGH AND A CENTRAL ATLANTIC OCEAN DEEP LAYER TROUGH. THE CENTRAL ATLANTIC OCEAN DEEP LAYER TROUGH SUPPORTS A 1000 MB LOW PRESSURE CENTER NEAR 37N54W...AND A SURFACE TROUGH FROM 31N43W TO 26N45W TO 23N51W. THE BASE OF THIS TROUGH REACHES THE EASTERN CARIBBEAN SEA NEAR 15N60W. CYCLONIC FLOW AROUND THE TROUGH COVERS THE ATLANTIC OCEAN NORTH OF 12N BETWEEN 36W AND 62W. AN UPPER LEVEL RIDGE IS ALONG 13N39W 23N39W 29N36W BEYOND 33N33W. BROAD SURFACE ANTICYCLONIC WIND FLOW IS NORTH OF 22N BETWEEN 60W AND 76W. MIDDLE TO UPPER LEVEL CYCLONIC WIND FLOW IS NORTH OF 14N BETWEEN 6W AND 23W...AROUND A NORTHERN MAURITANIA CYCLONIC CIRCULATION CENTER. $$ MT