000 AXNT20 KNHC 280546 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT SAT JUN 28 2008 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 0515 UTC. ...TROPICAL WAVES... A WEAK TROPICAL WAVE IS ALONG 26W S OF 14N MOVING W NEAR 10-15 KT. WAVE REMAINS EMBEDDED WITHIN THE ITCZ WITH LITTLE IN THE WAY OF CONVECTION. ONLY SCATTERED SHOWERS WITHIN 120 NM ON EITHER SIDE OF THE WAVE AXIS BETWEEN 6N-9N. A TROPICAL WAVE HAS BEEN ADJUSTED SLIGHTLY AND IS ALONG 36W S OF 11N MOVING W NEAR 15 KT. A BROAD MID TO LOW LEVEL CIRCULATION IS NOTED ON INFRARED SATELLITE IMAGERY AND SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS FROM 6N-11N BETWEEN 30W-35W. A TROPICAL WAVE IS ALONG 50W/51W S OF 13N MOVING W NEAR 15-20 KT. THE WAVE LACKS ANY SIGNIFICANT DEEP CONVECTION AND THIS HAS MADE IT DIFFICULT TO TRACK...BUT A LOW LEVEL CIRCULATION IS OBSERVED ON SATELLITE IMAGERY CENTERED AROUND 9N. ISOLATED MODERATE CONVECTION IS WITHIN 150 NM W OF THE WAVE AXIS FROM 8N-10N. A WEAK TROPICAL WAVE PREVIOUSLY ALONG 60W HAS BEEN REPOSITIONED ON THE 28/0000 UTC SURFACE ANALYSIS AND IS NOW ALONG 66W S OF 18N. THE MIMIC-TPW PRODUCT SUGGESTS THE WAVE POSITION WITH SCATTERED MODERATE/ISOLATED STRONG CONVECTION ACROSS N CENTRAL VENEZUELA. THIS CONVECTION IS ALSO BEING AIDED BY THE BASE OF AN UPPER TROUGH ACROSS THE ERN CARIBBEAN SEA. A TROPICAL WAVE IS ALONG 93W S OF 19N ACROSS SRN MEXICO. IT NOW LIES MAINLY IN THE EASTERN PACIFIC OCEAN. HOWEVER...SCATTERED MODERATE CONVECTION ASSOCIATED WITH THE WAVE IS FOUND IN THE BAY OF CAMPECHE S OF 20N...ACROSS SRN MEXICO AND WRN GUATEMALA. PLEASE SEE THE EASTERN PACIFIC TROPICAL WEATHER DISCUSSION... TWDEP...FOR FURTHER DETAILS ON THIS WAVE. ...ITCZ... THE ITCZ AXIS IS CENTERED ALONG 11N15W 10N24W 8N28W 7N35W 7N38W 5N44W 6N50W. IN ADDITION TO CONVECTION ASSOCIATED WITH TROPICAL WAVES...CLUSTER OF SCATTERED MODERATE TO STRONG CONVECTION IS MOVING OFF THE WEST AFRICAN COAST FROM 9N-16N BETWEEN 13W-18W. ISOLATED MODERATE CONVECTION IS FROM 5N-7N BETWEEN 42W-45W. ...DISCUSSION... GULF OF MEXICO... A HIGHLY AMPLIFIED UPPER PATTERN OVER THE GULF OF MEXICO IS NOTED WITH A LOW OVER THE WRN GULF AND A RIDGE OVER THE ERN GULF. AT THE SURFACE...THE WESTERN EXTENT OF THE CENTRAL NORTH ATLC RIDGE EXTENDS INTO THE EASTERN GULF WHILE A LOW PRESSURE TROUGH MOVING INTO THE SOUTHERN PLAINS IS INDUCING SOUTHEASTERLY GULF RETURN FLOW INTO THE TEXAS COAST. AS A RESULT...DEEP SOUTHERLY SURFACE FLOW DOMINATES THE CENTRAL GULF AND IS HELPING TO SUPPLY MOISTURE...IN CONJUNCTION WITH SW UPPER LEVEL FLOW... IN PRODUCING A LARGE SWATH OF CLOUDINESS ACROSS THE CENTRAL AND ERN GULF. SCATTERED SHOWERS AND ISOLATED TSTMS ARE FROM THE BAY OF CAMPECHE TO THE CENTRAL GULF NEAR 25N90W WITHIN THE REGION OF STRONGEST UPPER LEVEL DIVERGENT FLOW FOUND BETWEEN 85W AND 92W. ELSEWHERE...ISOLATED SHOWERS WITH EMBEDDED TSTMS ARE OVER THE CENTRAL GULF COAST NEAR BILOXI MISSISSIPPI AND ANOTHER AREA OFFSHORE OF SRN FLORIDA W OF FORT MYERS. CARIBBEAN... STRONG EASTERLY TRADE WINDS ON THE SOUTHERN EDGE OF THE SUBTROPICAL RIDGE CENTERED ALONG 30N DOMINATES THE LOW LEVEL PATTERN IN THE CARIBBEAN. RELATIVELY DRY CONDITIONS AND UPPER LEVEL CONVERGENCE OVER THE CENTRAL CARIBBEAN DUE TO UPPER LEVEL TROUGHING ARE SUPPRESSING CONVECTION OVER MUCH OF THE REGION WITH ONLY SCATTERED SHOWERS E OF THE UPPER TROUGHING ACROSS THE NRN LEEWARD ISLANDS. THE TROPICAL WAVE ALONG 66W IS GENERATING LITTLE SENSIBLE WEATHER...WITH ONLY WIDELY SCATTERED SHOWERS AND THUNDERSTORMS PRIMARILY OFF THE NRN VENEZUELA COAST BETWEEN 62W-68W. MORE VIGOROUS CONVECTION CAN BE FOUND IN THE SW CARIBBEAN OFF THE NICARAGUA/COSTA RICA COAST AND ERN PANAMA COAST WHERE DEEP MOISTURE IS MORE PLENTIFUL AND SPEED DIVERGENCE ALOFT IS PROVIDING LIFT. ATLANTIC... THE SUBTROPICAL HIGH PRESSURE AT THE SURFACE CONTINUES TO DOMINATE THE LOW LEVEL FLOW ACROSS THE ATLC...WITH EASTERLY TRADE WINDS FOUND NORTH AND WEST OF 10N30W AND FLOW GENERALLY TURNING MORE N TO NE TO THE EAST OF THIS LOCATION. THE HIGH PRESSURE RIDGE WHICH EXTENDS FROM THE CENTRAL ATLC ALONG 30N TO OVER THE NRN GULF OF MEXICO IS ANCHORED BY A QUASI-STATIONARY 1030 MB HIGH CENTERED NEAR 35N35W. IN THE UPPER LEVELS...BROAD TROUGHING REMAINS ACROSS THE W ATLC WITH ONLY MID-UPPER LEVEL CLOUDINESS ACROSS THE NW BAHAMAS. ELSEWHERE AN UPPER LEVEL ANTICYCLONE CENTERED NEAR 13N52W EXTENDS A RIDGE NORTHWARD AND COVERS MUCH OF THE CENTRAL ATLC. ANOTHER UPPER LEVEL ANTICYCLONE IS LOCATED NW OF THE CANARY ISLANDS NEAR 22N28W AND IS PROVIDING UPPER DIVERGENCE TO SUPPORT CONVECTION ALONG THE ITCZ. $$ HUFFMAN