000 AXNT20 KNHC 201155 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT MON AUG 20 2007 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1015 UTC. ...SPECIAL FEATURE... EXTREMELY DANGEROUS CATEGORY FOUR HURRICANE DEAN WAS NEAR 17.8N 81.5W...OR 380 NM/710 KM EAST OF BELIZE CITY AT 20/1200 UTC. DEAN IS MOVING WEST 18 KT. THE MAXIMUM SUSTAINED WIND SPEEDS ARE 130 KT WITH GUSTS TO 160 KT. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 926 MB. ALL RESIDENTS IN THE WESTERN CARIBBEAN SEA...AND THE GULF OF MEXICO SHOULD MONITOR THE PROGRESS OF THIS POWERFUL HURRICANE. PLEASE SEE THE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT4/WTNT24 KNHC AND THE LATEST PUBLIC ADVISORY UNDER MIATCPAT4/WTNT34 KNHC FOR THE MOST RECENT WATCH AND WARNING INFORMATION. FOR STORM INFORMATION SPECIFIC TO YOUR AREA...INCLUDING POSSIBLE INLAND WATCHES AND WARNINGS. PLEASE MONITOR FORECASTS AND BULLETINS ISSUED BY YOUR LOCAL WEATHER OFFICE. NUMEROUS STRONG SHOWERS AND THUNDERSTORMS ARE FROM 16N TO 19N BETWEEN 80W AND 82W. STRONG SHOWERS AND THUNDERSTORMS ARE IN BANDS ELSEWHERE AROUND THE CENTER FROM 15N TO 20N BETWEEN 78W AND 83W. WIDELY SCATTERED MODERATE SHOWERS AND ISOLATED STRONG THUNDERSTORMS ARE FROM 12N TO 18N BETWEEN 72W AND 75W. ...TROPICAL WAVES... A LARGE ATLANTIC OCEAN TROPICAL WAVE IS ALONG 58W SOUTH OF 25N MOVING WEST 20 KT DURING THE LAST 24 HOURS. THE 1010 MB LOW PRESSURE CENTER FROM 6 HOURS AGO HAS DISSIPATED. NUMEROUS STRONG SHOWERS AND THUNDERSTORMS FROM 23N TO 25N BETWEEN 55W AND 58W... FROM 23N TO 25N BETWEEN 52W AND 55W...AND FROM 20N TO 21N BETWEEN 55W AND 57W. SCATTERED MODERATE SHOWERS TO ISOLATED STRONG THUNDERSTORMS FROM THE SOUTH AMERICA COAST OF GUYANA AND SURINAME NORTHWARD TO 27N BETWEEN 50W AND 65W...AND IN PART OF THE ITCZ STRETCHING NORTHWARD FROM 12N TO 22N BETWEEN 40W AND 50W. THIS WAVE WILL CONTINUE TO BE MONITORED AS SLOW DEVELOPMENT APPEARS POSSIBLE AS IT TRACKS WEST-NORTHWESTWARD DURING THE NEXT COUPLE OF DAYS. A GULF OF MEXICO TROPICAL WAVE IS ALONG 94W SOUTH OF 20N MOVING WEST 10 TO 15 KT. A MIDDLE TO UPPER LEVEL CYCLONIC CIRCULATION CENTER IS NEAR 26N93W. ALL THE PRECIPITATION IN THE GULF OF MEXICO WEST OF 85W APPEARS TO BE RELATED TO THIS CYCLONIC CENTER. NUMEROUS STRONG THUNDERSTORMS IN THE GULF OF TEHUANTEPEC. ...THE ITCZ... FROM THE AFRICA COAST NEAR 12N15W TO 9N33W TO 13N56W. STRONG SHOWERS AND THUNDERSTORMS ARE FROM 6N TO 8N BETWEEN 42W AND 46W. ISOLATED MODERATE SHOWERS TO LOCALLY STRONG THUNDERSTORMS ELSEWHERE FROM 2N TO 12N BETWEEN AFRICA NEAR 16W AND 40W... AND ELSEWHERE FROM 5N TO 10N BETWEEN 40W AND 50W. DISCUSSION... THE GULF OF MEXICO... A MIDDLE TO UPPER LEVEL CYCLONIC CIRCULATION CENTER IS NEAR 26N93W CONTINUING TO MOVE WESTWARD ACROSS THE GULF OF MEXICO. THE WESTWARD MOVEMENT OF 15 TO 20 KT THAT WAS PREDICTED BY MANY OF THE COMPUTER MODELS HAS BEEN PRETTY ACCURATE...THUS LIMITING ITS IMPACTS ON HURRICANE DEAN. CYCLONIC FLOW AROUND THE CENTER COVERS THE AREA WEST OF 85W. ISOLATED MODERATE SHOWERS ARE IN THE GULF WATERS NORTH OF 21N WEST OF 88W. WIDELY SCATTERED MODERATE SHOWERS TO ISOLATED STRONG THUNDERSTORMS ARE FROM 27N TO 28.5N BETWEEN 85W AND 86.5W IN MIDDLE LEVEL DIFFLUENT WIND FLOW. THE DIFFLUENT FLOW IS COURTESY OF A MIDDLE LEVEL ANTICYCLONIC CIRCULATION CENTER NEAR IN THE ATLANTIC OCEAN. MIDDLE LEVEL ANTICYCLONIC FLOW IS IN THE GULF OF MEXICO EAST OF 85W...AND FROM THE BAHAMAS NORTHWARD WEST OF 70W IN THE ATLANTIC OCEAN. A SURFACE RIDGE EXTENDS FROM SOUTHEASTERN GEORGIA TO SOUTHEASTERN LOUISIANA TO THE DEEP SOUTH OF TEXAS. A TROPICAL WAVE IS ALONG 94W SOUTH OF 20N. THE CARIBBEAN SEA... ALL THE ATTENTION REMAINS FOCUSED ON POWERFUL CATEGORY FOUR HURRICANE DEAN. DEAN WILL CONTINUE TO HAVE SIGNIFICANT IMPACTS ON THE CENTRAL AND WESTERN CARIBBEAN SEA AS WELL AS THE YUCATAN PENINSULA FROM NOW UNTIL AND INCLUDING TUESDAY NIGHT. A MIDDLE TO UPPER LEVEL TROUGH EXTENDS FROM THE ATLANTIC OCEAN NEAR 24N62W TO 14N64W IN THE NORTHEASTERN CORNER OF THE AREA. THE LARGE CYCLONIC ENVELOPE COVERS THE ATLANTIC OCEAN AND THE CARIBBEAN SEA FROM 16N TO 28N BETWEEN 50W AND 70W. THE ATLANTIC OCEAN... AN MIDDLE LEVEL ANTICYCLONIC CIRCULATION CENTER IS NEAR 30N75W. MIDDLE LEVEL ANTICYCLONIC FLOW IS IN THE ATLANTIC OCEAN FROM THE BAHAMAS NORTHWARD WEST OF 70W. THIS IS THE FEATURE STEERING DEAN FAIRLY QUICKLY TO THE WEST OR WEST-NORTHWEST ACROSS THE WESTERN CARIBBEAN SEA. DEAN'S STRONG CIRCULATION IS CAUSING DISTINCT SINKING/DRYING BEYOND ITS OUTFLOW ACROSS THE CENTRAL BAHAMAS AND REGIONS MORE TO THE NORTH. EASTERLY WINDS ARE QUITE STRONG...25 TO 30 KT WITH HIGHER GUSTS ACROSS THE EXTREME SOUTHWESTERN ATLANTIC OCEAN NEAR DEAN. A MIDDLE TO UPPER LEVEL TROUGH EXTENDS FROM THE ATLANTIC OCEAN NEAR 24N62W TO 14N64W IN THE NORTHEASTERN CORNER OF THE AREA. THE LARGE CYCLONIC ENVELOPE COVERS THE ATLANTIC OCEAN AND THE CARIBBEAN SEA FROM 16N TO 28N BETWEEN 50W AND 70W. THIS TROUGH IS RIGHT ON TOP OF THE 58W TROPICAL WAVE. A MIDDLE LEVEL ANTICYCLONIC CIRCULATION CENTER IS NEAR 14N40W. ANTICYCLONIC FLOW IS WITHIN A 360 NM RADIUS OF THE CENTER. A MIDDLE TO UPPER LEVEL TROUGH EXTENDS FROM A CYCLONIC CIRCULATION CENTER NEAR 30N30W TO 22N36W. A SURFACE RIDGE PASSES THROUGH 33N44W...TO JUST SOUTH OF BERMUDA...TO 31N80W. $$ MT