000 AXNT20 KNHC 180007 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT FRI AUG 17 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2330 UTC. ...SPECIAL FEATURE... THE CENTER OF HURRICANE DEAN AT 18/0000 UTC WAS NEAR 14.9N 65.1W OR ABOUT 695 NM/1290 KM EAST-SOUTHEAST OF KINGSTON JAMAICA...AND ABOUT 220 NM/410 KM SOUTH-SOUTHEAST OF SAN JUAN PUERTO RICO. DEAN IS MOVING WEST 19 KT WITH MAXIMUM SUSTAINED WIND SPEEDS NEAR 115 KT WITH HIGHER GUSTS. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 946 MB. DEAN IS NOW A CATEGORY FOUR MAJOR HURRICANE. PLEASE SEE THE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT4/WTNT24 KNHC OR THE LATEST PUBLIC ADVISORY UNDER MIATCPAT4/WTNT34 KNHC FOR MORE DETAILS INCLUDING THE MOST RECENT WATCH AND WARNING INFORMATION. FOR STORM INFORMATION SPECIFIC TO YOUR AREA...INCLUDING POSSIBLE INLAND WATCHES AND WARNINGS...PLEASE MONITOR PRODUCTS ISSUED BY YOUR LOCAL WEATHER OFFICE. NUMEROUS MODERATE TO STRONG CONVECTION IS OVER THE ERN CARIBBEAN FROM 12N-18N BETWEEN 61W-68W. THE EYE OF DEAN IS NOW APPARENT VIA THE SAN JUAN RADAR. ALL INTERESTS IN THE CARIBBEAN SEA AND THE GULF OF MEXICO SHOULD CLOSELY MONITOR THE PROGRESS OF DEAN. ...TROPICAL WAVES... A TROPICAL WAVE IS MOVING THROUGH THE E ATLC ALONG 32W MOVING W NEAR 20 KT. THIS WAVE CONTINUES TO EXHIBIT A BROAD ENVELOPE OF CYCLONIC TURNING IN THE SURROUNDING LOW TO MID CLOUD FIELD...ESPECIALLY FROM 12N-19N BETWEEN 28W-37W. HOWEVER...DEEP CONVECTION REMAINS MINIMAL NEAR THIS CIRCULATION WITH ONLY ONE SMALL CLUSTER OF MODERATE CONVECTION NOTED NEAR 16N32W. A MORE CONCENTRATED AREA OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS NEAR THE SRN PORTION OF THE AXIS FROM 6N-10N BETWEEN 24W-34W...WHICH MAY BE MORE ASSOCIATED WITH SPEED CONVERGENCE S OF THE ITCZ. AN ATLC OCEAN TROPICAL WAVE IS ALONG 44W SOUTH OF 20N. THIS WAVE IS GENERALLY MOVING W NEAR 15-20 KT...BUT THE MAIN AREA OF CYCLONIC TURNING HAS HAD A SW COMPONENT OVER THE LAST COUPLE OF DAYS. THE WAVE...AND THIS SW MOTION...SHOWS UP WELL IN THE 48 HR ANIMATION OF THE UW-CIMSS SSMI/AMSRE TOTAL PRECIPITABLE WATER PRODUCT. REGARDLESS...DEEP CONVECTION REMAINS MINIMAL NEAR THE WAVE. A WRN CARIBBEAN SEA TROPICAL WAVE IS ALONG 80W SOUTH OF 19N MOVING WEST 20-25 KT. AN INVERTED V PATTERN REMAINS EVIDENT WITH THIS WAVE. SCATTERED MODERATE CONVECTION IS OVER THE SW CARIBBEAN S OF 11N. ISOLATED SHOWERS AND TSTMS ARE ELSEWHERE WITHIN 120 NM OF THE AXIS. CLOUD TOPS OVER THIS ACTIVITY ARE BEING SHEARED TO THE NE WITH UPPER SW FLOW AHEAD OF AN UPPER TROUGH. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 16N16W 15N23W 16N30W 12N35W 11N42W 7N47W 15N59W. OUTSIDE OF THE CONVECTION ALREADY DESCRIBED WITH THE TROPICAL WAVES AND HURRICANE DEAN...DEEP CONVECTION IS MINIMAL NEAR THE ITCZ TONIGHT. SCATTERED MODERATE/ISOLATED STRONG ACTIVITY IS INLAND OVER AFRICA THOUGH...FROM 8N-15N BETWEEN 6W-12W...WHICH SEEMS ASSOCIATED WITH THE NEXT TROPICAL WAVE. DISCUSSION... THE GULF OF MEXICO... THE GULF IS MUCH QUIETER THIS EVENING AS T.D. ERIN CONTINUES TO MOVE FURTHER INLAND OVER TEXAS. LIGHTNING DATA STILL SUPPORTS A FEW ISOLATED TSTMS MAINLY NEAR THE NRN GULF COAST N OF 25N BETWEEN 85W-95W. THIS MOISTURE EXPECTED TO CONTINUE MOVING FURTHER INLAND WITH ERIN OVER THE NEXT DAY OR SO. FAIRLY UNIFORM UPPER NE FLOW IS OVER THE GULF TONIGHT BETWEEN THE UPPER HIGH OVER ERN TEXAS AND THE UPPER LOW NEARING FLORIDA FROM THE WRN ATLC. SFC RIDGING HAS BUILT OVER THE N GULF AND WILL SLIDE N THROUGH THE WEEKEND. HOWEVER...HURRICANE AND TROPICAL STORM CONDITIONS ARE EXPECTED TO SPREAD ACROSS THE SOUTHERN AND WESTERN GULF MON THROUGH WED AS HURRICANE DEAN MOVES ACROSS THE NW CARIBBEAN AND ENTERS THE SW GULF TUE AND WED. THE CARIBBEAN SEA... POWERFUL CATEGORY THREE HURRICANE DEAN IS OVER THE ERN CARIBBEAN AS DESCRIBED ABOVE. DEAN WILL CONTINUE TO HAVE SIGNIFICANT IMPACTS ON THE CARIBBEAN OVER THE NEXT FEW DAYS. AN UPPER TROUGH EXTENDS THROUGH THE NW CARIB BETWEEN CENTRAL CUBA AND ERN HONDURAS. THIS IS EXPECTED TO PUSH W INTO THE GULF AND WEAKEN OVER THE NEXT FEW DAYS WITH RIDGING STAYING N OF DEAN...KEEPING IT ON A WWD TRACK. UPPER CONFLUENCE BETWEEN THIS UPPER TROUGH AND OUTFLOW FROM DEAN IS PRODUCING A SWATH OF DRY UPPER AIR S OF HISPANIOLA AT THE MOMENT...BUT THIS WILL ALSO SHIFT W. THE TROPICAL WAVE CURRENTLY ALONG 80W WILL PUSH OUT OF THE CARIBBEAN AND THROUGH CENTRAL AMERICA OVER THE NEXT COUPLE OF DAYS. THE ATLANTIC OCEAN... THE DOMINANT FEATURE OVER THE WRN ATLC CONTINUES TO BE THE UPPER LOW SPINNING NEAR THE NW BAHAMAS. LIFT AHEAD OF THIS FEATURE IS SUPPORTING SCATTERED SHOWERS AND TSTMS OVER THE BAHAMAS AND ADJACENT WATERS S OF 28N W OF 72W. THE UPPER LOW WILL MOVE W INTO THE ERN GULF BY TOMORROW EVENING. UPPER RIDGING IS TO THE E OF THE UPPER LOW WHICH IS STEERING DEAN WWD. ANOTHER UPPER LOW IS NEAR 27N50W. LIGHTNING DATA HAS BEEN DEPICTING A FEW ISOLATED TSTMS ASSOCIATED WITH THIS FEATURE FROM 27N-32N BETWEEN 47W-52W. UPPER RIDGING EXTENDING W FROM AFRICA GENERALLY DOMINATES THE ERN ATLC. AT THE SFC A LARGE SCALE RIDGE DOMINATES...ANCHORED BY A 1031 MB HIGH JUST N OF THE AZORES AT 40N27W. THIS IS PRODUCING WIDESPREAD FAIR WEATHER AND MODERATE TRADES E OF 60W. E/NE WINDS ARE A LITTLE STRONGER AS DENOTED BY A RECENT QUIKSCAT PASS FROM 18N-27N BETWEEN 25W-41W. THIS IS IN RESPONSE TO THE INTERACTION BETWEEN THE HIGH TO THE N WITH THE LARGE TROPICAL WAVE TO ITS S ALONG 32W. $$ WILLIS