000 AXNT20 KNHC 221206 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT WED AUG 22 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 1045 UTC. ...SPECIAL FEATURE... HURRICANE DEAN IS CENTERED NEAR 20.5N 95.5W...OR 85 NM NNE OF VERACRUZ MEXICO AND ABOUT 105 NM ESE OF TUXPAN MEXICO...AT 22/1200 UTC MOVING WNW AT 17 KT. MAXIMUM SUSTAINED WIND SPEEDS ARE NEAR 80 KT WITH HIGHER GUSTS. ESTIMATED MINIMUM CENTRAL PRESSURE IS 976 MB. PLEASE SEE THE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT4/WTNT24 KNHC AND THE LATEST PUBLIC ADVISORY UNDER MIATCPAT4/WTNT34 KNHC FOR MORE DETAILS INCLUDING THE LATEST WATCH AND WARNING INFORMATION. DEAN IS SLOWLY RE-ORGANIZING OVER THE BAY OF CAMPECHE...EXPECTED TO MAKE LANDFALL LATER TODAY. SOME FURTHER STRENGTHENING IS POSSIBLE BEFORE LANDFALL...FOLLOWED BY WEAKENING AFTER LANDFALL. NUMEROUS MODERATE TO STRONG CONVECTION IS OVER THE WRN AND CENTRAL BAY OF CAMPECHE S OF 23N W OF 92W. IN ADDITION SATELLITE...BROWNSVILLE RADAR...AND LIGHTNING DATA DEPICT SCATTERED SHOWERS AND TSTMS ELSEWHERE OFF THE S TEXAS AND MEXICO COASTS S OF 28N W OF 93W. ...TROPICAL WAVES... TROPICAL WAVE IS TILTED ALONG 21N58W 7N55W MOVING W 15-20 KT. SHORTWAVE IR IMAGERY SHOWS AN ELONGATED AND NARROW ZONE OF LOW LEVEL CYCLONIC TURNING IN ASSOCIATION WITH THIS WAVE. DEEP CONVECTION IS OVERALL MINIMAL AND DISORGANIZED WITH THIS WAVE...THOUGH LIGHTNING DATA IS SUPPORTING SCATTERED TSTMS NEAR THE NRN PORTION OF THE AXIS FROM 20N-23N BETWEEN 55W-57W. SCATTERED MODERATE CONVECTION IS ALSO FURTHER S...MOVING TOWARDS TRINIDAD...WITHIN 120 NM EITHER SIDE OF THE AXIS FROM 9N-12N. TROPICAL WAVE IS ALONG 71W/72W S OF 30N MOVING W 15-20 KT. THIS WAVE HAS SHOWED UP WELL IN RECENT QUIKSCAT AND ASCAT PASSES. SATELLITE IMAGERY NOW SHOWS A LITTLE MORE CYCLONIC TURNING ALONG THE WAVE JUST E OF THE CENTRAL BAHAMAS. HOWEVER...AM NOT SURE THERE IS A CLOSED SFC LOW WITH THIS SPINNING...WITH BAHAMAS METAR DATA TO THE S OF THE CIRCULATION REPORTING LIGHT NE WINDS. WILL DIAGNOSE THIS AGAIN FOR THE 22/1200 UTC MAP AS MORE VISIBLE IMAGERY BECOMES AVAILABLE. DISORGANIZED SCATTERED SHOWERS AND TSTMS ARE BEGINNING TO MOVE THROUGH THE BAHAMAS FROM 21N-29N BETWEEN 72W-78W...WHICH IS ALSO BEING SUPPORTED BY DIFFLUENT FLOW ALOFT AROUND THE NRN PERIPHERY OF THE UPPER LOW JUST S OF CUBA. UPPER-LEVEL WINDS ARE NOT FAVORABLE FOR SIGNIFICANT DEVELOPMENT OF THIS SYSTEM. THERE IS ALSO NUMEROUS MODERATE/ISOLATED STRONG CONVECTION FURTHER S WITH THE CARIBBEAN PORTION OF THE WAVE...S OF 15N BETWEEN 73W-80W. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 11N15W 9N30W 10N40W 10N54W 9N62W. THERE IS A LITTLE MORE CONVECTION ALONG THE AXIS THIS MORNING BUT THE ITCZ REMAINS HIGHLY ZONAL ACROSS THE TROPICAL ATLC. NUMEROUS MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 90 NM EITHER SIDE OF THE AXIS BETWEEN 18W-33W. SCATTERED MODERATE/ISOLATED STRONG IS WITHIN 120 NM EITHER SIDE OF THE AXIS BETWEEN 34W-54W. DISCUSSION... GULF OF MEXICO... THE MAIN FOCUS THIS EVENING REMAINS HURRICANE DEAN THAT IS IN THE CENTRAL BAY OF CAMPECHE. SEE SPECIAL FEATURES ABOVE. DEAN IS BEING STEERED WWD BY A DEEP LAYER RIDGE TO ITS N/NE. DRY/STABLE AIR IS OVER THE ERN GULF EXCEPT FOR A SMALL PATCH OF MOISTURE AND A COUPLE ISOLATED TSTMS FROM 24N-28N BETWEEN 84W-88W. SFC RIDGING WILL REMAIN QUASI STATIONARY OVER THE N GULF OVER THE NEXT FEW DAYS. CARIBBEAN SEA... WITH DEAN NOW WELL W OF THE AREA...THE MOST SIGNIFICANT AREA OF WEATHER IN THE CARIBBEAN HAS SHIFTED TO THE SRN PORTION OFF THE COAST OF COLOMBIA AND PANAMA. THE CONVECTION IN THIS VICINITY MAY IN PART BE DUE TO THE TROPICAL WAVE ALONG 72W AS DESCRIBED ABOVE...BUT IS ALSO BEING SUPPORTED BY DIFFLUENT FLOW ALOFT. MOISTURE WITH THIS WAVE...AND THE WAVE NEARING THE WINDWARD ISLANDS...WILL PUSH W THROUGH THE BASIN OVER THE NEXT COUPLE OF DAYS. ELSEWHERE AT THE SFC LIGHT TO MODERATE TRADES ARE IN PLACE AND GENERALLY EXPECTED TO PERSIST THROUGH THU. THE UPPER PATTERN IS DOMINATED BY THE LARGE AND ELONGATED UPPER LOW JUST S OF CUBA...AND THE SRN PERIPHERY OF AN UPPER RIDGE OVER THE ERN PORTION. ATLANTIC OCEAN... THE AREA JUST OFF THE IMMEDIATE COAST OF FLORIDA AND GEORGIA IS EXPERIENCING FAIR WEATHER WITH DRY/STABLE MID TO UPPER AIR IN PLACE. HOWEVER...SHOWERS AND TSTMS ASSOCIATED WITH THE TROPICAL WAVE NOW MOVING THROUGH THE CENTRAL BAHAMAS ARE APPROACHING AND WILL AFFECT THE AREA OVER THE NEXT SEVERAL HOURS...SEE DETAILS ABOVE. AN UPPER HIGH IS NEAR 31N63W THAT HAS RIDGING EXTENDING S TO THE ERN CARIBBEAN. BENIGN UPPER LOWS ARE NOTED NEAR 24N49W AND 31N35W...WHILE THE REMAINDER OF THE FAR ERN ATLC AREA IS DOMINATED BY TYPICAL UPPER RIDGING. ELSEWHERE AT THE SFC A 1024 MB HIGH IS NEAR 30N52W...EXPECTED TO SLIDE SLOWLY SW IN ADVANCE OF THE FRONTAL SYSTEM N OF THE AREA. LIGHT TO MODERATE TRADE WINDS AND FAIR WEATHER AROUND THIS RIDGING DOMINATE MUCH OF THE AREA N OF 13N E OF 50W. $$ WILLIS