Show Selection: |
#31163 (Received by flhurricane at: 11:11 PM 08.Jul.2005) TCDAT4 HURRICANE DENNIS DISCUSSION NUMBER 18 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 11 PM EDT FRI JUL 08 2005 DENNIS CONTINUES MOVING ACROSS WESTERN CUBA AND IS APPROACHING THE STRAITS OF FLORIDA. SATELLITE IMAGERY AND RADAR DATA FROM THE KEY WEST WSR-88D SHOW SOME DEGRADATION OF THE EYE STRUCTURE OVER THE PAST FEW HOURS...ALTHOUGH DOPPLER WINDS CONTINUE TO INDICATE A TIGHT INNER CORE. BASED ON EXTRAPOLATION OF THE DOPPLER WINDS... THE INITIAL INTENSITY IS REDUCED TO 95 KT...ALTHOUGH THERE IS A LARGE MARGIN FOR ERROR ON BOTH THE WINDS AND THE ESTIMATED CENTRAL PRESSURE. THE INITIAL MOTION IS A SOMEWHAT UNSTEADY 310/12. THERE IS LITTLE CHANGE IN THE SYNOPTIC STEERING PATTERN OR THE FORECAST PHILOSOPHY. DENNIS IS ON THE SOUTHEAST SIDE OF A MID/UPPER-LEVEL RIDGE THAT EXTENDS FROM THE WESTERN ATLANTIC ACROSS FLORIDA INTO THE GULF OF MEXICO...WHILE AN MID/UPPER-LEVEL TROUGH EXTENDS FROM THE MID-MISSISSIPPI VALLEY SOUTHWESTWARD TO THE TEXAS COAST. LARGE- SCALE MODELS FORECAST THE ATLANTIC RIDGE TO BUILD NORTHWESTWARD... WHICH SHOULD KEEP DENNIS ON A NORTHWESTWARD OR NORTH-NORTHWESTWARD TRACK UNTIL IT REACHES THE NORTHERN GULF COAST. TRACK MODEL GUIDANCE IS CLUSTERED BETWEEN LANDFALL IN SOUTHEASTERN LOUISIANA AND THE WESTERN FLORIDA PANHANDLE. THE GFDL AND GFS HAVE SHIFTED TO THE RIGHT OF THEIR PREVIOUS FORECASTS...WHILE THE UKMET REMAINS TO THE LEFT OF CENTER OF THE GUIDANCE ENVELOPE. CONSENSUS MODELS REMAIN CLUSTERED AROUND A LANDFALL BETWEEN PASCAGOULA AND FT. WALTON BEACH. THE FORECAST TRACK IS SHIFTED A LITTLE TO THE LEFT OF THE PREVIOUS TRACK...TO MATCH THE INITIAL POSITION AND MOTION IN THE FIRST 24 HR AND TO BE A LITTLE CLOSER TO THE CONSENSUS MODELS FROM 24-48 HR. DENNIS SHOULD BE OVER WATER SHORTLY...AND UPPER-LEVEL WINDS AND SEA SURFACE TEMPERATURES APPEAR FAVORABLE FOR RE-INTENSIFICATION. ALL INTENSITY GUIDANCE INDICATES THE SYSTEM SHOULD REGAIN MAJOR HURRICANE STATUS...AND THAT IS FOLLOWED IN THE INTENSITY FORECAST WHICH BRINGS DENNIS BACK TO 110 KT IN 24 HR AND MAINTAINS THAT INTENSITY UNTIL LANDFALL. THERE IS A POSSIBILITY THAT DENNIS COULD STRENGTHEN MORE THAN CURRENTLY FORECAST. AFTER LANDFALL...DENNIS SHOULD WEAKEN AND EVENTUALLY BECOME A LOW PRESSURE AREA OVER THE MID-MISSISSIPPI AND OHIO VALLEYS. 34 KT WIND RADII IN THE EASTERN SEMICIRCLE WERE INCREASED ON THE BASIS OF SURFACE OBSERVATIONS. THERE IS AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT FLYING ALONG THE NORTH COAST OF CUBA WAITING FOR DENNIS TO EMERGE. HOWEVER... THE AIRCRAFT IS EXPERIENCING MAJOR COMMUNICATION PROBLEMS AND ONLY LIMITED DATA CAN BE TRANSMITTED AT THIS MOMENT. A VORTEX MESSAGE MAY BE AVAILABLE ONCE DENNIS MOVES BACK OVER THE WATER. FORECASTER BEVEN FORECAST POSITIONS AND MAX WINDS INITIAL 09/0300Z 23.0N 82.1W 95 KT...INLAND 12HR VT 09/1200Z 24.4N 83.4W 100 KT...OVER WATER 24HR VT 10/0000Z 26.3N 84.9W 110 KT 36HR VT 10/1200Z 28.5N 86.2W 110 KT 48HR VT 11/0000Z 30.9N 87.5W 100 KT...INLAND 72HR VT 12/0000Z 35.5N 90.0W 30 KT...INLAND 96HR VT 13/0000Z 38.0N 89.0W 25 KT...INLAND DISSIPATING 120HR VT 14/0000Z 39.0N 85.5W 20 KT...INLAND REMNANT LOW |