|
Show Selection: |
| #307018 (Received by flhurricane at: 10:03 PM 08.Nov.2009) TCDAT1 HURRICANE IDA DISCUSSION NUMBER 21 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL112009 900 PM CST SUN NOV 08 2009 THE SATELLITE APPEARANCE OF IDA HAS CHANGED VERY LITTLE SINCE THE AIRCRAFT DEPARTED THE HURRICANE JUST BEFORE 0000 UTC. DURING THE LAST COUPLE OF PASSES THROUGH THE CENTER THE AIRCRAFT MEASURED A MAXIMUM 700 MB FLIGHT-LEVEL WIND OF 108 KT AND A SFMR SURFACE WIND OF 84 KT. THESE DATA SUPPORT AN INTENSITY OF 90 KT. ANOTHER AIR FORCE PLANE IS SCHEDULED TO REACH IDA AROUND 0600 UTC. THE LAST FEW AIRCRAFT FIXES PROVIDE A FAIRLY CONFIDENT INITIAL MOTION OF 345/12...A LITTLE FASTER THAN BEFORE. IDA IS FORECAST TO CONTINUE MOVING NORTHWARD BETWEEN A MID/UPPER-LEVEL TROUGH OVER THE WESTERN GULF MEXICO AND A MID/UPPER-LEVEL RIDGE OVER THE EASTERN GULF OF MEXICO AND THE NORTHERN CARIBBEAN SEA. THE TRACK MODELS APPEAR TO BE IN A LITTLE BETTER AGREEMENT ON A NORTH-NORTHWESTWARD TO NORTHWARD TRACK DURING THE NEXT 24-36 HOURS. THE 12Z RUNS OF THE ECMWF AND UKMET ARE A LITTLE WEST OF THE REMAINDER OF THE GUIDANCE AND SHOW A TRACK NEAR EXTREME SOUTHEASTERN LOUISIANA. DURING THE FIRST 24-36 HOURS...THE NEW OFFICIAL FORECAST IS NEAR THE MODEL CONSENSUS AND THE PREVIOUS TRACK...BUT IS A LITTLE FASTER. AFTER LANDFALL ALONG THE NORTHERN GULF COAST...THE MODELS TURN IDA EASTWARD THEN SOUTHEASTWARD AND THE NHC FORECAST FOLLOWS SUIT...BUT DOES NOT SHOW AS SHARP A SOUTHEASTWARD TURN AS SOME OF THE GUIDANCE INDICATES. THE AIR FORCE ALSO FLEW A SURVEILLANCE MISSION AROUND AND NORTH OF THE HURRICANE THIS AFTERNOON AND THAT DATA SHOULD BE ASSIMILATED INTO THE 0000 UTC MODELS. IDA IS FORECAST TO TRAVERSE COOLER WATERS...AND MOVE INTO A COOLER AIRMASS AND INCREASING SHEAR DURING THE NEXT 24-36 HOURS. AS THE CYCLONE APPROACHES THE NORTHERN GULF COAST IT WILL ALSO LIKELY BEGIN EXTRATROPICAL TRANSITION. HOWEVER...IT IS BECOMING MORE LIKELY THAT IDA WILL RETAIN ITS TROPICAL CHARACTERISTICS THROUGH LANDFALL. THE INTENSITY GUIDANCE FORECASTS GRADUAL WEAKENING AND ALL SHOW IDA AROUND HURRICANE STRENGTH AT LANDFALL. THE OFFICIAL FORECAST IS IN LINE WITH THE GUIDANCE AND KEEPS THE CYCLONE A HURRICANE WHEN IT REACHES THE COAST. THIS HAS REQUIRED THE ISSUANCE OF A HURRICANE WARNING FOR A PORTION OF THE NORTHERN GULF COAST. FORECAST POSITIONS AND MAX WINDS INITIAL 09/0300Z 23.7N 86.7W 90 KT 12HR VT 09/1200Z 25.8N 87.5W 85 KT 24HR VT 10/0000Z 28.5N 87.7W 75 KT 36HR VT 10/1200Z 30.5N 87.1W 65 KT...INLAND 48HR VT 11/0000Z 31.2N 85.8W 40 KT...EXTRATROPICAL 72HR VT 12/0000Z 30.5N 82.0W 30 KT...EXTRATROPICAL 96HR VT 13/0000Z...DISSIPATED $$ FORECASTER BROWN |
