Flhurricane.com - Central Florida Hurricane Center - Tracking Storms since 1995Hurricanes Without the Hype! Since 1995
The Atlantic is quiet
|
Show Selection: |
| #452598 (Received by flhurricane at: 11:03 AM 23.Aug.2011) TCDAT4 HURRICANE IRENE DISCUSSION NUMBER 13 NWS NATIONAL HURRICANE CENTER MIAMI FL AL092011 1100 AM EDT TUE AUG 23 2011 THE LAST FEW VISIBLE SATELLITE IMAGES SHOW A HINT OF AN EYE... WHILE RECENT MICROWAVE DATA SHOW AN EYEWALL THAT IS OPEN TO THE SOUTH. THE LATEST SATELLITE INTENSITY ESTIMATES FROM SAB AND TAFB WERE 77 AND 90 KT...RESPECTIVELY...AND SUPPORT MAINTAINING AN INITIAL INTENSITY OF 85 KT. THE RECONNAISSANCE AIRCRAFT SCHEDULED TO INVESTIGATE IRENE THIS MORNING HAD ISSUES WITH THE ON-BOARD RADAR. THIS REQUIRED A CHANGE IN AIRCRAFT AND THE NEW PLANE JUST PASSED THROUGH THE CENTER...REPORTING A MINIMUM PRESSURE OF 980 MB...ABOUT THE SAME AS DURING THE PREVIOUS MISSION. A SHEAR ANALYSIS FROM UW-CIMSS SHOWS ABOUT 10-20 KT OF SOUTHWESTERLY SHEAR OVER IRENE....AND THE SHIPS GUIDANCE DOES NOT WEAKEN THIS SHEAR DURING THE NEXT COUPLE OF DAYS. AS A RESULT...THE SHIPS/LGEM MODELS DO NOT SHOW MUCH STRENGTHENING DURING THAT TIME. ON THE OTHER HAND...THE GFDL/HWRF MODELS ARE MUCH MORE AGGRESSIVE AND MAKE IRENE A MAJOR HURRICANE WITHIN 24 HOURS. THE NEW INTENSITY FORECAST IS HIGHER THAN THE STATISTICAL GUIDANCE...BUT NOT AS AGGRESSIVE AS THE GFDL/HWRF. THE UPDATED FORECAST IS SLIGHTLY BELOW THE PREVIOUS ADVISORY. IRENE HAS BEEN MOVING WEST-NORTHWESTWARD OR 295 DEGREES AT 10 KT. A MID/UPPER-LEVEL TROUGH MOVING OVER THE NORTHEASTERN UNITED STATES IS EXPECTED TO WEAKEN THE WESTERN PORTION OF THE SUBTROPICAL RIDGE DURING THE NEXT DAY OR SO. THIS SHOULD ALLOW IRENE TO TURN NORTHWESTWARD WITHIN THE NEXT 24-36 HOURS...AND THE TRACK GUIDANCE IS IN EXCELLENT AGREEMENT DURING THE FIRST 48 HOURS. LATER IN THE FORECAST PERIOD IRENE IS FORECAST TO TURN NORTHWARD AS IT ROUNDS THE WESTERN PORTION OF THE RIDGE. THE SPREAD IN THE GUIDANCE INCREASES BY DAY THREE...RANGING FROM THE COASTAL MID-ATLANTIC STATES TO WELL OFFSHORE...WITH THE UKMET ALONG THE LEFT SIDE AND THE GFS/NOGAPS ALONG THE RIGHT SIDE OF THE GUIDANCE ENVELOPE. THE UPDATED TRACK IS CLOSEST TO THE ECMWF AND IS A LITTLE LEFT OF THE MULTI-MODEL CONSENSUS. IT IS IMPORTANT TO REMIND USERS NOT TO FOCUS ON THE EXACT FORECAST TRACK...ESPECIALLY AT DAYS 4 AND 5...SINCE THE MOST RECENT 5-YEAR AVERAGE ERRORS AT THOSE FORECAST TIMES ARE 200 AND 250 MILES...RESPECTIVELY. FORECAST POSITIONS AND MAX WINDS INIT 23/1500Z 20.5N 71.0W 85 KT 100 MPH 12H 24/0000Z 21.3N 72.3W 90 KT 105 MPH 24H 24/1200Z 22.3N 73.8W 100 KT 115 MPH 36H 25/0000Z 23.6N 75.2W 105 KT 120 MPH 48H 25/1200Z 25.3N 76.5W 110 KT 125 MPH 72H 26/1200Z 29.2N 77.5W 110 KT 125 MPH 96H 27/1200Z 33.0N 77.5W 100 KT 115 MPH 120H 28/1200Z 37.5N 76.0W 65 KT 75 MPH...INLAND $$ FORECASTER BROWN |
