000 WTNT44 KNHC 240846 TCDAT4 HURRICANE IRENE DISCUSSION NUMBER 16 NWS NATIONAL HURRICANE CENTER MIAMI FL AL092011 500 AM EDT WED AUG 24 2011 THE LAST PENETRATION OF THE EYE BY THE AIR FORCE HURRICANE HUNTERS WAS JUST AFTER 0500 UTC...AND THEY FOUND THAT THE CENTRAL PRESSURE HAD DROPPED TO 966 MB. THEY ALSO MEASURED 700 MB FLIGHT-LEVEL WINDS OF 92 KT OUTBOUND IN THE SOUTHEAST QUADRANT. IT IS LIKELY THAT HIGHER WINDS WERE OCCURRING OVER THE NORTHEAST QUADRANT OF THE HURRICANE. OVER THE PAST FEW HOURS..THE SATELLITE PRESENTATION OF IRENE HAS BECOME QUITE IMPRESSIVE WITH THE EYE EMBEDDED WITHIN VERY COLD CLOUD TOPS. DVORAK INTENSITY ESTIMATES FROM BOTH TAFB AND SAB ARE 100 KT. COMBINING THE ABOVE INFORMATION...THE CURRENT INTENSITY IS SET CONSERVATIVELY AT 95 KT FOR THIS ADVISORY. ANOTHER HURRICANE HUNTER MISSION IS SCHEDULED FOR 1200 UTC TO MEASURE THE INTENSITY OF THE HURRICANE. ALTHOUGH THE NUMERICAL GUIDANCE INDICATES SOME SOUTH-SOUTHWESTERLY SHEAR OVER THE AREA...THIS SHEAR IS NOT EXPECTED TO PREVENT FURTHER STRENGTHENING AND IT SEEMS HIGHLY LIKELY THAT IRENE WILL INTENSIFY TO CATEGORY 3 STATUS LATER TODAY. SOME FLUCTUATIONS IN STRENGTH COULD OCCUR IN 1 TO 2 DAYS DUE TO EYEWALL REPLACEMENTS. IN FACT...THE UW-CIMSS OBJECTIVE TECHNIQUE SHOWS A CONSIDERABLY HIGHER THAN CLIMATOLOGICAL PROBABILITY OF SECONDARY EYEWALL FORMATION WITHIN 24 TO 48 HOURS. THE OFFICIAL INTENSITY FORECAST IS CLOSE TO THE NUMERICAL CONSENSUS AND LIES BETWEEN THE GFDL/HWRF MODELS AND THE LGEM GUIDANCE. SATELLITE ANIMATION AND CENTER FIXES SHOW THAT THE EYE OF IRENE HAS BEEN WOBBLING BETWEEN A WEST AND NORTHWEST HEADING OVER THE PAST SEVERAL HOURS. SMOOTHING THROUGH THESE WOBBLES YIELDS A MORE REPRESENTATIVE MOTION OF ABOUT 295/8. THERE HAS BEEN LITTLE CHANGE TO THE TRACK FORECAST REASONING FROM THE PAST FEW ADVISORIES. OVER THE NEXT COUPLE OF DAYS...THE HURRICANE IS EXPECTED TO GRADUALLY TURN TOWARD THE NORTHWEST AND NORTH AS IT MOVES THROUGH A PRONOUNCED WEAKNESS IN THE SUBTROPICAL RIDGE. AROUND 72 HOURS...A SHORTWAVE TROUGH MOVING THROUGH THE GREAT LAKES SHOULD BEGIN TO INDUCE AT LEAST A SLIGHT TURN TOWARD THE NORTH-NORTHEAST WITH SOME ACCELERATION AFTERWARDS. THE DYNAMICAL TRACK MODEL CONSENSUS HAS...AGAIN...SHIFTED A LITTLE TO THE EAST FROM THE PREVIOUS PACKAGE. THE OFFICIAL FORECAST IS NOT SUBSTANTIALLY DIFFERENT FROM THE PREVIOUS ONE AND LIES A LITTLE TO THE LEFT OF THE CONSENSUS. USERS ARE REMINDED THAT SIGNIFICANT ERRORS ARE POSSIBLE WITH FORECASTS AT LONGER LEAD TIMES...SO ONE SHOULD NOT FOCUS ON THE EXACT FORECAST POSITIONS AT 96 AND 120 HOURS. FORECAST POSITIONS AND MAX WINDS INIT 24/0900Z 21.6N 72.9W 95 KT 110 MPH 12H 24/1800Z 22.5N 74.1W 105 KT 120 MPH 24H 25/0600Z 24.1N 75.4W 110 KT 125 MPH 36H 25/1800Z 25.8N 76.6W 110 KT 125 MPH 48H 26/0600Z 27.7N 77.0W 110 KT 125 MPH 72H 27/0600Z 32.0N 76.8W 105 KT 120 MPH 96H 28/0600Z 36.5N 75.0W 90 KT 105 MPH 120H 29/0600Z 42.0N 71.5W 70 KT 80 MPH...INLAND $$ FORECASTER PASCH/KIMBERLAIN