000 WTNT44 KNHC 260255 TCDAT4 HURRICANE IRENE DISCUSSION NUMBER 23 NWS NATIONAL HURRICANE CENTER MIAMI FL AL092011 1100 PM EDT THU AUG 25 2011 TWO HURRICANE HUNTER AIRCRAFT...ONE AIR FORCE AND ONE NOAA...ARE AGAIN TONIGHT SUPPLYING VERY VALUABLE METEOROLOGICAL DATA TO THE NATIONAL HURRICANE CENTER. BOTH PLANES INDICATE THAT THE CENTRAL PRESSURE IS GRADUALLY FALLING AND IS NOW NEAR 942 MB...BUT THE WINDS HAVE NOT INCREASED YET. THE INITIAL INTENSITY IS KEPT AT 100 KNOTS AT THIS TIME. IRENE HAS MOVED AWAY FROM THE NORTHWESTERN BAHAMAS AND IS NOW OVER OPEN WATERS. THE EYE HAS BECOME A LITTLE BETTER DEFINED ON SATELLITE AND MICROWAVE IMAGERY AND IT APPEARS THAT THE EYEWALL IS CONTRACTING. GIVEN THE CURRENT STRUCTURE AND THE WARM WATERS ALONG THE TRACK OF THE HURRICANE...SOME STRENGTHENING IS INDICATED DURING THE NEXT 12 TO 24 HOURS. A SLOW WEAKENING SHOULD BEGIN THEREAFTER...BUT IRENE IS EXPECTED TO APPROACH THE COAST OF NORTH CAROLINA A POWERFUL HURRICANE. IN FACT...THE HIGH RESOLUTION ECMWF SHOWS A VERY INTENSE CYCLONE APPROACHING THE NORTH CAROLINA COAST. SATELLITE AND RECONNAISSANCE FIXES INDICATE THAT IRENE IS MOVING TOWARD THE NORTH OR 350 DEGREES AT 12 KNOTS. THE HURRICANE IS ALREADY ON THE WEST SIDE OF THE SUBTROPICAL RIDGE AND IS READY TO INTERACT WITH SOUTH-SOUTHWESTERLY FLOW AHEAD OF THE THE APPROACHING MID-LATITUDE TROUGH. IRENE HAS NOWHERE TO GO BUT NORTHWARD WITH A GRADUAL TURN TO THE NORTH-NORTHEAST AFTER THE CENTER CROSSES OR PASSES NEAR THE NORTH CAROLINA COAST. THE TRACK GUIDANCE HAS BEEN VERY CONSISTENT AND CONTINUES TO BE TIGHTLY CLUSTERED...GIVING NO REASON TO MAKE A SIGNIFICANT CHANGE TO THE OFFICIAL FORECAST. GIVEN THE CURRENT FORECAST...IT IS NOT NECESSARY TO ADJUST THE U.S. WATCHES AND WARNINGS AT THIS TIME. FORECAST POSITIONS AND MAX WINDS INIT 26/0300Z 28.3N 77.3W 100 KT 115 MPH 12H 26/1200Z 30.0N 77.8W 105 KT 120 MPH 24H 27/0000Z 31.8N 77.6W 110 KT 125 MPH 36H 27/1200Z 33.7N 77.1W 105 KT 120 MPH 48H 28/0000Z 36.0N 76.3W 90 KT 105 MPH 72H 29/0000Z 42.0N 73.0W 70 KT 80 MPH...INLAND 96H 30/0000Z 51.0N 66.0W 40 KT 45 MPH...POST-TROP/EXTRATROP 120H 31/0000Z 58.0N 50.0W 40 KT 45 MPH...POST-TROP/EXTRATROP $$ FORECASTER AVILA