000 WTNT42 KNHC 302047 TCDAT2 HURRICANE EARL DISCUSSION NUMBER 22 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL072010 500 PM AST MON AUG 30 2010 THE RECONNAISSANCE AIRCRAFT MEASURED 116 KT FLIGHT-LEVEL WINDS AND 108 KT SFMR SURFACE WINDS SHORTLY AFTER 1500 UTC. THIS WAS THE BASIS FOR THE EARLIER INCREASE IN INTENSITY. SINCE THAT TIME...THE PRESSURE HAS CONTINUED TO DROP AND WAS DOWN TO 955 MB ON THE LAST DROPSONDE RELEASED IN THE EYE AROUND 1700 UTC. SINCE THE AIRCRAFT DEPARTED EARL...THE EYE HAS CONTINUED TO CLEAR AND IS SURROUNDED BY CLOUD TOPS TO -70 DEGREES CELSIUS OR COLDER. OBJECTIVE SATELLITE INTENSITY ESTIMATES HAVE INCREASED TO JUST ABOVE 6.0 ON THE DVORAK SCALE AND SUPPORT AN INITIAL INTENSITY OF 115 KT...CATEGORY FOUR ON THE SAFFIR-SIMPSON HURRICANE WIND SCALE. EARL IS EXPECTED TO REMAIN IN A LOW SHEAR ENVIRONMENT AND OVER WARM WATER DURING THE NEXT FEW DAYS AND SOME ADDITIONAL STRENGTHENING IS LIKELY IN THE SHORT TERM. THEREAFTER...EYEWALL CYCLES WILL LIKELY INDUCE SOME FLUCTUATIONS IN INTENSITY...WHICH ARE DIFFICULT TO PREDICT. THE NHC FORECAST IS AGAIN NEAR THE HIGH END OF THE INTENSITY GUIDANCE. AT DAYS 4 AND 5...THE HURRICANE IS FORECAST TO MOVE OVER COOLER WATER AND INTO AN AREA OF INCREASING SHEAR WHICH SHOULD RESULT IN WEAKENING. THE INITIAL MOTION IS 290/13. THE FORECAST REASONING REMAINS UNCHANGED AS EARL IS EXPECTED TO TURN NORTHWESTWARD IN ABOUT 24 HOURS AROUND THE WESTERN PERIPHERY OF THE SUBTROPICAL RIDGE. THE TRACK GUIDANCE HAS SHIFTED NOTICEABLY WESTWARD DURING THE FIRST 48 HOURS...WITH THE GFS AND ECMWF ON THE EASTERN EDGE OF THE ENVELOPE. THE OFFICIAL FORECAST HAS BEEN ADJUSTED WESTWARD... PRIMARILY THROUGH 72 HOURS...AND LIES BETWEEN THE GFS/ECMWF AND THE MULTI-MODEL CONSENSUS. THIS IS A GOOD TIME TO REMIND EVERYONE THAT NHC AVERAGE TRACK FORECAST ERRORS ARE 200 TO 300 MILES AT DAYS 4 AND 5. GIVEN THIS UNCERTAINTY...IT IS TOO SOON TO DETERMINE WHAT PORTION OF THE U.S. EAST COAST MIGHT SEE DIRECT IMPACTS FROM EARL. FORECAST POSITIONS AND MAX WINDS INITIAL 30/2100Z 19.3N 64.7W 115 KT 12HR VT 31/0600Z 20.2N 66.3W 125 KT 24HR VT 31/1800Z 21.7N 68.1W 130 KT 36HR VT 01/0600Z 23.4N 70.1W 130 KT 48HR VT 01/1800Z 25.8N 72.1W 125 KT 72HR VT 02/1800Z 31.6N 74.7W 115 KT 96HR VT 03/1800Z 38.0N 71.0W 95 KT 120HR VT 04/1800Z 45.5N 63.0W 70 KT...INLAND $$ FORECASTER BROWN