ZCZC MIATCDAT1 ALL TTAA00 KNHC DDHHMM HURRICANE ARTHUR DISCUSSION NUMBER 11 NWS NATIONAL HURRICANE CENTER MIAMI FL AL012014 1100 AM EDT THU JUL 03 2014 Data from Air Force Reserve and NOAA Hurricane Hunter aircraft show that Arthur continues to strengthen this morning. The Air Force plane has reported peak 700 mb flight-level winds of 83 kt. The NOAA aircraft reported 91 kt from 8,000 ft, and both aircraft have measured surface winds of around 80 kt from the SFMR. Based on these data, the initial intensity is increased to 80 kt. Arthur is forecast to remain in low shear and move over warm water during the next 24 hours. This should allow for some additional intensification. The updated NHC intensity forecast now calls for Arthur to reach category two strength prior to its landfall or closest approach to the coast, in agreement with tightly clustered intensity guidance. After that time, Arthur will be moving over cooler waters north of the Gulf Stream, and the shear is forecast to increase as Arthur interacts with a deep-layer trough that will be moving off the east coast of the United States. Arthur is forecast to become a strong extratropical cyclone in 48 hours and should steadily weaken after that. Aircraft and radar data indicate that Arthur is moving a little faster and appears to have turned north-northeastward, although the motion over the last hour or two was northward. The hurricane should turn northeastward later today and accelerate ahead of the deep-layer trough nearing the U.S. east coast. The models are in good agreement in showing the center of Arthur grazing the North Carolina coast during the next 24 hours, however only a slight westward shift in the track would bring the strongest winds inland over eastern North Carolina. After 24 hours, the spread in the models increases some with the GFS and HWRF faster and along the western side of the guidance. The ECMWF is a bit slower and to the right. The NHC forecast leans toward the faster GFS solution, but has been adjusted a little to the east at days three through five. The forecast track brings the center of the cyclone near or over portions of Nova Scotia and Newfoundland in two to three days. Users are reminded to not focus of the exact forecast track since the associated hazards extend well away from the center. The new experimental potential storm surge flooding map is available at: http://www.nhc.noaa.gov/graphics_at1.shtml?inundation FORECAST POSITIONS AND MAX WINDS INIT 03/1500Z 32.4N 78.5W 80 KT 90 MPH 12H 04/0000Z 33.8N 77.3W 85 KT 100 MPH 24H 04/1200Z 36.3N 74.4W 90 KT 105 MPH 36H 05/0000Z 39.4N 70.2W 80 KT 90 MPH 48H 05/1200Z 42.7N 66.0W 70 KT 80 MPH...POST-TROP/EXTRATROP 72H 06/1200Z 48.5N 58.0W 50 KT 60 MPH...POST-TROP/EXTRATROP 96H 07/1200Z 55.0N 50.0W 35 KT 40 MPH...POST-TROP/EXTRATROP 120H 08/1200Z 60.0N 45.0W 35 KT 40 MPH...POST-TROP/EXTRATROP $$ Forecaster Brown NNNN