ZCZC MIATCDAT1 ALL TTAA00 KNHC DDHHMM HURRICANE ARTHUR DISCUSSION NUMBER 14 NWS NATIONAL HURRICANE CENTER MIAMI FL AL012014 500 AM EDT FRI JUL 04 2014 Arthur still has a well-defined eye in radar imagery, and the cloud pattern features an area of cold cloud tops wrapping around the northern and western portions of the circulation as some dry air works its way into the southern semicircle. Before the Air Force Hurricane Hunters left Arthur, they measured flight-level winds of 91 kt and SFMR winds of 82 kt, which support maintaining the initial intensity at 85 kt. The central pressure is set to 973 mb based on a measurement of 975.5 mb at an NOAA National Ocean Service station at Oregon Inlet with a wind of 35 kt. Another Hurricane Hunter aircraft will be sampling Arthur later this morning. Gradual weakening is expected today and tonight, and Arthur will complete extratropical transition by 36 hours. After passing Nova Scotia, post-tropical Arthur should weaken rapidly over the North Atlantic. Arthur is accelerating northeastward, with an initial motion estimate of 040/20, and a northeastward motion is expected to continue for the next 48 hours as Arthur recurves ahead of an advancing mid-latitude trough. The track model guidance is in good agreement in taking the center of Arthur well offshore of the U.S. mid-Atlantic coast today and southeast of New England tonight before moving over Nova Scotia in about 36 hours. After that time, Arthur is expected to continue across Newfoundland and into the North Atlantic. The NHC track forecast is near the center of the guidance envelope through 72 hours and is close to the GEFS ensemble mean at days 4 and 5. 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 04/0900Z 36.0N 75.3W 85 KT 100 MPH 12H 04/1800Z 38.4N 72.3W 80 KT 90 MPH 24H 05/0600Z 42.2N 68.0W 75 KT 85 MPH 36H 05/1800Z 45.5N 64.6W 65 KT 75 MPH...POST-TROP/EXTRATROP 48H 06/0600Z 47.5N 61.0W 55 KT 65 MPH...POST-TROP/EXTRATROP 72H 07/0600Z 53.5N 53.0W 35 KT 40 MPH...POST-TROP/EXTRATROP 96H 08/0600Z 59.0N 43.5W 30 KT 35 MPH...POST-TROP/EXTRATROP 120H 09/0600Z 63.0N 35.0W 30 KT 35 MPH...POST-TROP/EXTRATROP $$ Forecaster Brennan NNNN