ZCZC MIATCDAT1 ALL TTAA00 KNHC DDHHMM HURRICANE EDOUARD DISCUSSION NUMBER 18 NWS NATIONAL HURRICANE CENTER MIAMI FL AL062014 500 PM AST MON SEP 15 2014 Edouard is approaching category 3 strength. The eye of the hurricane has become circular this afternoon, and deep convection has increased in the eyewall. Flight-level and SFMR winds, as well as dropsonde data from two NOAA reconnaissance aircraft, indicate that maximum winds are near 95 kt and the minimum pressure has decreased to 963 mb. Radar images from one of the NOAA aircraft indicate that the convective pattern is quite symmetric. The hurricane could strengthen some more during the next day or so while both the atmospheric and oceanic conditions remain favorable. After that time, however, cooler water, drier air, and a notable increase in shear should cause Edouard to weaken at a steady pace. The cyclone is forecast to transition to a post-tropical cyclone by day 4 when it is expected to be over very cold water and interacting with a frontal zone. The NHC intensity forecast is at the high end of the model guidance for the next 36 hours, and then follows the intensity model consensus, IVCN. Edouard continues to move northwestward but at a slightly slower pace than earlier, 305/11 kt. Water vapor imagery and satellite- derived winds indicate that the western side of the ridge that has been steering the hurricane is eroding in response to a trough over the western Atlantic. This change in the large-scale pattern should cause Edouard to turn northward during the next 24 hours. By late Tuesday and Wednesday, the system is expected to accelerate northeastward and then eastward when it becomes embedded in the mid-latitude westerlies. A slow down and a turn toward the southeast is predicted by the end of the forecast period when the weakening system is steered by the flow on the west side of a deep-layer low over the northeast Atlantic. The NHC track forecast has again been nudged to the left to come into better agreement with the latest guidance. FORECAST POSITIONS AND MAX WINDS INIT 15/2100Z 28.0N 56.5W 95 KT 110 MPH 12H 16/0600Z 29.5N 57.3W 105 KT 120 MPH 24H 16/1800Z 31.6N 57.4W 105 KT 120 MPH 36H 17/0600Z 34.0N 55.7W 95 KT 110 MPH 48H 17/1800Z 36.8N 52.6W 85 KT 100 MPH 72H 18/1800Z 40.6N 43.3W 70 KT 80 MPH 96H 19/1800Z 40.5N 37.0W 50 KT 60 MPH...POST-TROPICAL 120H 20/1800Z 39.5N 33.5W 35 KT 40 MPH...POST-TROPICAL $$ Forecaster Cangialosi NNNN