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#904640 (Received by flhurricane at: 4:49 AM 26.Sep.2017) TCDAT5 Hurricane Maria Discussion Number 41 NWS National Hurricane Center Miami FL AL152017 500 AM EDT Tue Sep 26 2017 Maria is feeling the effects of the cool sea surface temperatures left in the wake of Hurricane Jose. Satellite imagery shows that the convective pattern is gradually losing organization, with the remaining convection in a cluster to the southeast of the center and in bands well to the east of the center. In addition, the aircraft-reported central pressure has risen to 970 mb. While there have been no observations of hurricane-force winds from the Stepped Frequency Microwave Radiometer on the NOAA Hurricane Hunter currently in the cyclone, it is likely that they still exist in areas east of the center where the airplane has not yet sampled. The initial intensity is lowered to a somewhat uncertain 65 kt based mainly on the rising central pressure since the last advisory. The combination of the cool water and moderate shear should cause Maria to gradually weaken during the forecast period, with the system now expected to weaken to a tropical storm in less than 24 h. Near the 120 h point, the cyclone is expected to merge with a frontal system and become extratropical. The new intensity forecast is an update of the previous advisory. The initial motion remains 360/6, with Maria moving northward on the western side of the subtropical ridge. A mid- to upper-level ridge over the northeastern United States to the north of the cyclone is likely to keep the motion slow for the next 36-48 h. After that, the mid-latitude westerlies are forecast to move southward across the northeastern United States and break down the subtropical ridge. This should lead to Maria turning east-northeastward and accelerating after 48 h. The track guidance is in good agreement with this scenario, and the new forecast track is close to the previous track until 120 h, where it is nudged a bit to the south. The track is also close to the center of the guidance envelope. KEY MESSAGES: 1. Maria is forecast to continue moving northward, paralleling the U.S. east coast for the next 36-48 hours, and it is likely that some direct impacts will occur along portions of the North Carolina coast beginning later today, where a Tropical Storm Warning is in effect. 2. Storm surge flooding, especially along the sound side of the North Carolina Outer Banks, is expected beginning later today, and a Storm Surge Watch has been issued for portions of eastern North Carolina. 3. Swells generated by Maria are affecting much of the east coast of the United States from Florida through southern New England. These swells are also affecting Bermuda, Puerto Rico, the northern coast of Hispaniola, the Turks and Caicos Islands, and the Bahamas. These swells are likely to cause life-threatening surf and rip current conditions. Please consult products from your local weather office for more information. FORECAST POSITIONS AND MAX WINDS INIT 26/0900Z 32.9N 73.1W 65 KT 75 MPH 12H 26/1800Z 33.7N 73.2W 65 KT 75 MPH 24H 27/0600Z 34.6N 73.1W 60 KT 70 MPH 36H 27/1800Z 35.4N 72.7W 60 KT 70 MPH 48H 28/0600Z 35.8N 71.7W 55 KT 65 MPH 72H 29/0600Z 37.0N 66.0W 55 KT 65 MPH 96H 30/0600Z 41.0N 53.0W 55 KT 65 MPH 120H 01/0600Z 48.0N 35.5W 55 KT 65 MPH...POST-TROP/EXTRATROP $$ Forecaster Beven |