Show Selection: |
#904744 (Received by flhurricane at: 10:47 PM 26.Sep.2017) TCDAT5 Tropical Storm Maria Discussion Number 44 NWS National Hurricane Center Miami FL AL152017 1100 PM EDT Tue Sep 26 2017 Practically all of the deep convection associated with Maria is over the eastern semicircle of the circulation, and the center is exposed near the edge of the dense overcast due to moderate west-northwesterly shear. SFMR-observed surface winds from an Air Force Hurricane Hunter aircraft support a current intensity of 60 kt, although satellite classifications indicate a much weaker cyclone. Since SSTs are not expected to cool significantly along the projected path of Maria over the next couple of days, only slight weakening is forecast up to 72 hours. Later in the forecast period, the global models depict the cyclone as embedded in a frontal zone, so the system is forecast to become extratropical by day 4. Maria continues to move slowly northward along the western periphery of a subtropical ridge. In 24-48 hours, the mid-latitude westerlies should shift southward in association with a broad mid-tropospheric trough moving across eastern North America. This should cause Maria to turn east-northeastward and then accelerate ahead of the trough by late in the week. The track models are in general agreement on this scenario, however, the guidance has become less tightly clustered. This is especially true later in the forecast period, where the ECMWF is much slower than the GFS and HWRF models. The official track forecast lies between these options and is a little to the left of the previous one in the early part of the period, in deference to the ECMWF solution. KEY MESSAGES: 1. Maria is forecast to move roughly parallel to the U.S. east coast for the next day or so, bringing some direct impacts to portions of the North Carolina coast through Wednesday 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, and a storm surge warning and watch are in effect for portions of eastern North Carolina. 3. Swells generated by Maria are affecting much of the east coast of the United States. These swells are also affecting Bermuda, 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 27/0300Z 34.9N 72.9W 60 KT 70 MPH 12H 27/1200Z 35.4N 72.8W 60 KT 70 MPH 24H 28/0000Z 36.1N 72.2W 55 KT 65 MPH 36H 28/1200Z 36.5N 70.7W 55 KT 65 MPH 48H 29/0000Z 36.8N 68.0W 55 KT 65 MPH 72H 30/0000Z 39.5N 57.5W 55 KT 65 MPH 96H 01/0000Z 46.0N 39.5W 50 KT 60 MPH...POST-TROP/EXTRATROP 120H 02/0000Z 53.0N 17.0W 45 KT 50 MPH...POST-TROP/EXTRATROP $$ Forecaster Pasch |