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#904570 (Received by flhurricane at: 4:43 PM 25.Sep.2017) TCDAT5 Hurricane Maria Discussion Number 39 NWS National Hurricane Center Miami FL AL152017 500 PM EDT Mon Sep 25 2017 Maria`s coldest cloud tops and deepest convection continue to be over the far eastern and northern portions of the circulation, but a small area of convection has re-developed near the center this afternoon. SFMR data from a NOAA aircraft investigating Maria indicate that the maximum winds remain near 70 kt, and that the area of hurricane-force winds extends about 90 nm from the center over the eastern semicircle. Maria continues its slow northward trek. A slow northward motion should continue for another couple of days as Maria moves around the western side of a subtropical ridge over the western Atlantic, but the forward speed is atypically slow due to ridging over the northeastern United States. A deep mid-latitude trough will be moving into the northeastern U.S. late this week, which is expected to cause Maria to accelerate northeastward after 72 hours. The track guidance remains tightly clustered through the first 48 to 72 hours, but there are still some speed differences beyond that time. The NHC forecast track lies near the middle of the guidance envelope through 72 h, and is close to the various consensus aids late in the period. Cooler waters, moderate westerly shear, and dry air are expected to cause a gradual decrease in wind speed over the next few days. However, Maria is likely to remain a strong cyclone throughout the forecast period. Extratropical transition is likely to begin in 96 h with Maria completing this process near the end of the forecast period. KEY MESSAGES: 1. Maria is forecast to continue moving northward, paralleling the U.S. east coast, and it is likely that some direct impacts will occur along portions of the North Carolina coast beginning Tuesday, where a Tropical Storm Warning is in effect. 2. Storm surge flooding, especially along the sound side of the North Carolina Outer Banks, is possible beginning on Tuesday, 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 25/2100Z 31.7N 73.1W 70 KT 80 MPH 12H 26/0600Z 32.5N 73.2W 65 KT 75 MPH 24H 26/1800Z 33.5N 73.2W 65 KT 75 MPH 36H 27/0600Z 34.4N 73.1W 60 KT 70 MPH 48H 27/1800Z 35.3N 72.8W 60 KT 70 MPH 72H 28/1800Z 36.3N 69.6W 60 KT 70 MPH 96H 29/1800Z 38.8N 60.5W 60 KT 70 MPH 120H 30/1800Z 45.0N 45.0W 60 KT 70 MPH...POST-TROP/EXTRATROP $$ Forecaster Brown |