je.st
news
Hurricane Maria Forecast Discussion Number 42
2017-09-26 16:41:40| National Hurricane Center (Atlantic)
Issued at 1100 AM EDT Tue Sep 26 2017 000 WTNT45 KNHC 261441 TCDAT5 Hurricane Maria Discussion Number 42 NWS National Hurricane Center Miami FL AL152017 1100 AM EDT Tue Sep 26 2017 The satellite presentation of Maria has continued to slowly degrade over the past 24 hours, as deep convection is now confined to the southeastern portion of the circulation. Peak surface wind estimates from the Stepped Frequency Microwave Radiometer on the reconnaissance aircraft have been around 60 kt both overnight and this morning, but due to sampling considerations for such a large wind field the initial wind speed is held at 65 kt for this advisory. Cool waters and moderate west-northwesterly shear are expected to cause a gradual decrease in intensity over the next couple of days, and Maria is forecast to weaken to a tropical storm later today or tonight. Little change in strength is expected later in the period while Maria accelerates east-northeastward and begins to interact with a frontal boundary over the north Atlantic. Maria continues to move slowly northward around the western side of a subtropical ridge. A mid- to upper-level ridge over the northeastern United States to the north of Maria is likely to keep the cyclone's forward motion slow for the next 24-36 h. After that time, a mid-latitude trough moving across the Great Lakes region is expected to lift Maria east-northeastward or northeastward at an increasing forward speed. The track guidance remains in good agreement on the scenario but there continue to be large speed differences after 48 hours. The new official forecast is a little slower than the previous one at days 3-5 to be more in line with the various consensus aids. KEY MESSAGES: 1. Maria is forecast to continue moving northward, paralleling the U.S. east coast for the next 36 hours, and will likely bring 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 26/1500Z 33.6N 73.1W 65 KT 75 MPH 12H 27/0000Z 34.3N 73.1W 60 KT 70 MPH 24H 27/1200Z 35.1N 73.0W 60 KT 70 MPH 36H 28/0000Z 35.7N 72.4W 55 KT 65 MPH 48H 28/1200Z 36.1N 70.9W 55 KT 65 MPH 72H 29/1200Z 37.6N 63.6W 55 KT 65 MPH 96H 30/1200Z 42.5N 49.5W 55 KT 65 MPH 120H 01/1200Z 50.5N 30.0W 50 KT 60 MPH...POST-TROP/EXTRATROP $$ Forecaster Brown
Tags: number
discussion
maria
forecast
Category:Transportation and Logistics