After inundating Texas and Louisiana for days, Harvey will race across the Ohio Valley and northeastern United States with rain during part of the Labor Day weekend.
While Harvey is not expected to bring widespread flooding, or flooding anywhere close to the disaster in Texas, enough rain is likely to fall to bring urban and isolated flash flooding to some states farther north.
“Harvey will drift inland for the last time on Wednesday, near the Louisiana/Texas border and begin to accelerate northeastward across the interior U.S. late this week,” according to AccuWeather Hurricane Expert Dan Kottlowski.
This increase in forward speed will prevent Harvey from repeating the feet of rain which has fallen near the Gulf coast.
Harvey will transition from a tropical storm to a tropical depression then a tropical rainstorm.
“Since Harvey will remain an efficient producer of rain, a general 2-4 inches is likely to fall near and just north of its path,” Kottlowski said.
Some places will get a little more. The heaviest rain from Thursday to Friday is likely to track within 100 miles or so of the lower Mississippi and Ohio rivers.
Much of the rain from Harvey may pass south of Chicago and Detroit.
A slight north or south shift in track will affect the corridor of heaviest rain. Southeast of the track of the center of the storm, locally severe thunderstorms are possible with strong wind gusts and flash flooding.
During Saturday into Sunday, Harvey may blend with a non-tropical storm and rainfall may become more spread out as it reaches the Northeast.
A general 1-2 inches of rain is likely with locally higher amounts in the Northeast. On occasion, old tropical systems can pulse and cause much heavier rain to erupt in a small area well inland from the Gulf of Mexico or the Atlantic Ocean. This risk is greatest in hilly terrain, such as the Appalachians.
In addition to the risk of isolated urban and flash flooding, fans heading to high school and college football games on Friday and Saturday should check their local forecast and dress accordingly. The use of umbrellas may not be allowed in some stadiums.
The wet conditions on the road may slow highway travel, especially for those heading out for a getaway during the Labor Day weekend.