Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 346 PM EDT Fri Jul 31 2020 Valid 00Z Sat Aug 1 2020 - 00Z Mon Aug 3 2020 ...Hurricane Isaias, a slow moving front, and very hot conditions out West will be the main weather stories this weekend... The main thing that will be making weather headlines this weekend will be Hurricane Isaias and its approach toward the Southeast U.S. from the Bahamas. It is currently a category one hurricane with a general northwest trajectory, and it is expected to be very close to the east coast of Florida by Saturday night and into Sunday, based on the latest National Hurricane Center track. As a result, hurricane watches and tropical storm warnings are now in effect for portions of the eastern Florida Peninsula, and revisions to these watches and warnings are likely through Saturday as the eventual track and intensity become more certain. Preparations for hazardous weather conditions should already be underway. Additional information pertaining to this storm is available from the National Weather Center and local forecast offices. Unsettled weather conditions are expected to continue across much of the Ohio Valley, Appalachians, and Great Lakes region as a slow moving surface low and cold front focus moisture with enhanced lift and instability. There is both a Slight Risk of severe thunderstorms and flash flooding on Saturday from the western Ohio Valley to the northern Mid-Atlantic region. Some locations may get 2 to 4 inches of rainfall through Sunday evening. Behind the front across much of the Plains and Upper Midwest will be more refreshing air mass, with temperatures running 10 to perhaps 20 degrees below normal for this time of year, with the coolest readings where extensive cloud cover exists. Across the western U.S., an upper level ridge is expected to result in continued hot and dry conditions, especially for the lower elevations of the Desert Southwest where expected high temperatures in the 110s should continue. Excessive Heat Warnings and Heat Advisories are in effect for much of the Great Basin, Desert Southwest, and southern parts of California. Fire weather concerns also exist owing to the dry conditions, with the greatest concerns of elevated fire danger across the Desert Southwest on Saturday based on the Storm Prediction Center outlook. Hamrick Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php