Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 250 PM EDT Sat Oct 14 2017 Valid 00Z Sun Oct 15 2017 - 00Z Tue Oct 17 2017 ...Heavy rain expected for the Midwest and Great Lakes... ...Pattern change for the eastern U.S. by Monday morning... A developing surface low over the Midwest and strong cold front will be the main weather story across the central and eastern U.S. through the weekend and into Monday. This will herald a pattern change for the eastern half of the nation given the recent warm weather compared to October standards, with a pristine airmass settling in behind the front and making it feel truly fall-like. Ahead of the front and near the surface low, heavy rain and strong to severe thunderstorms are expected from eastern Kansas to Lower Michigan through early Sunday. Rainfall amounts of 1 to 3 inches are possible this weekend within this corridor, which includes the greater Chicago metro area. Flash flooding will be possible for those areas that have repeated rounds of thunderstorm activity. Easterly flow across Florida will bring deep moisture and instability to the peninsula. This will yield showers and thunderstorms throughout the weekend. By Monday, showers and thunderstorms will be confined mostly to South Florida and the Keys as the East Coast cold front progresses farther south. Across the western U.S., an upper level ridge will be centered over the West Coast through Monday, with a sprawling surface high across the western half of the nation. With the exception for some showers across western Washington state, this will equate to a very dry weather pattern with warm temperatures for the West Coast states and cold for the central and northern Rockies. Gusty winds will also aggravate existing fire weather concerns across California this weekend. D. Hamrick Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php