Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 314 AM EDT Tue Oct 18 2016 Valid 12Z Tue Oct 18 2016 - 12Z Thu Oct 20 2016 ...Well above average temperatures expected through Wednesday for much of the central and eastern U.S... ...Mountain snow and valley rain expected from the Northwest to the northern Rockies today... A building upper-level ridge of high pressure from the southern plains to the Southeast will result in continued above average temperatures across much of the central and eastern U.S. today and Wednesday. High temperatures are forecast to be 10 to 20 degrees above average. Temperatures will rise into the 80s for much of the Mid-Atlantic and portions of the Northeast, with 90s from portions of Texas to the lower Mississippi valley. The October hot spell will be broken by a series of cold fronts that will sweep across the central and eastern U.S. through the short range. The first cold front will move across the Great Lakes, Ohio valley, and portions of the Northeast today, bringing scattered showers and thunderstorms. A second area of low pressure will develop along this front across the southern plains on Wednesday, which will spread scattered to numerous showers and thunderstorms from the southern plains to the Ohio valley. Some of these showers and storms could produce locally heavy rainfall. A second cold front, the leading edge of a much cooler autumn air mass, will move across the Midwest today and Wednesday, and into the Ohio valley by Thursday. Farther west, an upper-level disturbance will bring mountain snow and valley rain from the Pacific Northwest to the northern Rockies today. The Pacific Northwest will dry out for a brief period from Tuesday night into Wednesday morning before another frontal system spreads rain back into the region by late Wednesday. Ryan Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php