Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 359 PM EDT Tue Oct 18 2016 Valid 00Z Wed Oct 19 2016 - 00Z Fri Oct 21 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... Much of the central and eastern states with continue to have warmer than seasonal average temperature through midweek as an upper-level ridge build across the South. Afternoon highs 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 unseasonably warm stretch will end as a series of cold fronts roll through the central and eastern states over the next few days. Scattered showers and thunderstorms are forecast from the Great Lakes region eastward to the Northeast with the first front. An area of low pressure will develop along the front over the southern Plains on Wednesday, which will generate another round of showers and thunderstorms that will span from the southern Plains to the portions of the Ohio valley - periods of heavier rainfall may be possible. A second cold front will usher in noticeably cooler air into the northern-tier states today and into portions of the Great Lakes region and Ohio valley by Thursday. An upper-level disturbance is generating mountain snow and valley rain from the Pacific Northwest to the northern Rockies today, but the air will dry out some over this region during the late evening an overnight hours. An approaching frontal system is expected to spread rain across the region by late Wednesday and persisting through the end of the work week.. Campbell Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php