Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 339 PM EDT Mon Aug 17 2020 Valid 00Z Tue Aug 18 2020 - 00Z Thu Aug 20 2020 ...Record heat expected to continue across the western U.S into midweek... ...Relatively cool conditions expected from the Plains to the East Coast with ares of showers and storms from the Mississippi Valley to the East Coast... A strong mid/upper-level ridge of high pressure will persist across the southwestern U.S. into midweek as it very slowly weakens. The ridge will keep record high temperatures fairly widespread both Tuesday and Wednesday across the Southwest and the Great Basin, becoming a little less numerous each day. High temperatures will soar well beyond the century mark through Wednesday, with many locations surpassing 110 deg F, and perhaps isolated spots exceeding 120 deg. Additionally, the hot and dry conditions will lead to elevated/critical fire danger, especially from the Great Basin to portions of the northern Intermountain West. Isolated afternoon/evening thunderstorms will be a possibility, although they will be few/far between, and are not expected to significantly reduce the heat or the fire risk. Farther east, conditions will be quite different, with an upper-level trough forecast to cross the Great Lakes and Northeast. This system will be accompanied by near/below average temperatures across the majority of the eastern half of the nation. A cold front associated with the upper trough will bring a round of showers and thunderstorms to the Northeast tonight into Tuesday, with a secondary front expected to bring showers and storms to portions of the Ohio Valley. The trailing end of this frontal system is forecast to linger from the Mid-Atlantic to the Southeast/Gulf Coast through Wed as a few weak waves of low pressure traverse the boundary. This front will will keep scattered to numerous showers and thunderstorms in place from the Southeast to portions of the Mid-Atlantic through Wednesday. Ryan Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php