Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 358 AM EDT Fri Apr 17 2020 Valid 12Z Fri Apr 17 2020 - 12Z Sun Apr 19 2020 ...Accumulating wet snow to stretch from the Ohio Valley/Great Lakes region to parts of the Northeast through early Saturday... ...Thunderstorm threat increases for the Southern Plains Saturday and moves into the Southeast Sunday... ...Temperatures forecast to be 15 to 25 degrees below normal for portions of the Plains, Mississippi Valley, and Great Lakes today... A low pressure system is forecast to move northeastward across the Ohio Valley and into the Northeast through early Saturday before moving offshore and strengthening over the Atlantic. North of this low, anomalously cold air will lead to the potential for springtime snow across northern portions of the Ohio Valley and the Great Lakes region, spreading into the Northeast. Highest snowfall amounts over 6 inches are expected in the Northern Appalachians into the Catskills and highest elevations of the Berkshires. Farther south, rain and storms are possible along the cold front associated with the low pressure system, across the Tennessee Valley and Southeast Friday toward the Mid-Atlantic by Friday night into Saturday. Rainfall totals will generally remain light with the progressive nature of the precipitation. In the West, upper-level energy moving into California could cause locally heavy rainfall for the central part of the state on Friday. By Saturday into Sunday, the back end of the front at the surface lifting north plus the upper-level energy moving eastward across the Southwest should combine to cause an increasing threat for rain and thunderstorms in the Southern Plains to Lower Mississippi Valley Saturday. Thunderstorm hazards are forecast to ramp up significantly for the Southeast on Sunday, with a Moderate Risk of flash flooding in place along with an Enhanced Risk for severe weather. Near average or colder than average temperatures are forecast for much of the country today, though the Northwest and southern Florida should be above normal. The most anomalously cool temperatures today are expected from the Southern/Central Plains, Middle Mississippi Valley, and into the Upper Ohio Valley into the Great Lakes region. Record low temperatures could occur across the Central High Plains, and Freeze Warnings and Frost Advisories are in effect for portions of the Central Plains, Ohio Valley, and the Mid-Atlantic. Temperatures should moderate some on Saturday, but cool conditions are still expected from the Southern Plains northeastward to the Northeast, over California and the Southwest, and moving into the Northern High Plains behind a cold front--which should have some light precipitation associated with it as well. Tate Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php