Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 251 AM EST Thu Nov 21 2019 Valid 12Z Thu Nov 21 2019 - 12Z Sat Nov 23 2019 ...Heavy mountain snow for parts of the Desert Southwest, Great Basin, Southern and Central Rockies... ...Heavy snow possible across portions of the Upper Mississippi Valley and Upper Great Lakes... ...Moderate to heavy rainfall expected through the end of the week across south-central U.S... An upper-level low tracking across the Southwest and into the Southern/Central Rockies will provide ample lift and instability to help generate moderate to heavy precipitation--primarily in the form of snow in the areas of elevated terrain. Surface low pressure traveling along the sprawling cold front over the southern tier of the country will provide focus for scattered to widespread rain to track across the Southern/Central Plains, Lower Mississippi Valley and into the Tennessee Valley by this weekend. Daily totals of 1 to 2 inches are expected along with an increased potential for flash flooding, WPC has a Marginal Risk for excessive rainfall across portions of the South through Sunday morning. To the north, an area of low pressure lifting to the northeast through the Great Lakes region Thursday will drag a cold front with it through the Northeast on Friday and offshore by late Friday night/early Saturday. Snow, which at times may be heavy, will move across the Upper Mississippi Valley in through the Upper Great Lakes region. Generally, amounts are expected to be light across the Northeast. Campbell Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php