Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 257 PM EST Tue Dec 24 2019 Valid 00Z Wed Dec 25 2019 - 00Z Fri Dec 27 2019 ...Heavy snow for mountains of Southern California... ...Temperatures will be 15 to 30 degrees above average over parts of the Upper/Middle Mississippi Valley into the Ohio/Tennessee Valley and Southern/Central Plains... ...There is a slight risk of excessive rainfall over parts of Southern California... An upper-level trough over the West Coast will strengthen as an upper-level low develops overnight Christmas. Snow and lower elevation rain will develop over parts of the Southwest northward into the Northern Intermountain Region on Tuesday evening, Christmas Eve. Lingering snow showers will persist for the Rockies On Christmas. Lower elevation rainfall may exceed a quarter to half an inch over portions of Arizona, which may lead to localized flooding. Heavier amounts are likely in the favored terrain areas (which will fall as snow with levels lowering to about 5000-6000ft). On Christmas, rain heavy at times will develop over parts of Southern California with snow over the higher elevations of the mountains. The rest of the lower 48 will see relatively dry and mild conditions as the Southeast system departs the coast. A frontal boundary will waver over the Central Plains through the Corn Belt and Great Lakes into the Mid-Atlantic. Southerly flow to the south of the boundary will bring well above normal temperatures to the areas along I-70 between western Kansas to the Appalachians. Record highs are possible on Christmas Day around St. Louis in the lower 60s. Below normal temperatures are forecast for much of the Southwest behind the cold front, only in the upper 50s and low 60s for southern California and the lower deserts of Arizona. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php