Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 253 PM EST Thu Feb 27 2020 Valid 00Z Fri Feb 28 2020 - 00Z Sun Mar 01 2020 ...Very heavy lake-effect snow event downwind from Lake Erie and Lake Ontario... ...Temperatures will be 10 to 15 degrees below average from the Mississippi Valley to mostly the East Coast... Cold air and a deep upper-level trough over the Great Lakes and with the major Great Lakes being ice free lake-effect snow will develop downwind from all the Great Lakes and into the Central Appalachians through Saturday afternoon. The lake-effect will continue downwind from Lake Erie and Lake Ontario through Saturday evening. In addition, blizzard warning are up downwind of the Lakes. Downwind from Lake Ontario will reach up to 48 inches by the end of the event. The Upper Great Lakes will precondition the air that will flow over the Lower Great Lakes. Over the Northern Rockies to the Northern High Plains, low pressure will bring a quick round of rain or mixed precipitation across the Central Plains through Thursday evening. Meanwhile, moisture from the next Pacific system is forecast to reach the Pacific Northwest later on Friday, and could reach the Intermountain West by Friday night as snow and snow showers develop over the area by Friday night. Temperatures will mainly be colder than average for the eastern half of the country in contrast with warmer than average reading for the western half through Saturday morning. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php