Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 305 PM EST Sat Nov 30 2019 Valid 00Z Sun Dec 01 2019 - 00Z Tue Dec 03 2019 ...Heavy snow for the Upper Mississippi Valley/Upper Great Lakes and the Northeast with rain/freezing rain over parts of the Great Lakes into Northeast... ...Heavy snow for the Sierra Nevada... ....There is a slight risk of severe thunderstorms over parts of the Lower Mississippi Valley/Tennessee Valley... A storm over the Middle Missouri Valley will move eastward to off the Northeast Coast by Monday evening. The system will produce heavy snow over parts of the Upper Mississippi Valley/Upper Great Lakes on Saturday evening into Sunday evening. In addition, rain/freezing rain and sleet will develop over parts of the Northern Lower Peninsula of Michigan overnight Saturday into Sunday morning. As the storm moves eastward, rain/freezing rain will develop over parts of the Northern Mid-Atlantic, late on Saturday night, that will move into parts of Southern New England on Sunday evening into Monday. On Sunday afternoon into Monday evening, heavy snow will develop over parts of the Northeast. Difficult to dangerous driving conditions will be associated with the winter weather over the Upper Midwest into the Northeast. Additionally, the storm will produce showers and thunderstorms over parts of the Tennessee and Lower/Middle Mississippi Valleys overnight Saturday into Sunday morning with some becoming severe. The showers and thunderstorm will move into parts of the Southeast and Southern Mid-Atlantic on Sunday moving off the Southeast/Southern Mid-Atlantic Coast by Sunday night. Rain will also develop over parts of the Middle Mississippi Valley into parts of the Great Lakes/Ohio Valley overnight Saturday into Sunday morning. The rain will turn over to snow overnight Sunday. Rain will develop over parts of the Mid-Atlantic on Sunday, ending overnight Sunday for the Southern Mid-Atlantic. The rain will continue over parts of the Northern Mid-Atlantic and changing over to snow with some rain near the coast on Sunday evening into Monday. Farther south, rain and thunderstorms are forecast along and ahead of the cold front associated with this low. Locally heavy rainfall is possible in parts of the Tennessee and Ohio Valleys today. Additionally, severe weather is a threat, particularly in the Lower Mississippi and Tennessee Valleys, where the Storm Prediction Center has delineated a Slight Risk of severe weather today and tonight. Rain should spread into southern parts of the Mid-Atlantic and Southeast later today into Sunday. Warmer than average temperatures are expected east of this cold front. Along with the original low pressure system, another surface low will develop on Sunday in the Mid-Atlantic and move as a nor'easter Sunday night and into Monday. Mixed precipitation should spread into the northern Mid-Atlantic and Northeast this weekend due to both these lows. Freezing rain will be the initial threat for portions of Pennsylvania and New York, as well as the Central Appalachians, with ice accumulations over a tenth of an inch possible in some areas. Snowfall amounts in the Northeast are currently forecast to be 4 to 8 inches from parts of New York, southern Vermont and New Hampshire, and Massachusetts through Sunday night, with more expected on Monday. Travel impacts can be expected on this busy travel weekend. Upper-level energy over the Eastern Pacific and a couple of frontal systems will lead to an atmospheric river/plume of moisture entering California today and persisting through the weekend. More precipitation is thus expected for the West Coast, in the form of rain in lower elevations and snow in higher elevations. Some flooding is possible in parts of Northern California, especially for areas with burn scars. Meanwhile, the Sierra Nevada could once again see snowfall measured in feet. Lighter snow should spread into the Intermountain West Sunday. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php