From the National Weather Service:
Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 309 AM EST Sat Nov 30 2019 Valid 12Z Sat Nov 30 2019 – 12Z Mon Dec 02 2019 …Heavy snow is forecast for the north-central to northeastern U.S., along with freezing rain and high winds… …Rain and thunderstorms, some severe, are expected farther south in the Lower Mississippi, Tennessee, and Ohio Valleys… …Another system approaching the West Coast will cause more precipitation there this weekend… A low pressure system will move eastward across the Central Plains and Middle Mississippi Valley today and tonight and into the Great Lakes region by Sunday. North of the low, heavy snow is forecast to spread across the Northern/Central Plains and Upper Mississippi Valley today and tonight, ending there on Sunday. A large swath of snow totals from 6 to 12 inches are expected from the Northern Plains into Minnesota, Wisconsin, and Upper Michigan, and locally higher snow amounts above 18 inches are possible. Precipitation could start as light freezing rain in the Upper Mississippi Valley and Upper Great Lakes before transitioning to snow, with less than a tenth of an inch of ice expected to accumulate. High winds are expected, and Blizzard Warnings are in effect for parts of the Northern/Central Plains. Dangerous conditions will make travel almost impossible. High Wind Warnings and Wind Advisories are in effect for the Central/Southern Plains, south of the snow impacts. 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.
