Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 224 PM EST Fri Jan 03 2025 Valid 00Z Sat Jan 04 2025 - 00Z Mon Jan 06 2025 ...Highly impactful winter storms will affect large portions of the Lower 48 late this week into this weekend... ...Heavy lake effect snows likely through Saturday downwind of all of the Lakes, continuing Sunday downwind of Lake Ontario... ...A larger scale and high impact major winter storm to affect areas from the Northern to Central Plains, Lower Missouri Valley, Mid Mississippi Valley, Ohio Valley, Central Appalachians into the Mid-Atlantic Saturday, Sunday and Monday... ...Below to much below average temperatures to stretch from the Northern to Central Plains, eastward into the East, while temperatures remain above average west of the Rockies to the West Coast and across the Southern Plains into the Lower Mississippi Valley and central Gulf Coast... ...Severe weather and heavy rain possible Sunday afternoon/night across the Lower Mississippi Valley... A broad mid to upper level vortex centered across eastern Canada is supporting a cold weather pattern late this weekend going into the weekend across large sections of the Lower 48 from the Northern to Central Plains, eastward to the eastern U.S. While these colder than average temperatures are not expected to set any records over the next few days, it will continue to support ongoing heavy lake effect snows downwind of the Great Lakes and into the upslope of the Central Appalachians, and support a developing highly impactful winter storm that will affect areas from the Northern to Central Plains into the Lower Missouri Valley, Mid Mississippi Valley, Ohio Valley, Central Appalachians into the Mid-Atlantic Saturday, Sunday and Monday. Heavy Lake effect snows are likely to continue into Saturday downwind of all of the Great Lakes and into Sunday to the east and southeast of Lake Ontario as this cold air streams across the relatively warm lake waters. Lake effect snow warnings continue downwind of lake Erie and Ontario from northeast Ohio, across far northwest Pennsylvania, and portions of western and northwest New York State. Snow totals in these areas will likely be in the 1 to 2 foot range, creating very hazardous and extremely difficult driving conditions. While not as great, locally heavy snows also possible across portions of the Upper Peninsula of Michigan and the western portions of the Lower Peninsula of Michigan downwind of lakes Superior and Michigan. Winter storm warnings and winter weather advisories are currently in place across these areas for snowfall forecast of up to 4-6 inches. In addition, winter storm warnings and winter weather advisories are in effect in the upslope regions of the Central Appalachians from western Pennsylvania into West Virginia and far western Maryland for snow totals greater than 6 inches. Along the west coast, a storm system that has produced heavy lower elevation rains and higher elevation snows Friday from Northern California into the Pacific Northwest will continue to push inland tonight into Saturday through the Great Basin and into the Central Rockies. This system will be the primary driver for the expected widespread major winter storm from the Northern to Central Plains, Lower Missouri Valley, Mid Mississippi Valley, Ohio Valley, Central Appalachians into the Mid-Atlantic over the next few days. Through Saturday, the primary area of heavy snows will be across sections of north central to southeast Montana into northwest South Dakota where winter storm warnings and winter weather advisories are in place for snowfall totals of 4-6"+. By Saturday night into Sunday, heavy snows and significant icing will develop across the Central Plains into the Lower Missouri Valley, Mid Mississippi Valley and Ohio Valley. Snowfall totals of 8-12"+ possible from northeast Kansas, far southeast Nebraska, across northern Missouri, south central Illinois, southern Indiana, northern Kentucky and southern Ohio. Across these regions, the expected heavy snowfall may be the greatest in the past decade for some regions. To the south of the forecast heavy snow axis, significant icing is possible from southeast Kansas, across southern Missouri, far southern Illinois, much of Kentucky, far northeast Tennessee, Southwest Virginia and southern West Virginia, with ice accumulations of .10-25"+. Travel of all kinds will likely be very difficult and extremely dangerous across both the expected heavy snow and significant icing areas. By late Sunday night into Monday, the heavy snow threat from this storm will push into portions of the Central Appalachians and Mid-Atlantic. Similar to areas farther to the west, heavy snowfall totals of 6-12" are possible across central to northern West Virginia, northern Virginia, nearly all of Maryland, the District of Columbia, far southern Pennsylvania and most of Delaware with very difficult and extremely dangerous travel conditions also likely. Winter storm watches are currently in effect from the Central Plains into the Ohio Valley and will likely be extended into the Mid-Atlantic. Across the Lower 48, there are currently approximately 50 million people living in areas under some sort of winter weather warning, advisory or watch. In contrast to the widespread winter weather across much of the central to eastern U.S., above average temperatures on tap for areas to the west of the Rockies to the West Coast. Heavy snows still possible through the Central to Northern Rockies, Wasatch of Utah and the Washington and Oregon Cascades, but in general, high temperatures will be 5 to 10+ degrees above average through this upcoming weekend from the Rockies westward to the West Coast. Much above average temperatures also possible on Saturday across much of Texas and Oklahoma and on Sunday from South and east Texas into the Lower Arkansas, Lower Mississippi Valley and central Gulf coast before arctic air surges south and east by late in the weekend and brings much colder temperatures to these regions by Monday. This arctic front will also bring the threat of a line of thunderstorms moving across the Lower Mississippi Valley region Sunday afternoon/night with heavy rains, isolated flash flooding and severe weather potential. Oravec Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php