Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 229 PM EST Thu Jan 18 2024 Valid 00Z Fri Jan 19 2024 - 00Z Sun Jan 21 2024 ...Next arctic blast to spread across much of the central to eastern U.S.... ...Accumulating snows possible from the Mid-West into the Mid Atlantic... ...Lake effect snows increasing Friday into Saturday... ...Heavy precipitation moving into much of California for the weekend... ...Significant icing and heavy snows possible from the Cascades of Washington into eastern Washington and northeast Oregon... The next surge of arctic air, currently pushing across the Northern Plains into the Upper Mississippi Valley Thursday afternoon, will continue to surge south through the remainder of the Plains and the Mississippi Valley tonight into Friday. This cold air will then sweep into the eastern U.S. on Saturday. While not as cold as the previous arctic outbreak that produced numerous records across the Plains and Lower Mississippi Valley last week, this next surge will result in high temperatures 20 to 25 degrees below average on Friday across much of the Plains and Mississippi Valley. These 20 to 25 degree below average temperatures will persist across most of the Plains and Mississippi again on Saturday, while also spreading east into the Tennessee and Ohio Valleys. Ahead of the arctic surge, an area of low pressure moving across the Ohio Valley, Central Appalachians and the Mid-Atlantic will produce a swath of accumulating snows from the Mid-West, east into the Upper Ohio Valley, Central Appalachians and Mid Atlantic. Snowfall totals are expected to be in the light to moderate range, generally 2 to 4 inches, with some locally heavier totals over 6 inches in the terrain regions of the Central Appalachians from eastern Kentucky/Southwest Virginia into West Virginia. As the arctic air spreads across the Great Lakes on Friday and Saturday, lake effect snow showers will be increasingly widespread downwind of the Upper Lakes on Friday and the Lower Lakes by Saturday. Locally heavy snows likely across portions of the Upper Peninsula of Michigan, the western portions of the Lower Peninsula of Michigan, across northwest Indiana and from northeast Ohio, across far northwest Pennsylvania into portions of western New York State. While the central to eastern U.S. will be entrenched in much below average arctic air, much of the west from the Rockies to the West coast will see above average temperatures over the next few days. In addition, the next in the recent series of storms to move off the Pacific will bring heavy precipitation into large portions of California beginning Friday afternoon and continuing through the weekend and into early next week. The exception to above average temperatures across the west will be over the interior Pacific Northwest from north central to northeast Oregon into Washington State to the east of the Cascades. The western extent of the arctic air over the Northern Plains will remain in place across these regions. This will support potential for very dangerous icing conditions through the Columbia River Gorge from Thursday afternoon into Friday and heavy snows across the Washington Cascades as the next storm system moves off the Pacific and into the Pacific Northwest. Oravec Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php