Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 236 PM EST Wed Jan 15 2020 Valid 00Z Thu Jan 16 2020 - 00Z Sat Jan 18 2020 ...A powerful winter storm with areas of heavy snow and ice will cross the Northwest tonight, and drive east across the Plains and Midwest by the end of the week... ...Much warmer than normal temperatures over the Eastern U.S. will give way to a strong area of Arctic high pressure and much colder air for Thursday and Friday as a quick hitting snowstorm crosses the Northeast tonight... A very strong area of low pressure currently focused offshore of the Pacific Northwest will be advancing inland tonight and traversing the Intermountain West Thursday through early Friday. This will drive a surge of Pacific moisture which coupled with the cold air currently pooled across the interior should yield heavy snowfall for the Olympic Mountains, the Cascades and extending well south down across the Sierra-Nevada. As much as 2 to 3 feet of snow will be possible for the highest elevations going through Friday morning. Meanwhile, heavy rain is expected for the immediate coastal ranges of Washington, Oregon and central to northern California where locally a few inches of rain is expected for the event by the end of the week. This winter storm will then reorganize by late Friday out across the High Plains and aim for the Midwest by Friday evening. As it does so, moisture returning north from the Gulf of Mexico will allow a widespread area of precipitation to break out, including a swath of locally heavy snow, sleet and freezing rain from portions of the central Plains northeast through the Upper Midwest. This is expected to result in a fairly widespread area of travel difficulty over the central U.S. by Friday night, with very slippery roads and locally poor visibility. Several inches of snow can be expected with this system as it advances east. Ahead of this system though will be a significant change in temperatures across the eastern U.S. as very mild temperatures for this time of the year will give way to the arrival of an area of Arctic high pressure surging southeast down from Canada tonight and Thursday in the wake of a quick-moving storm system crossing the Great Lakes region this evening, and New England by early Thursday. A swath of heavy snow is expected with this system, with some areas over portions of northern New York and northern New England expected to receive in excess of 6 inches of snow by midday Thursday. The very cold air in the wake of this storm will settle in through Friday, but then begin to modify and pull away by this weekend as the associated area of high pressure moves off the East Coast ahead of the approaching winter storm crossing the Plains and Midwest. Orrison Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php