Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 341 PM EDT Sat Sep 28 2019 Valid 00Z Sun Sep 29 2019 - 00Z Tue Oct 01 2019 ...Major winter storm to bring heavy snow and high winds to parts of the Northern Rockies... ...Much below average temperatures across the Northwest, with much above average temperatures east of the Rockies... ...Heavy rainfall and severe weather possible across parts of the north and central U.S. through Monday... A major to potentially historic early season winter storm is ongoing today across parts of the Northern Rockies as an anomalous upper level low pressure system rotates aloft. Heavy snowfall, strong winds, and potential blizzard conditions will continue across the Northern Rockies through Sunday. Widespread winter storm warnings and advisories are in effect from the interior Pacific Northwest through western Montana and northwest Wyoming. As much as 1 to 3 feet (locally more) of snowfall is possible, especially across western Montana which would create dangerous to impossible travel conditions across the region. This system will also usher in a very cold airmass, at least for September standards, with daytime highs 20 to 30+ degrees below average across much of the Northwest. Many daily record low maximum temperature records are possible through Monday, especially across the Northern Great Basin/Rockies, and California. Meanwhile east of the Rockies, strong upper-level ridging will continue to promote much above average temperatures from the Plains to the East Coast. The core of the heat will be from the Southeast to the Ohio Valley where widespread daytime highs in the mid to upper 80s (north) and mid to upper 90s (south) could approach or exceed record values. This stretch of record warmth across the East is expected to last through the short range period and into the middle to end of next week as well. Warm, dry, and gusty conditions across eastern Colorado will also bring critical fire weather conditions where red flag warnings are currently in effect. In between the anomalous Western trough and Eastern Ridge, moisture funneling into the central U.S. should focus along a frontal boundary as it begins to lift northward through the central Plains. Through tonight, the best chance for heavy to locally excessive rainfall and severe thunderstorms are possible, mainly from eastern Kansas to northern Illinois. By Sunday into Monday, the focus shifts to a developing surface low ejecting out of the Rockies. To the north of the low, heavy to locally excessive rainfall is expected across the northern High Plains into the Upper Mississippi Valley, while in the warm sector south of the low, there is a threat for severe weather. SPC shows a slight risk for severe thunderstorms for tomorrow across parts of the north-central Plains. Santorelli Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php