Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 359 AM EDT Sat Sep 28 2019 Valid 12Z Sat Sep 28 2019 - 12Z Mon Sep 30 2019 ...Major winter storm to bring heavy snow, high winds, and potential blizzard conditions to the Northern Rockies... ...There is a slight risk of excessive rainfall across parts of the Central Plains into parts of the Middle Mississippi Valley with a second area over parts of the Great Basin and severe weather possible over parts of the Central Plains... ...Much below average temperatures across the West, with much above average temperatures across the East... A strong storm over the Northern Rockies will move out over the Northern Plains by Monday. This storm will be responsible for the development of an early season/major to potentially historic winter storm across portions of the Northern Rockies through Monday. This system will bring very heavy snowfall, high winds, blizzard conditions, and extreme impacts to travel to the region. Western Montana is forecast to see the brunt of the snowfall, with as much as 1 to 3 feet (locally more) possible. This system will also usher in a very cold airmass, at least for September standards, with daytime highs 20 to 30+ degrees below average. Many daily record low maximum temperature records are possible Saturday into Monday, especially across the Northern Great Basin/Rockies, and California. Meanwhile east of the Rockies, a strong upper-level ridge is expected to develop resulting in much above average temperatures from the east of the Mississippi River to the Mid-Atlantic. The possible record breaking high temperatures will be from the Central Gulf Coast to the Mid-Atlantic where widespread daytime highs in the mid to upper 80s (north) and mid to upper 90s (south) could approach or exceed record values. In the meantime, moisture will funnel northward along a front from the Central Plains to the Great Lakes. Heavy to excessive rainfall and severe weather is possible along this boundary on Saturday, from Central Plains into parts of the Middle Mississippi Valley. The hazards associated with the severe thunderstorms are frequent lightening, high wind, and large hail. The heavy rain associated with the storms will produce scattered flash flooding mainly in localized areas. In addition, persistent heavy rain will develop over parts of the Great Basin that will produce scattered flash flooding mainly in localized areas. On Sunday, the western part of this boundary should briefly stall across the Central Plains before it begins to lift northward as a warm front into the Upper Midwest. Showers and thunderstorms will develop along the front, with heavy rain and strong to severe weather possible. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php