Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 343 AM EDT Fri Sep 27 2019 Valid 12Z Fri Sep 27 2019 - 12Z Sun Sep 29 2019 ...Early season heavy snow and strong winds likely for the Northern Rockies... ...There is a slight risk of excessive rainfall over parts of the Great Lakes into the Middle Mississippi Valley/Central Plains... ...There is a slight risk of severe thunderstorms over parts of the Middle Mississippi Valley into the Central Plains... ...Temperature will be 10 to 20 degrees above average over parts of the Ohio Valley to the Southern Plains, while temperatures will be 10 to 20 degrees below average over parts of the Pacific Northwest into the Northern Rockies... A front extending from parts of the Upper Great Lakes/Upper Mississippi Valley southwestward to the Southern Plains will move eastward off the Northeast/Mid-Atlantic Coast by Sunday. Showers and thunderstorms will develop along and ahead of the boundary with some of the storms becoming severe. The major hazards associated with the storm are frequent lightening, gusty/damaging wind, and large hail. Likewise, the heavy rain associated with these storm may produce scattered, mainly localized flash flooding on Friday into Saturday. Overnight Saturday, the showers and thunderstorms will move off the Northeast/Mid-Atlantic Coast. Showers and thunderstorms will also develop over parts of the Middle Mississippi Valley into the Southern Plains Saturday into Sunday. Meanwhile, a developing storm along a front over the Northern Rockies will produce snow over parts of the area starting overnight Friday and continuing into Sunday that will expand into parts of the Northern High Plains and parts of the Northern Intermountain Region/Great Basin. The hazards with this system will be heavy snow, strong wind producing blizzard conditions, and dangerous wind chill temperatures of zero to 10 degrees above zero. These hazards will in turn produce downed power lines with power outages and tree damage. The temperatures will be below average over parts of the Pacific Northwest, Great Basin, California, into the Northern Rockies and Northern High Plains. In contrast, temperatures will be much above average over parts of the Central to Southern Plains into the East. While the worst winter weather is expected over the Northern Rockies, record low maximum temperatures are possible Friday and especially Saturday across the Pacific Northwest, Northern Great Basin, and California. The opposite is forecast from the Central to Southern Plains into the East. Widespread much above average temperatures are forecast across the Southeast, Tennessee Valley, Ohio Valley and Mid Atlantic. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php