US Day 3-7 Hazards Outlook NWS Weather Prediction Center College Park MD 253 PM EST Tue Feb 18 2020 Valid Friday February 21 2020 - Tuesday February 25 2020 Hazards: - Heavy precipitation across portions of the Pacific Northwest, Sun-Mon, Feb 23-Feb 24. - Heavy rain across portions of the Central Plains, the Lower Mississippi Valley, the Tennessee Valley, the Middle Mississippi Valley, the Mid-Atlantic, the Southern Appalachians, the Southeast, the Southern Plains, and the Ohio Valley, Sun-Mon, Feb 23-Feb 24. - Heavy snow across portions of the Pacific Northwest, the Northern Rockies, and the Northern Great Basin, Sun-Mon, Feb 23-Feb 24. - Heavy snow across portions of the Central Plains, the Central Rockies, the Central Great Basin, the Southern Rockies, the Southern Plains, and the Southwest, Sat-Sun, Feb 22-Feb 23. - Flooding possible across portions of the Southeast. - Flooding occurring or imminent across portions of the Lower Mississippi Valley, the Tennessee Valley, the Middle Mississippi Valley, the Mid-Atlantic, the Southeast, the Pacific Northwest, and the Ohio Valley. - Flooding likely across portions of the Southeast and the Ohio Valley. - Much below normal temperatures across portions of the Central Plains, the Central Rockies, the Central Great Basin, the Northern Plains, the Northern Rockies, the Southern Rockies, the Northern Great Basin, the Southern Plains, and the Southwest, Mon-Tue, Feb 24-Feb 25. - Much below normal temperatures across portions of the Southeast, the Mid-Atlantic, the Southern Appalachians, and the Tennessee Valley, Fri-Sat, Feb 21-Feb 22. - Much below normal temperatures across portions of the Northeast, Fri, Feb 21. - Heavy precipitation across portions of the Alaska Panhandle and mainland Alaska, Fri, Feb 21 and Mon, Feb 25. - Much below normal temperatures across portions of mainland Alaska, Fri-Sat, Feb 21-Feb 22. Detailed Summary: The medium range period (Friday, Feb. 21 to Tuesday, Feb. 25) will feature a semi-active pattern as two systems enter the western U.S. and traverse across the country. The first area of concern will come from a cut off low entering the Southwest. This will bring areas of rain and heavy mountain snow to portions of Arizona and the southern Rockies beginning on Saturday and lasting through the weekend. By Sunday, an area of surface low pressure is forecast to develop across the Southern Plains. Heavy rain will be possible ahead of this low and along an associated warm front on Sunday and Monday. Total rainfall amounts of 1 to 2 inches could lead to flooding concerns from the Southern Plains to the Southeast, particularly across areas currently enduring flooding from Mississippi to northern Georgia. This system is forecast to exit the East Coast by Tuesday, with the possibility of light snowfall across the Interior Northeast. The next area of unsettled weather to enter the U.S. will approach the Pacific Northwest on Sunday. Heavy coastal rain and mountain snow is likely across the Olympic and Cascade mountain ranges on Sunday and Monday. This heavy snow will also impact portions of the northern Great Basin and Northern Rockies during this time frame. Uncertainty increases with this system by Tuesday as it enters the central United States, therefore no significant hazards are currently forecast. Well below normal temperatures, thanks to a large area of arctic high pressure, are forecast across portions of the East to start the medium range period. Low temperatures are forecast to be around 10 to 20 degrees below average across northern New England on Friday, which equates to temperatures between 0 and minus 20. Meanwhile, cold temperatures will also be found across the Southeast Friday and Saturday. Here, temperatures could reach below freezing as far south and northern Florida. Considering reports of trees and plants getting off to an early bloom in this area, a hard freeze could pose issues. Across the Rockies, an upper-level trough is expected to set up over the region and lead to temperatures well below average for this time of year. These cold temperatures could linger later into next week. Hazardous weather across Alaska will be confined to the southern coastline and northern Panhandle. A low pressure system over the northern Gulf of Alaska will funnel heavy rain and snow on Friday across the Panhandle and southern Mainland. By Tuesday, a second system could bring another round of heavy precipitation to similar areas. Meanwhile, temperatures well below normal are expected on Friday and Saturday across central and western portions of the state. This cold air is forecast to moderate by Sunday. Snell