US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
322 PM EST Wed Feb 20 2019
 
Valid Saturday February 23 2019 - Wednesday February 27 2019
 
Hazards:
Heavy precipitation across portions of California and the Pacific Northwest, Sun-Wed, Feb 24-Feb 27.
Heavy rain across portions of the Southeast, the Southern Appalachians, the Lower Mississippi 
Valley, the Southern Plains, and the Tennessee Valley, Mon-Tue, Feb 25-Feb 26.
Heavy rain across portions of the Mid-Atlantic, the Lower Mississippi Valley, the Central 
Appalachians, the Tennessee Valley, the Middle Mississippi Valley, the Northeast, the Southern 
Appalachians, and the Ohio Valley, Sat, Feb 23.
Heavy snow across portions of California, the Central Great Basin, the Pacific Northwest, and the 
Northern Great Basin, Sat-Wed, Feb 23-Feb 27.
Heavy snow across portions of the Central Plains, the Middle Mississippi Valley, the Great Lakes, 
the Upper Mississippi Valley, and the Northern Plains, Sat-Sun, Feb 23-Feb 24.
Heavy snow across portions of the Northeast, Sun, Feb 24.
Severe weather across portions of the Lower Mississippi Valley, the Tennessee Valley, the Middle 
Mississippi Valley, the Southeast, the Southern Plains, and the Ohio Valley, Sat, Feb 23.
Flooding possible across portions of the Lower Mississippi Valley, the Central Appalachians, the 
Tennessee Valley, the Middle Mississippi Valley, the Mid-Atlantic, the Southern Appalachians, the 
Southeast, and the Ohio Valley.
Flooding occurring or imminent across portions of the Middle Mississippi Valley, the Lower 
Mississippi Valley, the Ohio Valley, and the Tennessee Valley.
High winds across portions of the Central Plains, the Middle Mississippi Valley, the Great Lakes, 
the Ohio Valley, and the Upper Mississippi Valley, Sat-Mon, Feb 23-Feb 25.
Much below normal temperatures across portions of the Central Plains, the Northern Plains, the 
Great Lakes, the Northern Rockies, the Middle Mississippi Valley, the Northern Great Basin, the 
Upper Mississippi Valley, and the Southern Plains, Sat-Wed, Feb 23-Feb 27.
Much below normal temperatures across portions of the Southern Rockies, the Central Rockies, the 
Central Great Basin, and the Southwest, Sat-Sun, Feb 23-Feb 24.
Enhanced wildfire risk across portions of the the Southern Plains, Sat, Feb 23.
Heavy precipitation across portions of mainland Alaska and the Aleutians, Sat-Mon, Feb 23-Feb 25.
High winds across portions of mainland Alaska and the Aleutians, Sat-Sun, Feb 23-Feb 24.
High winds across portions of mainland Alaska and the Aleutians, Sun-Mon, Feb 24-Feb 25.
Much above normal temperatures across portions of mainland Alaska, Sat-Wed, Feb 23-Feb 27.
High significant wave heights for coastal portions of the Aleutians, Mon-Tue, Feb 25-Feb 26.
 
Detailed Summary:

The biggest threat during the medium range will be a significant winter storm moving from the 
Plains to the Midwest and Great Lakes this weekend. Heavy accumulating snowfall is likely from 
portions of the Central Plains to the Upper Great Lakes, and combined with strong/gusty winds, will 
lead to potential blizzard conditions for some locations. As the low lifts into southeast Canada by 
the end of the weekend, it may also clip far northern New England with heavy snows as well. Farther 
south, heavy rains at the end of the short range period will linger into the very beginning of the 
medium range period across the Tennessee/lower Ohio Valleys into the Mid-Atlantic. SPC has also 
highlighted a chance of severe thunderstorms across the lower Mississippi Valley and into the 
Tennessee Valley as well. As this system initially lifts into the Plains on Saturday, warm, dry, 
gusty conditions on the backside of it could result in enhanced fire weather conditions, with SPC 
showing a small area in western Texas. At the end of the period, a warm front lifting northwards in 
the Gulf of Mexico will bring rounds of heavy rainfall to much of the Central Gulf Coast into the 
Southeast next Tuesday and Wednesday. 

Meanwhile, the western U.S. will be dominated by a long-standing wintry upper trough through much 
of the medium range period. This will result in unsettled weather across parts of the Northwest and 
Intermountain West. The best chance for heavy snowfall will be in the Cascades into the northern 
Sierra with additional rounds of heavy rain/mountain snows also possible across parts of northern 
California and southwest Oregon. Temperatures across the region appear to be well below normal 
across the Four Corners region (mainly just this weekend), with temperatures remaining below normal 
through the entire period from the Northwest to the northern and central Plains. The core of the 
cold will be across Montana into the northern Plains Monday-Wednesday next week where anomalies 
could be 30 to 40 degrees below normal.  

For Alaska, one system moving moving through the Bering Sea will bring high winds and some 
precipitation to parts of the Aleutians, Peninsula region, and the western mainland this weekend. A 
second deep surface low follows behind into the Aleutians with another round of high winds and 
significant waves possible for the Island Chain early next week. Strong upper ridging situated over 
central and eastern Alaska will result in an extended period of much above normal temperatures, 
especially across northern Alaska where temperatures could be 40+ degrees above normal, with highs 
approaching or surpassing freezing. 

Santorelli