US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
312 PM EST Tue Jan 15 2019
 
Valid Friday January 18 2019 - Tuesday January 22 2019
 
Hazards:
Heavy rain across portions of California and the Pacific Northwest, Sat, Jan 19.
Heavy rain across portions of the Central Plains, the Mid-Atlantic, the Lower Mississippi Valley, 
the Central Appalachians, the Tennessee Valley, the Middle Mississippi Valley, the Northeast, the 
Southern Appalachians, the Southeast, the Southern Plains, and the Ohio Valley, Fri-Sun, Jan 18-Jan 
20.
Heavy snow across portions of the Central Rockies and the Central Great Basin, Fri, Jan 18.
Heavy snow across portions of the Central Plains, the Northeast, the Central Appalachians, the 
Northern Plains, the Middle Mississippi Valley, the Mid-Atlantic, the Upper Mississippi Valley, the 
Great Lakes, and the Ohio Valley, Fri-Sun, Jan 18-Jan 20.
Flooding occurring or imminent across portions of the Southeast, the Lower Mississippi Valley, and 
the Southern Plains.
Flooding likely across portions of the Southeast.
High winds across portions of the Mid-Atlantic and the Northeast, Sun-Mon, Jan 20-Jan 21.
Much below normal temperatures across portions of the Central Plains, the Middle Mississippi 
Valley, the Southern Plains, the Upper Mississippi Valley, and the Northern Plains, Fri-Sun, Jan 
18-Jan 20.
Much below normal temperatures across portions of the Lower Mississippi Valley and the Southern 
Plains, Sun-Mon, Jan 20-Jan 21.
Much below normal temperatures across portions of the Central Plains, the Northeast, the Central 
Appalachians, the Middle Mississippi Valley, the Mid-Atlantic, the Upper Mississippi Valley, the 
Great Lakes, and the Ohio Valley, Mon-Tue, Jan 21-Jan 22.
Heavy precipitation across portions of the Alaska Panhandle, Sat-Mon, Jan 19-Jan 21.
High winds across portions of the Alaska Panhandle, Sat-Sun, Jan 19-Jan 20.
High significant wave heights for coastal portions of the Alaska Panhandle, Sat-Sun, Jan 19-Jan 20.
 
Detailed Summary:

The upper level system which is expected to bring significant precipitation and heavy mountain 
snows to parts of the Western U.S. in the short range period, will dig inland by Day 3 (Friday). 
Lower elevation rain and mountain snows will continue into Friday across the Intermountain West and 
Rockies, with heavy snow possible in parts of the Central Rockies. On the Coast, another brief 
period of heavy rainfall along the Pacific Northwest Coast may be possible this weekend as another 
upper level system nears the coast. 

By the end of the week and this weekend (days 3-5), attention shifts towards the central and 
eastern U.S. states with the potential for another winter storm. There remains a multi-model signal 
for a swath of heavy snowfall from the Midwest to parts of the Northeast, with heavy rainfall 
across the lower Ohio Valley, the Mid-Atlantic, and the South. Somewhere in between, some models 
continue to indicate a transition zone which may include some mixed precipitation or ice. There 
continues to be plenty of uncertainty on the details of where the heaviest snow and/or ice will 
occur so refinements to these areas are likely as the event gets closer in time. High Winds are 
also likely along the Mid-Atlantic and Northeast Coast Sunday and Monday as the surface low 
intensifies and moves away from the Coast.

Backside of this system will usher in a very cold air mass with much below normal temperatures 
(anomalies on the order of -12 to -20) across the northern and central Plains Friday to Sunday, 
moving into the Ohio Valley and the Northeast by early next week. Gusty winds associated with the 
deep surface low combined with cold temperatures may also result in dangerous wind chills for some 
locations. Much below normal temperatures may also reach down towards portions of the lower 
Mississippi Valley as well.

In Alaska, heavy precipitation, significant waves, and high winds are possible across mainly the 
Alaskan panhandle as a storm moves through the Gulf Fri-Sun. Another storm near/south of the 
Aleutians later in the period may generate a period of significant waves or high winds as well, but 
uncertainty in placement, track, and intensity of this system remains high and so a hazard area was 
not included on the chart this time.

Santorelli