US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
158 PM EST Mon Dec 31 2018
 
Valid Thursday January 03 2019 - Monday January 07 2019
 
Hazards:
Heavy precipitation across portions of the Pacific Northwest and the Northern Great Basin, Thu-Fri, 
Jan 3-Jan 4.
and Mon, Jan 7.
Heavy precipitation across portions of the Middle Mississippi Valley and the Ohio Valley, Fri, Jan 
4.
Heavy rain across portions of California and the Southwest, Sat-Sun, Jan 5-Jan 6.
Heavy rain across portions of the Southeast, the Mid-Atlantic, the Lower Mississippi Valley, the 
Southern Appalachians, and the Tennessee Valley, Thu-Fri, Jan 3-Jan 4.
Heavy snow across portions of the Central Great Basin, California, and the Southwest, Sat-Sun, Jan 
5-Jan 6.
Flooding occurring or imminent across portions of the Southeast, the Mid-Atlantic, the Lower 
Mississippi Valley, and the Southern Plains.
Flooding likely across portions of the Southeast, the Lower Mississippi Valley, the Southern 
Plains, and the Tennessee Valley.
High winds across portions of the Pacific Northwest, Thu-Fri, Jan 3-Jan 4.
Much below normal temperatures across portions of the Southern Rockies, the Southern Plains, the 
Southwest, the Central Great Basin, and the Central Rockies, Thu-Fri, Jan 3-Jan 4.
High significant wave heights for coastal portions of the Pacific Northwest, Thu-Fri, Jan 3-Jan 4.
 
Detailed Summary:

A strong closed upper-level low will move from the Southern Plains on Thursday to the Mid-Atlantic 
by Saturday. A stalled frontal boundary ahead of the system will be responsible for an area of 
heavy rain from the Lower Mississippi Valley to the Southern Appalacians. On the northwest side of 
the surface low, heavy rain will be possible from Missouri to Indiana. The rain could change to a 
burst of snow/sleet on Friday. Meanwhile, temperatures 10 to 20 degrees below normal will be felt 
across portions of the Southern Rockies and Southwest Thursday and Friday behind the system. 

In the Pacific Northwest, a strong low pressure system will track into British Columbia and bring a 
swath of high winds (>34 mph), significant waves (>20 feet) and heavy precipitation on Thursday and 
Friday. Another round of heavy precipitation will be possible on Monday.  

A storm system will also bring active weather to the Southwest on Saturday and Sunday. Heavy snow 
will be possible in the Sierra Nevadas, while heavy rain (>1 inch) will be possible across parts of 
Southern California and Southern Arizona.

Snell