US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
300 PM EST Wed Jan 02 2019
 
Valid Saturday January 05 2019 - Wednesday January 09 2019
 
Hazards:
Heavy precipitation across portions of California, the Pacific Northwest, and the Northern Great 
Basin, Sat-Wed, Jan 5-Jan 9.
Heavy snow across portions of the Central Great Basin, California, and the Southwest, Sat-Mon, Jan 
5-Jan 7.
Heavy snow across portions of the Northern Rockies and the Northern Great Basin, Sun-Wed, Jan 6-Jan 
9.
Heavy snow across portions of the Northern Rockies and the Northern Great Basin, Sun-Tue, Jan 6-Jan 
8.
Heavy snow across portions of the Southern Rockies, the Central Rockies, the Central Great Basin, 
and the Southwest, Sun-Mon, Jan 6-Jan 7.
Heavy snow across portions of the Northeast and the Great Lakes, Tue-Wed, Jan 8-Jan 9.
Heavy snow across portions of the Great Lakes, Mon-Tue, Jan 7-Jan 8.
Flooding possible across portions of the Southeast, the Mid-Atlantic, the Lower Mississippi Valley, 
the Southern Plains, and the Tennessee Valley.
Flooding occurring or imminent across portions of the Central Plains, the Lower Mississippi Valley, 
the Tennessee Valley, the Middle Mississippi Valley, the Mid-Atlantic, the Southeast, and the 
Southern Plains.
Flooding likely across portions of the Southeast, the Southern Plains, the Lower Mississippi 
Valley, and the Central Great Basin.
High winds across portions of California and the Pacific Northwest, Sun-Tue, Jan 6-Jan 8.
High winds across portions of California, Sat-Sun, Jan 5-Jan 6.
High winds across portions of the Great Lakes, Mon, Jan 7.
High significant wave heights for coastal portions of the Pacific Northwest, Mon-Wed, Jan 7-Jan 9.
High significant wave heights for coastal portions of California and the Pacific Northwest, 
Sat-Sun, Jan 5-Jan 6.
High significant wave heights for coastal portions of the Aleutians, Sat-Tue, Jan 5-Jan 8.
 
Detailed Summary:

A storm moving onshore Saturday will bring high winds (>34 mph sustained) and significant waves 
(>20 ft) to the Central/Northern California Coast. Rain one inch or greater will fall from northern 
California to western Washington. The system will also produce 6 inches or more snow over parts the 
Northern Cascades Saturday. Snowfall of 6 inches or more will also develop over parts of the 
Sierras from Sunday into Monday. The active weather will continue through the middle of next week 
with more heavy rain and mountain snow. Heavy snow will also reach into the northern Rockies and 
northern Great Basin Sunday. Another round of heavy snow could develop across portions of the 
Southern Rockies Sunday into Monday as the system pushes east.

A tight pressure gradient over the Upper Great Lakes between high pressure over East-Central Canada 
and low pressure over the Northern Plains/Upper Mississippi Valley will produce high wind on 
Monday. The low pressure system will track into the Lower Great Lakes by Tuesday and off the New 
England Coast by Wednesday. Heavy snow will be possible ahead of, and north of the low. Uncertainty 
remains, but the areas with the most likely chance to see 4 inches or more of snow include northern 
Michigan and New England.

In Alaska, significant waves will be possible across the western Aleutians from Saturday until 
Tuesday as multiple storm systems impact the islands.

Snell