US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
258 PM EST Mon Jan 11 2021
 
Valid Thursday January 14 2021 - Monday January 18 2021
 
Hazards:
- Heavy precipitation across portions of the Northeast, Fri-Sat, Jan 15-Jan 16.
- Heavy snow across portions of the Great Lakes and the Upper Mississippi Valley, Thu-Fri, Jan 
14-Jan 15.
- Flooding possible across portions of the Pacific Northwest.
- Flooding occurring or imminent across portions of the Mid-Atlantic.
- Flooding likely across portions of the Pacific Northwest.
- High winds across portions of the Central/Northern Plains, Thu-Fri, Jan 14-Jan 15.
- Heavy precipitation across portions of the Alaska Panhandle and mainland Alaska, Thu-Mon, Jan 
14-Jan 18.
 
Detailed Summary:

During the medium range period (Thursday, January 14 - Monday, January 18), the upper-level pattern 
over the contiguous U.S. will be mainly dominated by troughing, with the exception of the West 
Coast. A deep upper-level low is forecast to move into the core of the trough for the latter part 
of the workweek, and in conjunction with that at the surface, a low pressure/frontal system will 
track across south-central Canada and the north-central CONUS. This low should spread potentially 
heavy snow across portions of the Upper Midwest and the Upper Great Lakes region Thursday, 
lingering on Friday especially in the Upper Peninsula of Michigan. Given the tight pressure 
gradient behind the deep surface low, high winds are also a concern across northern and central 
portions of the Plains on Thursday and Friday. As the fronts associated with the surface low shift 
eastward, precipitation is possible for the East late week, and the heaviest amounts look to be in 
New England. The precipitation type there is currently uncertain and may switch between snow, rain, 
and mixed precipitation. Behind the system, westerly winds should promote the development of 
possibly heavy lake effect snow in localized areas downwind of the Lower Great Lakes on Saturday.

Temperatures are not forecast to be hazardous during the period. Milder than normal temperatures 
are generally forecast across the northern tier, with low temperatures periodically 15 to 30 
degrees above average in the north-central and northeastern U.S., but most lows at least stay below 
freezing there. Warmer than normal temperatures in California and in the Desert Southwest could 
lead to daily record highs on Thursday and Friday.

Over Alaska, a deep low pressure system is forecast over the Gulf of Alaska Thursday into Friday, 
and heavy precipitation is likely to spread ahead of it into the Southcentral region and into the 
Alaska Panhandle. This could also cause marine hazards of high winds and significant waves, but 
mainly offshore, and coastal flooding is not expected. The pattern remains favorable for additional 
rounds of precipitation early next week, along with the possibility of gusty winds.

Tate