US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
243 PM EST Fri Jan 08 2021
 
Valid Monday January 11 2021 - Friday January 15 2021
 
Hazards:
- Heavy precipitation across portions of the Pacific Northwest and the Northern Great Basin, 
Mon-Tue, Jan 11-Jan 12.
- Flooding occurring or imminent across portions of the Mid-Atlantic and the Pacific Northwest.
- Flooding likely across portions of the Mid-Atlantic.
- High winds across portions of the Central Rockies, and the Northern/Central Plains, Thu, Jan 14.
- Heavy precipitation across portions of the Alaska Panhandle and mainland Alaska, Mon, Jan 11.
 
Detailed Summary:

Low pressure over the Northern Gulf of Mexico on Monday moves to the Southeast on Tuesday and off 
the East Coast by Wednesday.  This system had a lot of uncertainty associated with the storm.  At 
times the system looks like it would bring heavy snow to the parts of the Tennessee Valley into the 
Southern/Central Appalachians and the Mid-Atlantic, and parts of the Northeast.  Now the system 
will move off the East Coast, and there will be a lack of cold air over the eastern third of the 
country.  The storm will produce some snow around the periphery over parts of the Tennessee Valley 
and Central Appalachians, with the greatest likelihood of any heavy snow to occur at night or the 
highest elevations.  Any areas of widespread heavy snow are unlikely at this time. 

Meanwhile, a front will approach the Northwest will have some moisture associated with it.  The 
system will produce rain and higher elevation snow across parts of the Pacific Northwest on Monday 
and Tuesday.  An area of heavy precipitation is depicted on the hazards chart with this system.  
After Tuesday, the system has less moisture to work with. Thus, no other areas of heavy 
precipitation are on the chart.  However, over the Cascades' eastern slopes, there will be a few 
pockets of water equivalent of one inch of precipitation on Wednesday.  The low associated with the 
system will move into Western Canada on Wednesday, moving eastward to Central Canada by Thursday. 
The pressure gradient over the Central Rockies/Central High Plains and the Northern Plains will be 
strong enough to produce high wind over parts of the region; therefore, an area of high winds is on 
the map.

Over Alaska, an area of deep low pressure will be near the Alaska Peninsula Coast on Monday. The 
storm will have a plume of moisture that will move over portions of the Alaska Panhandle, producing 
an area of heavy precipitation from Kendal Peninsula eastward to Alaska's Panhandle on Monday.  
Another area of low pressure will move into the Alaska Panhandle on Tuesday.  This system will be 
lacking in moisture, so the precipitation associated with the low will be less. 

Ziegenfelder