US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
424 PM EST Tue Dec 28 2021
 
Valid Friday December 31 2021 - Tuesday January 04 2022
 
Hazards:
- Heavy precipitation across portions of California, the Great Basin, and the Pacific Northwest, 
Sun-Tue, Jan 2-Jan 4.
- Heavy precipitation across portions of the Northeast and the Great Lakes, Sat, Jan 1.
- Heavy precipitation across portions of the Southwest, Fri, Dec 31.
- Heavy rain across portions of the Central/Southern Appalachians, the Tennessee Valley, the 
Mid-Atlantic, the Southeast, and the Ohio Valley, Sat-Sun, Jan 1-Jan 2.
- Heavy snow across portions of the Central/Southern Rockies, the Central Great Basin, the Central 
Plains, and the Southwest, Fri, Dec 31.
- Heavy snow across portions of the Great Lakes and the Upper Mississippi Valley, Sat, Jan 1.
- Severe weather across portions of the Middle Mississippi Valley, the Lower Mississippi Valley, 
the Southern Plains, and the Tennessee Valley, Fri, Dec 31.
- Severe weather across portions of the Lower Mississippi Valley, the Tennessee Valley, the Middle 
Mississippi Valley, the Southern Appalachians, the Southeast, and the Ohio Valley, Sat, Jan 1.
- Much below normal temperatures across portions of the Upper Mississippi Valley, the Pacific 
Northwest, the Northern Rockies, the Northern Great Basin, and the Northern Plains, Fri-Sat, Dec 
31-Jan 1.
- Much below normal temperatures across portions of the Northern/Central Plains, the Middle 
Mississippi Valley, the Great Lakes, and the Upper Mississippi Valley, Sat-Sun, Jan 1-Jan 2.
- Heavy snow across portions of the Alaska Panhandle and mainland Alaska, Fri-Sat, Dec 31-Jan 1.
- High winds across portions of the Alaska Panhandle and mainland Alaska, Sat-Sun, Jan 1-Jan 2.
- Much below normal temperatures across portions of the Alaska Panhandle and mainland Alaska, 
Sun-Tue, Jan 2-Jan 4.
 
Detailed Summary:

Cold high pressure over Western Canada will move southward over the Northern Plains and the Great 
Basin on Friday into Saturday and continue southward to the Southern Plains and Southwest by 
Sunday.  The eastern High will move to Mid-Atlantic by Tuesday.  The high will bring much below 
temperatures to parts of the Northern Intermountain Region to the Northern Plains/Upper Mississippi 
Valley on New Year s Eve and New Year s Day.  The much below normal temperatures will expand into 
parts of the Central Plains to the Upper Great Lakes on Saturday and Sunday.  Furthermore, low 
pressure and upper-level energy will aid in producing an area of Heavy Precipitation(rain and snow) 
over parts of the Southwest and heavy snow over the Central Rockies on Friday, New Year s Eve.

Meanwhile, a strong front along the leading edge of the high pressure over the Lower Mississippi 
Valley will destabilize the atmosphere producing conditions favorable for severe thunderstorms on 
New Year s Eve.  As the strong front moves eastward, the area favorable for severe thunderstorms 
will move eastward to the Southern Ohio and Tennessee Valleys to the Southern Appalachians and 
parts of the Southeast.  Along with the severe weather on New Year s Day, heavy rain will develop 
along the front from parts of the Mid-Atlantic to the Southeast and Tennessee Valley.  Therefore, 
an area of Heavy Rain is depicted on the Hazards Chart on Saturday into Sunday.

However, the area of heavy rain on Sunday will be smaller and mostly over the Mid-Atlantic.  
Moreover, as the front associated deep surface low crosses the Great Lakes into the Northeast on 
New Year s Day, Heavy Snow will develop over parts of the Great Lakes.  In addition, an area of 
rain and snow will develop over the Northeast.  Therefore, with some uncertainty of where the heavy 
snow and rain will be, an area of Heavy Precipitation is placed on the Hazards Chart over the 
Northeast for Saturday.  Additionally, an area of deep low pressure will move southeastward out of 
the Gulf of Alaska, moving onshore over the Northwest on Sunday into Tuesday.  As a result, the 
storm will produce a region of Heavy Precipitation extending from the Pacific Northwest to Central 
California on Sunday into Tuesday. The precipitation will be higher elevation snow and lower 
elevation rain. 

Over Alaska, an area of deep low pressure will move over the Alaska Peninsula into the Gulf of 
Alaska on New Year s Eve and New Year s Day.  The pressure gradient associated with the area of 
deep low pressure will produce an area of High Wind with a wind speed of greater than 50 knots.  
Moisture associated with the low will stream into the Alaska Panhandle on New Year s Eve and New 
Year s Day producing an area of Heavy Snow over the region.   Behind the system, very cold high 
pressure will build over the Far North producing a very cold Arctic air mass that will spread below 
normal temperatures across eastern sections of Interior Alaska, much of southwestern and 
south-central Alaska, and possibly into the Panhandle m Sunday into Tuesday.

Ziegenfelder