January's Cold Reality Sets in Next Week

Brian Donegan
Published: December 31,2016
As January arrives, a pattern change will bring a reality check by ushering in much colder temperatures for a large swath of the United States that will last for several days in many areas.
(MAPS: 10-day Forecast High/Low Temperatures)
A southward diversion of the polar jet stream will allow arctic air to flow southward out of Canada into much of the Lower 48 states by later next week.

European model forecast jet stream (white lines) and surface temperatures (color contours) for Thursday, Jan. 5, 2017, based on the 00 UTC, Dec. 28, 2016, model forecast.

The chill looks to arrive just after the New Year's holiday weekend in the northern Plains and northern Rockies before expanding its reach south and east through the week.
(MORE: New Year's Holiday Weekend Outlook)

Chilly Forecast

High temperatures Monday will be 15 to 30 degrees below average in the northern Rockies and 10 to 25 degrees below average in parts of the northern Plains and Pacific Northwest. This translates to highs mainly in the teens and single digits from Montana and northern Wyoming into North Dakota and western South Dakota.

Forecast Highs Compared to Average Monday

The arctic air will spread a little farther south and east each day next week.
By late next week, the below-average temperatures should cover much of the Lower 48 states, with the exception of parts of Florida.
Highs in the 20s are possible as far south as the Texas panhandle, which is at least 15 degrees below average for the first week of January.
(MORE: When Is the Coldest Time of the Year?)

Forecast Highs Compared to Average Next Friday

The worst of the cold, however, appears likely to remain locked into the northern Plains and Rockies, with highs remaining up to 30 degrees below average late next week. Some places won't even reach zero degrees Wednesday through Friday, especially across parts of Montana, North Dakota and Minnesota.
(FORECAST: Missoula, Montana | Fargo, North Dakota | International Falls, Minnesota)
Since high temperatures will be so cold, you can bet on low temperatures being even more frigid.

Forecast Lows

Morning lows could reach the teens and 20s below zero in the coldest locations of the northern Plains and Rockies next week. These readings are 20 to 40 degrees colder than average for this time of year.
The 6-10 day temperature outlook issued Thursday from the Climate Prediction Center has a very large area of 90 percent probability for below-average temperatures, the largest area in the 15 year history of the outlook according to climatologist Brian Brettschneider. This indicates the high confidence level of the colder than average temperatures and not how much below average temperatures will be.
According to the National Weather Service, temperatures may reach below zero in 15 states by Thursday morning. A few record lows are also possible next week, mainly in the Pacific Northwest.
Wind chills will reach dangerously cold levels, placing you at risk for frostbite or hypothermia if you are outdoors and not properly bundled up.
(MORE: What Does Wind Chill Really Mean?)

Rockies, Plains Forecast Next Week

This cold reality check won't reach the East until the end of next week or next weekend, and the air mass will likely modify by that point and not be quite as bitter as it will be over the rest of the country.
However, it will be a noticeable temperature change in the East compared to early week. High and low temperatures will be 10 to 25 degrees warmer than average into midweek and then colder conditions return.

Five Day Forecast

Many locations in the East will see temperatures 20 to 30 degrees colder late in the week compared to the mild temperatures early in the week.
For more details on what the rest of January may bring, check out our January outlook.

MORE: Coldest Places on Earth