Ag Weather Forum

As mentioned last week, we're entering a much colder period to start 2025. (https://www.dtnpf.com/…)

That is starting to come into focus now as we near the expected pattern change that will bring in the really cold air for those of us east of the Rockies.

For some of us, that pattern has already had a head start. After a very warm end to December 2024, a system that has moved through the Plains Dec. 30 and into the Midwest on Dec. 31 is pulling down some modestly cooler temperatures and a stark contrast to the anomalies seen across much of the country over the last several days. Temperatures near or slightly below normal are filling in and will last into the new year.

However, a much more potent burst of cold air is setting up to move through next week behind a big storm system. The system will develop in the Plains on Saturday, Jan. 4, and push east through the Ohio Valley Jan. 5-6. Details on the storm are still being worked out in the models. But the general idea calls for widespread showers to develop in the Plains, increasing in intensity as the system pushes east. To the south, thunderstorms are likely to occur, some of which may be severe. Across the Northern Plains and Midwest, snow is likely to form, and a band of heavy snow is currently forecast from Kansas to Virginia on most model runs. The exact path of the heavy snow could change. Amounts are uncertain, as those details tend to shift around quite a bit but could amount to more than 6 inches within the heaviest band. In between the thunderstorms and heavy snow, a band of freezing rain will be possible, perhaps 50-100 miles wide that could lead to some dangerous conditions for travel. Winds with the system are being monitored as well. Elevated gusts could lead to further damage, especially if it coincides with the ice.

The pattern then sets up to bring in some extremely cold air in waves throughout the week and possibly much of the following week as well. An upper-level ridge will develop on the West Coast, particularly in western Canada. That will cause a downstream trough to be persistent across the eastern U.S. and Canada. Flow from the northwest between the two features will pull down some very cold, arctic air from northern Canada and the North Pole through the Canadian Prairies and U.S. Behind the weekend storm, temperatures will take a dive of at least 20 degrees below normal in the coldest spots. But some model runs are suggesting that those anomalies could be 30-40 degrees Fahrenheit below normal. That will depend on where these domes of cold air settle in, if that coincides with where snow covers the ground, and how strong the winds are. If you find yourself with a heavy burst of snow over the weekend and the domes settle in right overhead, these temperatures could fall dramatically during the overnight and early morning hours and could struggle to rise much during the day.

Additional clipper-like systems could lead to reinforcing cold air through the middle of the month, as the upper-level pattern is not forecast to change much between Jan. 6 and 18 and could still display a colder overall look through the end of the month.

To put into perspective just how cold these temperatures may be, the chart below displays the average temperatures for certain spots of the country that are most likely to be in line for the coldest air. Average highs and lows may be off by a degree or so based on the timing of the cold air. The "expected anomalies" may only last a day or two but will be possible. This is how far below the normal levels that temperatures may fall at the peak of the cold. Some of these temperatures may break records for the lowest lows or lowest highs.

To find more weather conditions and your local forecast from DTN, head over to https://www.dtnpf.com/…

John Baranick can be reached at john.baranick@dtn.com

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