Ag Weather Forum

Do you remember where you were in late January 2017? That's the last time a strong cold wave enveloped the contiguous U.S. Or, let's go back a little further, how about 2014? That cold wave was a rip-snorter, too. Those questions are, of course, neither here nor there, but they do highlight the fact the forecast for much of the U.S. east of the Rockies over the next week or so -- and, maybe a bit longer on the East Coast -- is going to bring some shivers at the very least.

And yes, the polar vortex is a big factor in the oncoming cold wave.

"The strong polar vortex is expected to be over southern Ontario and the Great Lakes region during ... next Wednesday and Thursday," wrote my colleague, DTN Senior Analyst Joel Burgio, Friday morning. "The U.S. model shows a somewhat stronger Arctic high pressure system than does the European model ... but, in either case, it will be extremely cold in the Midwest."

How cold are we talking about? Generally, from ten to 25 degrees Fahrenheit below normal over the northern Midwest during this Jan. 25-27 weekend. The intensity of the cold is getting forecasters' attention relative to recent history. Here's a comment from the Chicago, Illinois, National Weather Service office at 4:20 a.m. CST Friday:

"To put some perspective on this potential cold, only eight times since 1872 has Chicago recorded sub-zero highs on at least two consecutive days, the most recent being early February 1996.

"Additionally, 850hPa temps of -30 Celsius (-22 Fahrenheit) are a rarity for this region, with central Illinois sounding climatology dating back to 1949 indicating around only a handful of occurrences." (Note: 850hPa temperatures are temperatures recorded by the Weather Service balloons; the barometric pressure level indicated is about 1,000 feet altitude.)

This cold wave is going to have several agricultural effects. First, of course, transportation will be affected. My colleague, DTN Cash Grains Analyst Mary Kennedy, is preparing coverage of how the intense cold will complicate river grain transportation on the Ohio and Mississippi Rivers. There could be some impact on local grain hauling to ethanol plants as well, although, with ethanol plants having a tough time economically, that demand is not as strong as we have seen in previous winters. Livestock will see some cold-weather stress, especially with late-winter calving. But, the biggest threat could be cold-weather damage to soft red winter wheat. The eastern and southern Midwest will see the full force of this cold wave, and snow cover in much of the SRW areas is not very heavy.

This polar vortex incursion is expected to modify in the ten-day time frame, with temperatures getting back toward normal. However, we may see additional cold outbreaks during February. That possibility is a big reason why our DTN forecast call continues to be for winter to last longer than usual in the central U.S. And, that also gives a hint that fieldwork for the 2019 crop year could be later than usual in getting underway.

Bryce Anderson can be reached at bryce.anderson@dtn.com

Follow him on Twitter@BAndersonDTN

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