Old Man Winter holds the central US in his icy grip

Chilling air haunted the central United States much of last week. After a brief milder period this weekend, a reinforcing blast of cold is forecast to cruise through the Plains again early this week, risking another round of frost and freeze damage for crops and sensitive plants.

After an entire week of below-average temperatures in the 30s and 40s, Grand Forks, North Dakota, reached 61 degrees Fahrenheit on Saturday, which is 6 degrees above the normal high temperature for mid-April there. Omaha, Nebraska, reached 60 F on Sunday, which is around normal there. Rapid City, South Dakota, reached 64 degrees on Sunday after struggling to hit 35 last Thursday.

Residents may not want to get too comfortable with these barely mild conditions, as another wave of chill is on its way.

"By Monday, bitterly cold air will sweep southward out of Canada and build as far south as the southern Rockies and central Plains," said AccuWeather Meteorologist Mary Gilbert.

A strong cold front is forecast to escort this cold air into the central United States, also producing spring snow in areas, primarily from southern Canada to Kansas and Missouri.

"The mercury for some across the northern Rockies, as well as portions of the northern and central Plains will struggle to climb into the 30s F and 40s on Monday and overnight low temperatures will come crashing into the teens and 20s," said Gilbert.

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The Mississippi Valley can be affected as well, according to AccuWeather Lead Long-Range Forecaster Paul Pastelok. Temperatures can reach the freezing point across southern Kansas, central Missouri and northern Illinois during the early week.

"Locations unlucky enough to be impacted by this brutally cold mass of air will encounter temperatures generally 10-20 degrees below average for mid-April. Some locations can even encounter departures from average up to 30 degrees," Gilbert said.

"Heating demands will be high," Pastelok added.

Afternoon snow is forecast to hinder Denver's ascent in temperatures on Monday, keeping the city from reaching any higher than 44 F, which approaches 20 degrees below normal! As snow continues through Monday night, temperatures are expected to drop into the teens. The city usually sits at a low of 34 F in mid-April.

Oklahoma City is expected to make a 37-degree dive from a high of 72 on Monday to a low of 38 F on Monday night as the core of cold descends on the region.

Several cities in the central U.S. will approach record low temperatures Monday night, including Wichita, Kansas, which is forecast to tie the record low from 1978 by reaching 31 F.

"On Tuesday, the core of the cold will spread even farther south into the southern Plains. High temperatures in the 40s and lower 50s will be common as far south as Oklahoma and the Texas Panhandle," Gilbert said.

In Oklahoma City on Tuesday, the high temperature is likely to top out only a degree or two from 50, according to Gilbert. A normal high temperature for the city is in the low 70s.

On Tuesday night, Dallas, Texas, is expected to break its 1918 record of 39 by one degree. Oklahoma City is also likely to smash its own 1966 record by diving to 31, which is 2 degrees below the record.

These low temperatures, particularly those at night, can be dangerous for sensitive and unprotected plants.

"Those across the affected area who have already begun to plant for the season will need to be prepared to protect their crops from near-freezing or even below-freezing temperatures," Gilbert said.

Frost protection is especially important for tender plants such as tropical houseplants, succulents, begonias, impatiens, peppers, and tomatoes, according to the Farmer's Almanac.

Potatoes and carrots may be able to withstand a light frost, but less likely a freeze. The more cold adjusted a plant is, the less likely it will be damaged by a freeze or frost.

The chill from early this week across the Plains, Great Lakes and even much of the South will continue through most of the week, suggested Pastelok. It will then briefly start to moderate before a potential surge of cold air moves into the Plains and Midwest toward next weekend. Chilly air may not retreat for a couple of weeks.

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