Frigid air has overtaken the northern Plains, and conditions will get evencolder through the weekend. Temperatures will continue to plummet today as adip in the jet stream remains settled over the nation's midsection. This hasleft the door wide open for bitterly cold air to dive southward across thePlains.Typical temperatures for this time of the year on the northern Plains range inthe upper 20s to lower 30s. High's today will hover in the 10s and 20s, andSunday will be even colder. On Sunday into early next week temperatures willfail to warm out of the single digits in parts of Montana, Wyoming and theDakotas.

Story By AccuWeather.com Meteorologist Katie Storbeck.