The recent cold snap appears to be on the way out, as the upper air pattern starts to change. The large ridge of high pressure in the upper atmosphere, which has been responsible for driving the unseasonally cold air our way, is pushing to the west and weakening. As we head into the last week of January, a change in the upper air pattern will bring a series of storms into the northern plains. The first significant storm will arrive late in the weekend or early next week, followed by another storm mid to late next week.
A temperature roller coaster will develop, with unseasonally cold air giving way to unseasonally mild air for a few days. Freezing rain may affect portions of the area with the passage of the first storm system. Behind this, expect a dramatic return to unseasonally colder air. During the first week of February, storm systems will move across the mid west, continuing a temperature roller coaster of sorts. With bitter cold air to the north, and warm moist air to the south, there is the threat for more precipitation, some of it a wintry mix.
What is often typical during the passage of strong low pressure systems can be dangerous wind chill events. As the low pressure systems develop and pass through the area, southerly flows will increase causing bitter wind chills. Then, once the cold front passes and high pressure builds in, wind chills again become a threat. Depending on the strength of the wind, the intensity of the cold air moving in and available moisture, light snow will often accompany the passage of the low systems. The combination of falling snow and wind may cause reduced visibility, especially in open country.
Please remember this is a general threats outlook for the overall weather pattern through the start of Feburary. While overall colder than normal weather is expected the next two weeks, day-to-day variability will occur. Please pay attention to the actual forecasts issued by your NOAA’s National Weather Service, as well as any watches, advisories or warnings. Also, please check out the National Hazards Briefing here.
For additional infomation please contact your National Weather Service or visit our web site at www.crh.noaa.gov/fgf