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A Quick Change In Weather
by Joel Young, Meteorologist/Reporter
January 19, 2013 11:27 PM
For those of us who call the Upper Midwest home, we’re no stranger to rapid temperature changes. In fact, Spearfish, South Dakota holds the world record for the fastest change in temperature ever recorded. The morning of January 22, 1943, which will be exactly 70 years ago this upcoming Tuesday, the temperature went from -2°F to 54°F in only two minutes. The phenomena that caused this rapid increase in temperature is known as a Chinook wind, a gust of warm, dry air rapidly moving down the slopes of a mountain range. Once the Chinook had settled, the temperature dropped back down to -4°, a 58° drop over the course of 27 minutes. Without a doubt, it was an impressive event in weather history for not only us South Dakotans, but for everyone worldwide.
Although Saturday’s rapid drop in temperature didn't come close to any records; it was certainly enough to get people talking. The entire second half of this week, we were spoiled with pleasant spring-like temperatures well above average. Here’s a look at Sioux Falls’ highs throughout the week, including Saturday’s maximum temperature just before the cold front moved through.
If you walked outside Saturday morning, you probably didn’t think to grab a jacket unless you already knew the forecast for the afternoon. Here’s a look at one of our forecast models showing temperatures just above the surface around noon on Saturday. As you can see, an area of low pressure centered over NE Minnesota and Lake Superior was wrapping air counterclockwise bringing a shot of cold air out of Canada. At this point, the cold front seemed to be draped across our region from east to west. Once it passed, temperatures dropped continuously.
As you can see in the next four graphics, Saturday’s warmest temperatures were felt later in the morning before this cold front moved through. Looking at temperatures from midnight Saturday morning through 10 PM, you can clearly see about what time the cold front moved through each location. Obviously, the cold front passed through Aberdeen before Pierre and Sioux Falls shortly after noon dropping temperatures from 30° to 17° in only two hours. The cold front later passed through Pierre and Sioux Falls roughly about the same time dropping temperatures dramatically in a very short time frame.
ABERDEEN TEMPERATURES & WIND CHILLS
SIOUX FALLS TEMPERATURES & WIND CHILLS
PIERRE TEMPERATURES & WIND CHILLS
Along the cold front, winds picked up dramatically making this dramatic drop in temperature seem even more intense. Winds seemed to be much stronger along and east of the James River where winds were sustained between 20 and 30 miles per hour compared to 10 to 20 mile per hour winds across the west. Either way, wind chills bit much harder this afternoon than they did over the past few days and even this morning. In fact, for a few hours shortly after midnight, temperatures were so warm that wind chills read “not-applicable” for a short period of time. By the end of the day, however, wind gusts had peaked between 31 and 53 miles per hour across our region with the strongest gusts found around Sisseton in NE South Dakota.
As you can imagine, this colder air mass is here to stay, at least through the first of this week. In fact, another system will be moving through Sunday morning bringing us a shot at light snow and a reinforcing shot of cold air. This snow event, however, is not expected to be of significance because of a limited amount of moisture available and high winds which will drive snow totals down quite a bit. Here’s a look at what our Futurecast Snowfall expects us to receive with Sunday morning’s light snow, which will likely be out of here by early Sunday afternoon.
Once the snow is out of here, temperatures are forecast to plummet once again; this time, even colder than Saturday night as clouds will gradually clear during the overnight hours. Lows will likely dip into the 20s and teens below zero across the region with only a few locations across our extreme southern counties remaining in the single digits below zero. That, along with breezy conditions, wind chills will drop dangerously likely prompting wind chill advisories, or even warnings. Here’s a look at where we expect the coldest wind chills to be felt.
Of course, we will keep you updated with the very latest information as it comes our way right here on KDLT and KDLT.com. You can also follow all of us on Twitter.
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