The switch has finally flipped where the chances for snow have dramatically lessened. No snow is forecast for the Eastern US this week, but the theme of this article is where the snow will be falling, which is across portions of the northern Rocky Mountains Monday into Tuesday.
On Monday, a moderate to heavy snow will break out across much of southern Montana and northern Wyoming while rain showers fall across the remainder of Wyoming. Then in the afternoon and evening hours, snow will work a bit farther south in Wyoming. Overnight Monday, the moisture will more a bit to the east, and with cold air in place heavy snow is expected across western South Dakota. Meanwhile back to the west, the snow will taper off as the night progresses in Montana and Wyoming.
On Tuesday, a light snow is possible across eastern portions of Wyoming and western South Dakota and Nebraska. By the end of the day, however, all of the snow will have cleared out of the region as the moisture heads toward the Southern Plains by Wednesday.
Through Tuesday, up to a foot and a half of snowfall is possible in the highest of elevations:
We’re nearing the end of April but Mother Nature continues to hold strong. Based on the long-range pattern, it appears that the chance for additional snow east of the Rocky Mountains is lessening. Let’s hope because it’s been a snowy, endless winter for many. The past 30 days have featured a widespread one to two feet of snow across the Northern Tier.
This significant snowfall, especially from recent, historical snowstorms, is making for a higher-than-normal snow cover for this time period. Typically, 11.7 percent of the contiguous United States is covered in snow on April 19th, which is based on the 10-year average since 2009. The current snow cover across the Lower 48 this year is at 20.7 percent, which is above average by 9 percent. At least it’s an improvement from the 36.7 percent this time last month. The last time there was this much snow covering the ground this time of the year was back in 2013. Compared to last year, as shown in the animation below, there was only 5.9 percent of snow on the ground due to the fact that April 2017 was the 11th warmest on record nationally, according to NCEI.
The two main reasons why there is still snow on the ground: an active storm track and cold air. We’ve been in a locked-in pattern overall since the start of this year, allowing for many storms to move across the country every week. With cold air in place, that allows for snow to fall, and significant amounts at times. Many climate stations in the eastern two-thirds of the US have recorded a top 5 coldest April-to-date. Widespread locations in the Northern Plains and Upper Midwest have even measured their coldest April-to-date, as noted by the boxes with a ‘1’ on the map below. That cold has allowed for the snow to stick around longer than normal given the fact that it’s now spring and the sun is becoming stronger due to the higher sun angle. Let’s hope this snow melts soon.
It’s been an abnormally — if not record — cold start and snowy start to April for the Northern Plains the Midwest. Let’s first talk about the cold: a near-constant supply of cold air intruding from Canada has allowed for dozens of climate stations in the region to record their coldest start to April on record. Cities like Minneapolis, Omaha, Des Moines, and Chicago have all had a top three coldest start to April (April 1-14) in history. It’s not only the Northern Plains and Midwest that have been feeling the chill — almost all of the region east of the Rocky Mountains have recorded below average temperatures overall month-to-date. The only exception is in the Florida Peninsula where it has been warmer than normal.
Daily record low minimum and maximum temperatures have also outpaced record high minimum and maximum temperatures, something that has not been common in recent years. According to NOAA, 2017 was the third-warmest year on record for the United States. Year-to-date for 2018, warm temperature records have been outpacing cold temperature records, but not by nearly as much as during 2017. In terms of what has been happening so far this April, there have been 3546 cold temperature records compared to the only 1280 warm temperature records. That is almost a 3:1 ratio, so for every one warm temperature record, three cold records have been accomplished.
Based on the long-range outlook, the cooler than average temperatures will persist for about the next week before milder temperatures move into the Central Plains up through the Great Lakes and New England. The Mid-Atlantic and Southeast, however, should remain on the cooler side as we end April and get into the start of May.
Now let’s talk snow: so many snow records have been broken so far this April, especially from the most recent snowstorm that impacted the Northern Plains, Midwest, Great Lakes, and Northeast between April 13th and 16th. Here’s some of the notable records and statistics from this storm or that this storm has contributed to in terms of snowfall this month:
- 7th snowiest winter in Sioux Falls, South Dakota with 64.2 inches. The record snowiest winter is 94.7 inches from 1968-69.
- 3rd snowiest start to the year in Sioux Falls with 53.3 inches. The record snowiest year-to-date is 71.1 inches from 1962.
- 13.7 inches of snow on April 13th in Sioux Falls shatters the daily and monthly highest snow records and also breaks the total monthly snowfall record by over 6 inches.
- Largest April snowstorm with 15.8 inches in the Twin Cities (Minneapolis/St.Paul, Minnesota). This breaks the previous record of 13.6 inches set back in 1983.
- 12th largest all-time snowstorm in the Twin Cities. The record is 28.4 inches set in 1991.
- All-time snowiest start to the year in the Twin Cities with 70.3 inches. This breaks the previous record of 69.5 inches set in 1982.
- 23.5 inches of snow from this snowstorm makes it the largest April snowstorm on record and the 2nd all-time largest snowstorm in history in Green Bay, Wisconsin.
To say the weather this April has been wild is an understatement. The National Weather Service office in the Twin Cities compiled the graphic below to show some of the fun (or not-so-fun) facts related to the cold and snow this April.
Now is any more snow on the way? For some: yes. Another winter storm will bring snow to portions of the Northern Plains and Midwest midweek, but based on climatology, the snow will eventually have to stop as summer gradually approaches. Most locations in this region have either already passed their average last measurable snowfall date or are about to reach it. The only locations that typically see the measurable snow come to an end in May is in the Rocky Mountains.
It’s unusual to get snow in the Northern Plains and Midwest in the month of May, but it has happened several times in the past before. Let’s hope the snow comes to an end real soon this year!