Rollercoaster Temperature Pattern in April

Rollercoaster Temperature Pattern in April:

For the first 11 days of April, the average temperatures around the state were generally 4 to 8 degrees F cooler than normal, with many agricultural areas of the state reporting multiple frosts, even some single digit morning low temperatures. But since April 11th, temperatures have averaged 4 to 14 degrees F warmer than normal, with some areas reporting afternoon high temperatures in the 80s F on both the 12th and the 16th. Many climate observers have reported measurable rain on 9 or 10 days this month, as well as wind gusts of 30 mph or greater on 10 or 11 days.

April 13th brought severe weather to portions of southern Minnesota, with tornado reports from Blue Earth, Faribault, and Freeborn Counties. Fortunately, little damage was reported. In addition, 17 southern Minnesota counties reported large hail, ranging in diameter from 1 inch to 3.5 inches. There were reports of car damage and even some damage to buildings due to the hail. It is an interesting coincidence that the first tornadoes of the year, and first widespread hail reports would occur during Severe Weather Awareness Week (April 13-17). A comprehensive summary of the severe weather from April 13th can be found at the Minnesota State Climatology Office web site.

Another wild swing in weather this week can be seen in the dew point temperatures, which is a measure of the water vapor content of the air. Earlier in the week, prior to the severe weather, climate stations reported the first dew points of the year in the 60s F with high values of relative humidity (65 to 85 percent). Three days later, on April 16th, many parts of western Minnesota were under a Red Flag Warning with dew points in the upper 20s F to low 30s F, and relative humidity values only ranging from 10 to 19 percent, exceptionally dry air.

2026 Agricultural Season Getting Underway:

Agricultural soils have thawed and drained in most places and farmers are starting to work in coarse textured soils and medium textured soils. In fact, it is estimated that some small grains (mostly oats and spring wheat) have already been planted, while corn planting is just getting underway this week. Soils temperatures at a 4-inch depth are averaging in the upper 40s F to low 50s F around most of the state. Planting will begin at full throttle around the state the week of April 20th. Timely planting is so critical for many producers that they will often work 16 to 20-hour days to take full advantage of good spells of weather. This in part explains why you see so many headlights moving along farm fields at night during the spring.

Over most of the state, rains earlier this month have helped to restore topsoil moisture conditions for planting crops. Some Moderate Drought remains in north-central and southwestern Minnesota. Outlooks for above normal rainfall over the last 10 days of the month should brighten the outlook for good crop germination.

Weekly Weather Potpourri:

For those who may be interested, I will be doing a special program with Cathy Wurzer, host of Minnesota Public Radio’s Morning Edition Program, on April 29th from noon to 1pm at the Landmark Center in downtown St Paul. We will talk about our experiences from doing Morning Edition for the last 26 years, as well as doing the State Fair Weather Quiz, sharing stories, weather trivia, listener questions, as well as a few humorous gaffes. The program is free, but seating is limited, so you must register here. Registration is limited to two tickets.

I will be doing another upcoming weather related presentation that may be of interest on April 30, from 6:30 pm to 7:30 pm at the Mahtomedi Community Education Center, 1520 Mahtomedi Ave. This one is called “The Art and Science of Cloud Forms & Cloud Appreciation.” We will examine the history of cloud classification, cloud forms and what they tell us about the weather, and cloud art captured in photos from members of the Cloud Appreciation Society. You must register to attend at the Mahtomedi Community Education web site.

As online sources of weather information have become more prolific, the art of headline writing has become more and more oriented to capturing browser’s attention by using stronger or more threatening language about the weather. This is designed to capture the web browser’s attention and get more hits. The UK Meteorological Office has recently undertaken a dissection of weather headlines to investigate how they often do not depict the “official weather forecast” which is usually more balanced or tempered in its jargon and careful not to express complete certainty in what will happen. This week the UK Met Office blog offers some examples of this.

MPR listener question:

It wasn’t that many years ago that a new statewide record was set for May snowfall in Minnesota. Can you please remind us where and when it was?

Answer:

Yes, the memorable date was May 2 of 2013, when Dodge Center (Dodge County) in southeastern Minnesota reported an all-time record daily snowfall for May of 15.4 inches. Actually, I believe that the National Weather Service was predicting record snowfalls that day, but not quite that much. Dodge Center ended up with 17.2 inches of May snowfall that year, not quite up to the 17.8 inches of May snowfall reported on the Iron Range at Virginia, MN in May of 1954.

Twin Cities Almanac for April 17th:

The average MSP high temperature for this date is 57 degrees F (plus or minus 12 degrees F standard deviation), while the average low is 38 degrees F (plus or minus 8 degrees F standard deviation).

MSP Local Records for April 17th:

MSP records for this date: highest daily maximum temperature of 85 degrees F in 1985; lowest daily maximum temperature of 33 degrees F in 1953; lowest daily minimum temperature of 10 degrees F in 1875; highest daily minimum temperature of 61 degrees F in 1976, and record precipitation of 1.44 inches in 1975. Record snowfall for this date is 2.7 inches in 1939.

Average dew point for April 17th is 32°F; the maximum dew point on this date is 62°F in 1977 and the minimum dew point on this date is 4 degrees F in 1989.

All-time statewide records for April 17th:

The state record high temperature for this date is 93 degrees F at Stillwater (Washington County) in 2002. The state record low temperature for this date is -5 degrees F at Gunflint Lake (Cook County) in 1983. The statewide record for precipitation on this date is 3.00 inches at Lambert (Red Lake County) in 1896. A record 15.0 inches of snow fell at Wild River State Park (Chisago County) on this date in 2014.

Past Weather:

With 3 to 10 inches of snow cover still on the ground, many Minnesota climate stations reported record-setting cold minimum temperatures on the morning of April 17 in 1983. Many areas reported morning lows in the teens, while far northern communities saw single digit temperatures. Portions of Cook, Lake, and St Louis County reported subzero low temperatures. The daytime high temperature at Duluth only reached 27°F.

On perhaps the warmest April 17th in state history, over 60 climate stations set high maximum temperature records on this date in 2002. Over 40 counties reported afternoon temperatures of 80°F or greater. Farmers around the state were quite busy planting crops.

A late season winter storm brought record-setting snowfall amounts to many parts of central Minnesota over April 16-17 of 2014. Most observers reports from 8 to 16 inches of snowfall, but North Branch and Princeton reported over 20 inches of snow. Several schools in east-central Minnesota closed for both April 16th and 17th. There were numerous traffic accidents as well. That April proved to be one of the snowiest in history for parts of the state.

Outlook:

Breezy and much cooler over the weekend, with below normal temperatures prevailing. There will be more widespread freezing overnight temperatures too. Then, temperatures will rebound to above normal levels starting on Monday when it will also be quite breezy. For most of next week temperatures will be above normal and not cooling off until next weekend. There will be chances for more rain across the state late on Wednesday and into Thursday.