Variable amounts of June rain continue

Variable amounts of June rain continue:

This last week brought highly variable rainfall to Minnesota. Many areas received over 1 inch of rain, and there were several reports of 2 to 3 inches. Generally, northern-central and northwestern areas, along with some southwestern counties received less than 1 inch of rain for the week. On the other hand, portions of Faribault, St Louis, and Chippewa Counties reported over 4 inches of rain.

Severe weather reports were numerous around the state on Monday, June 16th. Awaiting confirmation from National Weather Service storm surveys, there were reports that day of tornadoes in Otter Tail, Wadena, Todd, Cass, Aitkin, St Louis, and Nicollet Counties. There were also reports of large hail from Otter Tail, Cass, Meeker, Wright, Carver, and Blue Earth counties, with some reports of 2” and 3” diameter hailstones in Carver County. In addition, there were reports of trees down or damaged from thunderstorm winds in Stearns, Hennepin, Crow Wing, and St Louis counties. Some of the thunderstorms brought record-setting daily amounts of rainfall, including:

3.50” at Wells (Faribault County_
2.25” at Embarrass (St Louis County)
2.55” at Ely (St Louis County_
1.83” at Grand Portage (Cook County)

According to the U.S. Drought Monitor slightly less than 10 percent of the state is still in Moderate Drought, mostly northwestern Minnesota (Kittson and Roseau Counties), and a few areas of the non-agricultural north-central portions of the state. According to the recently released seasonal drought outlook (as of June 19) from the NOAA Climate Prediction Center, these areas of Minnesota are likely to remain in drought through the balance of the growing season (until September 30 at least)). The current climate outlooks favor above normal rainfall across most of the state for the balance of June and into the first week of July.

Close to 75 percent of the Minnesota corn and soybean crops are currently rated to be in good to excellent condition by the USDA, and stored soil moisture is adequate to surplus in most agricultural areas of the state. These are all positive signs for agricultural prospects in Minnesota so far this season. 

Weekly Weather Potpourri:

The BBC features an article this week about how many European families are recently tweaking their summer holiday plans to avoid more frequently occurring Heat Waves that have impacted many Mediterranean vacation destination sites in the holiday months of July and August. In fact 81 percent of those surveyed have responded that climate-change induced extremes have affected their holiday planning.

Speaking of Heat Waves, the Weather Underground web site provides a good general overview of the project Heat Wave that will affect the eastern two-thirds of the USA this weekend. As a result of temperatures in the 90s with dew points in the 70s F, many areas may see Heat Index values exceed 100°F. Some areas of western Minnesota could see Heat Index values top 105°F. If traveling this weekend, be sure to check the Heat Index forecast for your destination.

MPR listener question:

I’m a statistician and researcher in a completely differenr field (I know little about climate). In my line of work, I always have noticed how people more easily understand averages but can struggle with variance. I’ve not heard an index of variance in climate change, but I am curious if you know of any index that captures that variance in climate change?

Answer:

Yes, this question was addressed by the climate science community back in the 1990s, when Dr. Thomas Karl of NOAA along with others derived the Climate Extremes Index (CEI) for the USA. The NOAA operation CEI considers extreme anomalies in temperature, precipitation, and drought on an annual basis, and factors in the landscape area of the USA that is affected by these. In recent years, the CEI includes a 4th factor which is the wind velocity of landfalling tropical storms and hurricanes and the area encompassed. Computation of the CEI have been done back to 1910 and updated each year through 2024. The CEI clearly shows increased climate variability across the USA, especially since the 1990s. The two years with the highest CEI index are 2012 and 2024 (both noted for setting climate records and huge anomalies in climatic patterns). You can read more at the NOAA Climate Extreme Index web site.

Twin Cities Almanac for June 20th:

The average MSP high temperature for this date is 80 degrees F (plus or minus 9 degrees F standard deviation), while the average low is 62 degrees F (plus or minus 7 degrees F standard deviation).

MSP Local Records for June 20th:

MSP records for this date: highest daily maximum temperature of 101 degrees F in 2022; lowest daily maximum temperature of 54 degrees F in 1946; lowest daily minimum temperature of 41 degrees F in 1992; highest daily minimum temperature of 79 degrees F in 2022; and record precipitation of 1.92 inches in 1927. There has not been any snowfall on this date.

Average dew point for June 20th is 55°F; the maximum dew point on this date is 78°F in 1909 and the minimum dew point on this date is 31 degrees F in 1992. 

All-time state records for June 20th:

The state record high temperature for this date is 104 degrees F at Olivia (Renville County) in 1988. The state record low temperature for this date is 23 degrees F at Remer (Cass County) in 1985. The state record precipitation for this date is 10.45 inches at Two Harbors (Lake County) in 2012. No snowfall has occurred on this date. 

Past Weather:

June 20 of 1988 brought a real Heat Wave to the state, with temperatures of 100°F or higher reported from 22 Minnesota counties. As far north as Gunflint Lake reached an afternoon temperature of 90 degrees. The summer of 1988 remains the hottest summer in Minnesota history.

June 20 of 1992 brought the only known case of damaging frost on the summer solstice. Frosts were reported in agricultural counties like Todd, Wadena, Otter Tail, Polk, Fillmore, Wabasha, and Stearns Counties. Morning temperatures were as low as the mid-20s F up north. Summer of 1992 was one of the coldest of the 20th Century in North America thanks to the eruption of Mt. Pinatubo of the Philippines in 1991.

Slow-moving and strong thunderstorms brought the worst flooding in history to portions of northeastern Minnesota over June 19-20 of 2012. Areas of Aitkin, Carlton, Lake, and St Louis Counties reported 6 to 10 inches of rainfall. Two Harbors reported 10.69 inches. Knife River flooded and closed Hwy 61 between Duluth and Two Harbors, and MN hwy 210 was completely washed out near Jay Cooke State Park. Much of the rest of the state was in the middle of a Severe Drought. 

Outlook:

Mostly sunny and hot this weekend. Heat Index values may range between 100 and 110°F. Increasing cloudiness late Sunday with a chance for showers and thunderstorms carrying over into Monday. Continued chances for showers and thunderstorms with much cooler temperatures for much of next week as temperatures fall back closer to normal and even cooler than normal in some areas.