Cold and Snow Persist

Cold and Snow Persist:

After a cool, cloudy, and windy first three months of the year, April has not turned a corner into Spring (yet). Many Minnesota citizens are complaining about the slow onset of Spring weather this month. So far through the first week of April temperatures are averaging from 2 to 6 degrees F cooler than normal, while precipitation (including snow) is accumulating at a greater than normal rate as well. Though residents of Browns Valley, Canby, and Wheaton in western Minnesota had a brief taste of 60°F for an hour or two this week, residents in northeastern Minnesota were greeted with subzero temperatures on a couple of mornings. Ely in northeastern Minnesota reported the coldest temperature in the 48 contiguous states on Tuesday (April 5) with a morning reading of 8°F.

Most climate observers around the state are reporting above normal precipitation through the first week of April. Some areas of northeastern Minnesota have already reported 6 to 11 inches of new snow this month. Many other climate stations which have received less snow, have reported more rain, in some cases over 1.5 inches through the first week of the month.

NOAA Climate Prediction Center outlooks for Minnesota continue to favor cooler and wetter than normal weather conditions for another week or so.

Verifying Extreme Climate Records:

This week’s AGU-EOS Bulletin features an interesting article about how the World Meteorological Organization investigates and verifies all time climate extreme records. It particularly details the process for the 100°F air temperature measured on June 20, 2020 inside the Arctic Circle at Verkhoyansk (Siberia). The article goes on to say how climate change is driving the higher frequency of measured climate extremes.

Weekly Weather Potpourri:

A new report from the IPCC Sixth Assessment, “Mitigation of Climate Change” was released on April 4th this week. It provides a comprehensive look at many options for mitigating the rise in global temperatures by halving the emissions of greenhouse gases by the year 2030. But actions must become more aggressive and widespread throughout the world to achieve this. The full report is available online.


The BBC featured an interesting article this week explaining how dinosaur fossils from Tanis (part of the Hell Creek formation) in southwestern North Dakota may be showing evidence of the asteroid impact 66 million years ago which caused the massive extinction event. Analysis of the composition of sediments, as well as evidence from the fossils themselves suggest the destructive energy from the asteroid impact may have reached this part of North America and caused the sudden deaths of both aquatic and terrestrial species.


A new study from the Desert Research Institute published in the Journal of Hydrometeorology finds that evaporative demand has increased in portions of many western states in the USA. This is due to increased temperature, changes in humidity, wind, and variations in solar radiation. Annual evapotranspiration has increased from 6 to 9 inches in the Rio Grande Basin, while the southern Colorado River Basin has also exhibited an increase. According to this report “increased atmospheric thirst due to climate warming has the potential to decrease water availability and increase wildfire risks in water-scarce regions.”


The Australian Bureau of Meteorology reported recently that March of 2022 was the wettest in history (back to 1900) for portions of central and northern New South Wales where a number of rivers reached major flood stage. Lismore a city of approximately 30 thousand residents had to be evacuated due to flooding, while some climate stations measured 24-hour rainfall of 10-12 inches on March 28th.

MPR listener question:

Do we have La Niña to thank for the snail-like arrival of spring this year?

Answer:

Yes, at least partially. According to research by NOAA Climate Modelers who use the El Nino/La Nina features of the equatorial Pacific Ocean as a prediction tool for North America weather, cooler than normal average temperatures for November, December, January, February, and March across Minnesota and the High Plains states show historical correlation with La Nina episodes, at least back to 1950. In addition, La Nina episodes are also correlated with above normal snowfall across Minnesota for November through April.

These are not perfect correlations, but they certainly suggest that the dominant pattern for cooler temperatures (as well as above normal snowfall in some northern areas) this winter is likely associated with the current La Nina episode, which began in November of last year and is expected to endure into the summer months. This would be the longest episode of La Nina since 2011.

Twin Cities Almanac for April 8th:

The average MSP high temperature for this date is 53 degrees F (plus or minus 11 degrees F standard deviation), while the average low is 34 degrees F (plus or minus 7 degrees F standard deviation).

MSP Local Records for April 8th:

MSP records for this date: highest daily maximum temperature of 83 degrees F in 1931; lowest daily maximum temperature of 30 degrees F in 1928; lowest daily minimum temperature of 9 degrees F in 1997; highest daily minimum temperature of 55 degrees F in 1988; record precipitation of 0.73 inches in 1906. Record snowfall is 5.0 inches also in 1980.

Average dew point for April 8th is 27°F; the maximum dew point on this date is 58°F in 1903; and the minimum dew point on this date is -4 degrees F in 1997.

All-time state records for April 8th:

The state record high temperature for this date is 92 degrees F at Canby (Yellow Medicine County) in 1931. The state record low temperature for this date is -12 degrees F at Saw Bill Camp (Cook County) in 1939. The state record precipitation for this date is 2.45 inches at Dawson (Lac Qui Parle County) in 1894. Record snowfall is 13.2 inches at Moorhead (Clay County) in 1904.

Past Weather Features:

April 8 of 1923 brought cold, mid-winter like conditions to many parts of the state. In the north, portions of Lake of the Woods, Roseau, and Clearwater Counties saw morning lows in the single digits below zero. Many other areas of the state reported lows in the single digits above zero. The afternoon high temperature at Campbell (Wilkin County) only reached 27°F.

April 8 of 1931 was the warmest in state history with afternoon temperatures of 80°F or greater being reported from 35 counties, and most of the rest of the state seeing 70s and 60s F. The warmest spot was Canby with 92°F while Grand Marais on Lake Superior only reached a high of 50°F.

A late season winter storm brought rain, sleet, and snow to most of Minnesota over April 6-8 of 1956. Many areas reported 5 to 10 inches of snowfall, while some parts of north-central and northeastern Minnesota reported 12 to 16 inches of snowfall. The snowfall and moisture were much appreciated as areas of the state were in moderate drought going into April of 1956.

Outlook:

Sunny, with temperatures closer to normal for Saturday. A few degrees warmer on Sunday, but with increasing cloudiness and a chance for rain or snow. Monday and Tuesday may bring temperatures a few degrees above normal but with chances for showers. More chances for rain or snow for Wednesday and Thursday as a strong low-pressure system crosses the region. Temperatures will be cooler than normal following the storm.