Last week’s rain/snow event helped alleviate drought:
The widespread precipitation of last week was welcome relief from the year-long drought conditions that prevailed, mostly in northern Minnesota. Many climate stations reported 1.5 to 2.0 inches of precipitation. In fact, 40 daily precipitation records were tied or set within the state climate network by this storm system. Along the shoreline communities of Lake Superior from Two Harbors to Grand Portage, many climate stations reported over 3 inches, up to nearly 4 inches. There was flooding in downtown Grand Marais. In areas with colder temperatures some significant snowfall amounts were reported. Thorhult (Beltrami County), Big Falls (Koochiching County), and Warroad (Roseau County) reported over a foot of snowfall last week.
With the abundant precipitation of last week, the landscape area in Severe to Extreme Drought across Minnesota shrunk to just 27 percent this week according to the US Drought Monitor. The area in Extreme Drought is down to just three percent of the Minnesota landscape, mostly in northern Lake and Cook Counties of the northeast. With soil temperatures dropping now into the mid to upper 30s F, they will soon be freezing up. Precipitation that falls after soil freeze-up will no longer be as available to recharge soil moisture levels. Given the climate outlooks it appears that some portions of northern Minnesota will emerge from winter still in some form of drought.
This week brought the lowest temperatures of the fall season so far with many climate stations reporting overnight lows in the single digits and teens. Some northern communities saw high temperatures remain the twenties on Monday of this week.
Weekly Weather Potpourri:
The BBC reported on the record-setting rainfalls in British Columbia (Canada) earlier this week. Some areas received between 4 and 11 inches of rain in less than 24 hours, causing widespread flooding of stream and rivers, as well as flash flooding of roads and highways. There were a number of landslides as well. Thousands of people were stranded and damage to infrastructure was severe.
The Washington Post also reported on the flooding in British Columbia this week, as well as the flooding in Western Washington State, where as much as 10 to 17 inches of rain has fallen over the past week. Some of these rains occurred over areas that reported wildfires this past summer, so there was consequently a lot of soil erosion.
This week’s AGU-EOS Bulletin features an article from the EPA about how a growing number of lakes in the Midwest of the USA are exceeding the World Health Organizations thresholds for concentrations of cyanobacteria. Cyanobacteria is the main organism associated with harmful algal blooms and toxins, so typical of the July through October period. One by one the causes of this high level of cyanobacteria for individual lakes can be addressed by local mitigation efforts.
MPR listener question:
A question from Nancy Daley (Minneapolis) and Tom McCann (Grand Marais) ….we were examining this map from N.H. Winchell showing the mean annual rainfall in Minnesota circa 1911. Has Mark seen this map (which was widely published) and does he have any comments about it?
Answer:
N.H. Winchell was State Geologist for Minnesota in the late 19th Century. He produced a number of maps concerning the state’s soils, geology, and lakes, as well as some climate maps. For the Atlas Map of Minnesota showing mean annual rainfall, the data used were from the old Smithsonian climate network (established in 1850s), the Signal Corps climate network (established in the 1870s) and the National Weather Service (established in 1891 within the Department of Agriculture). For Winchell’s rainfall atlas of Minnesota, they would have climate records from less than 50 places in the state for constructing their map. Today there are about 230 climate histories to use in constructing a map of mean annual precipitation.
Average annual precipitation at Grand Marais is about 2.5 inches greater today than it was in 1911. The Twin Cities mean annual precipitation is about 3.5 inches more today than it was in 1911. Extreme values of annual precipitation for the period 1858 (statehood) to 1911 ranged from 18 to 51.5 inches. Today the extreme values (through the year 2020) are 6.37 inches at Ortonville in 1976 to 60.21 inches at Harmony in 2018. Further, as evidence of climate change in our state, over 30 climate stations have reported at least one year with 50 or more inches of precipitation since 1991.
Twin Cities Almanac for November 19th:
The average MSP high temperature for this date is 40 degrees F (plus or minus 11 degrees F standard deviation), while the average low is 26 degrees F (plus or minus 10 degrees F standard deviation).
MSP Local Records for November 19th:
MSP records for this date: highest daily maximum temperature of 65 degrees F in 1930; lowest daily maximum temperature of 13 degrees F in 1894; lowest daily minimum temperature of -5 degrees F in 1932; highest daily minimum temperature of 48 degrees F in 1930; record precipitation of 1.00 inches in 1983. Record snowfall is 6.2 inches in 1981.
Average dew point for November 19th is 24°F; the maximum dew point on this date is 55°F in 1942; and the minimum dew point on this date is -4 degrees F in 1921.
All-time state records for November 19th:
The state record high temperature for this date is 74 degrees F at Montevideo (Chippewa County) in 1897. The state record low temperature for this date is -29 degrees F at Roseau (Roseau County) in 1896. The state record precipitation for this date is 2.85 inches at Grand Portage (Cook County) in 1998. Record snowfall is 19.0 inches at Dawson (Lac Qui County) in 1948.
Word of the Week: Jeelit
A Scottish weather word for absolutely freezing outside is “jeelit.” Perhaps Minnesota should invent its own jargon for very cold temperatures. I nominate the phrase “Sota cold” out there today.
Past Weather Features:
November 19, 1932 was like a mid-winter morning with most areas of the state reporting subzero temperatures. Warroad started the day at -20°F and only warmed up to a high of 6°F.
November 18-19, 1948 brought an early winter storm with rain, sleet, and snow. In southwestern Minnesota many communities reported 15-20 inches of snowfall. Marshall ended up with 24 inches of snowfall that month.
November 19, 1999 was probably the warmest in state history with over 30 climate stations reporting afternoon high temperatures between 60°F and 70°F. Some golf courses were open that day (a Friday) as many took the afternoon off work.
Outlook:
The weekend will start out somewhat mild on Saturday under partly cloudy skies. It will turn colder and breezy on Sunday with temperatures cooler than normal, and a chance for snow in northern areas of the state. Temperatures will warm up closer to normal for Tuesday and Wednesday, then cooler again for Thanksgiving and towards next weekend. No real significant precipitation is expected.
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