Beneficial October Rains Continue:
Rains over the past week were more widespread, with significant amounts (over 1 inch) in roughly the southern half of the state. Many areas reported over 2 inches of rainfall, and some over 3 inches. The most rain occurred at places like St James (Watonwan County) and Marshall (Lyon County) which reported over 4 inches.
Over October 13 and 14 some long-term climate stations reported new daily record amounts of rainfall. A sampling:
On October 13:
2.50” at Marshall
2.42” at Albert Lea
2.34” at Milan
2.31” at St James
2.23” at Lamberton
2.13” at Collegeville
2.00” at Winnebago
On October 14:
1.87 inches at St James
1.43 inches at Owatonna
1.38 inches at Faribault
1.19 inches at Mora
These rains boosted the monthly totals to over 4 inches at many locations and certainly put a dent in the drought that has persisted through the summer and autumn seasons. The area of the state in Moderate Drought or worse fell by 14 percent from the previous week and now stands at roughly 58 percent of the state landscape. This is a drop of nearly 25 percent since the end of September. The rest of October is expected to see above normal rainfall, so we should expect some continued improvement in drought by the end of the month.
The NOAA Climate Prediction Center released a new Drought Outlook on Thursday, October 19 this week. It examines the expected weather patterns through January 31, 2024 and their impact on drought. The outlook suggests that over half of Minnesota will still be experiencing drought by the end of January, with some improvement in far southeastern portions of the state (primarily Houston, Winona, and Fillmore Counties).
Weekly Weather Potpourri:
The DNR-Minnesota State Climatology Office web site this week offers a detailed discussion of the winter weather impacts associated with an El Nino episode. It is clear that in most cases El Nino is associated with milder winter temperatures across Minnesota, as well as less seasonal snowfall, but it is not a 100 percent correlation. There have been exceptions to this association, like in the winters of 1991-1992 and 2018-2019.
A recent paper published in Hydrological Processes details the manner in which river water temperatures rise during episodes of drought. During drought conditions when river flow volumes are low, high atmospheric energy inputs can cause large increases in the water temperature. These very-high water temperatures have significant impact on freshwater ecosystem health. Climate change is bringing a higher frequency of drought and low waterflow volume to many areas. Potential ecosystem impacts of these frequent low flows, along with higher water temperatures need to be further studied to assess what management strategies might help mitigate detrimental effects on these freshwater ecosystems.
MPR listener question:
My favorite temps for working in the garden are the 60s … but we hardly EVER have highs in the 60s!! Seems like in the spring and fall, the normal daily highs in the Twin Cities are in the 60s F, but that is based on long-term averages, the reality is that the daily high temperatures seem to more often be in the 50s F or the 70s F. Can you verify this?
Answer:
Indeed, I have heard this before from other gardeners. For the Twin Cities climate normal high temperatures are in the 60s F in the spring from April 22 to May 17 (a period of 26 days), and they are in the 60s F during the autumn from September 25 to October 13 (a period of 19 days).
Based on long-term climatology, actual afternoon high temperatures during these periods of time in the spring and fall are in the 60s F only about one-third of the time. Most of the rest of the days bring high temperatures either in the 50s or 70s F. So in coping with reality and keeping your garden going, you must either bundle up and work in colder temperatures, or work in the morning hours before the temperatures climb above 70°F.
Twin Cities Almanac for October 20th
The average MSP high temperature for this date is 56 degrees F (plus or minus 11 degrees F standard deviation), while the average low is 39 degrees F (plus or minus 9 degrees F standard deviation).
MSP Local Records for October 20th:
MSP records for this date: highest daily maximum temperature of 83 degrees F in 1953; lowest daily maximum temperature of 32 degrees F in 1930; lowest daily minimum temperature of 18 degrees F in 1960; highest daily minimum temperature of 61 degrees F in 1920; record precipitation of 2.64 inches in 1934. There was a record 3.0 inches of snowfall in 1916.
Average dew point for October 20th is 37°F; the maximum dew point on this date is 66°F in 1920; and the minimum dew point on this date is 8 degrees F in 1952.
All-time state records for October 20th:
The state record high temperature for this date is 91 degrees F at Canby (Yellow Medicine County) in 1947. The state record low temperature for this date is -1 degrees F at Argyle (Marshall County) in 1916. The state record precipitation for this date is 3.95 inches at Chaska (Carver County) in 1934. The state snowfall record is 10.0 inches at Detroit Lakes (Becker County) in 1906.
Past Weather:
An early winter storm brought heavy snowfall to northwestern Minnesota on October 20 of 1906. Many areas reported 5 to 9 inches of snowfall. Detroit Lakes reported 10 inches, a statewide record for the date. It was a precursor to a heavy snow season for northern Minnesota during 1906-1907. Many areas had over 90 inches of snow and Leech Lake reported 110 inches.
With snow already on the ground in most places, October 20 of 1916 brought record-setting low temperatures to most of the state. Many climate stations reported morning lows in the single digits, while much of the rest of the state reported temperatures in the teens. The daytime high temperature at Fosston (Polk County) only reached 26°F.
The warmest October 20th occurred in 1947. Most areas of the state reported daytime high temperatures in the 70s and 80s F. Five southwestern Minnesota communities saw the thermometer reach 90°F. After a morning low of 38°F Wheaton (Traverse County) reported an afternoon high of 87°F.
Outlook:
Mostly warmer than normal and dry for Saturday through Monday, except for parts of northern Minnesota which will remain near normal temperatures with daily chances for showers. Chance for showers again late next Tuesday through Wednesday with much cooler temperatures. Temperatures will remain cooler than normal for the balance of the month after that.
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