Climate roller coaster continues this month:
It has already been a wild ride weatherwise through the first three weeks of this March. Statewide extremes have been 79°F at Winona airport on the 14th and -20°F at Seagull Lake (Cook County) on the 2nd. Many maximum daily temperature records have been set this month, including two new statewide records (77°F at Granite Falls on the 10th, and 79°F at Winona airport on the 14th). In addition, a number of snowfall records have been set as well, most notably on March 4th, 5th, 17th, and 18th. Even this week, on Wednesday the 19th, a number of southern Minnesota communities were under a blizzard warning, and several observers reported record daily snowfalls, including:
9.0 inches at Spring Valley (Fillmore County)
7.5 inches at Grand Meadow (Mower County)
7.3 inches at Hokah (Houston County)
6.8 inches at Caledonia (Houston County)
4.0 inches at Albert Lea (Freeborn County)
The month has already brought a number of days with Red Flag Warnings (for fire danger) and many climate stations have reported 10 or more days this month with wind gusts of 30 mph or greater. Some have reported wind gusts over 50 mph.
So, for the first 3 weeks of the month, most climate stations report an average monthly temperature that is 6°F to 10°F warmer than normal. Precipitation is mixed, being above normal in several southern and central counties, but below normal in western counties. Forecasts for the balance of the month suggest generally wetter than normal conditions will prevail, but temperatures will bounce around both above and below normal at times.
Weekly Weather Potpourri:
NOAA Climate Prediction Center released a new Drought Outlook for the spring season this week. Unfortunately, the outlook favors drought persistence for much of Minnesota through June 20th. Only the southeastern counties, currently in Moderate Drought, are expected to see some relief this spring with above normal rainfall forecast there.
There is an interesting article on the Weather Underground web site this week about record-setting hourly rainfall rates. For the USA, the record is 12 inches in one-hour at Hold, Missouri on June 22, 1947. From the standpoint of severe thunderstorm rainfall rates, a 1 inch per hour rainfall rate almost always induces flash flooding. In Minnesota we have occasionally measured rainfall rates of 3 inches per hour, and those rates tend to produce serious and damaging flash flooding wherever they occur.
A new research article documents a variety of ways to evaluate the most extreme of weather records using historical documents and diaries, documents about past historical events, along with tree rings and climate models that can estimate extremes for given geographic locations. This article was published in Nature Communications. The authors make a case for using estimates of “plausible extremes” rather than measured historical extremes of weather to plan for building resilience into community infrastructure.
MPR listener question:
Unlike earlier this year, it seems recently that southern Minnesota has been getting more snow this month than northern Minnesota. Is this right and is it unusual?
Answer:
Yes, many southern Minnesota observers have reported total snowfall this month from 10 inches to 17 inches, and much of northern Minnesota has reported less than 8 inches for the month. Up north, only International Falls and Kabetogama have reported nearly a foot of snow so far. According to the DNR State Climatology Office the northern area of the state with 8 or more inches of snow cover has shrunk dramatically this month.
Twin Cities Almanac for March 21st:
The average MSP high temperature for this date is 44 degrees F (plus or minus 12 degrees F standard deviation), while the average low is 27 degrees F (plus or minus 10 degrees F standard deviation).
MSP Local Records for March 21st:
MSP records for this date: highest daily maximum temperature of 76 degrees F in 1938; lowest daily maximum temperature of 13 degrees F in 1965; lowest daily minimum temperature of -8 degrees F in 1965; highest daily minimum temperature of 55 degrees F in 2012, and record precipitation of 0.83 inches in 1904. Record snowfall is 3.9 inches also in 2008.
Average dew point for March 21st is 22°F; the maximum dew point on this date is 56°F in 2012 and the minimum dew point on this date is -11 degrees F in 1965.
All-time state records for March 21st:
The state record high temperature for this date is 81 degrees F at Montevideo (Lac Qui Parle County) in 1910. The state record low temperature for this date is -33 degrees F at Cotton (St Louis County) in 1965. The state record precipitation for this date is 2.00 inches at Ortonville (Big Stone County) in 1893. The statewide snowfall record for this date is 15.0 inches at Milan (Chippewa County) in 2008.
Past Weather:
March 21 of 1910 was probably the warmest in state history, as dozens of communities reported record-setting high daily maximum temperatures. Over 30 counties reported afternoon high temperatures of 70°F or greater. At Windom (Cottonwood County) the temperature rose from 32°F in the morning to 76°F in the afternoon.
Probably the coldest March 21 was in 1965 when nearly all areas of the state reported subzero morning low temperatures. Five northern counties reported lows of -30°F or colder. The afternoon high temperature at Gunflint Lake only reached 7°F.
A memorial Easter weekend in 2008, as over March 21-23 a slow-moving weather system brought heavy snow to many areas of the state. Dozens of climate stations reported snowfall totals from 6 inches to 10 inches. Many western communities reported over a foot of snowfall. The fresh snow brought one of the coldest Easter Sundays in state history.
Outlook:
Increasing cloudiness on Saturday with near-normal temperatures. Chance for snow and rain by late evening, then snow or rain all day on Sunday, with blustery winds. Mostly dry on Monday, with a chance for rain in far southern Minnesota later on Tuesday. Temperatures will climb above normal by mid to late week.
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