The monthly total rainfall was above normal for most places in the state, except for a few isolated pockets of dryness. Many climate observers reported total monthly rainfall that was 2-3 times normal, and on a statewide basis it was the 3rd wettest August in history and wettest since 1980. For many communities it was a near-record or record wet August. Some examples include:
11.85 inches at Red Wing
11.82 inches at Theilman (2nd wettest)
11.70 inches at Waseca (2nd wettest)
11.37 inches at Redwood Falls
9.70 inches at Chanhassen
8.96 inches at Twin Valley
8.74 inches at downtown St Paul
9.90 inches at University of Minnesota St Paul Campus
7.86 inches at Kabetogama
9.66 inches at Faribault (4th wettest)
10.21 inches at Milan (2nd wettest)
10.23 inches at Wabasha (2nd wettest)
8.36 inches at St Cloud (2nd wettest)
7.82 inches at MSP (6th wettest)
Severe weather plagued the state during the month on several occasions: Over August 10-11 severe thunderstorms moved across the west-central part of the state, bringing 4-7 inch rains to the Willmar-Olivia area, and later in the day to Wabasha County. Then over August 23-24 heavy rains fell across portions of southeastern Minnesota delivering 2-3 inch amounts, and nearly 8.5 inches south of the border in Decorah, Iowa. Then over August 27-28 heavy rains, strong winds, and some tornadoes were reported in Polk and Norman Counties of northwestern Minnesota. Some farm buildings were damaged in Norman County.
With the added rainfall from August, following a wet July, this summer season (June-August) now ranks as the 4th wettest in state history, as the average 3-month rainfall for the state was just shy of 16 inches. For the Twin Cities this has been the 8th wettest summer in history with a total rainfall of 17.40 inches.
Weekly Weather Potpourri:I will be broadcasting the MPR State Fair Weather Quiz with Tom Weber from the Minnesota State Fair on Friday morning at 11am (Sept 2). This year I had help from Greg Spoden, Pete Boulay, and Kenny Blumenfeld of the DNR-State Climatology Office in crafting the questions for the quiz. If you cannot listen to the broadcast you can find the quiz and take it for yourself at the MPR web site.
Hurricane Hermine was expected to bring high winds and heavy rains to Florida and then up the Atlantic coast states over Friday through Saturday. In the western Pacific Ocean Typhoon Namtheun was expected to bring heavy rains to southern Japan this weekend, while in the Central Pacific Ocean Hurricane Lester was expected to bring heavy rains and strong winds to parts of Hawaii.
There is a fascinating article on the NPR web site by Christopher Joyce about how the frigatebird uses clouds and air currents to stay aloft above the world's oceans for weeks at a time. They also fly at unusually high altitudes, above 12,000 feet. You can read more at the NPR web site.
MPR listener question:Normally by state fair time my ragweed allergies are quite bad. Usually they start up right around August 15 when the ragweed blooms. However, this year my allergies are quite mild and it is already September. Has the wet summer affected the ragweed in some way? or is the more frequent rain simply taking more pollen out of the air?
Answer:I would guess that both the frequency of rain over the past month, as well as the higher dew points (more moisture in the air) have somewhat suppressed the ragweed pollen count which according to the Twin Cities monitoring samples has been in the low to moderate category most days. Atmospheric moisture in both liquid form and vapor form (relative humidity) has been shown to keep less ragweed pollen from becoming airborne.
Twin Cities Almanac for September 2nd:The average MSP high temperature for this date is 77 degrees F (plus or minus 9 degrees F standard deviation), while the average low is 58 degrees F (plus or minus 7 degrees F standard deviation).
MSP Local Records for September 2nd:
MSP weather records for this date include: highest daily maximum temperature of 97 degrees F in 1937; lowest daily maximum temperature of 55 degrees F in 1952; lowest daily minimum temperature is 42 degrees F in 1974; highest daily minimum temperature of 76 degrees F in 1953; record precipitation of 1.97 inches in 2000; and no snowfall has occurred on this date.
Average dew point for September 2nd is 56 degrees F, with a maximum of 75 degrees F in 1997 and a minimum of 29 degrees F in 1974.
All-time state records for September 2nd:The state record high temperature for this date is 103 degrees F at Beardsley (Big Stone County) in 1929. The state record low temperature for this date is 22 degrees F at Sawbill Camp (Cook County) in 1935. State record precipitation for this date is 5.91 inches at Halstad (Norman County) in 1957; and no measurable snowfall has occurred on this date.
Past Weather Features:The hottest September 2nd in state history was in 1929. Over 50 Minnesota communities reported daytime highs in the 90s F, and in the west Wheaton, Montevideo, and Beardsley surpassed 100 degrees F.
September 1-2, 1937 brought heavy thunderstorms across northern Minnesota communities which reported from 3 to 5 inches of rain. There was widespread flooding in both the Duluth and Grand Rapids areas.