A monthly electronic newsletter summarizing Minnesota's climate conditions and the resulting impact on water resources. Distributed on the first Thursday of the month.
State Climatology Office - DNR Division of Ecological and Water Resources, St. Paul
distributed: October 6, 2016
What happened in September 2016:
- September 2016 was essentially an extension of the Wet Summer 2016 for many locations in Minnesota. Waseca in south central Minnesota wound up with its wettest month ever with 14.80 inches. Through October 5, the annual total for 2016 at Waseca is 49.11 inches. This is only 4.41 inches short of the all time annual Minnesota precipitation record of 53.52 inches that was set at St. Francis in 1991. The preliminary average statewide precipitation total was 4.49 inches, or 1.31 inches above normal. This would be enough for the 13th wettest September on record (1895-2016). The heaviest rain fell across southern Minnesota, where monthly departures were in excess of 3-5 inches south of the Twin Cities. Much of central and northern Minnesota locations were near to slightly above normal. The exception was the far northwest which was about 1-3 inches above normal.
[see: September 2016 Precipitation Total Map | September 2016 Precipitation Departure Map | September 2016 Climate Summary Table | September 2016 Percent of Normal Precipitation Map]
September 2016 had one notable heavy rain event and some severe weather as well. Some notable events of the month include:
- September had one heavy rain episode that fell in two different places. The heavy rains of September 20-22 hit parts of the northern Twin Cities hard from Maple Grove, Brooklyn Park and Fridley, causing street flooding and damage to culverts. Heavy rains also affected a broad area of south central and southeast Minnesota. In particular, the town of Waseca was greatly affected with 75% of the homes in town affected by flooding. The University of Minnesota Southern Research and Outreach Center saw 10.16 inches for a two day total.
[see: September 20-22, 2016 Heavy Rain]
- A tornado struck Camp Ripley during the night of September 7, damaging barracks and a newly-installed solar panel farm. Luckily, the tornado struck during the week when there were few personnel present.
[see: Tornado at Camp Ripley: September 7. 2016]
- Nearly lost was the fact that September was a very warm month. The preliminary average statewide temperature was 60.8 degrees or about 3.1 degrees above normal. This would be enough for the fifteenth warmest September on record (1895-2016). The all time record was set in 2015 with 63.7 degrees. The highest temperature found for the state was 90 degrees in Sherburn in Martin County on September 21. The coldest temperature for the month was 29 degrees at Embarrass in St. Louis County on September 29.
[see: September 2016 Climate Summary Table | 2016 September Departure from Normal Temperature Map]
Where we stand now:
- Seasonal precipitation totals (April 1 through October 4) ranked above the historical median over much of Minnesota, with much of south central, southeast and east central Minnesota in the 95% for the wettest growing season. Some areas are in the 99 percentile or nearly the wettest on record. Also, parts of northwest Minnesota rank in the 95 percentile as well. There are a few areas in north central and west central Minnesota that fall short of the median.
[see: Seasonal Precipitation Ranking Map]
- The U. S. Drought Monitor map released on October 6, depicts the entire state free of any drought designation. The state has been completely free of any drought designation for five weeks in a row, beginning on September 6. This is the longest stretch since the summer of 2014. The U.S. Drought Monitor index is a blend of science and subjectivity where drought categories (Moderate, Severe, etc.) are based on several indicators.
[see: Drought Conditions Overview]
- The U.S. Geological Survey reports that stream discharge values are much above normal across large sections of western, central and southern Minnesota. Normal flows are in the north central and northeast.
[see: USGS Stream Flow Conditions]
- Water levels on most Minnesota lakes vary depending on lake and location in the state. Mille Lacs was above the median lake level for September. On October 6, Minnetonka was at 929.37 with 200 cfs flowing through Grays Bay Dam. White Bear Lake was at 922.62 feet on October 6, a rise of 1.26 feet from one year ago and a rise of 3.78 feet from the record low of 918.84 measured January 10, 2013. Rainy and Lake of the Woods are in the median range for September. Lake Superior was at 602.72 feet on September 30, seven inches higher than the monthly average for September.
[see: Mille Lacs Lake Water Level | Lake Minnetonka Water Level | White Bear Lake Water Level | Lake of the Woods Control Board Basin Data | Corps of Engineers Great Lakes Water Levels]
- The Agricultural Statistics Service on October 3 reports that topsoil moisture across Minnesota is 0 percent Very Short, 2 percent Short, 56 percent Adequate, and 42 percent Surplus. Soil moisture levels at Lamberton and Waseca are well above the historical median.
[see: Agricultural Statistics Service Crop Progress and Condition | U. of M. Southwest Research and Outreach Center (Lamberton) | U. of M. Southern Research and Outreach Center (Waseca)]
- The potential for wildfires is currently rated by DNR Forestry as Low across Minnesota, except for northwest and parts of north east sections where the fire danger is Moderate. Historically, 80 percent of all wildfires in Minnesota occur during April and May.
[see: Fire Danger Rating Map]
- The October precipitation outlook leans towards above normal precipitation across the western half of the state with equal chances over the eastern half of Minnesota. October precipitation normals range from about one-and-a-half inches in northwest Minnesota to about three-and-a-half inches in Cook County. Southern and central Minnesota range by about one-and-three-quarters of an inch in the southwest to about two-and-a-half inches in east central Minnesota.
[see: Climate Prediction Center 30-day Outlook | October Precipitation Normal Map]
- The October temperature outlook leans towards above normal temperatures throughout Minnesota for October, with the best chance in far northeast and southeast Minnesota. Normal October high temperatures are in the 60's to start the month, dropping to the low 50's to upper 40's by month's end. Normal lows are in the 40's early in the month, falling to the 30's by late October.
[see: Climate Prediction Center 30-day Outlook | October Temperature Normal Map]
- The 90-day temperature outlook for October through December has a continuation of above normal temperatures, heavily weighted for the anticipated warm October, The 90-day precipitation outlook for October through December indicates equal chances of below-normal, near-normal, or above-normal conditions across most of Minnesota.
[see: Climate Prediction Center 90-day Outlook]
- The National Weather Service produces long-range probabilistic river stage and discharge outlooks for the Red River, Minnesota River, and Mississippi River basins. These products address both high flow and low flow probabilities.
[see: National Weather Service - North Central River Forecast Center]
From the author:
- The Winter Outlook (December-February) From the Climate Prediction Center has a slight tendency for below normal temperatures and equal chances for below, normal and above normal precipiation.
[see: Climate Prediction Center December-February Outlook]
Upcoming dates of note:
- October 20: National Weather Service releases 30/90 day temperature and precipitation outlooks
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Pete Boulay, DNR Climatologist