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: December 6, 2018
What happened in November 2018:
- November fell short for precipitation across most of Minnesota. The only exceptions were in the far southeast and far northeast. In general precipitation departures were around a half inch below normal. The driest locations were in the north central part of the state. The wettest locations were in Winona and the far northeastern tip of Cook County that saw departures of 2.5 inches above normal.
[see: November 2018 Preliminary Precipitation Total Map | November 2018 Precipitation Departure Map | November 2018 Climate Summary Table | November 2018 Percent of Normal Precipitation Map]
- November was the second below normal month in a row. The preliminary average statewide temperature was 24.5 degrees or 6.5 degrees colder than normal. The coldest reading was -15F at Babbitt and Isabella on the 20th. The warmest high temperature reading was 61 degrees at Marshall in southwest Minnesota on the 1st
[see: November 2018 Climate Summary Table | 2018 November Departure from Normal Temperature Map ]
Where we stand now:
- As of December 6, 2018 there is snow cover southern and northern Minnesota, but snow cover is scant over central Minnesota. The deepest snow cover in the state is where the December 1-2 snow storm dropped a thick blanket of snow from Marshall to Mankato and Winona southward to the Iowa border. Four to eight inches of snow remains on the ground in these areas. There is also about four to six inches of snow cover in northeast Minnesota as well.
[see: NWS Snow Depth Estimation Map | Midwest Regional Climate Center Snow Depth Map| MNDNR Snow Depth Map for Dec 6]
- The US Drought Monitor Map released on December 6 depicts a small area in Northwest Minnesota in Abnormally Dry conditions. This is a reduction over the previous week. 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]
- Ice is affecting many streams across Minnesota, especially across the central and north. Where there is some open water the U.S. Geological Survey reports that stream discharge values are near normal across east central Minnesota, with above normal streamflows in southeast Minnesota.
[see: USGS Stream Flow Conditions]
- On December 6 the level of Mille Lacs was .66 feet above the median for the date and has been above the median since June. The final lake level reading for Minnetonka was on November 20 with 928.54 feet and Grays Bay Dam became closed for the season. White Bear Lake was at 923.99 feet on December 6, a rise of 1.13 feet from one year ago and a fall of .15 feet from the high point of 924.24 back on October 10-11, 2018. The current level of White Bear Lake is still 5.15 feet higher than the record low level 918.84 measured on January 10, 2013. Rainy and Lake of the Woods are in the median range for early December. Lake Superior was at 602.79 feet on November 30, ten inches higher than the monthly average for late November.
[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 November 25 reports that topsoil moisture across Minnesota is 0 percent Very Short, 1 percent Short, 75 percent Adequate, and 25 percent Surplus. Corn for grain harvest at 96% complete was five days behind the five-year average. Soil moisture levels at Lamberton and Waseca were above the historical median for the last report in early November.
[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. Historically, 80 percent of all wildfires in Minnesota occur during April and May.
[see: Fire Danger Rating Map]
- The soils froze over during the month of November. The deepest frost is across the north with a depth of 12 inches in Duluth.
[see: National Weather Service Frost Depth Data | National Weather Service Soil Temperature Data
- The December precipitation outlook that was released on November 30 is a bit of a reflection on the snowstorm that occurred on December 1-2, thus southern Minnesota is poised to have an above normal precipitation month, while there is a tilt for below normal precipitation for the areas that were missed by this storm over the north
[see: Climate Prediction Center 30-day Outlook | December Precipitation Normal Map]
- The December temperature trend has a tendency for above normal temperatures statewide, especially in the northwest. Normal December high temperatures are in the upper 20's to low 30's to start the month, dropping to the low to mid 20's by month's end. Normal lows are in the teens early in the month, falling to single digits by late December.
[see: Climate Prediction Center 30-day Outlook | December Temperature Normal Map]
- The 90-day temperature outlook for December through February shows an El Nino-like signature, tilting towards above normal conditions across Minnesota, and much of the northern tier states. The 90-day precipitation outlook for December through February indicates a slight edge for below-normal conditions across the Great Lakes, including northeast Minnesota, signifying a potential of less lake-enhanced snowfall for the Arrowhead. Otherwise, the outlook is equal chances for above normal and below normal precipitation for the rest 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 cold November caused most lakes and ponds to freeze over between November 13 and November 28, several days to ten days ahead of the median. Lengthy lake ice in records are difficult to come by. Waconia is an exception with 80 years of lake ice in records. In 2018 Waconia froze over on November 28th, the earliest since 2001, but much later than the record early lake ice in of November 7, 1991 in the aftermath of the Halloween Blizzard.
[see: Median Lake Ice in Dates]
- September to November 2018 ranked high on the “gloomy factor.” Looking at solar radiation records at the U of M St. Paul Campus Climate Observatory back to 1963, the 2018 meteorological autumn was the 4th gloomiest on record.
[see: Gloomy Autumn: 2018]
Upcoming dates of note:
- December 20: National Weather Service releases 30/90 day temperature and precipitation outlooks
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Pete Boulay, DNR Climatologist