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 4, 2015 (delayed distribution)
What happened in November 2015:
- November monthly precipitation totals were much above average across nearly all of Minnesota. In many locations, November monthly precipitation totals exceeded the long-term mean by more than one inch. Preliminary data indicate that the state-averaged precipitation total (nearly three inches) for November 2015 will rank among the ten wettest November totals on record.
- Four significant rainfall or snowfall events occurred in Minnesota during November. Heavy rainfall was reported on November 11 and again November 16-19. Heavy snowfall fell in some locales November 19-20 and again on November 30.
- Average monthly temperatures for November were well above historical averages across Minnesota, ranging from five to seven degrees above normal. Preliminary data indicate that November 2015 will rank among the three warmest Novembers of the modern record. Preliminary data also reveal that the "meteorological autumn" (September through November) of 2015 will rank among the warmest ever. Extremes for November ranged from a high of 78 degrees F at Madison (Lac qui Parle County) on the 2nd, to a low of -7 degrees F at Camp Norris (Lake of the Woods County) on the 28th. A number of warm minimum temperature records were set on November 16 and 17.
Where we stand now:
- Snow depths across Minnesota vary from zero to eight inches. The deepest snow cover is found in southwest and west central Minnesota and along the Lake Superior highlands of northeast Minnesota.
- The U. S. Drought Monitor map released on December 3 depicts portions of west central, northwest, and far southeast Minnesota as Abnormally Dry due to precipitation deficits incurred earlier in the year. The map shows no other areas in Minnesota in a dryness category. The U.S. Drought Monitor index is a blend of science and subjectivity where drought categories (Moderate, Severe, etc.) are based on several indicators.
- The U.S. Geological Survey reports that stream discharge values are much above historical medians for the date on many Minnesota rivers.
- In their final report of the 2015 growing season (November 23), the Agricultural Statistics Service reported that topsoil moisture across Minnesota was 1 percent Very Short, 9 percent Short, 79 percent Adequate, and 11 percent Surplus.
- Soil frost depth under sod is quite shallow at most Minnesota observing locations.
- Some Minnesota lakes, rivers, and wetland complexes are ice covered. Warm November temperatures delayed ice formation. Lake and river ice is never completely safe.
Future prospects:
- The December precipitation outlook offers equal chances of below-normal, near-normal, or above-normal conditions across most of Minnesota. The December precipitation outlook tilts towards below-normal conditions in northwest Minnesota. December precipitation normals range from around one-half inch in western Minnesota to over one and one-quarter inches in eastern sections of the state. The historical median snow cover at the end of December ranges from under five inches in southwest counties, to over 10 inches on the ground in northeast Minnesota (20 inches in the Lake Superior highlands).
- The December temperature outlook emphatically leans towards above-normal conditions across Minnesota. Normal December high temperatures are in the mid-20s to near 30 to start the month, dropping to the mid-teens to near 20 by month's end. Normal lows are around 10 degrees early in the month, falling to the mid-single digits above and below zero by late December.
- The 90-day precipitation outlook for the meteorological winter (December through February) indicates equal chances of below-normal, near-normal, or above-normal conditions in the southern one-third of Minnesota and a tilt towards below-normal conditions in the northern two-thirds of the state. The December through February temperature projection strongly favors above-normal conditions statewide.
- 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.
Greg Spoden, DNR Climatologist