A monthly electronic newsletter summarizing Minnesota's climate conditions and the resulting impact on water resources. Distributed on the first Thursday of each month.
State Climatology Office - DNR Division of Ecological and Water Resources, St. Paul
distributed: November 1, 2012
What happened in October 2012:
[see: October 23-25 Rains]
- October 2012 monthly precipitation totals were below-average across much of Minnesota, doing little to improve the state's overall drought situation. October rainfall totaled less than two inches in most locations, falling short of the historical average by an inch or more. There were a few exceptions to this overall pattern of dryness. Above-average precipitation was reported in some northwest, far northern, and far southeastern Minnesota counties.
- Significant precipitation events during October included an early-season snow event in northwest Minnesota on October 4, and widespread rain on October 23-25.
- Monthly mean temperatures for October 2012 were somewhat below historical averages throughout Minnesota. In the Twin Cities, it was the first below-average month since May 2011. Extreme temperature values for October ranged from a high of 83 degrees F at Milan (Chippewa County) on the 3rd; to a low of 8 degrees F at Babbitt (St. Louis County) on the 31st.
Where we stand now:
- The U. S. Drought Monitor, released on November 1, places portions of northwestern, west central, central, southwestern, and south central Minnesota in the Extreme Drought category. In total, 43% of Minnesota's landscape is considered to be in Extreme Drought or Severe Drought. Most of the remainder of the state is undergoing Moderate Drought. The drought situation in northwest Minnesota and in far southeast Minnesota is the result of an historically dry autumn in 2011, a snow-sparse winter, and a dry 2012 growing season. The moisture deficits elsewhere in Minnesota developed rapidly due to very hot and very dry conditions that began in late-June and continued into the autumn. For large portions of Minnesota, August-through-October 2012 rainfall totals rank at or below the lowest on record. 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 and Minnesota DNR report that stream discharge values are extremely low at numerous Minnesota reporting locations. Many stream flow values rank below the 10th percentile when compared with historical data for this time of year.
- Water levels on many Minnesota lakes are very low in response to the dry summer and autumn. Lake Superior water level is near its all-time record low for this time of year.
- In their October 31 report, the Minnesota Agricultural Statistics Service reported that topsoil moisture was 27% Very Short, 42% Short, 29% Adequate, and 2% Surplus across Minnesota. Subsoil moisture is said to be 88% Very Short or Short. Soil moisture measurements made during October at University of Minnesota Research and Outreach Centers indicate extraordinarily dry conditions in the soil profile. Soil moisture content in the top five feet of soil at these locations is near or below all-time lows for this time of year. Ample early-spring rains are critically needed to replenish soil moisture reserves before the commencement of the 2013 growing season.
- According to DNR Forestry, the potential for wildfires is "Moderate" to "High" in portions of northwest, east central, and southeast Minnesota. Elsewhere, the fire danger rating is "Low."
- The November precipitation outlook tilts towards above-normal conditions. November precipitation normals range from around one inch in western Minnesota to over two inches in eastern sections of the state. The average date of the first enduring snow cover ranges from the first week of November in northeastern Minnesota to the final week of November in south central counties.
- The November temperature outlook is weighted towards above-normal conditions in the western one-half of Minnesota, equal chances of below-normal, near-normal, or above-normal conditions in eastern Minnesota. Normal November high temperatures are in the mid-40s to upper 40s to start the month, dropping to the mid-20s to near 30 by month's end. Normal lows are in the upper 20s early in the month, falling into the mid-teens by late November.
- The 90-day precipitation outlook for November through January tilts strongly towards below-normal conditions across Minnesota. The November through January temperature projection offers an equal likelihood of below-normal, near-normal, or 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.