HydroClim Minnesota for Early October 2012
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: October 4, 2012
What happened in September 2012:
- Without exception, September 2012 monthly precipitation totals were very low across Minnesota. September rainfall totaled less than one inch in most locations, and less than one-half inch in numerous locales. The monthly precipitation totals fell short of the September average by two to three inches statewide. Preliminary data indicate that the state-averaged September 2012 precipitation total is either the driest or second driest in Minnesota's climate record. [see: September 2012 Climate Summary Table | September 2012 Monthly Precipitation Map | September 2012 Precipitation Departure from Normal Map]
- Monthly mean temperatures for September 2012 were very close to historical averages throughout Minnesota. Warmer than average days were offset by cooler than average nights. Large spreads between daytime and nighttime temperatures are common during spells of very dry weather. Extreme temperature values for September ranged from a high of 98 degrees F at Brownton (McCleod County) on the 11th; to a low of 16 degrees F at Warroad (Roseau County) on the 21st. Killing frosts occurred nearly everywhere in Minnesota in September. However, crops had reached full maturity and suffered little or no damage.
[see: September 2012 Climate Summary Table]
Where we stand now:
- The U. S. Drought Monitor, released on October 4, places portions of northwestern, southwestern, and south central Minnesota in the Extreme Drought category. Most of the rest of the state is depicted as undergoing Severe Drought or Moderate Drought. In total, 96 percent of Minnesota's landscape is considered to be in Moderate Drought or worse. 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 in southern Minnesota developed rapidly due to very hot and very dry conditions that began in mid-June and continued into the autumn. Extraordinarily dry conditions during the months of August and September 2012 caused rapid drought development in areas of Minnesota previously outside of the most intense drought regions. For those areas already undergoing significant drought, the late-summer/early-autumn extreme dryness exaggerated pre-existing conditions. Many Minnesota locales reported less than one and one-half inch of rainfall over the August plus September period. For large portions of Minnesota, August-plus-September 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.
[see: Minnesota Drought Condition Summary | Red River Basin Drought Decision Support System]
- 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.
[see: USGS stream flow conditions | MNDNR Weekly Stream Flow Maps and Tables]
- Water levels on many Minnesota lakes are very low in response to the dry, hot summer and early autumn. Lake Superior water level is similar to the 2011 level at this time of year, but well below the long-term average for the date.
[see: Lake Minnetonka Water Levels | White Bear Lake Water Levels | Lake of the Woods Control Board Basin Data | Corps of Engineers Great Lakes Water Levels]
- In their October 1 report, the Minnesota Agricultural Statistics Service reported that topsoil moisture was 44% Very Short, 41% Short, 15% Adequate, and 0% Surplus across Minnesota. This represents a significant degradation in conditions when compared with an early-June soil moisture survey reporting only 5% of the landscape Short or Very Short. Soil moisture measurements made in late September 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 autumn and early-spring rains are critically needed to replenish soil moisture reserves before the commencement of the 2013 growing season.
[see: Agricultural Statistics Service Crop Progress and Condition | U. of M. Southwest Research & Outreach Center (Lamberton) Soil Moisture | U. of M. Southern Research & Outreach Center (Waseca)]
- According to DNR Forestry, the potential for wildfires is explosively high in many areas of the state. Today's rain and snow in far northwest Minnesota has temporarily mitigated the situation there.
[see: Fire Danger Rating Map]
- The October precipitation outlook projects an equal likelihood of below-normal, near-normal, or above-normal conditions. Normal October precipitation ranges from one and one-half inches in northwestern Minnesota, to over two and one-half inches in portions of northeastern Minnesota.
[see: Climate Prediction Center 30-day Outlook | October Precipitation Normal Map]
- The October temperature outlook is weighted towards below-normal conditions across the state. Normal October high temperatures fall from the low to mid-60s early in the month, to the upper 40s by month's end. Normal October low temperatures drop from the low 40s early in the month to near 30 by late October.
[see: Climate Prediction Center 30-day Outlook | October Temperature Normal Map]
- The 90-day precipitation outlook for October through December offers an equal likelihood of below-normal, near-normal, or above-normal conditions across Minnesota. The October through December temperature projection tilts strongly towards above-normal conditions statewide.
[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:
Notes from around the state:
Upcoming dates of note:
- October 18: National Weather Service releases 30/90 day temperature and precipitation outlooks
- November 8: 20th Annual Kuehnast Lecture
Web sites featured in this edition:
- http://climate.umn.edu - Minnesota Climatology Working Group, Minnesota DNR Eco/Water Resources and U of M Dept. of Soil, Water, and Climate
- http://water.weather.gov/precip/ - National Weather Service, Advanced Hydrologic Prediction Service
- http://www.drought.unl.edu - National Drought Mitigation Center
- http://www.rrbdin.org/rddss - Red River Basin Drought Decision Support System, International Water Institute
- http://water.usgs.gov/cgi-bin/dailyMainW?state=mn&map_type=weekd - U.S. Geological Survey
- http://mndnr.gov/waters - Minnesota Department of Natural Resources, Division of Ecological and Water Resources
- http://www.minnehahacreek.org - Minnehaha Creek Watershed District
- http://lwcb.ca/ - Lake of the Woods Control Board
- http://www.lre.usace.army.mil - US Army Corps of Engineers, Detroit District
- http://www.nass.usda.gov - USDA, National Agricultural Statistics Service
- http://swroc.cfans.umn.edu - University of Minnesota, Southwest Research and Outreach Center, Lamberton
- http://sroc.cfans.umn.edu - University of Minnesota, Southern Research and Outreach Center, Waseca
- http://mndnr.gov/forestry - Minnesota Department of Natural Resources, Division of Forestry
- http://www.cpc.ncep.noaa.gov - National Weather Service, Climate Prediction Center
- http://www.crh.noaa.gov/ncrfc - National Weather Service, North Central River Forecast Center
To subscribe or unsubscribe to HydroClim Minnesota please notify .
Contributions of information and suggestions are welcome!