HydroClim Minnesota - December 2011
A monthly electronic newsletter summarizing Minnesota's climate conditions and the resulting impact on water resources. Distributed on the Wednesday following the first Monday of each month.
State Climatology Office - DNR Division of Ecological and Water Resources, St. Paul
prepared: December 6, 2011 (released one day early)
What happened in November 2011:
- November 2011 was another dry month across Minnesota. This marked the fourth consecutive month of widespread precipitation shortfalls. For many locations, November precipitation totals failed to reach one-half inch. In nearly all counties, monthly precipitation fell short of the historical average by one to one and one-half inches. In some locales, it was among the driest Novembers of the modern record.
[see: November 2011 Climate Summary Table | November Precipitation Departure from Normal]
- Monthly mean temperatures for November 2011 were warm, topping the historical average by four to six degrees across Minnesota. Preliminary data indicate that November 2011 will rank among the warmest Novembers in the historical record. Extreme temperature values for November ranged from a high of 67 degrees F at various southeast and east central Minnesota reporting stations on the 1st and again on the 12th, to a low of -6 degrees F at Hallock (Kittson County) on the 17th and Madison (Lac Qui Parle County) on the 20th. Maximum temperature records were set at numerous locations on November 23 and 24.
[see: November 2011 Climate Summary Table]
Where we stand now:
- Significant precipitation shortfalls were reported across Minnesota over the period from late-July through November. Precipitation totals for the period were less than three inches in many southern Minnesota counties, a negative departure from the long-term average of five to nine inches. When compared with the same period in the historical database, the late-summer through autumn 2011 precipitation totals rank among the lowest on record. Similar patterns are evident when looking at precipitation data for only the meteorological autumn (September through November). A significant portion of Minnesota reported autumn precipitation deficits of five or more inches. For a large section of the southern one-third of Minnesota, this autumn was the driest on record.
[see: Dry Late-Summer/Autumn 2011 | Driest Autumn Ever in the Twin Cities]
- The U. S. Drought Monitor, released on November 29, depicts every Minnesota county as experiencing some level of drought. Large sections of north central and northeast Minnesota are said to be undergoing Severe Drought or Moderate Drought. Stream flow and lake levels in those areas are very low due to the ongoing impact of precipitation deficits accrued during the 2010 growing season and spotty rainfall this season. The Drought Monitor also places much of southern Minnesota in the Severe Drought or Moderate Drought categories. Late-summer and autumn precipitation has been minimal across the southern one-third of Minnesota. 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: U.S. Drought Monitor]
- Northeast Minnesota counties report four to six inches of snow cover as of this writing. A narrow stripe of four-inch snow cover also extends through a few southeast Minnesota counties. Elsewhere in Minnesota, snow depths are generally one to three inches, with some locations reporting a snow-free landscape. In nearly all locations, the present snow depth is below the historical median.
[see: NWS Snow Depth Estimation Map | Snow Depth Maps]
- The Lake Superior water level is near its elevation of a year ago, but down 11 inches from the long-term seasonal average. The water level on White Bear Lake (Ramsey/Washington county border) remains quite low. The White Bear Lake elevation is up by roughly one-half foot after reaching an all-time record low level mark in November 2010. Lake levels in far northern Minnesota are very low when compared with historical averages, especially lakes along the Canadian border.
[see: Corps of Engineers Great Lakes Water Levels | White Bear Lake Water Level | Lake of the Woods Control Board Basin Data]
- In their final report of the season (November 7), the Minnesota Agricultural Statistics Service reported that topsoil moisture was 28% Very Short, 43% Short, 29% Adequate, and 0% Surplus across the state. Dry soils made autumn tillage very difficult in many areas and heightened concerns about the soil moisture profile for next growing season. Late-autumn conditions act as a predictor of the soil moisture situation entering the 2012 growing season.
[see: Agricultural Statistics Service Crop Progress and Condition | U. of M. Southwest Research Center (Lamberton) Soil Moisture]
- The upper layer of the soil profile is frozen to a few inches in most Minnesota locales.
[see: Corps of Engineers Snow, Ice, Frost Data | MnDOT Road Frost Depths | National Weather Service Frost Depth Data]
- Many Minnesota lakes and rivers are now ice covered. Sustained sub-freezing temperatures in early December enhanced ice development. Ice conditions are highly variable. Lake and river ice is NEVER completely safe for walking or driving.
[see: DNR Conservation Officer Reports]
- The December precipitation outlook presents an equal likelihood of below-normal, near-normal, or above-normal conditions across 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 median snow cover at the end of December ranges from under 5 inches in southwest counties, to over 10 inches on the ground in northeast Minnesota (20 inches in the Lake Superior highlands).
[see: Climate Prediction Center 30-day Outlook | December Precipitation Normal Map]
- The December temperature outlook also offers an equal likelihood of below-normal, near-normal, or above-normal conditions throughout the state. 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.
[see: Climate Prediction Center 30-day Outlook | December Temperature Normal Map]
- The 90-day precipitation outlook for December through February tilts towards above-normal snowfall in Minnesota, especially in northwest counties. The December through February temperature projection indicates a tendency towards below-normal conditions throughout Minnesota, particularly in the northern one-half of the state.
[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 are part of the National Weather Service's Advanced Hydrologic Prediction Service (AHPS).
[see: National Weather Service - North Central River Forecast Center]
From the author:
Notes from around the state:
Upcoming dates of note:
- December 15: National Weather Service releases 30/90 day temperature and precipitation outlooks
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.nohrsc.noaa.gov - National Weather Service, National Operational Hydrologic Remote Sensing Center
- http://www.lre.usace.army.mil - US Army Corps of Engineers, Detroit District
- http://mndnr.gov/waters - Minnesota Department of Natural Resources, Division of Ecological and Water Resources
- http://lwcb.ca/ - Lake of the Woods Control Board
- 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://www.mvp-wc.usace.army.mil - U.S. Army Corps of Engineers, St. Paul District
- http://www.dot.state.mn.us/materials/index.html - Office of Materials & Road Research, MnDOT
- http://mndnr.gov/enforcement - Minnesota Department of Natural Resources, Division of Enforcement
- 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
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