HydroClim Minnesota - July 2009
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 Waters
compiled 7/6/2009 (early release)
What happened in June:
- With a few notable exceptions, June 2009 was a seasonally dry month across nearly all of Minnesota. Many Minnesota locales reported June precipitation totals that fell short of the historical average by one to two inches. By contrast, some counties in the already-saturated Red River basin of northwestern Minnesota reported near to above-average rainfall for the month. Isolated areas of south central and southeastern Minnesota also received above-average June rain. The overall dryness in Minnesota extended a rainfall shortfall that began in early April and continues to the present.
[see: June 2009 Climate Summary Table | June 2009 Precipitation Departure Map]
Minnesota's heaviest rainfall event of the month occurred on June 16 when over six inches of rain fell on northern Wilkin County, leading to basement and road flooding. Heavy rain also fell June 26 and 27 in northwestern Minnesota. More than two inches of rain was reported in Polk, Red Lake, Pennington, Marshall, Kittson, and Roseau counties during the episode.
[see: Heavy Rain - June 16]
- Monthly mean temperatures for June were one to three degrees below the historical average statewide. The first half of June was very cool, with many days falling short of average by ten or more degrees. The cool early-June weather was offset somewhat by above-average temperatures during the third week of the month. Extreme temperature values for June ranged from highs in the mid-90's in many southern Minnesota locations on the 23rd, to a low of just 23 degrees in Embarrass (St. Louis County) on the 3rd. Across Minnesota many temperature records were set on June 5, 6, and 7 for coldest maximum or coldest minimum daily temperature.
[see: June 2009 Climate Summary Table | Cool June Weather]
Where we stand now:
- The U. S. Drought Monitor, released on June 30, placed areas of east central and southeastern Minnesota counties in the Moderate Drought and Severe Drought categories. Large portions of the rest of Minnesota are considered to be Abnormally Dry. The drought designations are the result of two spells of dry weather, one short-term and one longer-term. The shorter-term dryness has persisted since early April and impacts much of the state. The long-term dry spell commenced in mid-June 2008 and has persisted in east central and southeast Minnesota, producing 13-month precipitation deficits of eight or more inches. The U. S. Drought Monitor index is a blend of science and subjectivity where intensity categories are based on several indicators.
[see: Drought 2009]
- The U.S. Geological Survey reports that stream discharge values are low for many locations in south central, east central, and northeastern Minnesota. Flow rates at these locations rank below the 25th percentile in the historical distribution for early July. Stream discharge in a few east central and northeastern Minnesota rivers is below the 10th percentile for the date. By contrast, many points along the Red River its tributaries report flow rates well above the historical median for this time of year.
[see: USGS Streamflow | DNR Streamflow]
- The Lake Superior water level is down one inch from last year at this time and remains below the long-term average. Levels on many east central Minnesota lakes remain very low.
[see: Corps of Engineers Great Lakes Water Levels | White Bear Lake Water Level | Lake Minnetonka Water Level]
- The Minnesota Agricultural Statistics Service reports that as of July 5, topsoil moisture was 8% "Very Short", 23% "Short", 62% "Adequate", and 7% "Surplus". Topsoil moisture shortfalls exist across much of the central one-third of Minnesota. Soil moisture surpluses are found in northern Wilken, Polk, Marshall, Kittson, and Roseau counties.
[see: Agricultural Statistics Service Crop Progress and Condition]
- The potential for wildfires is currently rated by DNR Forestry as "Moderate" in east central and northeastern Minnesota counties. The fire danger rating is "High" in portions of Lake of the Woods and Koochiching counties. All other Minnesota counties are in the "Low" wildfire danger category as of this writing.
[see: Fire Danger Rating Map]
- The July precipitation outlook offers equal chances of above, near, and below normal rainfall. July precipitation normals range from just over three inches in far northwestern Minnesota to over four inches in eastern sections of the state
[see: Climate Prediction Center 30-day Outlook | July Precipitation Normal Map]
- The July temperature outlook indicates a tendency towards below-normal conditions. Normal July high temperatures are in the low to mid-80's. Normal July lows are around 60 degrees. July is the warmest month of the year in Minnesota.
[see: Climate Prediction Center 30-day Outlook | July Temperature Normal Map]
- The 90-day precipitation outlook for July through September shows no significant tendencies away from climatological probabilities. The July through September temperature projection also offers equal chances of above, near, and below normal conditions.
[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 River Forecast Center]
From the author:
Notes from around the state:
Upcoming dates of note:
- July 16: 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 Waters and U of M Dept. of Soil, Water, and Climate
- http://www.drought.unl.edu - National Drought Mitigation Center
- 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 Waters
- http://www.lre.usace.army.mil - US Army Corps of Engineers, Detroit District
- http://www.nass.usda.gov - USDA, National Agricultural Statistics Service
- 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
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