|HydroClim Minnesota - August 2005
A monthly electronic newsletter summarizing Minnesota 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
WHAT HAS HAPPENED
- precipitation totals fell short of historical averages across much of Minnesota in July 2005. Combined with high evaporation rates resulting from warm July temperatures, the precipitation shortfall led to low stream flows and increased wildfire danger in some communities. When compared with other July rainfall totals in the historical database, July 2005 rainfall totals rank among the lowest on record for many locations in central and northern Minnesota.
- the heaviest rain storm of July came on the 2nd. Due to very strong thunderstorms skirting the Minnesota/Canadian border, a small area of north-central Kittson county received over five inches of rain in a relatively short period of time. Falling upon already saturated ground, the deluge led to significant overland flooding.
- the most beneficial rain of the month arguably occurred on July 25 when thunderstorms dropped one to three inches of rain upon a substantial portion of Minnesota's corn and soybean growing areas. These crops were (and are) in their moisture-sensitive reproductive growth stages and the timely rain greatly bolstered yield potential.
- July 2005 monthly mean temperatures were one to three degrees above normal in most areas. As happened in June, temperatures in July were consistently warm. Roughly two thirds of all July days were at or above average. Relatively few cool spells broke up July's typically warm weather. The temperature extremes for July ranged from 99 degrees at Winona on the 17th, to 30 degrees at Embarrass (St. Louis county) on the 29th.
WHERE WE STAND NOW
- growing season precipitation totals to date (April 1 - early August) show substantial spatial variation across Minnesota. In very general terms, seasonal precipitation totals are above average in western Minnesota, below average in the east. In some sections of west central and northwestern Minnesota, seasonal precipitation totals are greater than 125 percent of normal. Kittson county seasonal rainfall totals are near or above all-time record values to date. By contrast, some eastern counties (both in the south and in the north) have experienced a dry growing season, with rainfall totals falling short of normal by 20 percent or more.
- as of July 26, the National Drought Mitigation Center (NDMC) - U. S. Drought Monitor indicated that portions of east central and northeastern Minnesota are judged to be in the "D0 - Abnormally Dry" category. All other Minnesota counties are free of drought designations. A continuation of the dry/hot weather will cause areas already in the "D0" category to rapidly degrade into a more severe drought category, and portions of central Minnesota will slip into a "D0" classification. The NDMC index is a blend of science and subjectivity where intensity categories are based on six key indicators and numerous supplementary indicators.
- the Minnesota Agricultural Statistics Service reports that as of July 29th, the state's topsoil moisture was 4% very short, 19% short, 72% adequate, and 5% surplus.
- the U.S. Geological Survey indicates that stream discharge values vary widely across Minnesota. Approximately two thirds of Minnesota's rivers and streams rank near the median for the date. Stream flows in east central and northeastern Minnesota are low, falling below the 10th percentile for the date in isolated locations. Stream flows in west central and northwestern Minnesota remain high, topping the 90th percentile for the date in many spots. Stream flow values have climbed above the 90th percentile in far-southeastern Minnesota as well.
- the potential for wildfires is rated by DNR Forestry as "High" across portions of central, east central, and northeastern Minnesota. The fire danger is "Moderate" over much of the northern two thirds of the state. A "Low" fire danger rating is posted for much of the southern one third of Minnesota and in far-northwestern counties.
- the August precipitation outlook from the Climate Prediction Center indicates no significant tendencies away from climatological probabilities across Minnesota. August precipitation normals range from under three inches in northwestern and west central Minnesota to over four and one half inches in southeastern counties.
- the August temperature outlook also shows no significant tendencies away from climatological probabilities. Normal August high temperatures are around 80 degrees to start the month, dropping to the mid-70's by month's end. Normal lows are around 60 degrees early in the month, falling to the mid-50's by late August.
- the 90-day precipitation outlook for August through October indicates no significant tendencies away from climatological probabilities across Minnesota. The August through October temperature outlook also shows no tendencies away from climatological probabilities.
- 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).
FROM THE AUTHOR
NOTES FROM AROUND THE STATE
- noneUPCOMING DATES OF NOTE
- August 18, Climate Prediction Center releases 30/90 day temperature and precipitation outlooksWEB SITES FEATURED IN THIS EDITION
http://climate.umn.edu - Minnesota Climatology Working Group
- St. Cloud State University Earth and Atmospheric Sciences Department
http://www.drought.unl.edu - National Drought Mitigation Center
http://www.nass.usda.gov/mn/ - Minnesota Agricultural Statistics Service
- U.S. Geological Survey
- Minnesota Department of Natural Resources, Division of Forestry
http://www.cpc.ncep.noaa.gov - Climate Prediction Center
http://www.crh.noaa.gov/ncrfc/ - National Weather Service, North Central River Forecast Center
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