HydroClim Minnesota - April 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

compiled 4/6/05


- March 2005 monthly precipitation totals were one half inch to one inch below average across most of Minnesota. Some portions of south central, southeastern, and eastern Minnesota received heavy rains from late-March thunderstorms, bringing monthly precipitation totals in these areas close to the historical March average.
(see: http://climate.umn.edu/cawap/monsum/monsum.asp )
- a late-winter storm dropped more than a foot of snow on the southern three tiers of Minnesota counties on March 17 and 18. Snowfall totals topping 18 inches were reported in many south central and southeastern Minnesota communities. The Rochester airport received 19.8 inches of snow on March 18, the largest single-day snowfall total ever recorded.
(see: http://climate.umn.edu/doc/journal/snow050318.htm )
- March 2005 monthly mean temperatures were near the historical average across Minnesota. Warmer than average temperatures at the end of March were offset by cooler than average temperatures early in the month. The temperature extremes for March ranged from 75 degrees at Browns Valley (Traverse county) on the 29th, to -30 degrees at Embarrass (St. Louis county) on the 8th.
(see: http://climate.umn.edu/cawap/monsum/monsum.asp )


- snow cover is sparse or nonexistent across most of Minnesota. Some snow remains on the ground in wooded areas of north central and northeast Minnesota, especially along the Lake Superior highlands.
- as of March 29, the National Drought Mitigation Center (NDMC) - U. S. Drought Monitor indicated that some counties in west central and central Minnesota fall in the "D0 - Abnormally Dry" category. All other areas in Minnesota are free of dryness designations. The NDMC index is a blend of science and subjectivity where intensity categories are based on six key indicators and numerous supplementary indicators.
(see: http://www.drought.unl.edu/dm/monitor.html )
- the frost is rapidly leaving the ground in most locales. Soil frost thaws from both the top and bottom, leaving a lens of ice between one and two feet below the surface. This lens of ice is the last to thaw; typically in early April in the south, early to mid-April in the north.
(see: http://climate.umn.edu/doc/observatory.htm , http://www.mvp-wc.usace.army.mil/projects/reservoirs.shtml )
- larger lakes in the southern one fourth of Minnesota are now free of ice. Many smaller lakes in the southern one half of the state are also ice free. Thus far this spring, lake ice-out dates have been close to average. Historically, average lake ice-out occurs during the first week of April in the southern tier of Minnesota counties; near the end of the second week of April in the Twin Cities metropolitan area; towards the end of the third week of April for Brainerd, Alexandria, and Detroit Lakes area lakes; and during the final week of April in far northern Minnesota.
(see: http://climate.umn.edu/doc/ice_out/ice_out_status_05.htm , http://www.dnr.state.mn.us/ice_out/index.html )
- the U.S. Geological Survey indicates that stream discharge values for approximately 60 percent of Minnesota's rivers are near the historical median for the date. Rivers are running high in the other areas. Stream discharge on the Red River and its tributaries is above the 90th percentile for the date at many gauging locations. Likewise, stream discharge tops the 90th percentile on the St. Croix and its tributaries. High flow is also reported on some north central and northeastern Minnesota rivers that have lost ice cover. Very high steam flows are anticipated for Lake Superior basin rivers in Minnesota.
(see: http://water.usgs.gov/cgi-bin/dailyMainW?state=mn&map_type=weekd , http://climate.umn.edu/dow/weekly_stream_flow/stream_flow_weekly.asp )
- the potential for wildfires is rated by DNR Forestry as "high" in east central Minnesota. The fire danger rating in northeast Minnesota and much of north central Minnesota is "low". Elsewhere the fire danger is designated as "moderate".
(see: http://www.dnr.state.mn.us/forestry/fire/ )


- the April precipitation outlook from the Climate Prediction Center indicates a tendency towards above normal conditions across Minnesota. April precipitation normals range from one and one half inches in northwestern Minnesota to around three inches in southeastern counties. The historical probability of measurable precipitation for any given day in April ranges from 20 percent in the far northwest to 35 percent in the southeast.
(see: http://www.cpc.ncep.noaa.gov/products/predictions/30day , http://climate.umn.edu/img/normals/precip/precip_norm_04.htm )
- the April temperature outlook from the Climate Prediction Center indicates a tilt towards above normal conditions across Minnesota. Normal April high temperatures are in the mid to upper 40's early in the month, rising to the low 60's by month's end. Early April normal low temperatures are near 20 in the north, near 30 in the south. By month's end, low temperatures average in the mid 30's in the north, near 40 in the south. 
(see: http://www.cpc.ncep.noaa.gov/products/predictions/30day , http://climate.umn.edu/img/normals/temp_norm_adj/temp_norm_adj_04.htm )
- the 90-day precipitation outlook for April through June indicates a tendency towards above normal rainfall across Minnesota. The April through June temperature outlook leans towards below normal conditions statewide.
(see: http://www.cpc.ncep.noaa.gov/products/predictions/90day/lead01/index.html )
- 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: http://www.crh.noaa.gov/ncrfc/ahps/ESPMAPS )


- none 


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- April 21, Climate Prediction Center releases 30/90 day temperature and precipitation outlooks


http://climate.umn.edu - Minnesota Climatology Working Group
http://www.drought.unl.edu - National Drought Mitigation Center
http://www.mvp-wc.usace.army.mil/projects/reservoirs.shtml - U.S. Army Corps of Engineers
http://www.dnr.state.mn.us/ - Minnesota Department of Natural Resources
http://water.usgs.gov/cgi-bin/dailyMainW?state=mn&map_type=weekd - U.S. Geological Survey
http://www.cpc.ncep.noaa.gov - Climate Prediction Center
http://www.crh.noaa.gov/ncrfc/ - National Weather Service, North Central River Forecast Center


- none

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