|HydroClim Minnesota - May 2006
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 for April 2006 were well above the historical average in the southern two thirds of Minnesota. Near to below average precipitation totals were reported in much of the northern one third of the state. Along the southern tier of Minnesota counties, April rainfall totals ranged from six to eight inches. These totals were three to five inches above long-term averages. For many communities in far southern Minnesota, it was the wettest April on record.
- the heaviest rainfall events of April occurred during the first and last weeks of the month. Rainfall totals topped three inches during the first week of April along the southern tier of Minnesota counties. An April 6-7 event broke daily rainfall records for Fairmont, Albert Lea, Rochester, and elsewhere. On April 6, 2.58 inches of rain fell at the Twin Cities International Airport, the wettest April day of the modern record. The month of April ended on a wet note as well. A remarkably persistent rain event dropped one to three inches of rain over a large portion of Minnesota during the final three days of the month.
- April 2006 monthly mean temperatures were very warm throughout Minnesota. April mean temperatures exceeded the historical average by four to eight degrees. Daily mean temperatures during a nine-day period in mid-April were consistently 10 to 20 degrees above normal. Many new records were broken in southern Minnesota on April 13 when maximum temperatures reached well into the 80's. The temperature extremes for April ranged from 90 degrees at St. James (Watonwan county) on the 13th, to 9 degrees at Embarrass (St. Louis county) on the 8th.
WHERE WE STAND NOW
- the prolonged high water season continues on the Red River. Water levels along the northern reaches of the river are finally expected to drop below flood stage by week's end. However, water levels along the southern portions of the river may again rise slightly above flood stage during the next day or two.
- as of April 25, the National Drought Mitigation Center (NDMC) - U. S. Drought Monitor indicated that all Minnesota counties are free of drought designations. 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 April 28, the state's topsoil moisture was 2% very short, 10% short, 75% adequate, and 13% surplus. This evaluation was made before the weekend rains affected most of Minnesota's agricultural regions.
- all of Minnesota's lakes are free of ice. Very warm temperatures during mid-April led to early lake ice-out in northern Minnesota. Lake ice-out was seven to fourteen days earlier than the historical average in many northern locations. In the southern half of Minnesota, lake ice-out was one to three days earlier than average.
- due to this past weekend's rains, stream discharge values for all southern and western Minnesota rivers and streams rank above the 75th percentile for the date. In a few of these basins, stream flow values are greater than the 90th percentile. Flows in most north central and northeastern Minnesota streams are near the historical median. Some low flows are reported in far northeastern Minnesota.
- the potential for wildfires is rated by DNR Forestry as "low" in nearly all Minnesota counties. A few northwest Minnesota counties fall in the "moderate" fire danger category.
- the May precipitation outlook from the Climate Prediction Center indicates no significant tendencies away from climatological probabilities across Minnesota. May precipitation normals range from just over two inches in northwestern Minnesota to just less than four inches in southeastern counties. The historical probability of measurable precipitation for any given day in May ranges from 25 percent in the northwest to near 40 percent in the southeast.
- the May temperature outlook from the Climate Prediction Center indicates no significant tendencies away from climatological probabilities across Minnesota. Normal May high temperatures are in the low to mid-60's early in the month, rising to the low to mid-70's at month's end. Normal May low temperatures are in the mid-30's to near 40 to start the month and climb to the mid-40's to low 50's as the month ends.
- the 90-day precipitation outlook for May through July indicates a tilt towards above normal rainfall across Minnesota, especially northern Minnesota. The May through July temperature outlook leans towards below normal temperatures statewide.
FROM THE AUTHOR
- fortunately, dry early-April weather in northwestern Minnesota helped to ease the flooding situation in the Red River basin. Nonetheless, moderate to major flooding was experienced in many locations within the watershed. Even though the April 2006 flood crest levels at many communities in the region ranked historically high, flood damage was held in check by short-term actions, long-term projects, and a well-timed dry spell.
NOTES FROM AROUND THE STATE
UPCOMING DATES OF NOTE
- May 18, Climate Prediction Center releases 30/90 day temperature and precipitation outlooksWEB SITES FEATURED IN THIS EDITION
- Minnesota Climatology Working Group
http://www.dnr.state.mn.us/waters - Minnesota Department of Natural Resources, Division of Waters
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://www.dnr.state.mn.us/forestry - Minnesota Department of Natural Resources, Division of Forestry
http://www.cpc.ncep.noaa.gov - Climate Prediction Center
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