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 6/6/01

WHAT HAS HAPPENED

- May precipitation totals were above normal across much of Minnesota. Some portions of southwestern, west central, and central Minnesota reported near average May precipitation, however the remainder of the state finished one to two inches above normal for the month. The precipitation was not only heavy in some areas, but unusually persistent. A very slow moving storm system brought daily rains to some locations for eight consecutive days (May 19 - May 26).  
(see: http://climate.umn.edu/cawap/monsum/monsum.asp , http://climate.umn.edu/doc/journal/morewet010529.htm , http://climate.umn.edu/doc/journal/coldwet010525.htm )
- when compared with historical data, April plus May 2001 precipitation totals ranked near all-time record high values for portions of southeastern, east central, central, northeastern, and north central Minnesota. April plus May precipitation totals ranked above the 90th percentile for most other locations.
(see: http://climate.umn.edu/doc/weekmap.asp )
- a flash flood occurred on May 20 in Nobles county, closing Interstate 90 for more than two hours and causing significant soil erosion. The largest recorded precipitation total for the event was 6.70 inches in Reading. The event was of limited geographical extent, affecting only central Nobles county.
- May temperatures were near to slightly above normal across most of Minnesota. Mid-May temperatures climbed into the 90's, setting new maximum temperature records at some locations on the 15th. However the warmth was offset by cold temperatures during the final two weeks of the month, with many low maximum temperature records broken on the 22nd and 23rd of May.
(see: http://climate.umn.edu/cawap/monsum/monsum.asp , http://climate.umn.edu/doc/journal/coldwet010525.htm )


WHERE WE STAND NOW

- as of June 4, growing season (beginning April 1) precipitation totals were more than 150 percent of normal across much of the state. Growing season precipitation totals exceeded 200 percent of normal in some north central and northeastern Minnesota counties. By contrast, growing season precipitation totals for portions of northwestern Minnesota were near historical averages for the period.
(see: http://climate.umn.edu/doc/weekmap.asp )
- the June 2 Palmer Drought Severity Index (PDSI) depicts southern central Minnesota as "Extremely Moist", the wettest designation. All other southern Minnesota counties, plus central and northeastern Minnesota, were categorized as experiencing a "Very Moist Spell". East central, north central, and northwestern Minnesota communities were undergoing an "Unusual Moist Spell". The Palmer Drought Severity Index is used for assessing long-term meteorological conditions.
(see: http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/regional_monitoring/palmer.gif )
- the Minnesota Agricultural Statistics Service reports that topsoil moisture statewide as of Friday, June 1 was rated 41% surplus, 59% adequate, 0% short, and 0% very short. The wet conditions continued to hinder agricultural field work and stress crops.
(see: http://www.nass.usda.gov/mn/cwmn.htm )
- streams flows remain high for most of Minnesota's rivers. The U.S. Geological Survey indicates that stream flows at many locations along the Red, Minnesota, and Mississippi rivers, and their tributaries, are above the 90th percentile for the date. For nearly all other locations, stream flows are above the 75th percentile when compared with historical values for the date.
(see: http://water.usgs.gov/cgi-bin/daily_flow?mn )
- the potential for wildfires is low in nearly all Minnesota counties. The fire danger rating is categorized as "moderate" in Cook county, as well as portions of Lake and St. Louis counties.
(see: http://www.dnr.state.mn.us/forestry/fire/ )


FUTURE PROSPECTS

- the 30-day outlook from the Climate Prediction Center shows a tilt towards above normal June precipitation for Minnesota. June is historically the wettest month of the year with precipitation normals ranging from three and a half inches in the far north to near five inches in Minnesota's southern tier of counties. The June temperature outlook calls for below normal conditions in the southwestern one half of Minnesota, with no significant tendencies away from climatological probabilities elsewhere in the state. Normal June high temperatures are in the low to mid 70's early in the month, rising to around 80 by month's end. Normal June lows are in the low 50's to start the month, and climb to around 60 as the month ends.
(see: http://www.cpc.ncep.noaa.gov/products/predictions/multi_season/13_seasonal_outlooks/color/seasonal_forecast.html )
- the 90-day precipitation outlook for June through August tilts towards above normal precipitation in the southwestern one half of Minnesota, with no significant tendencies away from climatological probabilities elsewhere in the state. The June though August temperature outlook shows no significant tendencies away from climatological probabilities.
(see: http://www.cpc.ncep.noaa.gov/products/predictions/multi_season/13_seasonal_outlooks/color/seasonal_forecast.html )
- the National Weather Service produces long-range probabilistic river stage and discharge outlooks for the Red River and Minnesota River basins. A hydrologic model is initialized using the current conditions of stream flow and soil moisture across a basin. The model is allowed to run into the future with multiple scenarios using more than 30 years of climatological data. The climatological data are weighted by the 90 day outlooks for temperature and precipitation trends. The model output offers a complete range of probabilistic values of stream stage and discharge for numerous forecast points. The product offers a risk assessment tool which can be used in long-range planning decisions involving flooding or low-flow concerns. These products are part of the National Weather Service's Advanced Hydrologic Prediction Service (AHPS) and will be produced near the middle of each month. The AHPS service will be available for the Mississippi River Basin in the autumn of 2002.
(see: http://www.crh.noaa.gov/fgf/ahps/ahpsmain.htm for the Red River basin, http://www.crh.noaa.gov/mpx/ahps/ for the Minnesota River basin)


FROM THE AUTHOR

- none


NOTES FROM AROUND THE STATE

- none


UPCOMING DATES OF NOTE

WEB SITES FEATURED IN THIS EDITION

http://climate.umn.edu - Minnesota Climatology Working Group
http://www.cpc.ncep.noaa.gov - Climate Prediction Center
http://www.nass.usda.gov/mn/ - Minnesota Agricultural Statistics Service
http://water.usgs.gov/cgi-bin/daily_flow?mn - U.S. Geological Survey, Minnesota
http://www.dnr.state.mn.us/forestry/fire/ - Minnesota Department of Natural Resources - Division of Forestry http://www.crh.noaa.gov/fgf - National Weather Service Forecast Office - Grand Forks
http://www.crh.noaa.gov/mpx - National Weather Service Forecast Office - Chanhassen


ACKNOWLEDGEMENTS

Contributions of information and suggestions are welcome!