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 11/7/01

WHAT HAS HAPPENED

- September precipitation patterns were highly variable. September precipitation totals in northwestern and west central Minnesota were somewhat above average. Conversely, precipitation in northeastern and south central counties was one to two inches below the norm. Elsewhere across the state, September precipitation was close to the long-term mean. October precipitation was also highly variable across the state. The northern one third of Minnesota received somewhat above average precipitation, whereas precipitation across the remainder of the state fell short of average by about one inch.
(see: http://climate.umn.edu/cawap/monsum/monsum.asp )
- the first blizzard conditions and heavy snow of the season occurred on October 24 and 25. Record breaking October snowfall fell in many northwestern Minnesota locations. Argyle (Marshall County) received a whopping 14 inches of snow. Hallock in Kittson County received 10 inches of snowfall. Eight inch snowfall totals were reported Crookston, Thief River Falls, and Roseau. Four inch totals were common across the remainder of the northern one half of Minnesota. High winds accompanying this powerful winter storm topped 40 miles per hour across most of the state. Very warm temperatures in the last few days of October and the first week of November has eliminated the snow cover.
(see: http://climate.umn.edu/doc/journal/011025.htm ) 
- September average temperatures finished near historical averages across Minnesota. Record warm temperatures early in the month were offset by cool mid and late-September weather. October temperatures also finished close to the historical mean. Like September, October offered wide swings in temperature. Record or near-record temperatures were reported early in the month, whereas very chilly weather prevailed in the later half of October. 
(see: http://climate.umn.edu/cawap/monsum/monsum.asp  )


WHERE WE STAND NOW

- seasonal precipitation maps from April 1 to November 5 reveal a highly variable pattern across Minnesota. Precipitation totals in far north central and northeastern Minnesota are very high for the period, ranking above the 95th percentile when compared to historical data for these months. Conversely, dry weather in central Minnesota has more than counterbalanced the impact of an extremely wet spring. In many of these areas, aggregate precipitation totals for April through October fall well below the historical median. Mid and late-summer precipitation shortfalls, along with a dry autumn, have led to an expanding area of moisture deficits in southwestern, central, and east central Minnesota.
(see: http://climate.umn.edu/doc/weekmap.asp )
- as of November 1, the National Drought Mitigation Center places a swath of counties through southwestern, central, and east central Minnesota in their "DO" category ("Abnormally Dry"). 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://enso.unl.edu/monitor/monitor.html )
- the November 3 Palmer Drought Severity Index (PDSI) from the Climate Prediction Center depicts southwestern, central, and east central Minnesota in the "moderate drought" category. The remainder of Minnesota is classified as "Near Normal". 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 as of Sunday, November 4 was rated 12% surplus, 65% adequate, 19% short, and 4% very short. They state that precipitation is needed before the ground freezes in order to replenish subsoil moisture.
(see: http://www.nass.usda.gov/mn/cwmn.htm )
- lake levels have dropped significantly in many areas from the record or near-record elevations reported this past spring. Lake levels remain relatively high in west central, northwestern, and far northern Minnesota. Lake levels are somewhat below average in central Minnesota, including metro lakes. Water levels in the Brainerd and Grand Rapids areas are near average for the date.
(lake level information for individual lakes can be found at:
http//www.dnr.state.mn.us/lakefind/index.html )
- the U.S. Geological Survey indicates that most stream flows in Minnesota fall in the normal category for the date. However, some exceptions exist. Stream flows on the Red River and its tributaries are relatively high, ranking above the 75th percentile. In some of these locations the discharge exceeds the 90th percentile. Stream flows in some east central Minnesota counties are relatively low, ranking below the 25th percentile for this time of year.
(see: http://water.usgs.gov/cgi-bin/dailyMainW?state=mn&map_type=weekd )
- the potential for wildfires is rated as "high" in east central Minnesota. Much of southern and central Minnesota, and some northern Minnesota counties are in the "moderate" potential category. Elsewhere across Minnesota, fire danger is characterized as "low" (see NOTES FROM AROUND THE STATE below)
(see: http://www.dnr.state.mn.us/forestry/fire/ )


FUTURE PROSPECTS

- the November precipitation outlook from the Climate Prediction Center tilts towards above normal values. November precipitation normals range from just under one inch in western Minnesota to around one and one half inches in eastern sections of the state. The average date of the first one inch snow cover ranges from the first week of November in northeastern Minnesota, to the final week of November in south central counties. The November temperature outlook leans towards colder than normal conditions. Normal November high temperatures are in the mid to upper-40's to start the month, dropping to the upper-20's by month's end. Normal lows are in the upper-20's early in the month, falling into the low-teens by late November.
(see: http://www.cpc.ncep.noaa.gov/products/predictions/multi_season/13_seasonal_outlooks/color/seasonal_forecast.html )
- the 90-day precipitation outlook for November through January shows no significant tendencies away from climatological probabilities. The November though January temperature outlook tilts towards below normal conditions. An important factor determining winter weather in the Midwest is the state of sea surface temperatures in the equatorial Pacific (El Niño and La Niña). At this time, neither El Niño nor La Niña conditions are prevalent. Climatologist sometimes jokingly refer to this as a "La Nada" condition. During "La Nada", winter weather in the Midwest can be quite variable, alternating between cold and mild spells, with intermittent snowy and dry periods.
(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/ahps/index.html )


FROM THE AUTHOR

- the growing season of 2001 was divided into two very distinct precipitation regimes. The period from April 1 until the third week of June was extraordinarily wet, ranking among the wettest springs on record. During the third week of June, the jet stream abruptly pushed north of the international border. The shift in the storm track has prevailed to this date, causing many storm systems to miss the state or to brush only the northern tier of counties. Surface hydrology in central Minnesota, including soil profiles, were maintained this summer by reserves built up during the wet early season. The bank account is running short in these areas, and late autumn recharge would be a welcome addition to surface water levels. Soil freeze-up is imminent. Therefore, early spring recharge will be especially critical in replenishing soil moisture reserves.


NOTES FROM AROUND THE STATE

UPCOMING DATES OF NOTE

WEB SITES FEATURED IN THIS EDITION

http://climate.umn.edu - Minnesota Climatology Working Group
http://enso.unl.edu/ndmc/ - National Drought Mitigation Center
http://www.cpc.ncep.noaa.gov - Climate Prediction Center
http://www.nass.usda.gov/mn/ - Minnesota Agricultural Statistics Service
http//www.dnr.state.mn.us/lakefind/index.html - Minnesota Department of Natural Resources
http://water.usgs.gov/cgi-bin/dailyMainW?state=mn&map_type=weekd - 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/ahps/index.html - National Weather Service - Central Region Headquarters


ACKNOWLEDGEMENTS

Contributions of information and suggestions are welcome!