|HydroClim Minnesota - November 2002
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
- October precipitation totals were well above normal over all but north central and northeastern Minnesota. Substantial, early October rains across the southern two-thirds of Minnesota, plus mid month snow events over northern and central sections of the state, pushed October precipitation totals above historical averages by one to two inches.WHERE WE STAND NOW
- a storm system moving through the Midwest on October 20 and 21 was responsible for laying down a band of heavy snow across central Minnesota. Snowfall totals ranging between six and eight inches were reported along a 20 mile wide swath from Fergus Falls in west central Minnesota to Hinckley in east central Minnesota. This snow event, along with other lesser snow events set new daily and monthly October snowfall records in some communities.
- October temperatures were extraordinarily cold across all of Minnesota. It was Minnesota's coldest October since 1925, and the third coldest October of the modern record. Mean monthly October temperatures were five to eight degrees colder than the historical average, presenting a temperature regime more typical of early to mid-November. Many daily low temperature records were set throughout the month.
- October was also quite gloomy. Solar radiation measurements made on the St. Paul campus of the University of Minnesota indicate that October 2002 finished with the lowest October daily average solar radiation value in the 40 year history of the data set (1963-present).
- seasonal precipitation accumulations to date (April 1 - November 4) are very high relative to historical values across northwest, central, and east central Minnesota. In these areas, precipitation totals exceeded historical averages by more than 50 percent for the season. In many communities, precipitation totals are near, or above, all-time record values for the April through October period. For some locales in the wettest areas, 2002 annual precipitation totals to date are already approaching all-time calendar year records.
- as of November 6, a light snow cover (one inch or less) blanketed portions of north central and northeast Minnesota.
- cold October temperatures resulted in ice formation on many ponds, wetlands, and small lakes across the state by early November.
- as of October 29, the National Drought Mitigation Center - U. S. Drought Monitor shows that all Minnesota counties are free of drought designation. The NDMC index is a blend of science and subjectivity where intensity categories are based on six key indicators and numerous supplementary indicators.
- the November 2 Palmer Drought Severity Index map from the Climate Prediction Center places central and east central Minnesota in the "Extremely Moist" category, the wettest designation. Northwest and southeast Minnesota are in the "Very Moist Spell" category. Southwest and south central Minnesota fall in the "Unusual Moist Spell" category. Other Minnesota regions are classified as "Near Normal". The Palmer Drought Severity Index is used for assessing long-term meteorological conditions.
- the Minnesota Agricultural Statistics Service reports that as of November 3, the state's topsoil moisture was 20% surplus, 79% adequate, and 1% short.
- the U.S. Geological Survey indicates that stream discharge values are in the normal range for roughly one half of Minnesota's rivers. Streamflows for most of the rivers not in the normal category are high (above the 75th percentile but below the 90th percentile for the date). Discharge values for a few northeast Minnesota streams are low, ranking below the 25th percentile for the date.
- the potential for wildfires is rated as "Low" across all of Minnesota.
- the November precipitation outlook from the Climate Prediction Center shows no significant tendencies away from climatological probabilities. 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 enduring 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 indicates a tilt towards above normal conditions. Normal November high temperatures are in the mid-40's 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.
- the 90-day precipitation outlook for November through January shows no significant tendencies away from climatological probabilities. The November though January temperature outlook indicates a strong bias towards above normal conditions.
- the National Weather Service produces long-range probabilistic river stage and discharge outlooks for the Red River, Minnesota River, and upper Mississippi 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 historical climatological data. The climatological data are weighted by 90-day climate outlooks for temperature and precipitation trends. Model output offers a complete range of probabilistic values of stream stage and discharge for numerous forecast points. The product provides 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 are produced near the middle of each month.
FROM THE AUTHOR
- (repeated and modified from last month) warmer than average sea surface temperatures presently exist in the eastern and central equatorial Pacific Ocean. This phenomenon, known as "El Niņo", can have a significant influence on winter weather in the United States and elsewhere. In Minnesota, El Niņos correlate highly with above normal winter temperatures, but have little correlation with winter snowfall totals. At present the conditions are indicative of a moderate El Niņo episode. All forecasts indicate that this episode will be weaker than the 1997-1999 El Niņo event, and therefore the corresponding impacts should be weaker than those observed during the winters of 1997-1998 and 1998-1999.
NOTES FROM AROUND THE STATE
- noneUPCOMING DATES OF NOTE
- November 21, Climate Prediction Center releases 30/90 day temperature and precipitation outlooks WEB SITES FEATURED IN THIS EDITION
- Minnesota Climatology Working Group
http://www.drought.unl.edu/ - National Drought Mitigation Center
http://www.cpc.ncep.noaa.gov - Climate Prediction Center
http://www.nass.usda.gov/mn - Minnesota Agricultural Statistics Service
http://swroc.coafes.umn.edu/ - University of Minnesota - Southwest Research and Outreach Center
http://water.usgs.gov/cgi-bin/dailyMainW?state=mn&map_type=weekd - U.S. Geological Survey, Minnesota
- Minnesota DNR Waters
http://www.dnr.state.mn.us/forestry/fire/ - Minnesota DNR Forestry
http://www.crh.noaa.gov/ahps/index.html - National Weather Service - Central Region Headquarters
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