|HydroClim Minnesota -
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 1/5/01 (delayed distribution)
WHAT HAS HAPPENED
- December precipitation was above normal across southeastern and south central Minnesota, below normal in northeastern Minnesota, and near normal elsewhere. December precipitation totals topped two and one half inches in south central and southeastern Minnesota, exceeding long-term December averages by more than an inch in some places.
- much of Minnesota experienced abundant snowfall in December. Frequent snow events in some southern counties led to snowfall totals of over two feet for the month. This is double or even triple the historical averages for these areas. Rochester reported a new record total snowfall for December of over 33 inches.
- December temperatures were extremely cold, averaging 10 degrees below normal statewide. It was the coldest December since 1985 and one of the coldest Decembers ever. Minimum temperature records were set in various locations on December 12, 22, 24, and 25.
WHERE WE STAND NOW
- frequent and sometimes heavy snow events led to a significant snow cover across most of Minnesota by the end of December. By month's end, nearly all of Minnesota reported over 8 inches of snow on the ground, and in many locations, over 12 inches. Snow depths in the southwestern two thirds of Minnesota rank above the 80th percentile for the date.
- as of their January 2 release, the National Drought Mitigation Center - "U.S. Drought Monitor" shows Minnesota to be free of any 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 December 30 Palmer Drought Severity Index (PDSI) depicts most of Minnesota in the "Near Normal" category. Counties in northwestern and north central Minnesota are categorized as experiencing an "Unusual Moist Spell". The Palmer Drought Severity Index is used for assessing long-term meteorological conditions.
- stream discharge values are difficult to determine during the frozen water season. However, for gauging locations that provide winter data, the U.S. Geological Survey indicates that most streams in the Red River basin are above the 90th percentile when compared to historical values for the date. Stream flows in the remainder of the state are near average for the date.
- cold temperatures in December led to rapid lake and river ice development. Lake and river ice is the thickest in four years.
- frost depths across the state range from 8 to 20 inches in areas with adequate snow cover. In those areas blown free of snow cover, frost depths are much deeper.
- the 30-day outlook from the Climate Prediction Center calls for near normal January precipitation across all of Minnesota. Normal January precipitation ranges from near one half inch in western Minnesota, to one and one quarter inches in the far northeast. The January temperature outlook is for below normal conditions statewide. Normal January high temperatures are in the upper teen's to low 20's. Normal January lows average in the below-zero single digits in the north, the above-zero single digits in the south.
- the 90-day outlook for January through March indicates near normal precipitation statewide. The January through March temperature outlook calls for below normal conditions throughout Minnesota.
FROM THE AUTHOR
- (repeated from last month) ... although historical precipitation averages drop off significantly during November, central and east central Minnesota overcame the probabilities and received relief in the form of very heavy rains. The rains came before the first significant cold spell of the winter season, thus soils were unfrozen and receptive to recharge. While the rains have done much to alleviate hydrological imbalances in these areas, adequate spring snow-melt runoff and early spring rains are still necessary to fully rejuvenate wetland, lake, and stream levels in 2001.
Conversely, soil moisture and surface water systems are at unusually high levels in northwestern Minnesota, and above average spring snow-melt runoff or above average early spring rains could pose problems in the spring of 2001.
NOTES FROM AROUND THE STATE
UPCOMING DATES OF NOTE
- January 18, Climate Prediction Center releases 30/90
WEB SITES FEATURED IN THIS EDITION
http://climate.umn.edu - Minnesota Climatology Working Group
Contributions of information and suggestions are welcome!