HydroClim Minnesota - February 2001

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 2/7/01


- January precipitation was near to above normal across the southern two thirds of Minnesota, below normal in the northern third of the state. January precipitation totals exceeded one inch in many southern and central Minnesota communities, primarily due to a significant rain/ice/snow storm which struck Minnesota on January 29 and 30. Up to that point, January precipitation had been quite light.
(see: http://climate.umn.edu/cawap/monsum/monsum.asp )

- in sharp contrast to December, January temperatures were mild. Temperatures across Minnesota averaged 6 to 12 degrees above normal. For many communities, January 2001 temperatures were warmer than the Januaries of the previous three mild winters.
(see: http://climate.umn.edu/cawap/monsum/monsum.asp )



- although January was mild, temperatures remained cold enough to retain most of the snow cover accumulated during November and December. The snows of late January added to the snow pack, leading to snow depths exceeding 12 inches across large areas of Minnesota by month's end. Snow depths in the southwestern third of Minnesota rank above the 80th percentile for the date, and snow depths for the remainder of the southern half of Minnesota are above median. Snow depths for the northern half of Minnesota are at or below the median.
(see: http://climate.umn.edu/doc/snowmap.htm )

- snow water equivalent data gathered by the National Weather Service show that the snow pack across Minnesota generally contained two to three inches of water as of February 5.
(see: http://www.crh.noaa.gov/ncrfc/html_frames/snowindex.html )

- frost depths across the state range from near zero to 12 inches in areas receiving early and persistent snow cover, 24 to 36 inches in areas blown free of snow.
(see: http://www.mvp-wc.usace.army.mil/bulletins/Snow_Ice_Frost.html )

- 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 many points in the Red River basin are above the 90th percentile when compared to historical values for the date. Stream flows in other areas of the state are near to above average for the date.
(see: http://water.usgs.gov/cgi-bin/daily_flow?mn )

- as of their February 1 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.
(see: http://enso.unl.edu/monitor/monitor.html )

- the February 3 Palmer Drought Severity Index (PDSI) depicts most of Minnesota in the "Near Normal" category. Counties in northwest, south central, and southeast Minnesota are categorized as experiencing 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 30-day outlook from the Climate Prediction Center shows no significant tendencies (equal chances of below, near, and above normal) in February precipitation for nearly all of Minnesota. February is the year's driest month on average with normal precipitation values ranging from one half to three quarters of an inch. The February temperature outlook is also indeterminate for almost the entire state. Normal February high temperatures are in the upper teen's to low 20's early in the month, rising to the upper 20's and low 30's by month's end. Normal February lows average near zero to start the month and climb to around 10 degrees 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 February through April offers no deviation from the climatological probabilities across the state. The February through April temperature outlook calls shows no significant tendencies for all but far northeastern Minnesota. In the northeast, the outlook favors near normal conditions.
(see: http://www.cpc.ncep.noaa.gov/products/predictions/multi_season/13_seasonal_outlooks/color/seasonal_forecast.html )

- the National Weather Service now 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 the river, water equivalent of the snow cover, and soil moisture. The model is then 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 of temperature and precipitation. The model output is 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 Services (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/index.html for the Minnesota River basin)



- the U.S. Geological Survey is testing a new Web site designed to offer water resources data for Minnesota (and other states). See: http://water.usgs.gov/mn/nwis . The USGS would appreciate comments from water resources professionals.



- none



- February 15, Climate Prediction Center releases 30/90 day outlooks
- February 16-21 (date may vary), Probabilistic Flood Outlook from the National Weather Service
- February 23, Flood Potential Narrative Outlook from the National Weather Service



http://climate.umn.edu - Minnesota Climatology Working Group
http://www.crh.noaa.gov/ncrfc - National Weather Service - North Central River Forecast Center
http://enso.unl.edu/ndmc - National Drought Mitigation Center
http://www.cpc.ncep.noaa.gov - Climate Prediction Center
http://water.usgs.gov/cgi-bin/daily_flow?mn - U.S. Geological Survey, Minnesota
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
http://www.mvp-wc.usace.army.mil - U.S. Army Corps of Engineers, St. Paul District
http://water.usgs.gov/mn/nwis - U.S. Geological Survey - Water Resources for Minnesota test site


- Greg Mitton, U.S. Geological Survey - Mounds View

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