|HydroClim Minnesota - February 2004
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
- while January 2004 snowfall was abundant in many Minnesota communities, precipitation (liquid equivalent) totals fell short of the historical average by around one half inch in most places. Many of January's snow events coincided with the presence of very cold temperatures, limiting the amount of water vapor available to the snow making processes. Only in far northwestern and far northeastern Minnesota did January precipitation meet or exceed normal. The below-normal precipitation pattern continues a spell of dryer-than-average weather that began in July 2003.
- the most significant snow event of the month occurred on January 25 through 27. A major snowstorm affected much of Minnesota over this three-day period. The greatest snowfall totals were along the Lake Superior shore, where lake-enhanced snowfall totals topped two feet in some locations. The 27.1 inches that fell in Duluth made this storm the 3rd largest snow producer in that city's history. Other significant snow events occurred on January 14 and 15 in northern Minnesota, and January 31 through February 2 in southeastern Minnesota.
- January 2004 mean monthly temperatures across Minnesota were near normal in the southern Minnesota, three to seven degrees below normal in the north. The month featured regular excursions of arctic air into Minnesota. Nearly every community in Minnesota experienced at least one day of minus 20 degree temperatures or colder. Many locations reported minimum temperatures below minus 30. The coldest temperature of the month was minus 50 at Fosston (Polk county) on January 30. A handful of low temperature records were broken during the final days of January. Temperatures in January 2004 were some of the coldest recorded since 1996. In contrast to the frigid temperatures late in the month, the first few days of January were quite warm. On the 2nd of January, the temperature in Canby (Yellow Medicine county) reached 51 degrees. The difference between the warmest January 2004 temperature in Minnesota (plus 51 degrees) and the coldest (minus 50 degrees), was an astounding 101 degrees.
WHERE WE STAND NOW
- tomorrow's (February 5, 2004) snow depth map will indicate that nearly all of Minnesota is covered by at least eight inches of snow. Snow depths are greater than 12 inches in the southern one quarter of the state, and the northern one half of Minnesota. Snow cover exceeds 18 inches across all of northeastern Minnesota, and snow depths top 30 inches along stretches of the Lake Superior highlands. Snow depth ranking maps compare the present snow cover with historical snow depth data for the date. Tomorrow's map will indicate that snow depths are above median across the southern one half of Minnesota, much of northwestern Minnesota, and much of northeastern Minnesota. In many of these areas, snow depths rank above the 80th percentile for the date. Elsewhere across Minnesota, this week's snow depths are near the historical median.
- as of January 27, the National Drought Mitigation Center - U. S. Drought Monitor indicated that most of Minnesota was judged to be in the "D0 - Abnormally Dry" or "D1 - Moderate Drought" categories. Southeastern and south central Minnesota counties were rated in the "D2 - Severe Drought" to "D3 - Extreme Drought" classification. The NDMC index is a blend of science and subjectivity where intensity categories are based on six key indicators and numerous supplementary indicators.
- soil frost depths around Minnesota range from 18 to 30 inches. Historically, frost steadily progresses deeper into the soil throughout the winter and reaches maximum depth in late February.
- the February precipitation outlook from the Climate Prediction Center shows no significant tendencies away from climatological probabilities. Historically, February is Minnesota's driest month with precipitation normals ranging from near one half inch in northwestern Minnesota to just over one inch in far eastern sections of the state. The median snow depth at the end of February ranges from under 5 inches in southwest Minnesota, to over 18 inches on the ground in northeastern Minnesota (greater than 30 inches in the Lake Superior highlands). The February temperature outlook also indicates no significant tendencies away from climatological probabilities. Normal February high temperatures range the low-teens in the north to near 20 in the south early in the month, climbing to the mid-20's to low 30's by month's end. Normal February low temperatures range from near minus 10 degrees in the far north to the single digits above zero in southern Minnesota early in the month; ascending to the low single digits in the north, mid-teens in the south by the end of February.
- the 90-day precipitation outlook for February through April shows no significant tendencies away from climatological probabilities. The February though April temperature outlook also indicates no significant tendencies away from climatological probabilities.
- the National Weather Service produces long-range probabilistic river stage and discharge outlooks for the Red River, Minnesota River, and Mississippi River basins. The latest model output indicates very low probabilities of significant river flooding between now and mid-April anywhere in Minnesota. The hydrologic model is initialized using current conditions of stream flow and soil moisture across a basin. The model is allowed to run into the future with multiple scenarios using multiple 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
NOTES FROM AROUND THE STATE
UPCOMING DATES OF NOTE
- February 19, Climate Prediction Center releases 30/90 day temperature and precipitation outlooksWEB SITES FEATURED IN THIS EDITION
- February 25, Interagency Flood Planning Coordination Meeting, National Weather
Service - Chanhassen
- Minnesota Climatology Working Group
http://www.drought.unl.edu - National Drought Mitigation Center
- U.S. Army Corps of Engineers
http://www.cpc.ncep.noaa.gov - Climate Prediction Center
http://www.crh.noaa.gov/ahps - National Weather Service, Central Region Headquarters
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