HydroClim Minnesota - February 2008
A monthly electronic newsletter summarizing Minnesota's 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 happened in January:
- January 2008 precipitation totals were well below historical averages across most of Minnesota. Many locations reported less than one quarter of an inch of liquid precipitation, and less than four inches of snow. Exceptions to this snow-sparse pattern include the far southeastern corner of Minnesota and some locations along the Lake Superior snow belt. In those locales, precipitation totals were at, to somewhat above, the historical average.
[see: January 2008 Climate Summary Table]
Monthly mean temperatures for January 2008 were near historical averages. Minnesota experienced a classic "January thaw" early in the month, and endured its infamous bitter cold in two episodes later in January. Extreme values for January ranged from highs in the upper 40s in many Minnesota locations on January 5 and 6, to a low of minus 39 degrees at Embarrass (St. Louis County) on the 24th.
[see: January 2008 Climate Summary Table | January Thaw | January 29 Blizzard]
Minnesotans were subject to an extraordinary plunge in temperature on January 29. The temperature fell 45 degrees or more in a 24-hour period at nearly all reporting locations.
[see: Extreme Temperature Drop]
Where we stand now:
- The snow depth map prepared on January 31 shows that the northern one-third of Minnesota has at least eight inches of snow on the ground. Much of Minnesota's Arrowhead region is covered by more than 18 inches of snow. In the southern two-thirds of Minnesota, snow depths range from one to eight inches. Portions of west central, central, and southwest Minnesota have very little snow cover, whereas some counties in far southeastern Minnesota report around eight inches on the ground. Snow depth values are less than the historical median for the date across nearly all of Minnesota.
[see: January 31 Snow Depth Map]
- The U. S. Drought Monitor, released on January 31, continues to place a relatively small area of west central and central Minnesota in the "Moderate Drought" category. Portions of northwestern and north central Minnesota remain designated as "Abnormally Dry". This is an acknowledgement of some lingering precipitation deficits. All other Minnesota locales are deemed to be free of drought conditions. The U. S. Drought Monitor index is a blend of science and subjectivity where intensity categories are based on several indicators.
[see: U.S. Drought Monitor]
- The U.S. Geological Survey reports that stream discharge values, for observation points where winter measurements are possible, are near to above the median for the date in most locations.
[see: USGS Streamflow]
- The Lake Superior water level is up six inches from last year at this time. While the Lake Superior water level is no longer near the all-time seasonal low, it remains below the long-term average.
[see: Corps of Engineers Great Lakes Water Levels]
- In their final report of 2007, the Minnesota Agricultural Statistics Service reported that despite the dry November weather, mid-November topsoil moisture was "Adequate" across 83% of Minnesota's landscape. Topsoil moisture deficits should not be a concern in most areas at the start of the 2008 growing season.
[see: Ag. Statistics Service Crop Progress and Condition]
- Soil frost was driven to lower depths during the month of January by the cold weather. In many locales, the snow pack settled and consolidated during January, causing the snow to lose some of its insulating properties. Frost depths range from 18 to 32 inches in these areas. In those locations with deeper and less compacted snow cover (north central, northeastern, far southeastern Minnesota), frost depths are around 12 inches. Frost depths typically reach their maximum in late February or early March.
[see: U of M Climate Observatory | Ag. Statistics Service Ag News | MnDOT Road Frost Depths]
- The seasonally cold temperatures in January increased lake ice thickness and improved ice integrity. Nonetheless, ice conditions are never completely safe and caution is always advised when venturing onto Minnesota's lakes.
[see: DNR Enforcement Conservation Officer Reports]
- The February precipitation outlook from the Climate Prediction Center leans towards above-normal conditions in Minnesota's Arrowhead region, and offers no significant tendencies away from climatological probabilities elsewhere. 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).
[see: Climate Prediction Center 30-day Outlook | February Precipitation Normal Map]
- The February temperature outlook tilts towards above-normal conditions in southeastern Minnesota, and offers no significant tendencies away from climatological probabilities elsewhere. Normal February high temperatures range from the low-teens in the north to near 20 in the south early in the month, climbing to the mid-20s to low 30s 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.
[see: Climate Prediction Center 30-day Outlook | February Temperature Normal Map]
- The 90-day precipitation outlook for February through April indicates no significant tendencies away from climatological probabilities across Minnesota. The February through April temperature projection offers equal chances of above, near, or below average conditions.
[see: Climate Prediction Center 90-day Outlook]
- The National Weather Service produces long-range probabilistic river stage and discharge outlooks for the Red River, Minnesota River, and Mississippi River basins. These products are part of the National Weather Service's Advanced Hydrologic Prediction Service (AHPS).
[see: National Weather Service River Forecast Center]
From the author:
The Minnesota Department of Natural Resources - Division of Waters has released their 2005-2006 Water Year Data Summary. The publication provides a review and summary of basic hydrologic data gathered through DNR Waters programs during the 2005 and 2006 Water Years.
[see: Water Year Data Summary: 2005 and 2006]
Notes from around the state:
Upcoming dates of note:
- February 21: National Weather Service releases 30/90 day temperature and precipitation outlooks
- On or before February 22: National Weather Service releases probabilistic flood outlooks
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