HydroClim Minnesota - November 2006
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 2006 precipitation totals were below average across Minnesota. October precipitation fell short of the historical normal by one to two inches in most locations. Many southern Minnesota communities received less than one half inch of rain for the month. The dry weather perpetuated the drought conditions that have been in place in the northern one half of Minnesota for the past six months. The unusually dry late-autumn weather has also increased concerns about topsoil moisture in the southern one half of the state. Most Minnesota communities saw at least a trace of snowfall. Some northern Minnesota locations received several inches of snow on October 12 and 13. By the end of October, some northern communities retained a light snow cover. However, warm temperatures in early November have eliminated the snow pack.
(see: http://climate.umn.edu/cawap/monsum/monsum.asp )
- monthly mean temperatures for October 2006 were cooler than average throughout Minnesota. Average temperatures for the month generally ranged from two to four degrees below normal. This was the coolest month, relative to normal, since May 2005. Very warm early October temperatures were more than offset by persistently cold temperatures in mid-October. Extreme values for the month ranged from near 90 degrees at various locations on October 2 and 3, to just 8 degrees at Embarrass on the 25th.
(see: http://climate.umn.edu/cawap/monsum/monsum.asp )
WHERE WE STAND NOW
- dryness has been entrenched across much of northern and central Minnesota for nearly six months. Rainfall totals over the past six months were less than nine inches in some areas of northwestern and north central Minnesota. Six-month rainfall totals have deviated negatively from historical averages by more than four inches across most of the northern one half of Minnesota. Rainfall deficits have exceeded six inches in many northern and central Minnesota communities. When compared with other mid-May to early-November rainfall totals in the historical database, this year's rainfall totals for the period rank below the 5th percentile (one year in twenty) in many northern and central Minnesota counties. For isolated areas of northern Minnesota, rainfall totals are among the lowest on record for the six-month period.
(see: http://climate.umn.edu/doc/journal/drought_situation_report_2006.htm , http://climate.umn.edu/doc/weekmap.asp )
- abnormally dry weather has returned to southern Minnesota. In the southern one half of the state, mid-summer dryness was ameliorated by substantial August and September rainfalls. However, for the past six weeks, rainfall totals have fallen short of average by two or more inches across most counties south of Interstate 94. In some of these areas, the late autumn is shaping up to be one of the driest on record.
- the National Drought Mitigation Center (NDMC) - U. S. Drought Monitor to be released on November 9 will continue to indicate that many northern Minnesota counties remain in the "Extreme Drought" or "Severe Drought" categories. The northern reaches of the Red River Valley are depicted in the "Moderate Drought" or "Abnormally Dry" classification. The November 9 map will introduce a "Abnormally Dry" polygon into sections of central and southwestern Minnesota. The NDMC index is a blend of science and subjectivity where intensity categories are based on several indicators.
(see: http://www.drought.unl.edu/dm/monitor.html )
- the Minnesota Agricultural Statistics Service reports that as of November 3, topsoil moisture for 35% of Minnesota's landscape was "Short" or "Very Short", a drop of 13 percentage points from the previous week. Subsoil moisture supplies were rated as 41% "Short" or "Very Short".
(see: http://www.nass.usda.gov/Statistics_by_State/Minnesota/Publications/Crop_Progress_&_Condition/index.asp )
- the U.S. Geological Survey indicates that stream discharge in roughly one third of Minnesota's rivers and streams falls below the 25th percentile when compared with historical data for this time of year. Flow conditions in many northern and central Minnesota watersheds remain below the protected flow threshold (lowest 10th percentile), leading the Department of Natural Resources to maintain surface water appropriation permit suspensions in these areas. Mississippi River flow conditions remain very low due to season-long rainfall deficits in the headwaters area. Lake levels continue to drop in northern and central Minnesota, exposing shoreline, and in some cases, making water access difficult.
(see: http://water.usgs.gov/cgi-bin/dailyMainW?state=mn&map_type=weekd, http://climate.umn.edu/dow/weekly_stream_flow/stream_flow_weekly.asp )
- the potential for wildfires is rated by DNR Forestry as "moderate" in portions of eastern Minnesota. The fire danger potential is rated as "low" elsewhere in the state.
(see: http://www.dnr.state.mn.us/forestry/fire/ )
- the November precipitation outlook from the Climate Prediction Center indicates no significant tendencies away from climatological probabilities across Minnesota. November precipitation normals range from around one inch in western Minnesota to over two 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.
(see: http://www.cpc.ncep.noaa.gov/products/predictions/30day , http://climate.umn.edu/img/normals/precip/precip_norm_11.htm )
- the November temperature outlook leans heavily towards above-normal conditions throughout Minnesota. Normal November high temperatures are in the mid-40's to upper 40's to start the month, dropping to the mid-20's to near 30 by month's end. Normal lows are in the upper 20's early in the month, falling into the mid-teens by late November.
(see: http://www.cpc.ncep.noaa.gov/products/predictions/30day , http://climate.umn.edu/img/normals/temp_norm_adj/temp_norm_adj_11.htm )
- the 90-day precipitation outlook for November through January indicates no significant tendencies away from climatological probabilities across Minnesota. The November through January temperature outlook indicates a tilt towards above-normal conditions throughout the state.
(see: http://www.cpc.ncep.noaa.gov/products/predictions/90day/lead01/index.html )
- 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: http://www.crh.noaa.gov/ncrfc/ )
FROM THE AUTHOR
NOTES FROM AROUND THE STATE
UPCOMING DATES OF NOTE
- November 16, Climate Prediction Center releases 30/90 day temperature and precipitation outlooks
WEB SITES FEATURED IN THIS EDITION
http://climate.umn.edu - Minnesota Climatology Working Group
http://www.drought.unl.edu - National Drought Mitigation Center
http://www.nass.usda.gov/Statistics_by_State/Minnesota/Publications/Crop_Progress_&_Condition/index.asp - USDA, National Agricultural Statistics Service
http://water.usgs.gov/cgi-bin/dailyMainW?state=mn&map_type=weekd - U.S. Geological Survey
http://www.dnr.state.mn.us/waters - Minnesota Department of Natural Resources, Division of Waters
http://www.dnr.state.mn.us/forestry - Minnesota Department of Natural Resources, Division of Forestry
http://www.cpc.ncep.noaa.gov - Climate Prediction Center
http://www.crh.noaa.gov/ncrfc - National Weather Service North Central River Forecast Center - Chanhassen
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