|HydroClim Minnesota - October 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
- September 2004 was among the wettest Septembers in the modern climate record. For many locations in southern, west central, and north central Minnesota, rainfall totals for the month topped seven inches. Rainfall totals for many locations in the southern tier of Minnesota counties exceeded ten inches in September. Monthly rainfall totals were three or more inches above normal for the month across large sections of Minnesota. When compared with other September rainfall totals in the historical database, September 2004 totals were at, or near, all-time record high values in many communities.
- in the southern tier of Minnesota counties, September rainfall totals were dominated by a single episode. Extremely heavy rains on September 14 and 15 produced one of the most significant flash flood events in Minnesota's climate history. During this event, a large section of north central Iowa and south central Minnesota was inundated by more than eight inches of rain over a 36 hour period. The deluge led to numerous reports of stream flooding, urban flooding, mudslides, and road closures.
- halting a tendency towards coolness initiated in May and continued throughout the summer, September 2004 temperatures were very warm. September monthly mean temperatures topped normal by three to seven degrees. For some communities, September 2004 was the among the warmest Septembers on record. In many locations, September temperatures were warmer than August temperatures. This is very rare, occurring only once before in the modern climate record. The temperature extremes for September ranged from 93 degrees at Browns Valley and Moorhead on the 2nd, to 19 degrees at Embarrass (St. Louis county) on the 28th.
WHERE WE STAND NOW
- growing season precipitation totals to date (April 1 through October 4) are very high for much of Minnesota. Bolstered by an extraordinarily wet September and an equally wet May, seasonal precipitation totals rank historically at or above the 70th percentile for approximately two thirds of Minnesota. Total seasonal rainfall for a significant portion of south central and southeastern Minnesota ranks at or above the 99th percentile, making this one of the wettest growing seasons on record in those areas. The wet weather was not universally distributed across the state during the warm season. Precipitation totals for the April through September time-frame fall short of normal by 20 or more percent in St. Louis, Lake, and Cook counties.
- as of September 28, the National Drought Mitigation Center (NDMC) - U. S. Drought Monitor indicated that all of the state of Minnesota is free of 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 Minnesota Agricultural Statistics Service reports that as of October 1, the state's topsoil moisture was 0% very short, 2% short, 75% adequate, and 23% surplus.
- U.S. Geological Survey stream gauging efforts indicate that stream discharge values across nearly all of Minnesota are high. Discharge values for approximately 40% of Minnesota's streams rank at or above the 90th percentile when compared with historical data for the date. More than 80% of all streams rank above the 75th percentile. Some monitoring locations in the Red River basin are showing all-time high 7-day average flow for this time of year. Stream discharge is below average only in some sections of northeastern Minnesota.
- the potential for wildfires is rated by DNR Forestry as "low" across Minnesota.
- the October precipitation outlook from the Climate Prediction Center indicates no significant tendencies away from climatological probabilities across Minnesota. Normal October precipitation ranges from one and one half inches in northwestern Minnesota, to over two and one half inches in portions of north central and northeastern Minnesota.
- the October temperature outlook shows a tendency towards below normal readings for most of Minnesota. Normal October high temperatures fall from the low to mid 60's early in the month to the upper 40's by month's end. Normal October low temperatures drop from the low 40's early in the month to near 30 by late October.
- the 90-day precipitation outlook for October through December indicates no significant tendencies away from climatological probabilities across Minnesota. The October through December 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. A 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 many 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
- we are pleased to announce that the 12th annual
presentation in the Kuehnast Lecture Series in Meteorology and Climatology
will be held Tuesday, October 12, 2004 at 330 PM. The lecture location is
Room 335 of Borlaug Hall on the University of Minnesota St Paul Campus.
The title of this year's lecture is "The Role of Sea Ice in Global
Climate", presented by Dr. Wallace Broecker of Columbia University.
Dr. Broecker has appeared frequently in the popular media in 2004
discussing the topic of abrupt climate change. The subject of abrupt
climate change was thrust into the limelight with the release of the movie
"The Day After Tomorrow" this past spring. The Kuehnast Lecture
Series honors our colleague, the late Earl Kuehnast, Minnesota State
Climatologist, 1968-1986. The Kuehnast family established an endowment
directed toward teaching and learning in atmospheric science. The lecture
series is co-sponsored by the University of Minnesota Department of Soil,
Water, and Climate - Kuehnast Endowment Fund and the local chapter of
Sigma XI (The Scientific Research Society).
NOTES FROM AROUND THE STATE
UPCOMING DATES OF NOTE
- October 12, Twelfth Annual Kuehnast LectureWEB SITES FEATURED IN THIS EDITION
- October 21, Climate Prediction Center releases 30/90 day temperature and precipitation outlooks
http://climate.umn.edu - Minnesota Climatology Working Group
http://www.drought.unl.edu/ - National Drought Mitigation Center
http://www.nass.usda.gov/mn/ - Minnesota Agricultural Statistics Service
- U.S. Geological Survey, Minnesota
- Minnesota Department of Natural Resources - Division of Waters
- Minnesota Department of Natural Resources - Division of Forestry
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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