Drought 2008 (updated October 7, 2008)
U.S. Drought Monitor - September 30, 2008
For the sixteen-week period beginning in mid-June and extending into early October, many Minnesota communities received less than eight inches of rainfall. This came at a time of year when rainfall rates average roughly one inch per week. Thus, rainfall deficits over the sixteen-week dry spell topped five inches in many areas. Described another way, sixteen-week rainfall totals in some locales were less than 60 percent of normal for the period. When compared with the same sixteen-week time span in previous years, 2008 growing season rainfall ranked below the 5th percentile (one year in twenty) in many southern Minnesota communities (see maps below). In a few south-central Minnesota locations, precipitation totals for the period June 17 through October 6 were at or near the all-time historical minimum for that sixteen-week period.
Temperatures over the sixteen-week period were very close to historical averages. Days with temperatures in the 90 were relatively rare. This kept evaporative demand near seasonal norms and mitigated the situation somewhat.
As of September 30, the U.S. Drought Monitor rated much of Minnesota in the D0 - Abnormally Dry category or worse (see map at right). Significant portions of the state were placed in the D1 - Moderate Drought classification. A small area of south central Minnesota was designated as undergoing a D2 - Severe Drought.
Previous week's weather:
The weekly rainfall map for September 30 through October 6 showed that significant rain fell in some sections of central and northern Minnesota. Some communities reported over an inch of precipitation for the week. Unfortunately, most of the heavy rain missed the most drought-stricken areas of Minnesota. Temperatures for the week were cool, averaging one to three degrees below the seasonal normal.
Weather as of this writing:
As of this writing (October 7), rain continues to fall across nearly all of Minnesota. Radar-based estimates of precipitation for the past 24 hours indicate that one to three inches of rain has fallen on drought-designated areas in southwestern and central Minnesota. Gentle rainfall rates and low evaporative demand will assure that the soil moisture profile will benefit from this event. Some of the rain fell after a Tuesday morning data cutoff imposed on the U.S. Drought Monitor map-creation process. Therefore, many of the impacts of today's rain will be incorporated into the Drought Monitor in next week's product.
Sector briefs:
- Agriculture - The Agricultural Statistics Service reported that as of October 3, topsoil moisture across 29 percent of Minnesota's landscape was "Short" or "Very Short".
- Stream flow - Early October stream discharge in Minnesota rivers and streams was highly variable across the state. Some Minnesota streams reported flows that were below the 25th percentile in the historical distribution for the first week of October. By contrast, the Red River and many of its tributaries reported above-median flows in response to heavy rains that fell in August and early September.
- Wildfire Danger - The Department of Natural Resources - Division of Forestry classified early October wildfire danger as Moderate along Minnesota's North Shore and Low elsewhere.
Precipitation maps:
