Minnesota Drought Situation Report - September 27, 2007

Drought Monitor - September 25, 2007
Drought Monitor Map
Drought Monitor Legend

Drought Status:
The latest U. S. Drought Monitor (see map at right) shows significant improvement from the previous week's map. Heavy rains last week eliminated Extreme Drought designations in northeastern Minnesota and substantially decreased the geographic extent of Extreme Drought areas in central Minnesota. Drought conditions across sizeable sections of northern and central Minnesota improved by two categories; advancing from Severe Drought to animation).

The U. S. Drought Monitor index is a blend of science and subjectivity where intensity categories are based on several indicators.

Weekly Precipitation Map Last week's weather:
Rainfall totals for the week ending Monday morning, September 24 were quite heavy across large sections of northern and central Minnesota. Weekly rainfall totals in excess of three inches were common (see map at left). Northwestern and southern Minnesota counties were missed by the heavy rains. Long-term average rainfall rates rainfall totals are beginning to drop off at this time of year to around one half inch per week. Temperatures last week were warm, averaging four to six degrees above normal. Temperatures in some southern and western Minnesota locations topped 90 degrees at least once last week.

Summer Dryness (June 5 - September 24):
Dryness was entrenched across northern and central Minnesota for much of the summer. September rains have significantly improved the situation in many areas. However, rainfall for the sixteen-week period from June 5 through September 24 totaled less than eight inches for some locations in west central and central Minnesota (see map below). In these areas, rainfall totals for the period were five or more inches short of the historical average (see map below). When compared with historical rainfall totals for the same sixteen-week time frame, 2007 values ranked at or below the 5th percentile (one year in twenty occurrence) in some counties (see map below). The period from May through September is historically the wettest time of the year in Minnesota. Long-term average rainfall rates during the heart of the summer are around one inch per week. Very dry weather, occurring during a time of year when ample rain is typical, leads to the rapid intensification of drought. The lack of precipitation, along with very high evaporation rates, produced deteriorating crop conditions, lower stream flows and lake levels, and increased wildfire danger.

June 5 to September 24 2007 Precipitation June 5 to September 24 2007 Precipitation Departure Map June 5 to September 24 2007 Precipitation Ranking Map

Sector briefs:

More drought information resources are found at http://climate.umn.edu/doc/journal/drought_information_resources.htm.

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URL: http://climate.umn.edu/doc/journal/drought_situation_report_2007_070927.htm
Last modified: September 27, 2007