A monthly electronic newsletter summarizing Minnesota's climate conditions and the resulting impact on water resources. Distributed on the first Thursday of the month.
State Climatology Office - DNR Division of Ecological and Water Resources, St. Paul
distributed: October 2, 2014
What happened in September 2014:
- September precipitation totals were generally below-normal across most of Minnesota. Monthly rainfall totals fell short of historical averages by one to two inches in most locations. Isolated pockets of relative wetness were reported in a few locales.
- The most notable heavy rain event of September occurred on the 3rd and 4th when slow moving thunderstorms dropped three or more inches of rain, along with damaging hail, on some central Minnesota counties.
- Average monthly temperatures for September in Minnesota were very near historical averages. Cool temperatures mid-month were counterbalanced by a late-month warm spell. Extremes for September ranged from a high of 89 degrees F at Amboy (Blue Earth County) on the 4th, to a low of 25 degrees F at International Falls on the 13th. Many corn and soybean fields in central and southern Minnesota were affected by frost during the morning hours of the 13th. Mid-September frost is quite uncommon in these areas.
Where we stand now:
- Despite a relatively dry July-through-September period, seasonal precipitation totals since April 1 remain above historical averages nearly everywhere in Minnesota. For large portions of the state, season-to-date precipitation totals rank above the 90th percentile when compared with the historical database for the April-through-September time period. Below-normal rainfall during the late summer and early autumn slowed the record-setting pace established earlier in the growing season.
- The U. S. Drought Monitor, released on October 2, indicated that Abnormally Dry conditions exist over a small portion of south central Minnesota, and in central St. Louis County. The U. S. Drought Monitor index is a blend of science and subjectivity where drought categories (Moderate, Severe, etc.) are based on several indicators.
- The U.S. Geological Survey and DNR Ecological and Water Resources report that stream discharge values are near, to above, the historical median for the date at most Minnesota monitoring locations. Lower-than-median stream flow is reported for a few northern Minnesota basins.
- Water levels on Minnesota lakes often reach their lowest levels of the year around October 1. The season-long decline in lake levels typically eases in late-autumn due to fall rains along with diminishing evaporation rates dictated by the shorter days and cooler temperatures.
- In their September 29 report, the Minnesota Agricultural Statistics Service reported that topsoil moisture across as 91% of Minnesota's landscape is Adequate or Surplus.
- The October precipitation outlook leans towards above-normal conditions 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 northeastern Minnesota.
- The October temperature outlook tilts towards below-normal conditions throughout Minnesota. Normal October high temperatures fall from the low to mid-60s early in the month, to the upper 40s by month's end. Normal October low temperatures drop from the low 40s early in the month to near 30 by late October.
- The 90-day precipitation outlook for October through December offers equal chances of below-normal, near-normal, or above-normal conditions in all Minnesota counties. The October through December temperature projection favors above-normal conditions.
- 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 address both high flow and low flow probabilities.
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Greg Spoden, DNR Climatologist