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: September 4, 2014
What happened in August 2014:
- August precipitation totals were highly variable across Minnesota. Rainfall totals were below historical averages in far northern Minnesota and some central Minnesota counties. Conversely, monthly rainfall totals were well above average in portions of west central, north central Minnesota, and some southeastern Minnesota locations.
[see: August 2014 Precipitation Map | August 2014 Precipitation Departure Map | August 2014 Climate Summary Table]
- One of the more notable heavy rain events of August occurred on the 16th and 17th when slow moving thunderstorms dropped two to five inches of rain across scattered portions of Minnesota.
[see: Heavy Rain: August 16-17]
- Average monthly temperatures for August in Minnesota were very near historical averages. Extremes for August ranged from a high of 91 degrees F at Hutchinson on the 24th, to a low of 35 degrees F at International Falls on the 27th. As was the case throughout the summer, 90-degree temperatures were infrequent during the month of August. For the calendar year, the Twin Cities International Airport has reported only two days of maximum temperatures at or above 90 degrees.
[see: August 2014 Climate Summary Table]
Where we stand now:
- In spite of the dry July and early August, 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 95th percentile when compared with the historical database for the April-through-August time period. Below-normal rainfall during the late-summer slowed the record-setting pace established earlier in the growing season.
- The U. S. Drought Monitor, released on September 4, indicated that Abnormally Dry conditions exist over a small portion of south central Minnesota. 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 well above the historical median for the date at many Minnesota monitoring locations, and somewhat above the historical median for the remaining watersheds.
[see: USGS Stream Flow Conditions | MNDNR Weekly Stream Flow Maps and Tables]
- Water levels on many Minnesota lakes are responding upwards to early-September rainfall events.
[see: Mille Lacs Lake Water Level | Lake Minnetonka Water Level | White Bear Lake Water Level | Lake of the Woods Control Board Basin Data | Corps of Engineers Great Lakes Water Levels]
- In their September 2 report, the Minnesota Agricultural Statistics Service reported that topsoil moisture across as 90% of Minnesota's landscape is Adequate or Surplus.
- The potential for wildfires is currently rated by DNR Forestry as Low in all Minnesota counties.
[see: Fire Danger Rating Map]
- The September precipitation outlook tilts towards above-normal conditions across the southeastern three-quarters of Minnesota. September precipitation normals range from near two inches in far western Minnesota to around three and one-half inches in eastern sections of the state.
[see: Climate Prediction Center 30-day Outlook | September Precipitation Normal Map]
- The September temperature outlook offers equal chances of below-normal, near-normal, or above-normal conditions throughout Minnesota. Normal September high temperatures are in the mid-70s to start the month, dropping to the low to mid-60s by month's end. Normal lows are in the mid-50s early in the month, falling to around 40 by late September.
[see: Climate Prediction Center 30-day Outlook | September Temperature Normal Map]
- The 90-day precipitation outlook for September through November depicts equal chances of below-normal, near-normal, or above-normal conditions in all Minnesota counties. The September through November temperature projection also indicates equal chances of below-normal, near-normal, or above-normal conditions.
[see: Climate Prediction Center 90-day Outlook]
- 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.
[see: National Weather Service - North Central River Forecast Center]
From the author: