Minnesota WeatherTalk

Comments on Soil Moisture Recharge: I have heard from many MPR listeners in recent weeks about their concern for the dryness this autumn season and its potential negative effects for gardens and agricultural soils. Indeed, the precipitation during the autumn season is one of the most critical features of our climate in terms of maintaining adequate soil moisture for gardens and for agricultural crops. Numerous studies over the decades by respected scientists like Donald Baker and Wally Nelson have shown that on average 50 to 60 percent of the total autumn precipitation across Minnesota is stored by the soil, the highest fractional storage of moisture for any season of the year. This relatively higher value of soil moisture storage for this time of year is due to several reasons. Most vegetation has died or is in the process of going dormant and using little soil moisture; surface evaporation is reduced because of the lower air temperatures, sun angle and declining daylength; and rain...

Flirting with a historically dry October: October continued to be extremely dry this week for most places in the state, with the exception of northeastern Minnesota where rainfall was recorded on both October 12 and 13. In fact some observers in the northeast reported between 1 and 2 inches of rainfall over those dates. A few reported new daily record rainfall amounts including: 1.44 inches at Wolf Ridge 1.36 inches at Embarrass 1.20 inches at Tower 1.12 inches at Grand Portage Still, many observers in the state have reported little or no rainfall for the month so far, and we are past the halfway point. The statewide average rainfall this month is only 0.26 inches, although it continues to look like the last week of this month may bring significant rainfall. Here are the 5 driest Octobers in state history based on statewide average precipitation: 1952 0.13 inches 1889 0.14 inches 1895 0.27 inches 1944 0.35 inches 1976 0.46 inches This week’s U.S. Drought Monitor showed that 97 pe...

Continued Record Dry Spell: Our record dry spell continues on a statewide basis. The average total precipitation across the state since August 31st is just 0.55 inches, about 3.25 inches below normal. So far this month only a few showers have occurred over northern Minnesota on October 5-6. Observers in Carlton, St Louis, Koochiching, Cook, Lake, Beltrami, Lake of the Woods, Roseau, and Cass Counties reported some measurable amounts of rainfall, but mainly less than a tenth of an inch. The impact of the dry spell has been exacerbated by temperatures that have averaged 5°Fto 8°F above normal. This combination has produced unusually high evapotranspiration (loss of water vapor from the landscape and area lakes), so consequently Minnesota is showing signs of the dryness in terms of declining lake levels, stream flow, and vegetative stress. This week’s U.S. Drought Monitor shows that 97 percent of the state is abnormally dry, 69 percent is in at least Moderate Drought, and 20 percent (...

Dry Spell Continues With Frosts: After a record-setting warm and dry month of September, October has begun warm and dry as well, with zero rainfall reported across 95 percent of the state. Speaking of rainfall, September was the driest in history for several long-term climate stations in Minnesota, including: Minneota (Lyon County) with 0” Canby (Yellow Medicine County0 with a Trace Alexandria (Douglas County) with .03” Melrose (Stearns County) and Elk River (Sherburne County) with .05” MSP with .06” Park Rapids (Hubbard County), Red Wing (Goodhue County), Windom (Cottonwood County) with .10” Brainerd (Crow Wing County) with .11” Marshall (Lyon County) with .15” Jordan (Scott County) with .16” Two Harbors 7NW (Lake County) with .17” Madison (Lac Qui Parle County) and St Peter (Nicollet County) with .18” Ottertail (Otter Tail County) with .19” Overall, the statewide average rainfall was 0.55 inches for September, a record low amount. The consequence of this prolonged dry spell contin...