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Wet Start to September

Wet Start to September:

This has been a very wet week in many places as much of Minnesota has shown rainfall totals over 2 inches since Monday (September 9th). For the first half of the month most Minnesota climate stations have seen double the normal amount of rainfall, and several have already reported 3 to 6 inches of rain. Pipestone has already received 8.50 inches for the month. There have also been many reports of new daily rainfall records set within the state climate station network. Too many to report here, but some of the more significant ones are:

September 10th, 2.23” at Wheaton
September 11th, 2.30” at Zumbrota and 2.63” at Red Wing
September 12th, 4.40” at Pipestone; 4.28” at Lake Wilson; 3.15” at Luverne; 3.11” at Lamberton; 2.45” at Marshall; 2.19” at Canby; and 2.14” at Windom
September 13th, 3.72” at Minnesota City; 3.66” at Grand Meadow; 3.00” at Spring Valley; 2.67” at Caledonia; and 2.52” at Preston

We continue to witness many areas of the state recording one of the wettest years in history. Many communities are 12-16 inches above normal so far this year. Fortunately it looks like the last third of the month may be drier than normal.

Weekly Weather Potpourri:

An episode of severe weather struck Sioux Falls, SD on Tuesday night this week, with tornadoes, hail, heavy rains, and strong straight-line winds. A preliminary survey rom the National Weather Service (reported by the Weather Underground) confirmed that three EF2 tornadoes had touched down, with estimated winds ranging from 125 mph to 130 mph. The NWS said eight people were injured. Strong winds were also reported in Winona, MN late that night.

ClimateCentral offers an interesting video about the relationships between climate, drought, and wildfires in the western states. It provides some scientific evidence about the disturbing trends we are seeing in the climate there.

It's only the beginning of the fire season in Australia, but more than 140 bushfires are already raging across Queensland and New South Wales. Bureau of Meteorology officials say they expect the fires this season to be hotter and more intense – and part of this is due to recent climate trends. More from the BBC.

This week’s AGU-EOS bulletin features a compelling commentary by former administrators in NOAA about the distorted statements that President Trump made regarding the Hurricane Dorian forecast guidance and the resulting correction by the Birmingham, AL office of the NWS.

MPR listener question:

Do you think fall color will progress near a normal pace this autumn, or be earlier than normal?


From a climate perspective, some early fall color change in the north was noted already as a result of some overnight low temperatures in the 30s F during the latter stages of August. The DNR reports some areas showing 10-25 percent color change already in portions of Cook, Lake, St Louis, Koochiching, and Lake of the Woods Counties. But the recent moderating temperatures, and next week’s warmer than normal temperatures will slow things down. I think for the balance of the state much of the fall color will emerge around normal dates in late September and early October.

Twin Cities Almanac for September 13th:

The average MSP high temperature for this date is 73 degrees F (plus or minus 9 degrees F standard deviation), while the average low is 54 degrees F (plus or minus 8 degrees F standard deviation).

MSP Local Records for September 13th:

MSP weather records for this date include: highest daily maximum temperature of 95 degrees F in 1939; lowest daily maximum temperature of 51 degrees F in 1873; lowest daily minimum temperature is 33 degrees F in 1890; highest daily minimum temperature of 72 degrees F in 1939; record precipitation of 1.29 inches in 1921; and no snow has fallen on this date.

Average dew point for September 13th is 49 degrees F, with a maximum of 71 degrees F in 1939 and a minimum of 22 degrees F in 1923.

All-time state records for September 13th:

The state record high temperature for this date is 100 degrees F at Redwood Falls (Redwood County) in 1939. The state record low temperature for this date is 17 degrees F at Roseau (Roseau County) in 1975. State record precipitation for this date is 4.92 inches at Elk River (Sherburne County) in 2005: and no snowfall has occurred on this date.

Past Weather Features:

On September 13, 1923 a hard freeze occurred over many western and northern counties with temperatures in the 20s F for several hours. This brought an end to the agricultural season over about half of the state. The Morris Agricultural Experiment Station reported 26°F while at Roseau, after a morning low of 24°F the temperature only climbed to 48°F by afternoon.

September 13, 1939 was the hottest in state history, with over 40 climate stations reporting afternoon highs in the 90s F. At Marshall the overnight low only dipped to 75°F.

September 12-13, 1978 brought strong thunderstorms to southern portions of Minnesota where 3 to 6 inches of rain fell, causing widespread flash flooding, especially around Rochester. Portions of Wabasha, Olmsted, Dakota, Goodhue, Winona, and Mower Counties were under flash flood warnings for many hours.


Partly cloudy skies and warming up over the weekend, with temperatures rising to a few degrees above normal. Chance for widely scattered showers on Saturday, then mostly sunny on Sunday. Warmer yet for Monday through Wednesday of next week, then a chance for showers and thunderstorms by Thursday with cooler temperatures.

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