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Wet start to September for some parts of Minnesota

Wet start to September for some parts of Minnesota:

The first ten days of September have brought a month's worth of rainfall and more for many locations in Minnesota.  The monthly normal rainfall for September ranges from 2.50 inches to 3.50 inches for most Minnesota climate stations.  Through the first 10 days of this month over 40 climate stations already report rainfall amounts within that range.  Brimson, Eveleth, Floodwood, Two Harbors, and Waseca have already reported over 4 inches of rain for the month, while Cotton and Keewatin have reported over 5 inches. 

On a few days several observers reported significant thunderstorm rainfalls, in some cases establishing new daily record rainfalls.  Some of these record values included:
September 2; 2.69 inches at Tracy
September 3; 1.98 inches at Cotton
September 5;2.02 inches at Lake Winnibigoshish
September 6;1.89 inches at Backus, 3.15 inches at Brimson, 3.70 inches at Cotton, 2.51 inches at Fergus Falls, 3.12 inches at New York Mills, 3.38 inches at Ottertail, 3.33 inches at Aitkin, 2.86 inches at Hill City, 2.77 inches at McGregor, and 2.51 inches at Sandy Lake Dam.
September 8; 2.68 inches at Wykoff, 2.33 inches at Cannon Falls, and 1.59 inches at Bricelyn

Worth further noting is that the National Weather Service outlooks for the rest of September favor continued above normal precipitation across Minnesota.

Seven Days of 70°F Plus Dew Points:

An unusually long run of hot, humid weather finally came to an end on Labor Day this week (August 31-September 6).  Many areas of the state, including the Twin Cities recorded 7 consecutive days with dew point readings in the 70s F and Heat Index Values ranging from the upper 80s F to over 100°F.  It was the warmest long spell of weather for the 2015 growing season and the most consecutive days with dew points in the 70s F for so late in the season.  No dew point reports reached the 80s F but a number of climate stations saw dew point values as high as 77°F.  Montevideo reported a Heat Index reading of 102°F on September 4th.  More analysis on the spell of high dew points can be found at the MN State Climatology Office web site.

A cool, Canadian air mass that swept over the state on Labor Day caused the dew points to drop from the low 70s F on Sunday night to the low 50s F by Monday morning.  This felt like natural air conditioning to most Minnesota citizens.

Community climate discussion at Owatonna, September 15th:

Next week I will be visiting Owatonna for a meeting about climate change and its impacts on Minnesota communities.  The meeting will take place at Camp Pillsbury, 315 S Grove Ave, Owatonna, MN 55060 on Tuesday, September 15 starting at 5:30pm.   Owatonna Mayor Thomas Kuntz will also speak.  You can find out more about this meeting and how to attend by visiting the Climate Generation web site or the University of Minnesota Extension’s Regional Sustainable Development Partnerships web site.

Weekly Weather Potpourri:

Typhoon Etau struck Japan on Wednesday (September 9) this week bringing high seas, strong winds, and heavy rains.  Some areas received over 2 feet of rain and there was widespread flooding in many areas with disruptions to all forms of transportation.  Thousands were evacuated from their homes due to flooding.  Tropical Storm Kilo may affect northern parts of the country with rain as well early this weekend.  You can read more at Japan Today or the Weather Channel web sites.

Also this week, strong thunderstorms brought flash flooding to parts of Spain, especially in the coastal provinces of Valencia, Almeria, and Granada.  As much as 8 to 10 inches of rain fell in places.  Waters swept away cars and trucks, as well as damaging roads and bridges.  The Daily Telegraph reported that up to ten people died in the floods.

The United Kingdom Meteorological Office announced this week that it will pilot a program to name strong wind storms in the North Atlantic this coming winter.  One primary reason is that the public seems to pay closer attention to forecasts and warnings if the storm system has a name assigned to it.

NOAA scientists noted earlier this week that although the North Atlantic Hurricane Season of 2015 has been a relatively quiet one, Hurricane Fred on August 31st was worth a headline mention.  Hurricane Fred became the easternmost hurricane to ever form in the Tropical Atlantic Ocean and caused the first ever hurricane warning to be issued for the Cape Verde Islands. 

MPR Listener Question:

In your book, 2nd edition Minnesota Weather Almanac you mention that some northern climate stations like Tower and Embarrass have recorded frost (32°F or less) in every month of the year.  Did this happen during the 2015 growing season?  What were the coldest summer temperatures in Minnesota?


No observer in Minnesota reported frost in each month for 2015.  This is more commonly the case.  In my book I found that in some exceptionally rare years, frost was reported in every month for some far northern locations.  For this year (2015), the summer’s lowest temperatures by month were: 25°F at Embarrass and Brimson in June; 34°F at Cook County Airport (Grand Marais) in July; and 33°F at Brimson, Embarrass, and Cotton in August.

Twin Cities Almanac for September 11th:

The average MSP high temperature for this date is 74 degrees F (plus or minus 10 degrees F standard deviation), while the average low is 55 degrees F (plus or minus 8 degrees F standard deviation).

MSP Local Records for September 11th:

MSP weather records for this date include: highest daily maximum temperature of 96 degrees F in 1931; lowest daily maximum temperature of 51 degrees F in 1924: lowest daily minimum temperature is 35 degrees F in 1962; highest daily minimum temperature of 75°F in 1931; record precipitation of 3.11 inches 1911; and no snowfall has been recorded on this date.

Average dew point for September 11th is 52 degrees F, with a maximum of 72 degrees F in 2000 and a minimum of 25 degrees F in 1955.

All-Time State Records for September 11th:

The state record high temperature for this date is 111 degrees F at Beardsley (Big Stone County) in 1931. The state record low temperature for this date is 22 degrees F at Ada (Norman County) in 1955.  State record precipitation for this date is 5.50 inches at Pleasant Mound (Blue Earth County) in 1900; and there has not been any snowfall on this date.

Past Weather Features:

The remnants of the famous Galveston Hurricane brought heavy rains and thunderstorms to southern Minnesota over September 9-11, 1900.  Several observers reported 4 to 7 inches of rainfall.  Olivia received 7.24 inches.

The September Heat Wave of 1931 (from the 8th to the 13th) brought by far the warmest September 11th in state history.  Except for Grand Marais Harbor on Lake Superior, every spot in the state saw temperatures reach into the 90s F, and ten communities reached an afternoon high of 100°F or greater, including Beardsley which reported 111°F the highest reading ever reported during September in Minnesota. 

By far the coldest September 11th in state history was in 1955 when a killing frost ended the growing season early for many farmers.  Morning lows fell into the 20s F in many areas of the state.  In southern Minnesota residents of Preston, Waseca, and Austin saw the thermometer drop to just 29°F.


Dry and sunny over the weekend, starting out with cooler than normal temperatures on Saturday and perhaps some frost in the northeastern counties.  Warming to near normal temperatures for Sunday through Wednesday, with an increasing chance for showers by Wednesday and Thursday next  week.

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Unknown said…
Your reference to the precipitation amounts on 9/6/15 brought to mind the inconsistency of precipitation reports for public consumption produced by the two NWS offices that cover the state of MN and parts of WI, namely the Duluth and Mpls. offices. As what I think is the proper way to post the recordings of the multiple Mpls. NWS observers (186 today, 9/17/15), is the daily Text report produced by this office which lists these observations even if the observation is zero (0).

On the other hand is the Duluth report which is only posted as a "Public Information Statement" at the discretion of the forecaster and on 9/6/15 liste 140 separate observations, none were zero (0). Precipitation reports from Duluth via the PIS did not appear until today, 9/17/15, again no reports of zero (0) precipitation from any of the reporting stations. What were the precipitation observations for the 140 Duluth NWS observers for the period 9/7-9/16/15? Were they all zero (0) or were there observations which did not pass the lower limit of the forecasters discretion?

Wouldn't the posting of daily reports of precipitation to include reports of zero (0) be the best policy to inform the public and to have information on precipitation ocurring in Minnesota for inclusion in the MNGuage report?
Mark Seeley said…
I will bring this up with the NWS offices for a response.....MS