Cooler Pattern Dominates August

Cooler Pattern Dominates August:

More than half of the days in August have produced cooler than normal temperatures. As such, most climate stations report a monthly mean temperature that is 1 to 2 degrees F cooler than normal, with the largest departures in western counties. Extremes ranged from 94°F at St James (Watonwan County) on the 4th to 35°F at Hibbing (St Louis County) on the 30th. Despite the cooler than normal temperature readings for the state Minnesota did not report the nation’s lowest temperature even once during the month, somewhat unusual for our history.

Rainfall was mixed around the state during August. Over 50 climate stations reported total rainfall of 6 inches or greater, while at least a dozen stations reported less than 2 inches for the month, including portions of southeastern Minnesota which up until August were reporting one of the wettest years in history. In the Twin Cities Metro Area ;portions of Edina and Richfield reported over 8 inches for the month. According to NOAA 17 new daily rainfall records were set within the Minnesota climate network during the month, including 3.10 inches at the University of Minnesota St Paul Campus, most of which came in under 1.5 hours early on August 18th.

On August 5th thunderstorms across central Minnesota produced some wind gusts over 60 mph and hail stones from tennis ball to grapefruit size (Delano). Also According to the DNR-State Climatology Office thunderstorms moved across central Minnesota on the evening of August 26th and two of those storms produced brief tornadoes in Mille Lacs county, one near Onamia (EF-0 intensity), and one near Milaca (EF-1 intensity. These were the first tornadoes to occur in Mille Lacs county since July 30, 2011.

One final note is that for the month of August it has been exceptionally windy. In many areas several days have produced wind gusts over 30 mph, and some climate stations have reported 5 or more days with gusts over 40 mph.

MPR Minnesota Weather Quiz at the State Fair:

If you are going to the State Fair on Friday, August 30th, please drop by Dan Patch Park between 10am and 11am. Tom Crann and I will be broadcasting the MPR Minnesota Weather Quiz, a tradition for 23 years now. We will have prizes for those who participate. It will be broadcast on MPR news, and also available for listeners to test their knowledge about weather and climate on the MPR web site.

Weekly Weather Potpourri:

According to a NOAA news release earlier this month an instrument equipped saildrone finished a 13,670 mile trip around the continent of Antarctica measuring atmospheric carbon dioxide content among other things. Until recently, scientists assumed that the Southern Ocean was a reliably uniform carbon sink, but preliminary results indicate that parts of the Southern Ocean emit carbon dioxide in winter.

The NOAA-National Hurricane Center was tracking, forecasting, and putting out advisories and warnings this week about Hurricane Dorian. It passed Puerto Rico with a glancing blow but is expected to come onshore this weekend along the east coast of Florida. Most of the models place the maximum intensity to range between category 3 (111-129 mph) and category 4 (130-156 mph) before coming onshore. Then there will be more rapid degradation of intensity, but the slow moving storm may bring a great deal of rain (6-12 inches). Dorian is the 4th named storm of the Atlantic Hurricane Season.

The Weather Underground reported that an estimated 3 to 5 inches of rain fell in many areas toward the south side of the New Orleans metro on Monday August 26th and closed some highways and roadways. In addition, on the same day, strong thunderstorms brought up to 6 inches of rain to the St Louis Area of Missouri, closing Interstate 44 for a time.

This week's AGU-EOS reported that climate change is leading to more and more exposure of fossils and artifacts in the Arctic landscapes, notably Greenland. This will provide archaeologists with more knowledge about earlier settlements there, but also see a degradation in preservation of those elements left on the landscape.

MPR listener question:

I read recently that the NOAA Climate Prediction Center was leaning more on trend analysis recently because El Nino is expected to be near neutral the rest of the year. What do the climate trends say about the month of September 2019?

Answer:

Over the past twenty years the September climate trends in Minnesota show 16 out of 20 warmer than normal months, and eleven out of 20 show wetter than normal months. So, there is a much stronger signal for warmth this year, than for wetter than normal conditions.

Twin Cities Almanac for August 30th:

The average MSP high temperature for this date is 78 degrees F (plus or minus 8 degrees F standard deviation), while the average low is 59 degrees F (plus or minus 6 degrees F standard deviation).

MSP Local Records for August 30th:

MSP weather records for this date include: highest daily maximum temperature of 96 degrees F in 1941; lowest daily maximum temperature of 60 degrees F in 1965; lowest daily minimum temperature is 45 degrees F in 1974; highest daily minimum temperature of 77 degrees F in 2010; record precipitation of 7.28 inches in 1977; and no snow has fallen on this date.

Average dew point for August 30th is 58 degrees F, with a maximum of 75 degrees F in 1951 and a minimum of 34 degrees F in 1931.

All-time state records for August 30th:

The state record high temperature for this date is 103 degrees F at Minneota (Lyon County) in 1976. The state record low temperature for this date is 26 degrees F at Sawbill Camp (Cook County) in 1935. State record precipitation for this date is 7.28 inches at MSP Airport in 1977: and no snowfall has occurred on this date.

Past Weather Features:

August 30, 1898 brought a Heat Wave to western and southern Minnesota with over 25 communities reporting afternoon high temperatures in the 90s F. There were strong winds and high fire danger that day as well, while up in Tower, MN the day started out at just 39°F. It was one of those odd weather days in Minnesota.

On August 30, 1976 campers in St Louis County awoke to frost with morning temperatures ranging from 28 to 32 degrees F. The daytime high reached only 61°F at Grand Marais that day.

Strong thunderstorms brought intense rainfall to the state over August 30-31, 1977. Many climate stations reported 3 to 7 inches of rainfall, including 7.36 inches in the Twin Cities. The 7.28 inches of rain on August 30th is the 2nd largest daily amount in Twin Cities climate history (behind 9.15 inches on July 23, 1987), and washed out a show by Mac Davis at the State Fair grandstand.

Outlook:

Mostly dry, with cooler than normal temperatures through the weekend. Warming up to above normal temperatures on Monday with a chance for showers and thunderstorms. Then, drier and cooler for the balance of next week, with some slight chance for showers later on Wednesday and early Thursday.