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Profound warm temperature signal over the past year

Profound warm temperature signal over the past year

There have been many reports of the extraordinary warm temperatures which have marked the past twelve months, actually the past 14 months across our region. This trend has been noted by scientists at all measurement scales: Twin Cities; statewide (MN); national (USA); hemispheric (northern); and global. Paul Huttner (MPR), Paul Douglas (Star Tribune), Pete Boulay and Greg Spoden (MN-State Climatology Office), Tom Hultquist and Ross Carlyon (National Weather Service), Professor Robert Weisman (St Cloud State University), and NOAA's National Climatic Data Center have all provided perspectives on this strong warming trend. I thought I might as well share some thoughts as well.

Over the past twelve months (June 2011 to May 2012) in Minnesota, monthly temperature values have been colder than normal only once, during June of 2011. All months since then, with the lone exception of September, 2011 (when temperatures were near normal) have been warmer than normal. Further, on a statewide basis five months have ranked in the top ten warmest historically for Minnesota, including: July 2011; October 2011; December 2011; January 2012; and March 2012 (warmest in state history). Over the 12 month period from June 2011 to May 2012, nearly 68 percent of all days brought above normal temperatures to Minnesota, and since November of 2011, 71 percent of all days have seen above normal temperatures.

The number of station daily maximum temperature records set over the past 12 months (June, 2011 to May 2012) has been remarkable. Among the network of daily climate observers in Minnesota (over 160 volunteer and automated stations) I have estimated the number of daily high maximum temperature records set by month (ignoring the hundreds of high minimum temperature records that have been set). The listing below shows the number of daily maximum temperature records set by month across the state of Minnesota:
June 2011 27 record maximum temperature values
July 2011 26 record maximum temperature values
August 2011 2 record maximum temperature values
September 2011 12 record maximum temperature values
October 2011 58 record maximum temperature values
November 2011 11 record maximum temperature values
December 2011 69 record maximum temperature values
January 2012 191 record maximum temperature values
February 2012 12 record maximum temperature values
March 2012 434 record maximum temperature values
April 2012 14 record maximum temperature values
May 2012 35 record maximum temperature values

The estimated total number of daily maximum temperature records set or tied in Minnesota over the past 12 months is at least 900, bearing in mind a like or greater number of record high minimum temperatures is a probable value as well.

During the same period from June 2011 to May 2012, 13 new statewide high temperature records were set, and one was tied. This level of statewide extremes in maximum temperature has not been seen since the 1930s. These records include:
103 degrees F at MSP on June 7, 2011
54 degrees F at Marshall on January 4, 2012
63 degrees F at Canby on January 5, 2012
59 degrees F at Marshall on January 10, 2012
66 degrees F at Amboy and Milan on March 10, 2012
68 degrees F at Marshall on March 11, 2012
74 degrees F at Rochester on March 14, 2012
82 degrees F at Redwood Falls on March 16, 2012
82 degrees F at Madison on March 17, 2012
84 degrees F at Canby on March 18, 2012 (tied state record)
84 degrees F at Madison on March 19, 2012
80 degrees F at Redwood Falls on March 20, 2012
90 degrees F at Luverne on April 1, 2012
88 degrees F at Pipestone on April 2, 2012

From a trend analysis point of view, this is one of the strongest warming trends ever seen in the Minnesota climate records. For the NOAA-Climate Prediction Center it will be difficult to ignore this trend in making mid-range and seasonal outlooks for the rest of the summer and autumn.

Further web resources for examination of this warming trend can be found at the following links:

Weekly Weather Potpourri

Among NOAA news releases this week was a story about the record warm spring across the country and the second warmest May in history. You can read more here.

NOAA-National Weather Service in Las Vegas reports that Death Valley, CA started the first week of June hot, with daytime temperatures ranging from 112 to 120 degrees F over the first four days. Las Vegas was cooler with highs ranging from 100 to 107 degrees F. Phoenix saw 101 to 111 degrees F each day.

A paper from Cornell University (Greene and Monger) published this week in Oceanography suggests that the continued melting of Arctic sea ice will influence the atmospheric circulation patterns in the mid latitudes of the northern hemisphere in a manner that may bring stronger winter storms, with associated stronger winds and heavier precipitation. You can read more about this here.

The U.S. Department of Interior announced that this coming Saturday, June 9th is "Get Outdoors Day", and admission to any of the country's 397 national parks will be free to the public. More information can be found at the following links:

The National Center for Atmospheric Research announced this past week that their scientists are working on new "weather-savvy car technologies" that will use wireless enabled vehicles with sensors to transmit updates of weather and road conditions to a central database which can then relay alerts to other drivers in the area. The goal is to reduce weather related driving mishaps by using mobile devices for sensing and transmitting environmental conditions. You can read more about this here.

The NOAA Storm Prediction Center received five reports of tornadoes in Wyoming, and five more in Colorado on Thursday (June 7) this week. An unusually strong tornado near Wheatland, WY destroyed several homes and derailed a train, while another tornado near Kiowa, CO destroyed several homes as well. Several reports of large hail were also filed.

MPR listener question

Can emission plumes from ethanol plants and power plants contaminate National Weather Service radar echoes and therefore lead to incorrect estimates of precipitation?

Answer: Indeed, this can happen. Each National Weather Service Forecast Office can tweak its own radar algorithms to reduce the impact of ground clutter or false echoes, especially when they know the source of the contamination. More often than not the source of the contamination comes from objects that are within a 25 mile radius of the radar. Perhaps the installation of the new dual polarity radar systems slated for later this year will further reduce any impacts of contamination in the radar signal.

Twin Cities Almanac for June 8th

The average MSP high temperature for this date is 75 degrees F (plus or minus 9 degrees F standard deviation), while the average low is 55 degrees F (plus or minus 7 degrees F standard deviation).

MSP Local Records for June 8th

MSP weather records for this date include: highest daily maximum temperature of 102 degrees F in 1985; lowest daily maximum temperature of 54 degrees F in 1937; lowest daily minimum temperature of 36 F in 1885; highest daily minimum temperature of 70 F in 1959 and 1976 (tentatively broken by a reading of 72 F on June 8, 2012); and record precipitation of 2.12 inches in 1918.
Average dew point for June 8th is 53 degrees F, with a maximum of 78 degrees F in 1911 and a minimum of 31 degrees F in 1980.

All-time state records for June 8th

The state record high temperature for this date is 102 degrees F at several places in multiple years, most recently in 1985 at MSP, Farmington, Chaska, and Owatonna. The state record low temperature for this date is 20 degrees F at Sawbill Camp (Cook County) in 1935. State record precipitation for this date is 8.07 inches at Thief River Falls (Pennington County) in 2001; and no snowfall has been reported on this date.

Past Weather Features:

June 8-9, 1911 brought a heat wave to many southern and western counties in Minnesota. Many communities reported temperatures in the 90s F, while Worthington, Winnebago, and Redwood Falls topped the century mark on the thermometer.

Between 5:30 pm and 10:00 pm on June 8, 1920 three tornadoes caused damage in Minnesota. The first, an F-3 (158-206 mph winds) moved 10 miles across Wilkin County, destroying 20 farm buildings and derailing a train. Two people were killed by that storm. The second tornado, also an F-3 touched down near Campbell and completely destroyed a farm there, killing two people. The third tornado struck near Brainerd after dark. It was an F-2 (winds 113-157 mph) and it mostly damaged farm buildings in the area.

June 8, 1935 brought a summer hard freeze to parts of northern Minnesota, damaging gardens and crops. Park Rapids, Roseau, Baudette, Hallock, Bemidji, Big Falls, and Itasca State Park all reported lows in the 20s F.

Strong thunderstorms brought heavy rainfall to southern Minnesota on June 8, 1953. Many crop fields were flooded and some roads washed out. Fairmont and Worthington reported over 3 inches of rainfall, while New Ulm reported over 5 inches. The observer at St James reported a record 6.10 inches of rainfall.

An early summer heat wave prevailed across southern Minnesota over June 7-9, 1985 bringing three consecutive days with daytime temperatures in the 90s F. Some topped the century mark, including Chaska, St James, St Peter, Owatonna, and Farmington which all reported 102 degrees F.


A warm and humid weekend, with chances for thunderstorms late Saturday in the north and statewide later on Sunday afternoon and evening. Some of the storms on Sunday could be severe. Temperatures will top 90 F in many places. Much cooler on Monday and Tuesday as temperatures fall back to near normal. Another chance for showers and thunderstorms by late Wednesday and into Thursday.
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