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Friday, June 29, 2012

Preliminary Climate Summary for June, 2012

Preliminary Climate Summary for June, 2012

Mean monthly temperatures for June were 2 to 5 degrees F warmer than normal, the 9th consecutive month with warmer than normal conditions going back to last September (2011). In fact the first half of this year has been warmer than any year since 1987. Extremes for the month ranged from 98 degrees F at New Ulm (June 27) to 30 degrees F at Embarrass (June 1st). Some observers reported 7 days with high temperatures of 90 degrees F or higher, and the National Weather Service had to issue Heat Advisories (Heat Index up to 105 degrees F) for a some areas. On a few days and nights dewpoints climbed into the 70s F, making for uncomfortable sleeping. Minnesota did not report the lowest temperature in the nation on any days during the month of June.

Rainfall for June was generally above normal for most observers (the 3rd consecutive month for some), except for those in northwestern and southwestern counties, most of which reported below normal rainfall. For some June total rainfall was record-setting, including Cannon Falls (15.11"), Wright (13.03"), Island Lake (11.06"), Red Wing Dam (10.95"), Moose Lake (10.42"), Duluth (10.03"), and Two Harbors (9.49"). The two most notable events of the month were the flash floods on June 14-15 in southeastern counties (Cannon Falls 8.83") and on June 19-20 in northeastern counties (7-10 inches in the Duluth area). Many observers reported measurable rainfall on 13-15 days during the month.

Winds in June were far diminished compared with April and May, and closer to normal. There were a few reports of exceptionally strong wind gusts over 70 mph on June 17th (near Appleton), and over 80 mph on June 19th(Scott County). The associated thunderstorms on these dates brought large hail as well. A weak tornado touched down near Belle Plaine on June 10th. June was the 4th consecutive month (Mar, Apr, May, Jun) with at least one tornado report filed in the state.

New Record Low Annual Heating Degree Days for the Twin Cities

The Minnesota State Climatology Office noted this week as the annual Heating Degree Day (HDD) season (July 1 to June 30) comes to an end, that 2011-2012 brought a new record low number for HDD with only 5852. The previous record low value was 6611 recorded in 2005-2006. HDD are calculated using the mean daily temperature when it falls below a base of 65 degrees F. Thus on a day with a mean daily temperature value (maximum + minimum/2) of 50 F, the HDD value would be 15. These are accumulated daily as an index for energy use to heat homes and commercial buildings. 

Weekly Weather potpourri

Tropical Storm Debby spun off the coast of the Florida panhandle bringing record amounts of rainfall to some areas this week. Tallahassee reported 8.80 inches from the storm, while Apalachicola reported nearly 13 inches. Further east and south Gainesville reported nearly 14 inches, while Tampa reported nearly 10 inches. Some cooperative observers reported over 20 inches, and many streets were flooded. Several tornadoes were reported associated with Tropical Storm Debby as well.

Elsewhere thunderstorm rains were bringing some relief and help to fire fighters in Colorado, where wildfires have been burning this week. Earlier in the week temperatures in the upper 90s F to over 100 degrees F had combined with single digit relative humidity readings and moderate winds had allowed many wildfires to spread rapidly. Hundreds of homes have been destroyed by these fires.

Tropical Storm Doksuri was spinning southeast of Hong Kong in the Western Pacific Ocean with winds up to 70 mph and sea waves over 20 feet. It was expected to bring heavy rainfall to areas south of Hong Kong over the weekend, before dissipating.

In science news, it was reported this week that scientists from Cardiff, Denmark, Sweden, and Russia have discovered a 3 billion year old impact crater in West Greenland. The is the oldest known impact crater on Earth from among 180 other known sites. This one was probably caused by an asteroid or comet. You can read more about it here.

NASA and NOAA announced this week the deployment of new sensors aboard the Suomi NPP polar-orbiting satellite are already assisting forecasting with numerical weather prediction. This represents a record speed for deployment of satellite data following launch, because it has only been seven months since the satellite went into orbit. Usually, there is a longer test and calibration period before the data are utilized. You can read more about this new satellite system here.

MPR listener question

It is coming up on the anniversary of the famous BWCA "blow down" on July 4, 1999, called a "derecho" storm. What type of storm is this and how frequent are they?
Answer: Yes, indeed, arguably the most destructive storm of this type, the derecho of July 4, 1999 brought a 600 square mile swath of straight line winds, 80-100 mph, across the BWCA leveling 250,000 acres of timber valued at $12-$18 million. This storm was highly organized as it traveled 1300 miles from eastern North Dakota to the New England states.

Derecho is a Spanish term meaning "direct" or "straight ahead." It was used back in 1888 by Dr. Gustavus Hinrichs of the University of Iowa to describe the strong winds that accompanied severe thunderstorms and to distinguish them from the rotating winds of a tornado. Derechos usually arise from a mesoscale convective complex composed of an organized cluster of interacting thunderstorms. They typically show up as a bow echo on Doppler radar systems. Fortunately these storms are rare, averaging 10-12 per year across the USA, and only appearing in Minnesota about every 5-6 years, mostly in the months of June, July, or August.

Twin Cities Almanac for June 29th

The average MSP high temperature for this date is 81 degrees F (plus or minus 8 degrees F standard deviation), while the average low is 61 degrees F (plus or minus 7 degrees F standard deviation).

MSP Local Records for June 29th

MSP weather records for this date include: highest daily maximum temperature of 102 degrees F in 1931; lowest daily maximum temperature of 64 degrees F in 1959; lowest daily minimum temperature of 47 F in 1924; highest daily minimum temperature of 83 F in 1931; and record precipitation of 3.48 inches in 1877.
Average dew point for June 29th is 58 degrees F, with a maximum of 77 degrees F in 19963 and a minimum of 38 degrees F in 1988.

All-time state records for June 29th

The state record high temperature for this date is 110 degrees F at Canby (Yellow Medicine County) in 1931. The state record low temperature for this date is 27 degrees F at Pine River Dam (Crow Wing County) in 1925. State record precipitation for this date is 6.37 inches at Worthington (Nobles County) in 1969; and no snowfall has been reported on this date.

Past Weather Features:

June 29-30, 1877 brought some heavy thunderstorms to parts of Minnesota, with 3.48 inches at St Paul. Elsewhere Fort Ripley saw 1.70 inches and Duluth reported 1.50 inches. In fact it was a wet June in Duluth with over 5 inches of rainfall, and measurable rainfall on 16 days.

June 24-30, 1931 brought the worst June Heat Wave in Minnesota history. Over two dozen Minnesota communities reported daytime highs of 100 degrees F or greater. Overnight lows at Canby never fell below 87 degrees F on the 28th and 29th. Crops wilted in the heat. July 1st brought some relief as temperatures dropped back into the 70s and 80s F.

Intense thunderstorms brought flooding rains to southern Minnesota on June 29, 1969. Worthington reported a record 6.37 inches, while Luverne received 3.64 inches. Pipestone reported 3.08 inches, Albert Lea 2.56 inches, and Slayton 2.12 inches.

In the drought year of 1988 June 29 brought frost to northern Minnesota. Brimson was 29 degrees F and Gunflint Lake dropped to 30 degrees F. Cotton, Isabella, Tower and Mora also reported frosts.


Warmer than normal temperatures continuing into the weekend and next week. Chances for scattered and isolated showers and thunderstorms each day, particularly on Tuesday. General dominance of high pressure next week will keep most places dry.

Friday, June 22, 2012

Another Traumatic June Flash Flood

Another Traumatic June Flash Flood

Following the devastating flash flooding in Goodhue, Rice, and Dakota Counties last Thursday and Friday (June 14-15) and the hail and wind storms of June 17 and 19 earlier this week (hail up to 1.5 inches in diameter and wind gusts up to 83 mph), another larger and more traumatic flash flood encompassed much of northeastern Minnesota over June 19-21 (Tue-Thu) this week. A slow moving thunderstorm complex brought 3 to 10 inches of rainfall over portions of Cook, Lake, St Louis, Carlton, Itasca, Cass, Crow Wing, and Aitkin Counties. A report filed by a National Weather Service employee in NE Duluth mentioned a measurement of 10.10 inches of rainfall in the northeastern part of Duluth. Officially the National Weather Service in Duluth reported new record daily rainfalls back to back, 4.14 inches on the 19th, followed by 3.11 inches on the 20th, for a total of 7.25 inches. The climate record from Duluth shows very few stormy periods that are analogous to what happened there this week. Arguments can be made that thunderstorms on September 5-6, 1876 (6.48 inches); July 20-22, 1909 (7.83 inches), and August 15-21, 1972 (7.91 inches) might be comparable, but of course the Duluth neighborhoods and landscape in general were vastly different in those times. It is expected that damage to infrastructure in Duluth will be considerable this time around, perhaps approaching or exceeding $100 million, compounded by a prolonged recovery and reconstruction period.

Some other observers reported record rainfalls: on June 19th, Grand Rapids with 4.78 inches, Hibbing with 2.57 inches, and Moose Lake with 3.12 inches; on June 20th, Wright with 6.11 inches, Two Harbors with 4.65 inches, Pine River Dam with 4.24 inches, Brainerd with 4.20 inches, Aitkin with 3.86 inches, and Grand Portage with 3.40 inches. This is just a sampling, as too many other observers reported record rainfall to report here.

Additionally a new statewide daily rainfall record was set on June 20th, with 7.41 inches reported from the Island Lake cooperative observer in St Louis County (about 18 miles north of Duluth). This broke the old statewide record for June 20th of 5.93 inches at Georgetown in 2000. This was the 2nd statewide daily rainfall record broken this month. Last week Cannon Falls set a new statewide rainfall record with 8.83 inches on June 14th, and this was associated with flash flooding over Goodhue, Rice, and Dakota Counties.

The St Louis River near Scanlon reported a new all-time record flood crest near 16.62 feet (flow volume over 45,000 cfs, about 15 times normal volume) beating the old flood crest record of 15.8 ft on May 9, 1950. The Kettle River at Sandstone also set a new record flood crest with1 17.55 feet, surpassing 15.38 feet on July 23, 1972. In fact many other watersheds flooded including the Knife River, Crow Wing River, Pigeon River, Cloquet River, and Mississippi River at Aitkin among others. The discharge volume on these watersheds flooded many roads, highways and parks.

This type of storm reminds us that climate is changing in Minnesota. Not only in terms of quantity of precipitation, but in the character of precipitation as well. In recent decades a larger fraction of our annual total precipitation is coming in the form of intense thunderstorms.

June monthly rainfall totals approaching record values

Many Minnesota weather observers are reporting near-record rainfall amounts for the month (and it is only June 22nd!). Red Wing Dam has reported a record 10.95 inches for June so far. Cannon Falls now reports 15.11 inches for June which is only the 4th time in Minnesota's climate history that an observer has reported 15 or more inches for June, the others were 15.00 inches at Milaca in 1944, 15.48 inches at Camp Norris in 2002, and 15.63 inches at Delano in 2002. With 8 days left in the month, Cannon Falls may yet surpass Delano for the largest June rainfall total in state history.

Duluth, of course, has already set a new June total rainfall record with 9.51 inches, while Two Harbors has also reported a record June rainfall of 9.33 inches. Other northeastern Minnesota climate stations reporting record amounts of June rainfall include Wright with 12.19 inches and Island Lake Reservoir with 10.65 inches.

More on the Duluth storm and flooding can be found at these links:

New Seasonal Climate Outlook

The NOAA Climate Prediction Center released the new seasonal outlooks on Thursday this week. For the period July through September the outlook favors above normal temperatures for southern Minnesota, and equal chances for above or below normal temperatures for northern counties. The precipitation outlook is for equal chances of above or below normal values over the period. Our current trend certainly favors wetter than normal conditions, as we are experiencing one of the wettest starts to a growing season in many eastern sections of the state.

Weekly Weather potpourri

The NOAA National Hurricane Center was watching the development of a low pressure system off the Yucatan Peninsula this week. It may develop into a tropical storm which would have implications for the southeastern coastal states of the USA this weekend and next week. They were sending out a air force reconnaissance aircraft to make measurements of this storm system.

In the Western Pacific, Typhoon Guchol lashed southwestern Japan with heavy rains and high winds this week. Rains of several inches (3 to 6 inch amounts) were accompanied by winds up to 81 mph. Weather conditions caused the disruption and stoppage of airline and rail services for a time. Yet, more rainfall was expected this weekend across Japan.

A recent paper in the journal Science documents a historical correlation between unusual warm periods in the Arctic Region with similar periods in the West Antarctic Ice Sheet. The correlation and the magnitude of the warm periods back 2.8 million years came as somewhat of a surprise to the international team of scientists who extracted lake sediment cores from the Arctic Region. You can read more about this paper here.

MPR listener question

This last winter you spent a good deal of time speaking about the threat of drought for this growing season. Now we are experiencing one of the wettest ever early growing seasons in Minnesota. Has this relatively rapid reversal in the moisture pattern ever occurred in the past?

Answer: Indeed, this is what happened to end the very damaging 1976 drought in Minnesota. Having barely survived the 1976 drought many western Minnesota farmers were pessimistic about 1977. Average statewide precipitation in 1976 was less than 16 inches. But then 1977 delivered the wettest year of the 20th Century with a statewide average precipitation of nearly 34 inches. All was good that year. Similarly a 1910 drought (statewide precipitation under 15 inches) brought bankruptcy to many Minnesota farmers (including my grandfather), but then 1911 brought a wet year (statewide average of nearly 28 inches of precipitation) and all was well again.

So, though rare in frequency, these dramatic and rapid reversals in moisture patterns have indeed happened in our Minnesota past.

Twin Cities Almanac for June 22nd

The average MSP high temperature for this date is 79 degrees F (plus or minus 8 degrees F standard deviation), while the average low is 60 degrees F (plus or minus 7 degrees F standard deviation).

MSP Local Records for June 22nd

MSP weather records for this date include: highest daily maximum temperature of 98 degrees F in 1911; lowest daily maximum temperature of 57 degrees F in 1906; lowest daily minimum temperature of 42 F in 1960; highest daily minimum temperature of 75 F in 1923; and record precipitation of 2.12 inches in 1930.
Average dew point for June 22nd is 56 degrees F, with a maximum of 80 degrees F in 1983 and a minimum of 27 degrees F in 1972.

All-time state records for June 22nd

The state record high temperature for this date is 107 degrees F at Canby (Yellow Medicine County) in 1988. The state record low temperature for this date is 20 degrees F at Kelliher (Beltrami County) in 2001. State record precipitation for this date is 5.42 inches at Itasca State Park (Clearwater County) in 1957; and no snowfall has been reported on this date.

Past Weather Features:

June 22, 1917 brought frost to northern Minnesota. International Falls reported 31 degrees F, while Brainerd reported just 30 degrees F. At the Experimental Farm near Duluth it was just 29 degrees F with damaged produce crops. It was also 29 F at Cloquet. Further inland at Meadowlands the thermometer fell to 28 degrees F.

June 22, 1957 saw strong thunderstorms cross the state bringing hail, high winds, and heavy rainfalls. Many observers reported over 3 inches of rain, while Winsted, Young America, St James and Hinckley reported over 4 inches. Many roads and farm fields were flooded.

In 1988 June 22nd marked the end of a five-day Heat Wave that plagued the state. Many observers reported five consecutive days with afternoon temperatures in the 90s F, causing crops to wilt and show signs of moisture stress. Later that month observers at Canby and Browns Valley would report temperatures as high as 107 degrees F.

About 4:00 pm on June 22, 1919 an F-5 (winds 261 mph) raced across Otter Tail County and leveled 400 buildings in Fergus Falls leaving "a vast acreage of kindling." The famous Lake Alice Grand Hotel was destroyed. The funnel traveled 20 miles on the ground and at times was 400 yards across. It injured 200 people and killed 57 others. It took Fergus Falls a decade to rebuild. 


Chance of showers and thunderstorms on Saturday, then drier with near seasonal temperatures for Sunday through Wednesday. Getting warmer towards the end of next week with a chance for showers and thunderstorms returning.

Friday, June 15, 2012

Strong winds on Sunday, June 10th

Strong winds on Sunday, June 10th

Both weekend days (June 9-10) brought temperatures in the 90s F to many areas, including 93 F at Milan and Crookston, and 94 F at Wheaton and Madison. Then, late afternoon and evening on Sunday, June 10th saw strong thunderstorms cross the state of Minnesota. A tornado was reported near Belle Plaine in Scott County (preliminary estimates are an EF-0 with winds of 65-85 mph) where some farm buildings were damaged, and there were at least 30 other reports of very strong winds, including 63 mph at Kabetogama Lake up north. Olivia reported winds to 59 mph and MSP airport recorded a wind of 52 mph, just around the time all of the tree damage was reported in the Highland Park neighborhood of St Paul. Many other communities reported winds over 40 mph. The cold front associated with the thunderstorms brought a rapid change in temperature, as the MSP airport reading fell from 87 degrees F to just 69 degrees F between 9:00 pm and 10:00 pm.

The rainfall was welcome in most areas. Some observers reported over 1 inch, including Belle Plaine, Princeton, Cambridge, St Peter, Little Falls, Rush City, and Plymouth. For many it was the first significant rainfall of the month.

Cold June 12th and 13th up north

Many northern Minnesota observers reported low temperatures in the 30s F on Tuesday, June 12th and Wednesday, June 13th. On Tuesday morning St Vincent reported 38 degrees F, while Fosston measured 37 degrees F. Hallock reported 36 degrees F, and Warroad reported a record-tying 32 degrees F (tied with June 12, 1969). Then on Wednesday morning Brimson reported a near-record 34 degrees F, while Hibbing and Embarrass recorded 36 F and 37 F, respectively. Some SD and ND communities across Minnesota's western border reported record-setting low temperatures as well. Northeastern Minnesota communities like Ely and Grand Marais did not see daytime highs climb out of the 50s F on June 12th as a result of the cool Canadian high pressure system that dominated the state.

Heavy rain and hail on June 14th

A low pressure system moving across southern Canada brought strong winds, hail, and heavy rains to many parts of Minnesota on Thursday, June 14th. There were numerous reports of hail from one half inch to one inch in diameter. Very strong winds brought down power lines along Hwy 2 in St Louis County. Some areas of central and eastern Minnesota received rainfalls from a half inch to over one inch during the morning and early afternoon. But the BIG STORY was the very heavy, record-setting rainfalls across Steele, Rice, Le Sueur, Dakota, and Goodhue Counties. Observers in these counties reported from 2 to 8 inches of rainfall during the afternoon and evening. Some record-setting amounts included 2.22 inches at Montgomery, 2.86 inches at Farmington, 6.37 inches at Red Wing Dam, and 8.83 inches at Cannon Falls. The rainfall at Cannon Falls was a new all-time statewide record for the month of June surpassing 8.67 inches at Minnesota on June 17, 1957. As a result of the heavy rainfalls the Cannon River and Little Cannon River rose several feet and exceeded flood state, causing road closures and evacuation of some homes. More information on the rainfall and flooding can be found at these links:

Weekly Weather Potpourri

NOAA-National Weather Service in Mobile, AL reported some tremendous rainfalls last weekend (June 9-10) across coastal Alabama and the Florida Panhandle. Some of the rainfall totals included: Pensacola, FL 15.05 inches; Orange Beach, AL 11.32 inches; Mobile, AL 12.90 inches; Brentwood, FL 14.57 inches; and Myrtle Grove, FL 17.50 inches. Many city streets were flooded.

NOAA-National Hurricane Center was monitoring Hurricane Carlotta in the Eastern Pacific off the southern coast of Mexico. It was producing sustained winds of 80 mph with gusts to 90 mph, and sea waves of 25 feet. Carlotta was expected to strengthen before making landfall in Mexico over the weekend. It may bring rainfalls of 6 to 10 inches to some areas.

Typhoon Guchol was intensifying off the east coast of the Philippines in the Western Pacific Ocean. It was producing sea waves near 35 feet and winds up to 115 mph. Fortunately it is expected to remain out to sea as it grows stronger over the weekend and heads north towards Kyoto and the south coast of Japan.

Dr. Robert Simpson, former Director of NOAA's National Hurricane Center, and originator of the Saffir-Simpson scale used in hurricane forecasting will turn 100 years old later this year. Retired in Washington, D.C. he was interviewed for a recent article in USA Today. You can find the article here.

MPR listener question

What causes thunderstorms to dissipate rapidly?

Answer: Since mature thunderstorms are fed by warm, moist air rising within the clouds the rainfall itself and the down drafts of the storm pulling cooler air to the surface tend to cause the dissipation of the storm. Also these storms may be impeded by wind shear aloft which does not allow the vertical motion to create high cloud tops. In addition animated satellite and radar imagery show that storms encountering an extremely dry or cold landscape may weaken rapidly and die off. This can certainly happen over the relatively cool waters of Lake Superior in the summer.

Twin Cities Almanac for June 15th

The average MSP high temperature for this date is 78 degrees F (plus or minus 7 degrees F standard deviation), while the average low is 59 degrees F (plus or minus 7 degrees F standard deviation).

MSP Local Records for June 15th

MSP weather records for this date include: highest daily maximum temperature of 94 degrees F in 1913; lowest daily maximum temperature of 61 degrees F in 1945; lowest daily minimum temperature of 41 F in 1989; highest daily minimum temperature of 71 F in 2007; and record precipitation of 2.80 inches in 1874.
Average dew point for June 15th is 54 degrees F, with a maximum of 73 degrees F in 1952 and a minimum of 32 degrees F in 1961.

All-time state records for June 15th

The state record high temperature for this date is 106 degrees F at Lamberton (Redwood County) in 1979. The state record low temperature for this date is 24 degrees F at Meadowlands (St Louis County) and at Roseau (Roseau County) in 1917. State record precipitation for this date is 7.50 inches at Albert Lea (Freeborn County) in 1978; and no snowfall has been reported on this date.

Past Weather Features:

June 15, 1874 brought thunderstorms that produced 2.80 inches of rainfall in the Twin Cities, and a rapid rise in the Mississippi River. That was the wettest June ever for the Twin Cities Metro Area. The month saw rainfall on 18 different days, and on four of those days it rained over 1 inch. June 1874 brought a total of 11.67 inches of rainfall, nearly a third of the entire year's precipitation for the Twin Cities Metro Area. Further north at Ft Ripley they received 9.30 inches of June rainfall, also a record.

June 15, 1892 also brought heavy thunderstorms to southern Minnesota communities. St Charles reported 2.69 inches, Blooming Prairie 4.50 inches, Sheldon 4.52 inches, and Grand Meadow reported 5.00 inches. Many fields were flooded and roads washed out.

June 15-19, 1913 brought a five day Heat Wave to Minnesota, with over 40 communities recording daytime highs in the 90s F. On June 15th it was 93 degrees F as far north as Two Harbors, still a record for the date there. At Farmington the mercury reached 100 degrees F. Other June Heat Waves occurred over June 15-19, 1933, and June 13-15, 1979, when many counties reported temperatures in the 90s F and some saw consecutive days with afternoon highs over 100 degrees F.

June 15, 1917 brought a hard freeze to some northern Minnesota communities. Meadowlands and Roseau reported morning lows of just 24 degrees F, while Pokegama Dam, Duluth, and Beardsley reported 28 degrees F. Light frost was observed as far south as Zumbrota.

June 14-15, 1978 brought heavy thunderstorms to parts of Freeborn, Faribault, and Blue Earth Counties in southern Minnesota. Rainfalls of 3 to 7 inches produced flash flooding and many road closures due to high water. Numerous basements were flooded in Albert Lea. Some of the rainfall amounts included 7.50 inches at Albert Lea, 5.50 inches at Blue Earth, and 3.51 inches at Winnebago.

On June 16, 1992 a total of 27 tornadoes were reported across Minnesota, including the last F-5 (winds 261 mph or greater) ever reported in the state. This F-5 tornado traveled from Leota to Chandler between 5:00 and 5:30 pm that afternoon, on the ground for 16 miles and at times a quarter of a mile in diameter. About the same time an F-4 tornado (winds 207-260 mph) was traveling through Lake Wilson, also in Murray County. These two tornadoes caused over $14 million in damages. Of the 25 other tornadoes reported that day, 6 were F-3 (158-206 mph), 15 were F-2 (113-157 mph), and 4 were F-1 (72-112 mph). Overall 20 counties reported tornado damage or damage from severe thunderstorm winds, totaling over $80 million.


Somewhat warmer than normal temperatures over the weekend with a chance for showers and thunderstorms on Saturday afternoon and evening. Some could be severe. Mostly dry and warm on Sunday, with a chance for showers by evening. Generally unsettled with a continued chance for showers through Thursday next week, then cooler and drier towards the end of the week.

Friday, June 8, 2012

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.

Friday, June 1, 2012

Preliminary Climate Summary for May 2012

Preliminary Climate Summary for May 2012

In the simplest of terms May was warm and wet. Mean temperatures for the month were 2 to 5 degrees warmer than normal, with several days in the 90s F. The extremes for the month were 97 degrees F at Madison on the 18th, and just 24 degrees F at Brimson and Embarrass on the 16th. Minnesota reported the coldest temperature in the nation just twice during the month.

Rainfall during May was abundant and above normal in all areas of the state except the northwest. Many individual climate observers saw their wettest ever May. Some of these included:

Pipestone with 11.06 inches
Windom with 10.83 inches
Lamberton with 9.87 inches
Hawley 6.72 inches
Floodwood 9.14 inches
New Ulm with 12.39 inches
Milaca with 10.46 inches
Sandstone 10.84 inches
Forest Lake with 11.29 inches
Chanhassen with 11.21 inches
Chaska with 10.69 inches

For many observers over half the days of May brought measurable rainfall (16-18 days), and there were many heavy thunderstorms. Overall, taking the average of all rainfall observations in the state it was the 4th wettest May of all time, averaging near 6 inches of rainfall. Only 1938, 1962, and 1908 were wetter on a statewide basis.

Another unusual feature of May was the frequency of strong winds. MSP Airport reported wind gusts over 30 mph on 19 days during the month, and six days with gusts over 40 mph. Some maximum wind gust during the month included: 58 mph at MSP; 62 mph at Alexandria; 69 mph at Rochester; and 74 mph at St Cloud.

Strong, persistent warm temperatures

Since June of 2011, 10 of 11 months have brought warmer than normal temperatures to Minnesota. According to Pete Boulay of the Minnesota State Climatology Office, this is the warmest spring ever (March-May) for some observers, including St Cloud, MSP, and Rochester among others. You can read more about the warm spring here.

In addition because January and February were warmer than normal as well, the first five months of 2012 (Jan-May) tie 1987 for the warmest such period in history. For the Twin Cities nearly 70 percent of all days in 2012 so far have seen above normal temperatures.

Cold May 31st

The month of May ended with some record-setting cold temperatures up north. International Falls tied their record low for May 31st with a reading of 29 degrees F. Grand Marais set a new record low with 28 degrees F, while Crane Lake reported a new record low as well with the same reading. Though not record-setting for the date Embarrass and Silver Bay reported lows of 27 degrees F, the coldest readings in the USA that day.

Weekly Weather Potpourri

The Joint Typhoon Warning Center was monitoring tropical storm Mawar located east of the Philippines this week in the western Pacific Ocean. This system is expected to develop into a typhoon over the weekend producing winds up to 100 mph and wave heights up to 20 feet. It is expected to remain out to sea, but bring heavy rains to parts of southern Japan next week.

The Social Brands 100 list was released this week. It is a ranking of brands (products and services) most commonly referenced and utilized by the social media (Facebook, Twitter, YouTube, Google, and blogs). Among the top ten was the United Kingdom Meteorological Office, the highest ranking service brand was ranked 9th. Just like our National Weather Service they have been striving to garner more public engagement through the use of social media.

NOAA released a new science fact sheet this week, "Atlantic Hurricanes, Climate Variability and Global Warming." You can find copies on the web here.

Mid-summer like temperatures are arriving in some parts of the northern hemisphere this week, as Blythe (CA), Imperial (CA), and Needles (CA) hit 112 degrees F, while Yuma (AZ) and Parker (AZ) hit 113 degrees F and 114 degrees F, respectively. Elsewhere, parts of Iran and Pakistan reached 119 degrees F this week, while Mecca in Saudi Arabia saw the thermometer climb to 122 degrees F, with more hot weather expected into the weekend.

NASA announced this week that it will use its pilot-less research aircraft, "Global Hawks" to fly over hurricanes and make specialized measurements to help better understand the dynamics of their formation, intensification, and dissipation. These aircraft can fly at altitudes of 60,000 ft. You can read more about the use of these aircraft here.

MPR listener question

 With all the rain this month, have most Minnesota rivers risen to normal or above normal flows?

Answer: Yes, indeed. The Mississippi River basin, Minnesota River Basin, and St Croix River Basin have all risen to normal or higher than normal volumes of flow. Even some of the northeastern Minnesota watersheds which had been extremely low, like the Pigeon River, have risen to above normal flow levels. The only section of the state showing some below normal flow levels are some of the smaller watersheds along the Red River Valley, including the Marsh River, Thief River, Wild Rice River, and Roseau River.

Twin Cities Almanac for June 1st

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 7 degrees F standard deviation).

MSP Local Records for June 1st

MSP weather records for this date include: highest daily maximum temperature of 92 degrees F in 1939; lowest daily maximum temperature of 51 degrees F in 1945; lowest daily minimum temperature of 37 F in 1946; highest daily minimum temperature of 72 F in 1939; record precipitation of 2.16 inches in 1944; and a trace of snow was reported at the St Paul downtown airport on this date in 1946.
Average dew point for June 1st is 48 degrees F, with a maximum of 73 degrees F in 1944 and a minimum of 29 degrees F in 1910.

All-time state records for June 1st

The state record high temperature for this date is 104 degrees F at Faribault (Rice County) and at Chaska (Carver County) in 1934; the state record low temperature for this date is 15 degrees F at Bigfork (Itasca County) in 1964. State record precipitation for this date is 7.98 inches at Stillwater (Washington County) in 1965; and Grand Portage (Cook County) still has one inch of snow cover on this date in 1897.

Past Weather Features:

Significant frost damaged both agronomic crops and vegetable crops on June 1, 1897. Nine counties reported morning lows in the 20s F. Farmers reported some damage to wheat, barley, rye and oat crops. Temperatures in the 20s F were observed as far south as Houston and Winona Counties.

June 1, 1934 brought record heat to over two dozen communities in the state. Temperatures broke the century mark (100 F) in 7 communities, and the overnight low at Winona never fell below 79 degrees F. For residents of Faribault June of 1934 brought six days with temperatures over 100 degrees F.

Overnight thunderstorms brought high winds, large hail, and heavy rains on June 1, 1965. Crops near Young America were damaged by large hail and had to be replanted. Lightning caused damage to buildings in Stillwater and Hastings. St Paul downtown received nearly 5 inches of rain, Hastings nearly 6 inches, and Forest Lake 6.50 inches. Flooded roads and highways were reported in many communities. Stillwater reported over 7 inches of rainfall, their most ever in a single day.


Warming up to above normal temperatures over the weekend, with a chance for widely scattered showers on Sunday. Warmer yet on Monday and Tuesday with a chance for showers returning by Wednesday and Thursday next week. Following the trend it looks like warmer than normal temperatures will dominate the first half of June.
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