Thursday, 2 January 2020

Top 10 Weather Stories of 2019 - Winnipeg Area

10 - Cold Late Spring with Early June Frost


After a very warm May in 2018, Mother Nature turned the tables in 2019 with the coldest May since 2009 in Winnipeg. It was especially the nights that were chilly with daily lows averaging 1.9°C, 2.4 degrees below normal and tied 17th coldest since 1872. Partly related to the cool conditions, no thunderstorms were recorded in May. Normally, 3 days would see a thunderstorm.

The chilly nights continued into the first couple days of June with Winnipeg Airport recording a low of -0.6°C on June 2, the first freeze in June since 2009. Once again, the station reached close to freezing on June 12 with a low of 1.0°C. Normally, the Airport sees its last freeze on May 24. June freezes have been uncommon since the 1970s with 2019 only being the 7th year with a June freeze since 1975.


9 - Dry December in the Northern Red River Valley


Dec 26 - not much snow on the fields west of Winnipeg
Most weather systems largely dodged the Winnipeg area and much of the Canadian side of the Red River Valley in December. However, south of the border it was a different story with storm after storm hitting the area. On December 29 alone, an intense Colorado Low brought a blizzard and over 30 cm of snow to Grand Forks and Fargo. The system had just clipped southeastern Manitoba with 5 to 10 cm, the largest snowfall of the month. Close to 60 cm of snow fell in Grand Forks in December, in sharp contrast to only about 20 cm in Winnipeg.  In Winnipeg, the 20 cm of snow that fell was very fluffy, resulting in little water equivalent. The snowfall (and some freezing rain) only amounted to about 5.7 mm of precipitation, making it tied for 8th driest December on record since 1872.

Snow on ground was quite meager throughout the month with grass blades still poking through the snow around Christmas. With about 7 cm of snow on the ground on Christmas morning, it was the lowest snow pack for the date since 2014. The month had started with only about 2 cm of snow on the ground. What little snow did fall also melted somewhat during a warm spell before Christmas. On December 22, temperatures reached 3.8°C at Winnipeg Airport and 7.9°C in Morden.

8 - June 7 Thunderstorms Break the Heat but Produce Damaging Winds


A brief influx of heat brought southern Manitoba its hottest temperatures of the year on June 7. Temperatures soared to the mid to high thirties, aided by low humidity. Winnipeg Airport reached 36.6°C, the hottest temperature in June since 1995. It also just missed the record high for the date of 36.8°C in 1988. In addition, only six other Junes since 1872 managed to reach a temperature this high. Carman and Emerson reached the highest temperatures during the event with highs of 37.3°C and 37.0°C respectively. 

A cold front moving through sparked off severe thunderstorms through the Red River Valley and Interlake late afternoon and evening. Damaging winds and large hail were the main stories. Gusts over 90 km/h occurred along a line from Windygates to Gimli. Winnipeg Airport (YWG) recorded a gust of 91 km/h, marking the first severe thunderstorm event at the Airport since June 2, 2017. Elsewhere, gusts over 100 km/h occurred, including impressive gusts of 133 km/h in Gimli and 113 km/h at Windygates. 

Maximum wind gusts on June 7 in southern Manitoba

Lightning sparked a grass fire in the Tuxedo area of Winnipeg, causing disruptions to rail service and damage to hydro poles. The strong winds caused the most damage, particularly north and west of Winnipeg where hydro poles, trees and small buildings were completely knocked over. The worst hit areas were in the RM of St Andrews and in Gimli where 24 hydro poles needed to be replaced. Close to 11,000 Manitobans lost power at the peak of the event, falling to 3,400 the next morning and 1,900 the next afternoon. Full restoration of power took about 2 days. Hail up to around 3 cm in diameter also fell with the storms from Manitou to Portage to Stonewall and northeast of Beausejour.

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Downed hydro poles along Hwy 8 posted on Twitter by Manitoba Hydro

7 - Cold October and Early November


Unseasonably cold and cloudy conditions occurred in October for the second year in a row. Daily highs averaged 6.8°C, a whopping 3.8 degrees below normal and tied 8th coldest on record since 1872 (2nd coldest since 1970). The mean temperature of 3.4°C tied for 28th coldest since 1872. This made it the second consecutive October to be among the top 30 coldest, a streak that has not occurred since the 1930s. The cold days were mostly the result of excessive cloudiness. Cloudy skies resulted in little diurnal temperature variation (milder at night but colder during the day). The average high was only 6.7 degrees warmer than the average low for the month, the second smallest spread in October since 1872. As a result, only 10 days dipped below freezing during the month, significantly less than the normal of 17 days. The maximum temperature in October was only 19.1°C, the 24th lowest since 1872 and the lowest since 2009 (16.6°C).

The unseasonably cold conditions continued into part of November. The first half of November was the 7th coldest on record since 1872 and the coldest since 1995, with a mean temperature of -8.3°C. No daily cold records were broken, showing that the cold temperatures were more persistent than they were extreme.

Coldest First Halves of November (Nov 1-15) Since 1872 in Winnipeg


6 - July 8-10 Deluge Soaked Up Like a Sponge Thanks to Extreme Drought


After exceptionally dry conditions throughout the year so far, much welcomed rains (with embedded thunderstorms) finally arrived on July 8, 9 and 10 in significant quantities. Widespread amounts of 50 or more mm fell through parts of southern Manitoba with local amounts over 100 mm. A rainfall event such as this would typically cause at least some overland flooding but instead, the exceptionally dry soils soaked up the rain like a sponge, with very little standing water after the event. The event did raise water levels on rivers however.

The highest rainfall amount recorded was about 140 mm in Winnipeg's Island Lakes neighbourhood, most of which fell within a 24 hour period. The rain came down in torrents for several hours on July 9 with 120 mm of rain recorded on the date, almost double what would normally be received in the entire month of July. For any location to receive over 100 mm in a single day within Winnipeg is rare. Even more rare is for this kind of rain to not cause any flooding issues other than some flooded streets, thanks to the dry soils. Generally, widespread amounts of 80 to 140 mm of rain fell in central and southern parts of the city. In addition, a swath of 100 + mm of rain fell south of the city from around Brunkild through to Sprague, while 100 + mm amounts were more localized in nature in southwestern Manitoba. In Winnipeg, one of the greatest impacts of the rain was its effects on traffic lights. Outages at some intersections caused traffic delays.

Some of the highest rainfall amounts in southern Manitoba July 8 to 10



5 - Record Heat and Humidity in Mid September


Once again, more record heat and humidity occurred in September in 2019. An unseasonable push of hot and humid air from the south sent temperature and humidity values soaring across southern Manitoba between September 15 and 21. Temperatures reached close to or exceeded 30C for three consecutive days from September 15 to 17. These temperatures were at least 10 degrees warmer than normal. At Winnipeg Airport, the maximum temperature was 30.6°C on September 17 (not a record). However, the main story was actually the humidity as dewpoints rose to 20°C for three consecutive days from September 16 to 18, smashing records. Dewpoints reached 21.2°C on September 16 and 17 at Winnipeg Airport, breaking the old records of 19.6°C in 2018 and 17.8°C in 1955 respectively. They were also the latest dates to reach such dewpoint values on record since 1953 (previously September 5, 1960). Humidex values reached the mid to high thirties, also records. At Winnipeg Airport, humidex reached 37.6 and 36.8, breaking the old records of 33.9 in 2018 and 34.5 in 1976. The only other time humidex values reached this high so late in the season was on September 19, 2004 (38.1). Thanks to high humidity, overnight lows were remarkably warm. On September 17, Winnipeg Airport had a minimum of only 21.3°C, breaking the record of 17.8°C in 1961. It was also the third highest daily minimum temperature in September since 1872.

In total, 11 daily records were broken at Winnipeg Airport during the event from September 15 to 21, including:

  • 7 high maximum and high minimum dewpoint records
  • 2 high humidex records
  • 2 high minimum temperature records

The hotspot in the province during the event was Dauphin with a high of 33.7°C and a humidex of 39 on September 17. Emerson recorded a daily minimum temperature of 21.6°C on the same date.

4 - Extreme Cold and Snowy Weather in Late January and February


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A prolonged cold snap gripped southern Manitoba and much of the central and western continent in the second half of January and much of February. At Winnipeg Airport, the maximum temperature between January 16 and March 7 (a 51 day stretch) was a measly -6.9°C on February 20. In fact, the -6.9°C  high for February was the 4th coldest on record since 1873. The 1981-2010 average February maximum temperature is 3.1°C. In addition, 23 days dipped below -20°C in February, tied 17th most since 1873. Overall, February averaged -19.9°C, a whopping 6.4 degrees below normal and tied 22nd coldest since 1873. It was also the second coldest February since 1979. In Brandon, February averaged -22.6°C, the 6th coldest February on record since 1890 and the coldest since 1979. Related to the cold, Winnipeg Airport did not reach a dewpoint of -10.0°C or higher in February, only the third month since 1953 to fail to do so and the first February to fail to do so.

The cold in Manitoba was at its worst during a brutal cold spell January 29 and 30 which saw temperature records broken in much of the US Midwest and Northern Plains. At Winnipeg Airport (XWG), the low of -39.9°C on January 30 was the coldest since February 2007 (-41.7°C). Although the official station XWG just missed a true -40°C, the Nav Canada YWG site did reach -40.0°C. Wind chill also dipped to -52.4, the first wind chill below -50 since 2014 and the lowest wind chill since 2004.

The cold in February was also accompanied by an unusual amount of snow for that time of year. February is normally a month with very little snowfall and that had held true through the 21st century so far. 38.4 cm of snow fell in February 2019 in Winnipeg, 2.7 times the normal of 14.0 cm. It was the snowiest February since 1987 and the wettest since 2009 (February 2009 had a lot of rain).

Manitoba had actually missed the worst of the snow and cold anomalies in February, with areas south of the border and in far western Canada recording one of the snowiest and coldest Februarys ever. In North Dakota, Minot had its second coldest February, Bismarck its fifth coldest February and Fargo its 11th coldest February. In Minneapolis, it was a top 10 snowiest month of all time. Even further west, Seattle, Washington had its snowiest and 3rd coldest February on record. In Alberta and Saskatchewan, cold anomalies greater than 10 degrees were recorded, including in Calgary and Saskatoon where February was about 12.8 degrees and 11.4 degrees colder than normal respectively. For both cities, it was the 4th coldest February on record (according to Weatherlogics). Edmonton International Airport dipped to -41.2°C on February 5, while Saskatoon and Regina dipped to -42.5°C and -42.0°C respectively during the February cold snap.

Thanks in part to the prolonged cold spell, the river trail in Winnipeg set a record for its longest season, being open for more than 70 days.
Agriculture and Agri-Food Canada map of Prairie temperature anomalies in February


3 - Driest First Half of the Year On Record


After exceptional dryness in 2017 and 2018, one of the last things Manitobans wanted to see was yet another year of extremely low precipitation. Although excessive rains and flooding arrived in September, the first half of the year was a different story with record dry conditions. In Winnipeg, it was the driest first half (January to June) of the year on record since 1872 with a measly 105 mm of precipitation (the Airport recorded 91.0 mm, however, accounting for undercatch in the winter by using The Forks results in 105 mm of precipitation - still the driest first half of the year). This continued a significant deficit that started in 2017 which was the 3rd driest year on record since 1873 and followed by 2018 which was the 15th driest year. In addition, not a single day received 10 or more mm of precipitation from January to June, the first time this has happened since 1872. The maximum daily precipitation was only 8.5 mm on May 3, breaking the old record lowest of 12.0 mm in 2006 for the period.

All months from January to June, except February, were drier than normal in Winnipeg. March was most notable with a measly 0.6 mm of precipitation at Winnipeg Airport, the driest March on record since 1872. Only 1.6 cm of snow fell, tied 5th least snowy March. March was dry throughout the Prairies with Regina also recording its driest March on record.

Driest Marches in Winnipeg since 1872

Overall, it was the 9th driest spring on record in Winnipeg and the driest since 1987. Extreme dryness continued into June, a month that is normally the wettest of the year. Only 26.3 mm fell, the 7th driest June since 1873 and the driest since 1974.

The Red River Valley saw rainfall in July and August that was closer to normal, helping to lessen the impacts of the drought. However, parts of the Interlake and Parklands remained dry through the period, causing the greatest impacts to be felt in those regions. Hay and feed for cattle faced a major shortage, causing more than ten municipalities to declare states of disaster to get help from higher governments. The provincial government allowed livestock producers to cut hay and let their animals graze on Crown land to help lessen the impacts. Some producers hauled in water and feed which was expensive. In September, both the provincial and federal governments outlined measures to provide financial assistance to affected producers. The series of three dry years also resulted in an increased prevelance of grasshoppers, particularly in and around the Red River Valley. In Winnipeg, it was a repeat of 2018's shifting soils, causing cracks in foundations and sinking buildings.


2 - Rainiest September on Record


After exceptional dryness most of the year, Mother Nature turned the taps back on big time in September, producing the greatest deluge Manitobans have ever seen in the fall. Most of the rain fell in the second half of the month, particularly in the period of September 20 to 30.

At Winnipeg Airport, 153.1 mm of rain fell in September, the rainiest on record and second wettest since 1872, and 3.2 times the normal.

The rainiest and wettest Septembers since 1872 in Winnipeg

Much of southern Manitoba had a wettest September on record, including Brandon which beat the old record of 140.4 mm in 1921 with a whopping 186.0 mm (more than four times the normal of 44 mm). In Carberry, the 179.4 mm of precipitation was the highest monthly total of all-time since 1962. Several locations in southern Manitoba recorded over 200 mm of precipitation in September, particularly in the southern Red River Valley and southeastern Manitoba. These amounts were completely unprecedented in September and rare for any month of the year, especially when considering the fact that most of the rain fell in only a period of two weeks. September is, on average, only the 5th wettest month of the year with around or under 50 mm, making this one particularly unusual and extreme. The highest monthly amounts were between 230 mm and 270 mm, generally in the Emerson, Morris, Steinbach and Zhoda areas. A Cocorahs site in Zhoda recorded close to 270 mm of precipitation in September, four times the normal. South of the border, Grand Forks, Minot and Williston also recorded their wettest September on record. Overall, it was the wettest September on record for the state of North Dakota.

The heaviest deluge occurred on September 20 and 21, when several rounds of heavy rain and severe thunderstorms pummelled southern Manitoba. The weather pattern was highly unusual for that time of year, with a surge of warm and very humid air from the south that lasted about a week. In the two-day period, Winnipeg received around 50 mm of rain, a month's worth by September standards. However, this was not even close to being the highest amount in southern Manitoba. Brandon recorded 122.2 mm, the greatest two-day precipitation amount of all-time since 1890 (the 48.3 mm on Sep 20 and the 73.9 mm on Sep 21 were both all-time daily records for September). Even that did not match parts of the southern Red River Valley and southeastern Manitoba where locally 130 to 160 mm of rain fell during the two-day period, double to triple the monthly normal.

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Two-day rainfall amounts Sep 20-21, 2019 across southern Manitoba at Manitoba Agriculture (MAFRI) stations (@robsobs)

Some might have said the thunderstorm event in the morning of September 20 in Winnipeg was the most significant of the year. A strong mesoscale convective system (MCS) moved through the Red River Valley around the morning rush hour, dumping significant amounts of rain and producing strong winds and frequent lightning. The intensity and scale of the system was unusual for so late in the season (stretching from Berens River to the US border). Wind gusts were generally between 80 and 90 km/h, with a gust of 81 km/h at Winnipeg Airport. The strongest gust was 97 km/h at the Reef Lake MB Fire station near Berens River. Rainfall amounts were the main story with locally 50 to 60 mm within an hour in southwestern parts of Winnipeg. Weather Underground stations in La Salle and Montcalm also recorded severe amounts of 50 mm and 61 mm within an hour respectively. The deluge flooded streets and water poured form the ceiling at the Fairmont Hotel. Nickel to loonie sized hail also fell south of Winnipeg, including in Winkler and Lorette. In Brandon's south end, nickel to hen egg sized hail was reported overnight along with strobe-light lightning. CJOB had a great timelapse of the ominous-looking storms as they moved into downtown Winnipeg, blanketing the city in darkness during mid-morning. Lightning also set off a house fire in Bridgwater. 

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Flooding on Chevrier Blvd in Winnipeg submitted to CBC MB
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Sanford MB webcam showing ominous skies around 9 am Sep 20

Yet more storms moved in late in the day on Sep 20 as well. This time, areas south of Winnipeg were hardest hit with flash flooding being the main issue. Emerson recorded 103.5 mm of rain for the date, an all-time daily rainfall record for September, breaking the old record of 81.3 mm in 1955. 64 mm of this total fell in just an hour. Widespread amounts between 70 and 120 mm occurred, including south of the border. Grand Forks, ND recorded over 100 mm within just a few hours, causing severe overland flooding that flooded farm fields and caused the closure of a portion of I-29

The greatest impact of the rains in September was on farmers. Rain was needed all year, but then came too late in the season and too heavily. The rain put a damper on harvest operations, with many crops being unharvested or harvested significantly later than normal. The heavy rains also caused rivers to swell at a time when they would normally be falling. Flood warnings were issued south of the border for the Red River. In addition, many MPI claims were submitted for hail and water damage to vehicles, particularly from Winnipeg and Brandon.


1 - Unprecedented October Snowstorm and Fall Flooding


One of the most impactful Colorado Lows to ever hit southern Manitoba moved in just before Thanksgiving. It was possibly the worst snowstorm to hit the province since the April 1997 blizzard.

Image may contain: plant, tree and outdoor
Carberry by Dallas McDonald
Generally, 40 to 70 cm of snow fell between Brandon and Winnipeg, with the highest amounts from Carberry to Portage southward to the US border, making it one of the worst snowstorms to ever hit southern Manitoba. The area of heaviest snow also stretched as far south as Bismarck and Jamestown in North Dakota. Brandon received 35.2 cm in total, 20.6 cm of which fell on October 11 alone, the 5th highest daily snowfall in October since 1885. 

In Winnipeg, 34.0 cm fell at the Charleswood site over 2 days, the largest October snowstorm on record in the city since 1872, beating 27.9 cm Oct 30-31, 1971. It was also the earliest snowstorm to dump over 20 cm of snow  (previously 20.3 cm Oct 16, 1878) and the earliest to dump over 30 cm (previously 35.8 cm Nov 7-8, 1986). 21 cm fell on Oct 10 alone, the 2nd snowiest October day since 1872 and the earliest date to record over 20 cm. The snow depth of 30 cm on Oct 12 following the storm obliterated the previous October snow depth record in Winnipeg of 18 cm on Oct 31, 1971. The old record for Oct 12 was just 2 cm in 2006, clearly showing the extremeness of the event. In total, 36.6 cm of snow fell in October, 31 cm above normal and the 2nd snowiest October on record since 1872 and the snowiest in 100 years. 

Snowiest Octobers since 1872 in Winnipeg

Being during the shoudler season, mixed precipitation occurred as well in the storm. The mixed precipitation zone flirted Winnipeg most of the event with mostly rain southeast of the city and snow to the west. 30-50 mm of rain fell through southeastern Manitoba. In Winnipeg, the snow mixed with ice pellets for several hours in the morning of October 11. This mixing zone resulted in lower amounts in eastern parts of the city compared to the western parts where Charleswood is located. Thundersnow and thunder-ice pellets also occurred east and southeast of the city, including in Steinbach


Virtually all main highways were closed during the storm, including highways 1, 2, 3, 10 and 14 (among others). I-29 and I-94 were also closed in North Dakota. Highways in Manitoba did not reopen until late in the day on October 12 or early in the morning on October 13. 


The storm caused a major hydro disaster with a record number of power outages across southern Manitoba. In total, around 150,000 homes and businesses lost power. The storm was estimated to cost Manitoba Hydro more than 110 million dollars. Thousands of hydro poles, and even some hydro towers, knocked over or snapped. The hydro damages were mostly due to a combination of three factors: (1) the extreme wetness/heaviness of the snow, which stuck to everything; (2) the strong wind gusts between 80 and 100 km/h; (3) the foliage still being present on the trees. At one point, the entire city of Portage was without power and residents were asked to not flush their toilets since lift stations were down. One woman was taken to hospital outside Morden due to carbon monoxide poisoning from a propane heater. Power outages continued in the following weeks after the storm due to the number of poles needing to be replaced and due to weakened poles causing new outages. Some 5,000 residents, mostly from First Nations, were also evacuated until power could be restored. 

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Fallen tree in Wininpeg posted by Brock Tropea
The storm also caused an unprecedented disaster to trees in Winnipeg (dubbed ''tree apocalypse''). Tens of thousands of trees were uprooted, knocked over and shredded by the heavy wet snowfall and strong winds. Fallen trees partially or entirely blocked roadways and sidewalks, making travel difficult. One person was injured by a falling tree. The danger of falling trees prompted the city to close city parks until the clean up could be completed. City parks did not fully reopen until November 19. The full clean up could take a year and the city's tree canopy may take ten years to recover. 

States of Emergency were issued by the City of Winnipeg and the Province of Manitoba to facilitate clean up efforts following the storm. Crews from Toronto, Saskatoon, Regina and Calgary arrived to Winnipeg to help clean up trees. Crews from Minnesota, Ontario and Saskatchewan were sent in to help Manitoba Hydro replace broken power poles and towers.

The Winnipeg Floodway was opened on October 9, the first time in the fall on record since 1968. This was a consequence of the storm (with snow melting in only a week) which was preceded by the rainiest September on record. Soils were already saturated and water levels high prior to the October storm. After the storm, the Red River crest on October 24 in Winnipeg was the highest ever recorded in the fall and reached within half a foot of the crest during the 2019 spring flood. Previously, the latest date the floodway was open was on August 4, 2002It did not close until November 8. High water advisories were issued for many rivers, including the Red, the Assiniboine and the Souris. The incredibly wet fall also put a damper on harvest operations and the potato harvest suffered for the second year in a row.


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Floodway in operation Oct 12 posted by Marc Tellier

Exceptionally high river levels continued through November
, as high water continued to move in from North Dakota. Such high levels this late in the fall is possibly unprecedented. As floodwaters receded later in November and December, the ice that had built up on the rivers due to a cold November subsided, causing an unusual display along the shores, as seen in the following photo.


Photo of collapsed ice along the shores of the Assiniboine in Winnipeg after floodwater receded
As a result of the storm, a long-standing city tradition was cancelled this year. Instead of using a donated tree from a resident, it used an artificial Christmas Tree for City Hall. The tree will be used for a few years. Crews were too busy cleaning up to cut down a tree for City Hall. 

Friday, 4 January 2019

Top 10 Weather Stories of 2018 - Winnipeg Area

10 - Three Severe Thunderstorm Rain Events in 2018

 

Three thunderstorm events brought torrential downpours in excess of 50 mm in an hour in Winnipeg in 2018. These events occurred on May 30, July 19 and September 12.
A heavy thunderstorm over Downtown Winnipeg on May 30

On May 30, a slow-moving thunderstorm (radar loop) moved through western and central parts of Winnipeg in the mid afternoon hours. It dumped 30 to over 50 mm of rain in an hour. The maximum recorded rainfall amount in an hour was 53 mm between 3:49 pm and 4:49 pm in Tuxedo. The heavy downpours resulted in flooded roadways (including Route 90), flooded underpasses, flooded basements and overflowing manholes. The Jubilee Underpass closed for at least an hour due to flooding. Flooding inside the Fairmont Hotel was also reported. According to Weatherlogics, the maximum recorded rainfall amount with the storm was 74.2 mm in River Heights. Their map, posted here, shows the tight gradient in rainfall amounts through the city. Generally, 30 to 70 mm of rain fell from Tuxedo to Downtown, with a secondary maximum in amounts of 30 to 50 mm along the West Perimeter from Wilkes to Centreport Canada Way. Amounts dropped dramatically eastward with only 5 to 10 mm in south St Vital and eastern Transcona.

Slow-moving pop-up thunderstorms once again drenched parts of the city on July 19 (radar loop). Waverley West, the Kildonans and Riverbend all received 40 to 60 mm of rain within an hour. The maximum 1-hour rainfall amount recorded was 61.5 mm in Riverbend. In total, the event dropped 60 to 85 mm of rain from North Kildonan to East St Paul. The City of Winnipeg's rainfall map shows well the isolated nature of these heavy downpours.

Yet another severe rain event occurred on September 12. This one once again affected the Riverview and East St Paul area with 50 to 60 mm in an hour. The same occurred further west around Red River College and Amber Trails. More details on this event will be provided in another story below.

9 - June 14 Thunderstorms Result in Second Longest CFL Game in History


The storms, as they moved in near Manitou, MB
Strong thunderstorms developed in southwestern Manitoba and southeastern Saskatchewan in the afternoon of June 14, then pushed eastward through the late afternoon and evening hours into the Red River Valley (radar loop). The storms were most intense in southwestern Manitoba, producing two main swaths of large hail and damaging winds; the first, from Estevan, SK to south of Melita and Killarney, MB, and the second from Minto and Ninette southeastward to Morden-Winkler. Weatherlogics produced a map of severe reports that illustrated these swaths very well. It was one of the biggest thunderstorm events of the year throughout southern Manitoba, dumping hail up to baseball sized and producing wind gusts over 100 km/h. The maximum recorded wind gust of 140 km/h occurred in Minto at the Manitoba Agriculture station. Baseball sized hail and wind gusts up to 128 km/h occurred in Ninette, causing significant property damage. A tornado also briefly touched down near Waskada, but with no reported damage. 18,000 Manitoba Hydro customers were without power as a result of the storms. Damages were significant, with insurance claims to MPI totalling close to 20 million dollars with total insured damages across southeastern SK and southwestern MB over 90 million dollars.

In Winnipeg, strong wind gusts in excess of 75 km/h occurred both ahead and behind the storms. The strongest wind gust of 87 km/h was recorded at the International Airport (YWG) ahead of the storms around 8:45 pm CDT. Long-lasting heavy rain also occurred with a wide swath of 20 to 40 mm throughout the city. The longevity of the event resulted in substantial delays at Investors Group Field. The Edmonton Eskimos were playing against the Winnipeg Blue Bombers. Lightning in the area resulted in a delay in play lasting 2 hours and 55 minutes, beating the previous CFL record for weather-related delays. The game, lasting over 5 hours, was the second longest in CFL history. 

The day was, in fact, primed for severe weather. The SPC south of the border had issued a rare moderate risk along the US border, bordering southeastern SK and southwestern MB. 


8 - March 4-5 Colorado Low Brings Beneficial Snowfall and Widespread Thundersnow


The strongest low pressure system of the year, a Colorado Low, moved into southern Manitoba on March 4 and 5. It brought the worst snowstorm of the year with a wide swath of 15 to 30 cm throughout southern Manitoba. Winnipeg received 18 to 23 cm of snow based on reports from CoCoRaHS and Twitter. Brandon received 26 to 28 cm. It was a heavy wet snow, bringing much needed moisture not only to southern Manitoba, but also throughout the Northern Plains of the US and the Canadian Prairies. In fact, ECCC coined it ''The Million Dollar Blizzard'', for its beneficial moisture after an exceptionally dry winter across the Prairies. According to CBC, the system also caused power outages to some 10,000 customers across southern Manitoba and the closure of some highways, including highway 75 and the Trans Canada. School buses were also cancelled in all Winnipeg school divisions.
ECCC lightning map March 4 530pm CST

What was most unusual about the system was the extensiveness of thunderstorms and thundersnow associated with it. Thunder in the first week of March, though not unheard of, is unusual in southern Manitoba. The system produced widespread thundersnow along, south and north of the US border, enough for several communities to experience it. Manitoba Storm Chasers has stunning video of the storms here. Another video from Saskatchewan can be seen here. South of the border, Grand Forks Airport recorded thunderstorm activity lasting two hours, along with heavy downpours of rain and small hail. Although no thundersnow was reported at Winnipeg International Airport, lightning was visible from the south side of the city as thundersnow occurred just southwest of the city just after midnight.

The visible satellite loop below shows the beginnings of the system as it moved into southern Manitoba. Building towering cumulus (TCU) can be seen in northern North Dakota and moving into southern Manitoba. These produced the thunderstorms and thundersnow that were observed.

Visible satellite loop showing building TCU with thundersnow moving into MB from ND on Mar 4, 3:22-5:17pm CST


7 - An Abundance of 30°C Days and a Lack of -30°C Days in 2018


Hot afternoons were a feature of summer 2018 as temperatures frequently reached the mid twenties to low thirties. In fact, 26 days throughout the year reached or exceeded 30.0°C at Winnipeg International Airport, all in the period of May to August. This was the most 30°C days in a year since 1988, a year which featured the hottest summer on record and 34 30°C days in Winnipeg. It tied with 1939, 1940, 1949 and 1955 for 8th most 30°C days in a year since 1873. The following table lists the years with the most 30°C days since 1873 in Winnipeg:


Rank
30°C days
Year(s)
1 (tie)
34 days
1961
1988
3
33 days
1983
4
32 days
1936
5 (tie)
30 days
1910
1923
7
27 days
1900
8 (tie)
26 days
1939
1940
1949
1955
2018

Conversely, there was a lack of -30°C days in Winnipeg in 2018. This was despite cold conditions in February and parts of January. -30°C weather has become harder and harder to come by in Winnipeg in recent years. Only 3 days saw temperatures reach or dip below -30.0°C in 2018, tied with 1960 and 2016 for 4th least -30°C days in a year since 1872. Normally, 13 days below -30°C would occur (1981-2010 normals). The following table lists the years with the least -30°C days since 1872 in Winnipeg:


Rank
-30°C days
Year(s)
1 (tie)
0 days
1931
2012
3
2 days
1928
4 (tie)
3 days
1960
2016
2018

6 - Second Coldest First Half of April Since 1872


Frigid weather conditions gripped the Northern US Plains and Canadian Prairies in the last few days of March and first half of April. These temperatures helped delay the snow melt and produce a later than normal start to spring.

Temperatures remained below freezing for several days in early April. In fact, 8 consecutive days never reached freezing from April 1 to 8 at Winnipeg International Airport, tied with April 1-8, 1874 for longest such streak in April since 1872. The daytime high of -10.6°C on April 2 was the first minus double digit high in April since 1997. The low of -20.5°C on April 3 was also the coldest in April since 1997. Averaged out, the first half of April was the second coldest on record in Winnipeg since 1872, with a mean temperature of -6.8°C according to Weatherlogics. It was even colder out west, where the first half of April was the coldest on record in Brandon (mean -8.9°C). In fact, tempeartures dipped to the -20s on several occasions in Alberta and Saskatchewan. 5 days dipped below -20°C in Saskatoon. At coldest, Edmonton dipped to -25.0°C (6th), Saskatoon -24.6°C (7th) and Regina -23.9°C (7th). These were all the latest dates to reach temperatures as cold as they were.

In the end, April ''only'' tied for 19th coldest since 1872 in Winnipeg with a mean temperature of 0.3°C. However, it was even colder to the south and west where the core of the cold air mass was placed in early April. South of the border, Fargo had a 6th coldest April and Grand Forks an 8th coldest April according to Daryl Ritchison. To the west, it was the 8th coldest April in Brandon and 11th coldest April in Regina according to Weatherlogics. Grand Forks, ND also had its coldest first half of April on record.

5 - More Than a Month's Worth of Rain in One Night Highlights Wet September


After exceptionally dry weather most of the year, the skies finally opened up in September in the Winnipeg area with frequent rain and thunderstorms. However, the timing of this rainfall could not have been worse for farmers who would have benefitted from more rain during growth in the summer instead of during the harvest season. Cool and muddy conditions made harvesting difficult and delayed.

In total, 5 days saw thunderstorms in Winnipeg, tied with five other years for 2nd most thunderstorms days in September since 1953. In addition, 18 days saw measurable rainfall in September at Winnipeg International Airport, well above the normal of 10 days. This included a 9 consecutive day stretch of measurable rainfall from the 20th to 28th.

The main event in September was a series of thunderstorms the night of September 12-13. Two rounds of heavy thunderstorms pounded Winnipeg the evening of the 12th and during the overnight hours of the 13th. The first round moved through between 8:30 pm and 10:30 pm, producing torrential downpours and intense thunder and lightning (radar loop). 46.6 mm of rain fell at the Airport, making it the 6th rainiest September day since 1872. Locally, 50 to 60 mm fell in a hour from Red River College and Amber Trails to Riverbend and East St Paul. These amounts were equal to or higher than the normal amount of rain for the entire month of September! One lightning strike struck a home in West St Paul around 10 pm, causing a fire which burned it down. Yet another round of storms moved through between 2 and 4 am, dumping yet another 15 to 40 mm of rain through the city. Frequent and intense lightning occurred as well (radar loop). Hail as large as nickels also fell in some parts of the city.

Generally, 25 to 70 mm of rain fell through the night throughout the city. Locally up to 90 mm was recorded in the East St Paul and Riverbend areas. With normal September rainfall only around 48 mm, this meant some parts of the city received more than a month's worth of rain in just one night. In the end, 114.9 mm of precipitation, 113.0 mm of which was rain, fell in September at Winnipeg International Airport. This made it the 9th rainiest and 9th wettest September on record since 1872. The 87.5 mm that fell in the first half of month made it the 5th wettest first half of September. It was also the wettest and rainiest September since 1977.

4 - Mid-August Heat Wave Reminiscent of Dirty Thirties


A full summary of the event was posted here.

3 - 4th Warmest May-June Period Since 1872


Widespread and exceptional warmth occurred throughout the Prairies and US Plains in May and June. In Winnipeg, it was the 4th warmest May-June period since 1872. In Brandon, it was the 2nd warmest May-June period since 1890.

May:
In Winnipeg, May tied with 1978 for 9th warmest on record since 1872 with a mean temperature of 14.5°C. This was 3.1°C above the 1981-2010 normal of 11.4°C and the warmest since 1991. The month saw especially warm days with daytime highs averaging 22.8°C, tied with 1901 for 4th warmest on record since 1872, the warmest since 1980 and 4.4°C above normal. Six days reached or exceeded 30.0°C, tied with 1919 for second most 30°C days in May since 1872. The period of May 23 to 25 was nearly an official heat wave as temperatures reached or exceeded 31.5°C three days in a row. Humidity even came into the equation on some days with dewpoints reaching 20-21°C on May 24 in parts of the Red River Valley. In Winnipeg, the dewpoint reached 20.9°C on May 29, the second highest dewpoint reading on record in May since 1953 and the highest since 1969.

The warmth in May was not isolated to southern Manitoba. In fact, what made the event so unusual and extreme was how widespread the warmer than normal conditions were. Much of North America saw a warm May. In fact, eight US states (from Oklahoma to Virginia) had their warmest May on record since 1895. 33 US states had a top 5 warmest May and 41 states had a top 10 warmest May. Exceptional heat peaked in Minnesota, Iowa and South Dakota on May 27 and 28 with highs reaching 36 to 39°C. Minneapolis reached 100°F (38°C) on May 28, the earliest such occurrence on record and only the second occurrence of 100°F temperatures in May on record. The only other time was on May 31, 1934. Minneapolis also had the most consecutive days above 90°F (32°C) on record in May (5 days). In the Canadian Prairies, Regina had its warmest May on record since 1884. Saskatoon, Calgary and Edmonton all had a top 5 warmest May.

The heat and humidity combined to create an active start to the thunderstorm season across southern Manitoba. Four severe thunderstorm days occurred in late May, with wind gusts of 90 km/h, hail up to golf ball sized and torrential downpours of 50 mm or more.

June:
June was also exceptionally warm, especially as compared to recent memory. It was in fact just as warm as a normal July, with a mean temperature of 19.6°C at Winnipeg International Airport. This tied for 11th warmest June since 1872. It was also the warmest June since 1995 (20.2°C). Daily highs averaged 25.7°C (tied 20th warmest and 2.6°C above normal) and daily lows averaged 13.4°C (tied 7th warmest and 2.8°C above normal). The main story was the consistency of the warmth as only four days reached 30°C. Throughout the May and June period, only one temperaure record was even broken. That record was a record high minimum temperature of 17.1°C on June 9.

Further west, Brandon had an 8th warmest June and Edmonton a 7th warmest June. Other major cities had a top 20 warmest according to Weatherlogics.

2 - A Very Cold Fall with Snow in September


Snow on Sept 22 in South St Vital, Winnipeg
Exceptional cold and snowy weather occurred in the second half of September across southern Manitoba. This came as a surprise after such a long stretch of warm Septembers. In Winnipeg, 20 of the last 24 Septembers were warmer than normal and the city had just experienced five consecutive warmer than normal Septembers. It had been so long since it had snowed in September that Winnipeggers had become complacent about its possibility. The last time it snowed in September was in 2003, but the last time snow actually accumulated in September was in 1984. On September 22, Mother Nature proved that it can still snow in September. A band of snow pushed through the Red River Valley in the evening which came down heavy at times. Winnipeg was right on the edge of the band with only a trace at the Airport, but 0.4 cm in Charleswood and as much as 1.0 cm along the South Perimeter. The city dodged a bullet however, with 5 to 10 cm recorded west and east of the city. Not only was this the first measurable snowfall in Winnipeg since 1984, but it was also the 3rd earliest date on record to see measurable snowfall since 1872. The earliest occurrence was on September 19, 1945. It was the earliest since 1947 when 0.8 cm fell on September 21. It was also the first time since 1872 that snow had been recorded on September 22.

As if one snowfall wasn't enough, it then went on to snow on three other days the remainder of September, giving a total of four snow days in September 2018. Only two of these days actually saw accumulation however (0.4 cm on September 22 and 0.2 cm on September 28). With 0.6 cm of snow in September at the official site in Charleswood, it was the 13th snowiest September on record since 1872 in Winnipeg. A trace snow depth was also recorded during the 12 UTC observation on September 28, only the second time since 1955 that snow was recorded on the ground in September during the 12 UTC observation time.

An unusually extensive snow pack on Oct 4
The snow was not the only story as it was unusually cold as well. Seven days in September had a daytime high in the single digits, tied 2nd most in September since 1872 (most was 8 days in 1873). Amazingly, only one temperature record was actually broken: a 6.0°C low maximum record on September 23. The coldest daily high was 3.7°C on September 28, the coldest high in September since September 28, 1981 (2.9°C). The cold and snowy weather continued through to mid October, with temperatures mainly in the single digits. In fact, a 2nd coldest first half of October on record occurred in Winnipeg, and both Regina and Brandon had a coldest first half of October on record according to Weatherlogics. A low maximum record was broken on October 14 with a high of only 1.4°C. 4.4 cm of new snowfall also fell on October 3, breaking the old record for the date of 0.2 cm in 1991. With 3 cm still on the ground the following morning, it was the first time snow was recorded on the ground during the 12 UTC observation on October 4 since 1955.

The cold weather conditions then continued into the remainder of fall with a November which was 3.3°C below normal and the coldest since 2014. October as a whole tied 19th coldest since 1872 with a mean temperature of 2.8°C, 2.3°C below normal. It was also the coldest October since 2002.

All-in-all, it was the 13th coldest fall (Sep to Nov) on record in Winnipeg with a mean temperature of 1.9°C, 2.6°C below the 1981-2010 normal. It was the coldest fall since 1991 (mean 1.8°C). Thanks to below normal snowfall in November, snowfall through the fall was actually below normal. Other than temperature and snowfall, an all-time minimum dewpoint (since 1953) was also recorded in September. The dewpoint of -11.1°C on September 30 eclipsed the previous all-time record for September of -8.9°C on September 25, 1965. Thanks to a relatively warm first half of September, September only finished as 20th coldest since 1872 in Winnipeg. However, the cold was most intense out west. Brandon tied for 5th coldest September while Calgary, Edmonton and Saskatoon all had a top 10 coldest September. The early cold weather put a damper on the golf season with some courses calling it one of the worst years on record.


1 - 2018 Continues the 2017 Dry Spell


After a second driest year on record in 2017, 2018 continued the dry trend with well-below normal precipitation. With only around 393 mm of precipitation in 2018, it was the 15 driest year since 1873. The two-year period of 2017-2018 was the second driest on record since 1873 with only about 727 mm of precipitation, about 69% of normal. The driest set of years was 1960-1961 with about 717 mm of precipitation. The impact of the dry weather in Winnipeg was mostly due to shifting soil, which resulted in numerous properties seeing cracks in their walls and foundations - a very expensive fix.

The dryness was at its worst from January to August overall (with a wetter period in late May). Winter 2017-2018 was exceptionally dry with a notable lack of snowfall. In fact, it was the driest winter on record since 1872 with only 14.7 mm of precipitation at Winnipeg International Airport. Farm fields outside the city were mostly bare or had very limited snowpack throughout January and February. January was the 5th driest on record (3.1 mm) and February the 4th driest (3.6 mm). The first major snowstorm of the winter in the Winnipeg area did not arrive until the first week of March. However, the dryness returned immediately after the early March snowstorm with exceptionally dry weather continuing through to mid May. The January to April period was the driest on record since 1873 with only 28.1 mm of precipitation, beating the old record of 36.9 mm in 1875. April was exceptionally dry with only 1.7 mm of precipitation, the 4th driest on record. It was also the 12th driest month on record.

There was, in fact, 32 consecutive days without measurable precipitation (0.2 mm +) from April 13 to May 14. This tied with May 7-Jun 7, 1917 for 6th longest such streak on record since 1872. It was the longest since 1980.

The dry spell did not fully break until September, which put an end to a 12-month streak of drier than normal months at the Airport (although, May was less than 1 mm below normal).

Smoke from fires on visible satellite April 29 evening
The dry conditions resulted in dust and fire, especially in the spring before the green up occurred. The worst day was April 29 when strong southerly winds, warm temperatures (in the twenties) and low relative humidity resulted in numerous grass fires and clouds of blowing dust through the Red River Valley. One grass fire destroyed the home of the Reeve of Stuartburn. Grass fires were also ignited around Winnipeg with one particular bad fire in South Transcona along with another in Charleswood. Two homes were also destroyed by grass fires in the Interlake in the RM of Armstrong. The largest fire occurred near Badger in southeastern Manitoba. This particular blaze stretched 8 km wide at one point. Blowing dust also choked skies across the Red River Valley, causing reduced visibility and brown skies. The City of Winnipeg had issued an open-fire ban as a result of the poor conditions.

Thanks to ongoing dry conditions, fires and blowing dust continued to be an issue through to mid May. Thunderstorms produced significant blowing dust on May 15 again. Fires also caused evacuations in Lac du Bonnet, but thankfully homes were saved. At one point, a couple dozens fires were being dealt with through central and eastern parts of southern Manitoba. A fire at Delta Marsh damaged hydro poles. Five homes burned down from grass fires in Little Saskachewan First Nation. Fires near Falcon Lake temporarily shut down the Trans Canada. Numerous other fires occurred as well:
-Evacuations of 4 first nations around Lake Winnipegosis
-Fire caused a full evacuation of Little Grand Rapids