Southern Manitoba 2014 Thunderstorm Statistics

This photo of a funnel cloud was taken just southwest of Winnipeg.
This photo of a funnel cloud was taken just southwest of Winnipeg.

Welcome to our summary of the 2014 thunderstorm season across Southern Manitoba! This post will summarize these statistics and compare this year’s thunderstorm season to the last couple seasons. In case you are curious, a brief explanation of how I gathered these statistics can be obtained by following this link.

Thunderstorm Days

The number of days with thunderstorms across southern Manitoba broken down into 6 regions. Includes the date of first thunderstorms and last thunderstorms.
The number of days with thunderstorms across southern Manitoba broken down into 6 regions. Includes the date of first thunderstorms and last thunderstorms.

In total, there were 94 thunderstorm days across southern Manitoba in 2014 (southern Manitoba being defined as the area shaded in the map above). This was slightly higher than in 2013 (89 thunderstorm days) but still much lower than in 2012 (~ 109 thunderstorm days). This is mainly the result of a late spring and thus, a late start to the season in both 2013 and 2014. 2012 featured an early spring with numerous thunderstorm events in March and April. This year, no thunderstorms occurred in March and only 2 thunderstorm days occurred in April. In fact, southeastern, eastern and Interlake portions of southern Manitoba did not see their first thunderstorm until the third or fourth week of May, at least a month later than usual. Winnipeg didn’t get its first thunderstorm until May 20, the 8th latest first thunderstorm on record since 1953.

The distribution of thunderstorm days, as seen in the map above, was fairly uniform across southern Manitoba overall. Similarly to 2012 and 2013, the region east of Lake Winnipeg saw notably less thunderstorm activity.

Interestingly, there was a thundersnow event in January! Although lightning detection products did not record the lightning, lightning was reported by residents west and southwest of Winnipeg on the evening of January 15; more specifically between Carman and Winkler. This was associated with a very strong cold front behind a potent Alberta Clipper. This clipper also brought record winds and high temperatures across the Prairies. Unfortunately, I could not find any data on winter thunderstorm activity in Manitoba historically. The only other occurrence of lightning in January I could find was a report in the Daily Free Press of lightning on January 16, 1876 (Penziwol, 2004). This is not to say that lightning has never occurred in January since then, but that is the only other report I could find. Nonetheless, this year’s thundersnow event was extremely rare for Manitoba.

In Winnipeg, 23 thunderstorm days occurred at the airport in 2014. Although this is the most since 2010, it is still below the normal of ~26–27 thunderstorm days. In fact, we have not had an above normal season since 2007. The last thunderstorm recorded was on September 8, tying for 10th earliest last thunderstorm since 1953. This puts the season at 112 days long, the 5th shortest on record. However, this statistic is a bit misleading. Thunderstorms did occur in southern parts of the city 3 times after September 8, including 2 events in October. I recorded 27 thunderstorm days here in South St Vital this year and the season lasted 156 days.

Severe Thunderstorm Warning Days

The number of days in which severe thunderstorm warnings were issued through 2014 in Manitoba, broken down by forecast region.
The number of days in which severe thunderstorm warnings were issued through 2014 in Manitoba, broken down by forecast region.

In total, there were 34 days with a severe thunderstorm warning issued in southern Manitoba. This is similar to 2012 but much less than in 2013 (45 severe thunderstorm warning days). The first warning was issued on May 24 and the last on September 8, putting the season at 108 days long. This is a tad less than in 2013 (110 days long) and 2012. As has been the case the last few years, southwestern Manitoba saw the most severe thunderstorm warning days in 2014.

Tornadoes

The number of days tornado warnings were issued across Manitoba in 2014, broken down by forecast region.
The number of days tornado warnings were issued across Manitoba in 2014, broken down by forecast region.

There were 4 tornado warning days in 2014, half the number in 2013 (8 days) but double the number in 2012 (2 days). The Red River Valley area saw the most. In fact, the warning zone southeast of Winnipeg, which Steinbach is situated in, saw 3 tornado warning days, the highest of all warning zones in Canada this year. However, only one of these warnings actually produced a confirmed tornado (an EF–0 southeast of La Salle on July 26).

From what I could find, 4 EF–0 tornadoes were confirmed in Manitoba this year. However, it is likely that there were more (many go unconfirmed). July 26 was the biggest tornado day of the year with 3 landspout tornadoes confirmed (all EF–0). 2 were in the Interlake near Waterhen and the other was southeast of La Salle.

A tornado might have touched down (unconfirmed) southwest of Winnipeg July 5. Part of the A Weather Moment team (Scott, Matt, Julien & Kyle) watched the storm as it evolved and managed to capture at least 2 funnel clouds. One of these is seen in Matt’s funnel cloud picture at the top of this post. After reporting this funnel to Environment Canada, a tornado warning was issued for the City of Winnipeg.

Monthly Frequency

Thunderstorm-related days per month (thunderstorms, severe thunderstorms and tornadoes) for Southern Manitoba in 2014.
Thunderstorm-related days per month (thunderstorms, severe thunderstorms and tornadoes) for Southern Manitoba in 2014.

For the first time since I started gathering these statistics in 2010, the busiest month of the year for thunderstorm activity across southern Manitoba was in June. The maximum is typically in July, but this year there was an unusual local minimum in activity in July with just 18 thunderstorm days. Residents in southwestern Manitoba were especially hard hit in June with multiple rounds of heavy thunderstorms and rains mid-late month. Over 150 mm of rain fell in the heaviest hit areas in just a period of 2 weeks. 251.6 mm of rain fell in June in Brandon, the rainiest June on record since 1890. 219.8mm of this fell in just the last 12 days of the month. Extensive overland and river flooding occurred as a result, as many of you likely still remember well.

If interested in comparing, follow these links for the 2013 and 2012 graphs: 2013, 2012.

Reference Cited
  1. Penziwol, Shelley. (2004). Storm Signals: A History of Weather In Manitoba. Great Plains Publications. Winnipeg, Manitoba. Page 3.

State of The Climate – Meteorological Fall 2014

Wow, what a fall temperature-wise in southern Manitoba this year! From record July-like heat in late September to January-like cold in November, we saw the extremes of all seasons… Here are the average temperature and total precipitation rankings for fall 2014 in Winnipeg:

Meteorological Fall Rankings for Winnipeg
CategoryFall 2014
Average/Total
Rank
High Temp.9.1°CTied 49th coldest
Mean Temp.3.8°CTied 48th coldest
Low Temp.-1.5°CTied 53rd coldest
Rainfall47.3 mm24th least
Snowfall18.2 cmTied 46th least
Precipitation59.7 mm (est.)18th driest

The meteorological fall (Sep-Oct-Nov) averaged 3.8°C or 0.7°C below the 1981-2010 normal. The negative anomaly was due to a frigid second half of November. September and October actually averaged warmer than normal with anomalies of +0.6°C and +1.6°C respectively. November on the other hand finished 4.2°C colder than normal with an average of -8.8°C, the 22nd coldest November on record since 1872 and the coldest since 1996.

Record Heat & Humidity In Late September

The dramatic burst of July-like heat we had in late September was perhaps the top weather event of fall 2014. The bulk of the warmth occurred September 22 to 27 with 6 of those days seeing highs over 25°C, a good 10-15°C above normal for that time of year. Overnight lows remained well into the teens.

Fall colours as seen in Henteleff Park on September 13, 2014.
Fall colours as seen in Henteleff Park on September 13, 2014.

September 26 was the hottest day with a high of 30.2°C at Winnipeg Airport, just shy of the old record of 31.7°C in 1952. However, it was even hotter in southwestern Manitoba where the heat was literally unprecedented for so late in the season (at least since records began). In Brandon, highs of 34.0°C and 32.8°C on the 25th and 26th respectively were the hottest on record for so late in the season since 1890. The provincial hotspots during the hot spell were Swan River and Wawanesa with maximums of 35.1°C!

In Winnipeg, only 1 temperature record was broken; a record high minimum of 17.4°C on September 26. This was the warmest minimum temperature for so late in the year since 1872. Humidity was the main story with dewpoints in the teens and humidex values in the 30’s. In fact, 6 daily high dewpoint records were broken in Winnipeg during the warm spell, with a maximum dewpoint of 18.1°C on September 26. A maximum humidex value of 35.8 on the 26th was the latest occurrence of humidex over 35 on record since 1953.

October Warmth & January in November

After a brief cool down early October, things warmed up again mid-month with highs commonly in the teens. 2 days exceeded 20°C. A high of 20.6°C on October 24 was the warmest for so late in the year since 1990. Thanks to generally warm conditions in October, The Forks weather station did not report its first freeze until October 30!
Of course, winter came in viciously in mid November with a prolonged cold snap lasting until the beginning of December. A low of -29.6°C at Winnipeg Airport on November 26 was the coldest in November since 1996. We only reached a measly high of -19.3°C on the 26th and 30th, the coldest highs in November since 1985.

Dry Fall

It was also a fairly dry fall, as many of you have probably noticed. Only around 60 mm of precipitation fell in Winnipeg, making it about the 18th driest fall on record since 1872. October was driest with just 4.9 mm of precipitation (all rainfall), the 3rd driest October on record.

The Year So Far

2014’s standing in terms of temperature has improved (warmed) slightly since the summer summary in September, thanks to warmer conditions in September and October. This January to November period averaged 2.3°C or 2.1°C below the 1981-2010 normal for the period. It is the 22nd coldest since 1873 and coldest since 1996, which is an improvement from the 17th coldest January to August period.

Monthly & year-to-date temperature deviations through Fall 2014 in Winnipeg, MB.
Monthly & year-to-date temperature deviations through Fall 2014 in Winnipeg, MB.

391.4 mm of rain has fallen this year up to now, which is actually about 37 mm below normal for an entire year. The deficit in rainfall can be attributed to a very dry fall and below normal rainfall in the spring.

State of the Climate – Meteorological Summer of 2014

As of September 1st, meteorological summer[1] has come to an end and the fall season is upon us. That means, of course, it’s time to take a look back on the summer of 2014 to see just how it fared in the grand scheme of things. Was it actually all that cold, or is that just our memories suffering from the prolonged winter? How wet was it actually? Was it a particularly stormy summer? We’ll take a look at how all of those things fared in Winnipeg as well as highlight a couple major events from the past 3 months across the province!

Meteorological Summer Rankings for Winnipeg International Airport
CategorySummer 2014 Total or AverageRank
Average High Temperature24.3°CTied 51st coldest
Mean Temperature18.2°CTied 67th coldest
Average Low Temperature12.1°CTied 53rd warmest
Total Rainfall276.9 mm29th rainiest
Thunderstorm Days17 daysTied 23rd least

Temperature-wise, there wasn’t much to talk about this summer in southern Manitoba. The summer averaged pretty much bang on normal in most areas, including Winnipeg where the average mean temperature of 18.2°C was just 0.2°C below normal. A similar story in Brandon where the average mean temperature of 17.4°C was just 0.1°C above normal. However, there was a notable lack of very hot days. There were only 5 days above 30°C in Winnipeg, below the normal of 12 days, and the least since 2009 when there were only 3 days over 30°C. Interestingly, the hottest day so far this year was actually in May when we hit a record 33.3°C on May 24th. Although it is not the first time our hottest day of the year was outside of the summer season, it is unusual. The last time this occurred was in 2004 when our hottest day of the year was on September 19th.

August Ends 10-month Cold Streak

Top 5 Longest Streaks of Colder Than Normal Months Since 1872
Rank# of consecutive below normal monthsTimeframe
118 monthsDec 1882-May 1884
214 monthsJul 1884-Aug 1885
311 monthsOct 1887-Aug 1888
410 monthsOct 2013-Jul 2014
59 months1949/50, 2008/09 & 2012/13

August finished 0.5°C above the previous 30-year (1984–2013) average mean temperature of 18.7°C. This marked the end of a 10-month streak, from October 2013 to July 2014, of months colder than the previous 30-year average. This 10-month streak was the 4th longest of its kind since 1872 and the longest since an 11-month streak in 1887–1888.

Summer Flooding

A grand total of 276.9 mm of rain fell at Winnipeg airport June, July and August. Although this may seem like a lot of rain, this is actually only 12% above the 1981–2010 normal of 247.5 mm. So overall, we were pretty close to normal rainfall totals this summer. However, the problem this summer was that the rain was not spread out through the entire season. Rather, the majority of our rain fell in mid-late June and mid-late August. These two periods featured flooding in parts of southern Manitoba as too much rain fell in too little time. In fact, over 130 mm of rain fell in just 17 days in the second half of June at Winnipeg airport. The month finished 12th rainiest on record with 147.1 mm.

Excessive rainfall over southwestern Manitoba this summer resulted in significant flooding along the Assiniboine river. Brandon, MB – pictured above – was one of many communities hit hard by the widespread flooding.
Excessive rainfall over southwestern Manitoba this summer resulted in significant flooding along the Assiniboine river. Brandon, MB – pictured above – was one of many communities hit hard by the widespread flooding.

Conditions were worst in southwestern Manitoba this summer with well above normal rainfall; over 300 mm of rain fell in some of the hardest hit locations. Brandon was one of these locations, receiving a whopping 347.2 mm, almost an entire year’s worth of rain in just 3 months. 251.6 mm of this fell in June alone, Brandon’s rainiest June on record. In fact, 219.8 mm fell in just the last 12 days of June, more than half a year’s worth of rain!

The Year So Far

2014 continues to be much colder than normal. Up to August, the year has averaged 1.7°C; 2.7°C colder than normal for the period. This ties for 17th coldest January to August period on record since 1873, and is the coldest since 1979 when we averaged 0.7°C in the same period. Here’s hoping the year ends on a warmer note!

The monthly and running year-to-date temperature deviation from normal (1981-2010).
The monthly and running year-to-date temperature deviation from normal (1981–2010).

In terms of rainfall, the airport has seen 344.1 mm so far this year (up to August 31), which is pretty much bang on normal for the period. Higher amounts, closer to 400 mm, have fallen in southwestern parts of Winnipeg where heavier rains fell in August.


  1. Metorological summer is considered June, July and August.  ↩

State of the Climate: Meteorological Spring 2014

Meteorological Spring Stats and Rankings for Winnipeg
CategorySpring 2014 Total or AverageRank (since 1872)
High Temp.5.6°CTied 19th Coldest
Mean Temp.-0.4°CTied 20th Coldest
Low Temp.-6.2°CTied 22nd Coldest
Rainfall67.2 mm59th Least Rainy
Snowfall31.4 cm59th Snowiest

Despite a seasonal May temperature-wise, the meteorological spring[1] of 2014 still averaged well below normal thanks to a frigid April and March. The spring averaged -0.4°C, 3.8°C below the 1981-2010 normal of 3.4°C. Thus this was the 9th coldest spring in the last century and tied for 20th coldest since 1872. In comparison, last spring in 2013 was a tad colder, averaging -0.6°C. It was just 2 years ago that we experienced our 2nd warmest spring on record. We’re sure paying for that now!

A Variety of Weather Conditions in May

Because I’ve already talked a lot of about March and April in 2014 – The Year so Far a few weeks ago, I’ll talk mainly about the month of May in this post.
May started out just like every other month since last fall: below normal. Things began warming up mid-month with our first 20°C of the year on May 10 when we reached 23.2°C. This marked the 18th latest first 20°C of the year since 1872 and the latest since 1996 when we did not reach 20°C until May 18. The 1981-2010 normal is April 20 and thus, we were a good 3 weeks behind schedule this year.

After some snow on May 14, mother nature had a dramatic mood swing in the 3rd week of May as July-like conditions arrived. Just 10 days after seeing snow, temperatures soared to a record 33.3°C on May 24, breaking the old record of 32.7°C in 1980. This also marked the first 30°C reading in May since 2007 and was the hottest May day since 1995. Temperatures soared again on May 29, reaching 32.7°C. With two days above 32°C, it was the most 32°C+ days in May since 1995 when there were also two.
With the warmer weather came thunderstorms. Winnipeg received its first thunderstorm of the season on May 20, the 8th latest start to the thunderstorm season since 1953. This follows the 2nd latest start last year. 1981-2010 normal first thunderstorm of the year is April 27.

In the end, May averaged 11.3°C which is pretty much bang on the normal of 11.4°C. However, at 0.1°C below this normal it is just enough to continue the streak of colder than normal months. May stands as the 8th consecutive colder than normal month, a streak which began last October. This ties for 7th longest below normal streak since 1872.

Top 12 Longest Streaks of Colder Than Normal Months Since 1872
Rank# of Consecutive Below Normal MonthsTimeframe
118 monthsDec 1882-May 1884
214 monthsJul 1884-Aug 1885
311 monthsOct 1887-Aug 1888
49 months1949/50, 2008/09 & 2012/13
78 months6 occurrences (including 2014)

Thankfully, May ended a 5-month streak of months averaging over 3.5°C below normal, the longest streak of its kind since 1872. Prior to this year, the longest was just 3 months.
May this year also continued a now 2 decade-long trend of cool Mays. We have not had a top 35 warmest May in 23 years. The last time was in 1991 which featured a tie for 5th warmest May. Since then, 6 Mays were among the top 35 coldest.

The Year So Far

The monthly and accumulated year-to-date temperature deviation from the normal monthly average temperatures.
The monthly and accumulated year-to-date temperature deviation from the normal monthly average temperatures.

So far this year we have averaged -8.2°C (January to May), 4.2°C below normal and the 16th coldest first 5 months of the year since 1873. It is also the coldest since 1996 and the 5th coldest in the last century. This is little improvement from the 15th coldest first third of the year (January to April) we experienced.


  1. Meteorlogical spring lasts through the months March, April and May.  ↩