Thursday 31 May 2012

May Summary

May stats. Click to enlarge.
     In terms of temperatures, May was actually very normal with several ups and downs. However, the average mean temperature was still +0.2°C above normal. Technically, a deviation of just 0.2 would be considered near normal rather than above normal. However, it is safe to say that this is the 11th straight month without below normal temperatures. Not very many Winnipeggers are complaining about this trend of above normal temperatures, however one begins to wonder just how long this can last?

     Rainfall and thunderstorms were the main stories of the month. As there were many convective events, rainfall amounts in the city varied greatly from place to place. Higher amounts fell in northern and western parts of the city with as much as 125 mm. The lowest amounts fell in southern and eastern areas, with as little as 85 mm. Those parts of the city missed out on some big rains on May 18th and 28th, which both dumped 20 to 30 mm of rainfall over western and northern parts of the city.

     There was an abnormally high number of thunderstorm events in southern Manitoba this month. The most memorable thunderstorm events in the Winnipeg area were on the 14th, 18th, 23rd and 27th.

The Thunderstorms:

     Storms on the 14th, along with a cold front, produced severe winds throughout southern Manitoba. These winds along with dry soil conditions created a dust storm over southern Manitoba. Dust storms are generally rare in southern Manitoba, however they do occur from time to time. This particular dust storm was different though. Fierce wind gusts as high as 90 to 100 km/h, along with flying dust and debris created near zero visibility in some areas outside of Winnipeg, making it the worst dust storm in recent memory.
     More storms brought a deluge to western and northern parts of the city on the 18th, dumping as much as 30 mm of rain in some areas. Southern parts of the city missed out on most of the rain, only seeing about 5 mm. The storm flooded some streets, produced frequent lightning, and even brought accumulating hail. A more in depth summary with pictures of May 18 here.

     Yet more storms rumbled through the city near midnight May 23. This particular storm will be known for its magnificient display of lightning. Lightning was flashing almost constantly at times, and there were many cloud-to-ground strokes.
     May 27 featured once again thunderstorms in the city in the evening. These ones once again drenched the city with over 20 mm of rainfall in a couple hours.

     Overall, a very active May...


  1. I will be giving a summary of Spring 2012 tomorrow afternoon before I leave. How warm has this Spring really been compared to other years? Check in tomorrow to find out!

  2. Severe thunderstorm warning out for Dunrea and Ninette. Watch out for quarter sized hail, strong winds gusts and torrential downpours in those areas.

    The storm over Winnipeg is dying out. This storm over the city was a pulse variety storm, or 'pop up'. These types of storms tend to dissipate faster than frontal storms like the ones in southwestern Manitoba.