Severe Weather

Photo credit   CBC

     It's going to be a bumpy ride in southern Manitoba over the next several days. Thunderstorms are possible everyday from today through to Sunday.
     Today is a hot and humid day in southern Manitoba, with highs near 30°C in the city of Winnipeg and humidex values in the mid thirties. This along with a cold front near the Saskatchewan border and high instability is providing the risk for some strong storms in southwestern Manitoba this afternoon. These storms will have the potential to be severe with the main threats being large hail, damaging winds, excessive rainfall due to the slow motion of the storms and even a small risk of an isolated tornado.
     Rains and storms moving north from North Dakota this evening and overnight will be bringing significant rainfall from the US Border up to the Swan River area. Locally up to 75 mm of rain will be possible in the Riding Mountains area from now to tomorrow morning. As a result of this potential, Environment Canada has issued a rainfall warning in some areas, calling for 40 to 70 mm of rain:

Rainfall warning for tonight. 40 to 70 mm possible.

     These rains and storms will move into the Interlake and eastern areas of Manitoba tomorrow, giving up to 40 mm in areas such as Fisher Branch and Bissett.
     Here in the RRV and southeastern Manitoba, you could say we will likely miss the worst of the storms, however the potential is still there. The best chance will be later in the evening and overnight. Locally heavy rain will be possible, however storms should remain non-severe in this area. A good light show is not out of the question.
     Lingering showers and storms are still possible in the morning and to start the afternoon, before things begin to clear later in the afternoon and evening Friday.

     The real action is Saturday. Uncertainty still exists, so it is recommended you stay tuned for updates as Saturday could feature the first significant severe weather outbreak of the year. High shear is possible Saturday which brings in some concern about the potential for tornadic activity in northern North Dakota and in southern Manitoba. Due to very high instability and moisture, very large hail will be possible as well. SPC in the US has us in a hatched risk already for Saturday, which signifies a 10% + probability of significant severe weather within 25 miles of a point. This risk could be upgraded in the future if needed.

     Sunday is even more uncertain at this point, therefore I wont say much about that day. Some models bring in the potential for more storms, while others don't. Stay tuned..

     A cool down will take place behind this system for next week. Highs in the high teens look possible, which will be quite different from what we've gotten used to the past week.

     A list of things you can do to prepare for a severe weather outbreak here.

Gorgeous

     The next few days will be absolutely perfect with lots of sunshine with warm and even hot temperatures. Enjoy it while it lasts!

     Today will be perfectly sunny, with perhaps a few clouds at times in the afternoon. Expect highs around 28°C. Tomorrow will be very similar with mainly sunny skies, and highs around 26 or 27°C. Wednesday could be one of the hotter days this week, as a breezy southeast wind pumps in an extra boost of warmth humidity. Our first 30°C of the year will be possible Wednesday.

     There may be some showers and storms in southern Manitoba late Wednesday, into Thursday. It does not look like a major event so far, however I will still keep an eye out. Thursday and Friday both look warm as well.

     Things get a lot more interesting on the weekend. Many models are hinting at a very strong low pressure system moving into Saskatchewan and the Interlake Sunday. With this, a cold front will slice southwards into the very warm and humid air mass. GFS is showing some significant shear, instability, LI's and a decent llj. All of this raises concern for a severe thunderstorm outbreak Saturday and Sunday. The SPC (Storm Prediction Center) in the US already has our areas in a day 6 and day 7 risk. To issue a risk of severe storms this far in advance is rare, especially for our area. This system will need to be monitored very carefully, as a tornado outbreak will be possible on both sides of the border if the current model solutions verify.

2nd Warmest Spring on Record

     With an average mean temperature of 6.8°C, Spring 2012 (March/April/May) was the second warmest Spring in Winnipeg since records began in 1872. That is 3.4 degrees above the normal of 3.4°C. This Spring beats the old second place which was held by 2010. It sure didn't take long to beat that record!

Top 5 warmest Springs in terms of mean temperature:

1.  1977      7.5°C
2.  2012      6.8°C
3.  2010      6.6°C
4.  1987      6.3°C
5.  1878      6.0°C

     March is really the reason why this ended up being the second warmest Spring on record. The so called ''heat wave'' we experienced in March will be famous for years to come, and commonly be known as ''March Madness''. It was the warmest March on record in Winnipeg, with over 25 records broken throughout the month. A summary of the extremes we experienced in March can be seen here.

     Even though April and May were not well above normal, an exceptionally warm March sealed the deal for the second warmest Spring. As a result of the warmth, Lake Winnipeg experienced the ealiest ice breakup in recent memory.

     Spring 2012 will also be known for its thunderstorms. The thunderstorm season began earlier than it ever has before, with strong thunderstorms on March 19. That storm produced incredible downpours of rain with frequent and intense lightning, unprecedented for so early in the year. More storms rumbled through the city on March 27, and by the end of the month, 43.5 mm of rain had fallen over the city. As a result, it was the 3rd wettest March on record.

     April was extremely dry with no thunderstorms in the city, however May made up for that. Several thunderstorm events during the second half of the month dumped significant amounts of rain over the city. By the end of the month, up to 125 mm of rain had fallen in western parts of the city for the entire month.

     In total, 180.5 mm of rain fell in the city from March to May. That is double the amount of rain we would normally see.