Tuesday, 22 May 2012

Another Round of Storms Tonight

     Thunderstorms are looking likely in southern Manitoba this evening and overnight. An area of low pressure is expected to move in overnight, and it, along with the associated fronts are expected to spark off many storms later this afternoon and especially in the evening. One area is near the warm front, and the second is near the cold front. Here's the current analysis early this afternoon:
Early afternoon analysis with fronts, SBCAPE (yellow) and llj (green arrows)
     The llj, moisture and instability will stream north ahead of the warm front this evening. Most of the storms are expected to form first in North Dakota and southeast Sask/southwest Manitoba later this afternoon, then move east. Some of these storms are expected to be severe. SPC in the US for instance has issued a 5% risk for tornadic activity near the International border, along with a 30% risk of damaging winds and large hail. Personally, I believe that that risk, especially the tornado risk, is a little hyped up for our side of the border; I believe the best risk is in North Dakota. However, large hail and damaging winds is certainly a possibility on our side of the border along and south of the Trans-Canada. The best risk for severe storms on our side of the border will be this evening.

     Storms will be more elevated in southern Manitoba later in the evening and overnight, eliminating the threat of tornadoes. Large hail and damaging winds will remain a threat through the night.

     Here is my thunderstorm forecast map below, valid for the whole night from this afternoon to tomorrow morning. The left is the non-severe storm risk, and the right is the severe risk.
Non-severe risk (left) - light blue = small   dark blue = moderate    green = high...   Severe risk (right) - yellow = slight
     Stay tuned to the comment section below this post for updates.


  1. Tornado watches have been issued in North Dakota, and that watch goes all the way up to the canadian border. Border towns such as Melita, Killarney, Morden have to watch out for some nasty weather over the next 6 hours.

  2. Things are actually getting a little more uncertain as we get closer. Some indications are pointing at the possibility that there will be a split in systems (what a surprise), with areas around Winnipeg only getting brushed by some showers on the northern edge of an mcs. At this point, all we can do is wait and see.

  3. Tornadoes confirmed near Estevan by a storm chaser in the area. The worst of that storm has moved south of the border, however a supercell has sprung up just south of the border, southeast of the Estevan storm, and moving northeast. For you guys around Melita, please watch out for warnings in the next hour as this supercell moves closer to your area. That storm is tornado warned south of the border. I'm surprised no watches have been issued yet at minimum.

  4. Severe thunderstorm watch issued for the Melita region. The tornado warning has ended south of the border with that supercell storm, however it is still important to be vigilant.

    It doesn't appear a watch is needed to be extended to other areas just yet, although some more may be issued later.

  5. Widely scattered showers and storms are blossoming across southern Manitoba now. Thunder likely for just about everyone at this point this evening.

  6. Had a brief moment of thunder and lightning in the city around 9.

    Although, now the worry of a split in systems is getting closer to reality. If nothing more develops upstream to Winnipeg, Altona, Steinbach regions, we may not get much tonight after all. So far the bulk of the rain and storms is staying to our north and south.

  7. Fiouf

    Line of storms filling in between the two complexes with lots of lightning being seen. Already can see lightning to my southwest. Get ready for storms in WPG.

  8. Brrr! Get ready for a serious cool down!

    Cold front passes this afternoon which will usher in, well, COLD air.

    Tomorrow, we are only expecting highs to barely reach 10°C. I'm saying 9°C for a high in the city. Saturday will be similar albeit a couple degrees warmer with highs in the low teens. Both days, a few showers will be possible. And sadly, a few flurries will even be possible over higher elevations in western Manitoba. Yikes!

    Sunday will be cool as well, though it looks to be a rainy day with up to 20 mm of rain possible. Thunderstorms look possible in the morning on Sunday, which could further increase amounts locally.

    If you're waiting for the next warmup like I am, we will have to wait until later in the week next week.

  9. Snow fell from Regina to Yorkton to Dauphin overnight and this morning! yikes! 2-5 cm locally was reported over western Manitoba.

    Frost warnings issued for much of southern Manitoba. The only areas not in the warning are areas of southeastern Manitoba, south and east of Winnipeg.