MANITOBA: Thunderstorm Forecast for Wednesday, May 10, 2023

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There is the risk of severe thunderstorms on Wednesday afternoon into the evening across much of Southern Manitoba. Some of these storms could be quite strong, particularly in the Minnedosa, Dauphin, Neepawa and Erikdale regions.

Isolated supercells are expected to develop along the Saskatchewan border later this afternoon and track into Western Manitoba. The environment is favourable for these storms to produce up to golf ball size hail and wind gusts in excess of 100km/h. Localized rainfall totals may also approach 50-75mm in pockets that are affected by storm activity.

As the storms make their way in a southeastern direction, we believe that the main storm threat will shift from large hail to damaging wind gusts as the storm mode becomes more liner instead of discrete supercells. This means those in Southcentral Manitoba including the Winnipeg area and Southeastern Manitoba are primarily at the risk of 90-100km/h wind gusts during the evening while the hail and tornado threat will be less of a concern.

Thunderstorms will continue until just before midnight as the cluster of storms moves out of Eastern Manitoba and into Ontario.

We have also revised our tornado risk forecast based on the latest data. The strongest tornado potential exists in a small pocket including Minnedosa, Dauphin, Neepawa and Eriksdale. There is a very good chance that we see at least one tornado today within this area although it isn’t guaranteed. Surrounding parts of Southwestern Manitoba into the Interlake region have an isolated tornado risk, but it’s fairly low.

TORNADO RISK

MANITOBA: Thunderstorm Forecast for Wednesday, May 10, 2023

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The storm threat across Southern Manitoba on Wednesday is looking stronger than initially expected. As a result, we have upgraded our forecast to include both a slight and isolated severe risk zone. Based on the latest model data it appears there is the potential for some storms to produce up to 3cm size hail and wind gusts in excess of 100km/h.

The strongest risk extends from Roblin/Russell through Dauphin and into Portage La Prairie. Storms are expected to develop along the Saskatchewan border and track into Western Manitoba by the late afternoon.

These storms are expected to continue to move across Southern Manitoba and should reach the Winnipeg area by the early evening. At this point, the main storm threat will shift towards 90+km/h wind gusts as the storms take more of a linear formation.

Thunderstorms will continue until just before midnight as the cluster of storms moves out of Eastern Manitoba and into Ontario.

An isolated tornado can’t be ruled out with the storms on Wednesday. The risk for tornadoes will be primarily focused on Southwestern Manitoba including Virden, Brandon, Dauphin and Portage La Prairie (see below).

TORNADO RISK

MANITOBA: Thunderstorm Forecast for Wednesday, May 10, 2023

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Widespread pop-up thunderstorm activity is expected to affect much of Western and Central Manitoba on Wednesday. The strongest potential is around the Roblin, Swan River and Dauphin region where storms that develop over Saskatchewan will likely track into this area by the afternoon or evening. Another zone in the southwest including Virden, Souris and Boissevain is also likely to see storms.

At this point, it appears that the severe risk with these storms should be minimal. We may have to introduce an ‘isolated’ severe threat zone somewhere along the Saskatchewan border when we update the forecast by Tuesday night.

MANITOBA: Thunderstorm Forecast for Tuesday, May 9, 2023

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Isolated thunderstorms are possible through parts of Southwestern Manitoba on Tuesday. These pop-up storms should remain non-severe with small hail, strong wind gusts and heavy rainfall as the main threats. Storms are expected to start by the late afternoon and continue into the evening.