More severe storms possible for S Manitoba


Manitoba


Area(s): Western and northern

Timing: Wednesday afternoon into the evening


Threats:

  • 2-3 cm hail,

  • 90+ km/h wind gusts over western Manitoba Parklands; gusty winds, pea sized hail, locally heavy downpours elsewhere


Isolated to scattered thunderstorms are expected to develop on this afternoon over southwestern Manitoba as well as much of northern Manitoba as a trough of low pressure tracks through the province. Non-severe thunderstorms are expected over most areas except near the Riding Mountains and Westman areas where isolated storms could produce wind gusts exceeding 90 km/h.

Manitoba..Surface low and associated trough will trigger isolated thunderstorms over western and northern Manitoba this afternoon.

Over the Westman and Parklands areas .... moisture will be rather limited in the wake of Tuesday's frontal system with MLCAPEs on the order of 500 J/kg or less. Meanwhile, wind shear profiles are rather impressive, albeit unidirectional, with 40-50 knots of effective bulk wind shear through 0-6 km over the Parklands dropping to 35 to 45 kts over the Westman area. Given the excessive shear and weak CAPE, BRN values are extremely low as a result thunderstorm development is expected to be inhibited somewhat over the Parklands area. In the Westman region. BRN values are slightly more favourable and with the passage of the surface low across the area isolated thunderstorms are expected with severe wind gusts being the primary threat. Over northern Manitoba, non-severe thunderstorms are generally expected over a rather large area due to broad forcing. Thunderstorms could be marginally severe in The Pas-Flin Flon-Lynn Lake corridor given slightly better thermodynamics and dynamics overlapping. Non-severe thunderstorms will likely persist eastwards across north central Manitoba into the evening hours.