A very slow-moving low-pressure system brought multiple rounds of rain and thunderstorms to Southern Manitoba Thursday. While most of the precipitation missed Portage, some storms were reported near the city and water spouts, that look very similar to tornados, were spotted over Lake Manitoba. 

“It all started with a trough of low pressure early in the morning which brought substantial precipitation to areas of the Red River Valley and Southeastern Manitoba,” said CMOS Accredited Weathercaster Chris Sumner. “For example, both Altona and Steinbach received more than 30mm (1.2 inches) in an hour or less during the early morning hours yesterday. Those totals were padded with additional storms and showers throughout the day.”

Sumner noted, because the system moved little during the day, once the activity picked up again late in the afternoon and early evening, many of the same places which received downpours earlier in the day received more precipitation.

“The moisture will be welcomed in many of these regions, some having gone several weeks since measurable rainfall,” he added.

The following are rainfall totals for August 18th, with the figure courtesy of Environment Canada and the Manitoba Ag Weather Network.

  • Steinbach - 55.2mm (just over 2.2 inches)
  • Altona (in town) - 54mm (almost 2.2 inches)
  • Winnipeg (airport) - 41.7mm (almost 1.7 inches)
  • St. Adolphe - 41.4mm
  • St. Pierre - 30.9mm (just over 1.2 inches)
  • Morris - 29.7mm (almost 1.2 inches)
  • Gretna - 27.9mm (1.1 inches)
  • Emerson - 24.6mm (just less than 1 inch)
  • Carman - 11.1mm
  • Stonewall - 9.6mm
  • Southport - 7.0mm
  • Morden - 6.4mm
  • Lake Francis - 5.9mm
  • Manitou - 4.1mm
  • Elm Creek - 2.9mm (just over 1/10th)
  • Portage la Prairie ICMS - 2.0mm
  • Pilot Mound - 1.5mm
  • 25mm = 1 inch

Meanwhile, Sumner tells the rainy weather won’t last long, with a return to sunshine and warmer conditions for the weekend.

“In behind this system, high pressure will build in, and that will clear things out late today, setting us on track for a sunny and warm weekend,” he said. “Saturday and Sunday there is little chance of rain, and highs will be in the 27 to 30 range. Humidity will continue to be a factor, with things feeling muggy at times the next couple days and into next week. We’re expecting a relatively quiet stretch of weather, with little chance of thunderstorms and temperatures flirting with 30 until at least Wednesday.”