This past Monday night and Tuesday brought significant amounts of precipitation into the Parkland Area of Southern Manitoba and the Qu’appelle Valley in Southeastern Saskatchewan. In an area already waterlogged and dealing with significant flooding risks, how much rain fell?
This system was a system of uncertainty. While there were good indications that there would be significant amounts of rainfall, it was uncertain as to where exactly it would fall. This is a common problem with systems that are primarily driven by convection; subtle shifts in areas of initiation for the convection can result in large-scale changes in which areas do or don’t see rain. This system was of exceptional concern, as early indications were that amounts of up to 50mm could fall in Southwestern Manitoba within the Assiniboine Watershed, which would have heightened the challenges that the region is already experiencing.
Fortunately, most of the rainfall pushed further west than originally forecast, with copious amounts of convection firing up close to the low centre in North Dakota and quickly wrapping around the north side of it then smearing out in a SW-NE line along the deformation zone. This may have spared areas currently fighting against the floodwaters of the Assiniboine River, but was still not exactly needed in an area that has already struggled with excess water this spring.
Saskatchewan Rainfall Totals
The highest amounts fell on the Saskatchewan side of the border where they experienced more active convection. Estevan was the leader with 48.2mm of fresh rain. Amounts diminished the further north and west a location was, with places like Assiniboia, Moose Jaw and Regina getting minimal amounts of rain. Still, several locales received an inch of rain or more. Environment Canada issued an AW bulletin this morning summarizing the totals:
- Estevan: 48.2mm
- Weyburn: 43.2mm
- Kipling: 34.2mm
- Yorkton: 27.5mm
- Broadview: 26.2mm
- Oxbow: 24.0mm
- Indian Head: 22.8mm
- Rocanville: 16.0mm
These amounts were valid as of 7AM Wednesday morning.
Manitoba Rainfall Totals
A similar story was seen over Southern Manitoba, where the Parkland was inundated with rain over a 36 hour period. Some areas that were originally forecast to receive in excess of 25mm saw very little, such as Brandon, whereas areas further north that looked like they may have been spared any heavy rainfall bore the brunt of this system. Ultimately, this “miscast” worked out for the best, as the last thing the residents of Brandon needed was another inch or two of rain. Totals across Southern Manitoba as provided by Environment Canada were:
- Dauphin: 32.9mm
- Pierson: 30.8mm
- Grandview: 30.4mm
- Melita: 29.0mm
- Birtle: 28.0mm
- Russel: 28.0mm
- Ste. Rose: 27.8mm
- Swan River: 27.6mm
- Deloraine: 27.2mm
- Ethelbert: 26.8mm
- Swan Valley: 24.6mm
- Roblin: 23.9mm
- Grand Rapids: 22.7mm
- Virden: 22.0mm
- Brandon: 6.0mm
This should be the last big rainfall for a while. Currently, long range models are indicating an upper ridge building into the Prairies next week which should bring warmer and dryer weather our way.
