Thunderstorms with a double tornado risk eyes Alberta Saturday
Severe weather may make an appearance today in heavily populated areas of Alberta, with the risk of thunderstorms that may produce very large hail and a double tornado threat.
According to Environment and Climate Change Canada (ECCC), thunderstorm outlooks from the Storm Prediction Centre show a double tornado risk in Alberta with severe thunderstorm activity today, July 18.
“A potentially explosive day, severe weather-wise. Recent runs of the RDPS and HRDPS are consistently suggesting MLCAPE values of 3000+ J/KG, which is nearly unheard of in Alberta,” the ECCC Prairie and Arctic Storm Prediction Centre significant weather discussion stated.
“The main question is where exactly the SFC low develops, as tornadic potential will be maximized in the NE quadrant. The best chance for strong and or multiple tornadoes will coincide with the intersection of a dryline and cold front. NWP guidance has been gradually pulling this feature north and west with successive runs, from the Sask border toward the Edmonton metro area.”
The discussion noted that the area will need to be monitored very closely by this afternoon, as any storms that form in that environment will likely be dangerous.
“It should be noted that this exact type of pattern, while rare, has historically been associated with long-track, tornadic supercells.”
There is an extreme-risk zone present in the province today, just east of Edmonton and almost to the Saskatchewan border.
Weather risks in that area include wind gusts of up to 130 kilometres an hour, with thunderstorms that could produce hail up to seven centimetres in size, the equivalent of a baseball. A higher-end tornado risk is also present.
A high risk zone exists just outside of the extreme risk, which encompasses Edmonton, Spruce Grove, St. Albert, Leduc, Devon, and Drayton Valley. Risks in that area include wind gusts of up to 12o kilometres an hour, with thunderstorms that could bring hail up to six centimetres in size, roughly the size of a tennis ball. A tornado risk is also present, and rainfall totals up to 75 millimetres.
ECCC Storm Prediction Centre
The risk of thunderstorms in Alberta rolls on when we hit the overnight hours, with the outlook for early Sunday showing a minor risk for most of the province, while a sliver of a moderate risk touches Lloydminster with wind gusts up to 70 kilometres an hour, hail up to two centimetres, and 30 millimetres of rain.
ECCC Storm Prediction Centre
You can check for any current weather watches and warnings on the ECCC website.