Tornadoes and golf ball-sized hail threat targets parts of Alberta today
Alberta could see some severe weather today, with thunderstorms that could produce a tornado and golf ball-sized hail in some areas.
According to Environment and Climate Change Canada (ECCC), thunderstorm outlooks from the Storm Prediction Centre are eyeing up thunderstorms across much of Alberta, including the north/northwest, the Foothills, and southeastern areas.
Forecasters say in southern Alberta, a developing low will focus thunderstorm activity this afternoon. The main feature will be a developing low and associated trough aligned along the Foothills, along with a dry line popping up along the southern Foothills and bulge eastward south of Calgary, roughly toward Medicine Hat by mid-afternoon.
“Mixed Layer Convective Available Potential Energy (MLCAPE) values exceeding 1500 J/KG and 0-6 KM shear of around 40 KT will lead to a favourable environment for supercells,” the outlook stated for Wednesday, June 18; however, a cap should keep storms from forming until around late this afternoon.
Large hail will be the main threat with those storms, but with the dry line, a tornado is possible as well.
The outlook added that initiation will be in the early afternoon along the Foothills, north of Calgary, with a slightly lower value of MLCAPE and 0-6 KM shear. Supercells are also expected to form here and track eastward, with hail being the main threat, and a chance of a tornado being produced.
Thunderstorms will also develop along a deformation zone stretching from Peace Country to Lloydminster. Forecasters say these storms will be “pulse storms”, and a surface trough northeast of Edmonton to the Peace Country will mean the possibility of funnel clouds in these areas. These funnel clouds may also briefly touch the ground as a land spout tornado.
There are two moderate risk zones for thunderstorms in the province, with one area covering Calgary and extending to the border with Saskatchewan.
The main risks for that area include 90 km/h wind gusts and hail up to two centimetres in size.
The second moderate risk zone is located just to the east of Calgary, with risks in that area including wind gusts of 90 to 110 km/h, hail up to five centimetres in size, a tornado, and 25 to 50 mm of rain.
The minor weather threat primarily affects the majority of Alberta, excluding the two moderate risk zones. The primary hazards today include hail up to one centimetre in size and wind gusts of up to 70 km/h. A section of Alberta, just northwest of Edmonton, stretches up to Grande Prairie and Peace River, where the risk of funnel clouds forming is present.
ECCC Storm Prediction Centre Edmonton
Severe thunderstorm watches were issued for parts of Alberta just before 11 a.m. on Wednesday, including for the City of Calgary.
The thunderstorm outlook for tonight shifts the minor thunderstorm threat to a swath from northern to central Alberta, with Red Deer, Edmonton, Peace River, Edson, and Lloydminster all seeing the potential for storms with wind gusts of up to 70 km/h, hail up to two centimetres in size, and 20 to 40 millimetres of rain.
ECCC Storm Prediction Centre Edmonton
Turning to the seven-day forecast for Edmonton and Calgary, it appears to be shaping up as a decently rain-filled weekend for YYC, with rain expected Friday through Sunday.
YEG is looking to be a bit drier, with a chance of thunderstorms and showers only popping up tonight through to Thursday.
Edmonton
Environment and Climate Change Canada
Calgary
Environment and Climate Change Canada