Figure 1 depicts the surface observations at 7:00 am EST, which shows an occluding low pressure near Edmonton with an occluding front extending across Southern Saskatchewan. The interaction with the Rocky Mountains, the low pressure and the front caused local veering of the winds and promoted vertical growth of supercells in the Edmonton vicinity, which ultimately led to two tornadoes on this day.
According to Environment and Climate Change Canada (2018), an F2 tornado touched down at 7:50 pm MDT near Riviere Qui Barre, AB. The path and width of the tornado was not documented by ECCC. No property damage was documented for this tornado.
Sources
NOAA Central Library. (2019). U.S. Daily Weather Maps. Tuesday July 14, 1981 [PDF]. Retrieved from https://library.noaa.gov/Collections/Digital-Collections/US-Daily-Weather-Maps
Environment and Climate Change Canada Data. (2018). Canadian National Tornado Database: Verified Events (1980-2009) – Public. Retrieved from: http://donnees.ec.gc.ca/data/weather/products/canadian-national-tornado-database-verified-events-1980-2009-public/
