Vancouverites witnessed an intense downpour around 4 p.m. on Monday, Sept. 9 that caused flash flooding in parts of the city.
While Vancouver received heavy rainfall during a short window of time, other parts of the Lower Mainland were sunny and bright.
Afternoon heavy rainfall as seen at Woodland-Clark Drive in #Vancouver 35mm/hr • Thanks to @CoolAirRentals for the vid#CityofVancouver #MetroVancouver #MetroVan #BCWx #BCStorm pic.twitter.com/0NgPgN8gll— MCC Weather (@MCC_Wx) September 10, 2019
Vancouver Is Awesome spoke to Matt MacDonald, a meteorologist at Environment Canada, about what caused the Vancouver downpour, as well as how this sort of weather event occurs.
MacDonald explained that a thunderstorm-like cell moved across the region from the south to the north between 3:50 p.m. to 4:10 p.m. on Monday afternoon.
“Our weather station at Vancouver Harbour Centre on Deadman’s Island in Stanley Park recorded 11.2 mm in one hour. There were weather stations north of Seattle that recorded one to two inches or 25 to 50mm of rain yesterday afternoon,” explains MacDonald.
“These convective cells had high precipitable water and were slow moving which is what produced the heavy downpours. The cloud tops were only about 7 to 8 km, so not deep enough to generate lightning. Lightning producing cumulonimbus clouds over the south coast typically have tops in the 10 to 13km range.”
Weather watchers across the city captured the downpour on their phones.
Meanwhile, in Gastown pic.twitter.com/mlkspFeh79— Nick Routley (@Phanyxx) September 9, 2019