Environment Canada has issued a special weather statement, advising that Ottawa could see “significant rainfall” this Sunday into Monday.
“Computer models are showing potential for a low pressure area from the Atlantic Coast of the US to move inland across New England to southern Quebec and intensify into a strong fall storm by Monday,” the statement says.
Environment Canada says the rain is expected to arrive Saturday night and continue through Monday; over 50 mm in 24 hours is “quite possible in many areas,” according to the statement.
That 50 mm, if we see it, would put Ottawa well over the total annual rainfall record, and there are still two full months left in the year.
According to data from Environment Canada, the wettest year on record was 2006, when 1000.7 mm of rain fell between January 1 and December 31 at the Ottawa Airport. The data at the Airport dates back to 1938. So far this year, 982.2 mm of rain has been recorded at the Airport.
It’s already been a record-breaking year for rain. Ottawa broke the record for the wettest July at the Airport with 249.8 mm recorded (a record 250.2 mm of rain set in July of 1899 at the Central Experimental Farm has yet to be broken). It was also the wettest May on record, with a total of 175.8 mm. There were also record-breaking individual days, such as July 24, when 79 mm of rain fell.
In addition to breaking the annual record, it’s also possible Sunday and Monday could be the wettest October 29th and 30th at the Airport, depending on how the storm moves in. The current record for most rain on October 29 is 17.4 mm, set in 2003, while the record for October 30 is 17.5 mm, set in 1973.
The incredible amounts of rain this year led to devastating flooding across the region in May. The continuing wet summer also ruined many farmers’ fields by delaying, stunting, or outright killing crops. Some people who lost their homes to the floods waited months for government aid.
The record for total precipitation in a year--the total rainfall and the water equivalent of the total snowfall combined--is a bit further away. The annual record at the Airport for precipitation is 1165.3 mm, set in 1972, according to Environment Canada's website. The total precipitation in Ottawa in 2017 currently stands at 1115.0 mm.
But that possibility of 50 mm could put the record within striking distance, meaning average November and December weather would be more than enough to topple it.