Summer comes to an end with spectacular weather

The waning Harvest Moon visible over Montreal as the sun rises on another sunny, warm September day. Fall arrives this Sunday at 8:44AM, but temperatures are expected to remain above normal. (Valley Weather)

There are signs the Rex Block will finally be breaking down this weekend and into next week, but what an incredible stretch of late summer weather it has been. Fall officially arrives at 8:44 AM this Sunday morning, however, the weather continues to be very summer like. 

Since September 12, we have had nothing but sunshine in southern Quebec, with dozens of record high temperatures. Highs have been running in the upper 20s, with even a 30 or two around. On September 16, Montreal managed a surprise record high of 31C (88F), surpassing the 1939 benchmark of 30.6C (87F). On many other days, our highs have settled into the 25C to 28C (77F-83F) range, well-above the normal value of 18C (65F). Our overnight lows have been even more impressive, in the 16 to 18C (60-65F) range, the normal low for mid to late September should be around 8C (48F). While cooler air in on the horizon, temperatures will likely still be at or above normal.

This has been a dry month in Montreal, especially when you compare it to our record-breaking wet summer. To date, 25.4mm (1 inch) of rain has been recorded at Trudeau Airport, falling on only 2 days, September 1st and 7th. No precipitation has occurred since, despite the elevated humidity we have been seeing over the last two weeks.

The pattern is showing signs of breaking down this weekend, as a backdoor cold front arrives from the northeast. A wind shift should bring in slightly cooler air, with just a chance for a sprinkle this weekend. Temperatures will still be mild, in the 23 to 25C range. Early next week, low pressure developing over the Great Lakes, will begin to influence our weather, with clouds and showers by midweek, along with cooler temperatures. Daytime highs will drop into the middle teens by Wednesday.

While we have been enjoying spectacular weather, the same Rex Block has been delivering heavy rain and high surf to portions of the Middle Atlantic States including Kure Beach, North Carolina, shown above. (AccuWeather)

While we have been enjoying this spectacular weather, parts of the middle Atlantic region have had strong northeast winds and coastal flooding. A non-tropical area of low pressure produced torrential rainfall across North Carolina, with some locations reporting in excess of 400mm of rain in less than 24 hours. Significant flash flooding was observed.

The persistent northeast flow caused by the Rex Block will continue to produce heavy surf and showers across the region through Friday. Widespread coastal flood watches and warnings are in effect from New Jersey to North Carolina.