Storm risk returns as heat builds in Atlantic Canada
Wednesday, August 8, 2018, 3:55 PM - Wednesday will see the returning risk for thunderstorms across Atlantic Canada, as oppressive heat and humidity fuel storms.
Wednesday's storms are less likely to be severe, as they were in New Brunswick Tuesday afternoon, but we are still looking at the risk for small hail, torrential downpours, and gusty winds with some cells. On top of the storm risk, heat warnings remain in effect for parts of the Maritimes and Newfoundland. While temperatures will only edge up toward the 30 degree mark, as always, it's the humidity that will have things feeling really uncomfortable, to say the least. Humidex values on Wednesday will creep into the 40s for many. We take a look at the sticky, stormy week ahead, below.
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- Risk of thunderstorms Wednesday for southern New Brunswick, Nova Scotia, P.E.I., and eastern Newfoundland
- Dangerous humidex values dominate through Thursday
- Some relief from the heat late week
WATCH BELOW: UNSETTLED WEATHER CONTINUES INTO THE WEEKEND
STORM RISK RETURNS WEDNESDAY
The stronger front responsible for Tuesday's severe storms tracked western Newfoundland overnight into Wednesday, and clears the island through the early afternoon, but that doesn't mean a clearer day ahead for Atlantic Canada. Lingering humidity and instability will be enough to spark another round of isolated showers and thunderstorms through Wednesday afternoon, before a new system pushes in Wednesday night into Thursday.
Storms are more likely to be non-severe on Wednesday, given that the strong trigger -- in the form of the cold front -- is pushing out of the region, but given the high humidity in the region, torrential downpours can be expected in some cells, along with small hail and gusty winds.
Tuesday afternoon saw the front initially push into Atlantic Canada with a bang, as storms quickly reached severe limits. A tornado warning was issued for Grand Falls and Victoria County, N.B., at 3:37 p.m. ADT on Tuesday. However, it was dropped shortly after 4 p.m. local time. At the height of the storms, nearly 30,000 NB Power customers were without power.
Our unsettled pattern continues Thursday and Friday, as a new bout of moisture pushes in from the west. This new system taps into subtropical moisture from the southern U.S. Eastern Seaboard, giving us, once again, the potential for heavy rain. Some significant rainfall totals are expected by the time this round of rain clears out on Friday.
A FEW MORE STICKY DAYS IN STORE
Heat warnings seem to have taken a shine to Atlantic Canada for the second half of summer.
High pressure sitting off the southeast coast of the U.S. has been to blame for the potent, and persistent, stream of high humidity that's been making itself at home over the region, leading to yet another round of heat warnings blanketing the Maritimes and Newfoundland. Fredericton has been working on a record-breaking streak of days with humidex above 30; a record that will fall this week before we see some relief.
Some hope is on the horizon for later this week, however, as an upper level trough of low pressure edges into the region from the west. This disturbance should be enough to cut into the high pressure that's dominated the east, and let temperatures and humidity relax somewhat as we head toward the weekend. That means more widespread relief by Thursday, although it won't be feeling chilly by any means.
"The warm pattern continues but a system tracks across the region late week with a period of rain and thunderstorms," says Weather Network meteorologist Dr. Doug Gillham. "Dry weather returns for the weekend, but we're watching the potential for showers to linger into early Saturday for the Avalon."