The storm parade continues in Atlantic Canada
Saturday, February 14, 2015, 1:52 PM - As one Nor’easter departs two more are hot on its tail, each upping their intensity game.
It’s well known there’s been no lack of weather to talk about if you’re in Atlantic Canada. This winter season started off fairly inactive, with many places feeling somewhat tropical on Christmas day – a very inaccurate insight to how the rest of winter would play out. Once the New Year hit, a more desirable atmospheric pattern set up: cool air filtered in and the east coast low pressure systems set their schedule for a parade towards our Atlantic provinces.
Southern New Brunswick and P.E.I are some of the places to have received the short end of the stick when it comes to snowfall, currently contending with over 4-5 feet on the ground -- or maybe I should say long end of the stick. With another few active days ahead, these regions could pick up an additional 1-2 feet. So let’s go over each system and their associated impacts.
Our first Nor’easter has come and gone and we found Newfoundland to be its target of choice – especially the Avalon Peninsula, which experienced a blizzard Thursday, dropping over 30 cm of snow combined with intense winds while just clipping Cape Breton. As we head into the weekend, the bulls-eye for the upcoming storms will progressively shift further west and begin to take on a more typical storm track: intensify along the eastern seaboard and barrel through the Gulf of St. Lawrence.
The next impact will come Friday - Saturday
As an Alberta clipper tracks offshore, south of Cape Cod, it will intensify as it approaches the Maritimes and Newfoundland. The difference with this storm compared to last is the placement of the low, which will track through the Avalon versus remaining south and offshore. When forecasting the hardest-hit locations, cities just north and west of the low will produce the highest amount of snow; so by placing it through the Avalon this time, it essentially shifts the bulk of the moisture off the Avalon into central Newfoundland and Cape Breton.
Please refer to our snowfall forecast for this system in Figure 1. Keep in mind this is subject to change.
Unfortunately, this is merely a warm up for a more widespread event set to take stage Sunday into Monday, with almost unnoticeable rest time in between for Newfoundland.
So what makes this Sunday system more potent? There are several ingredients that help to develop this into a potential blizzard for the majority of the Atlantic Provinces, as well as coastal cities into the Northeast U.S., two of which are:
1. An amplifying ridge in the jet stream over western Canada. This will treat them to above seasonal temperatures, all the while escorting impulses of brutal arctic air far south for their friends out in eastern Canada. A significant arctic high pressure will spread out Saturday into Sunday producing hazardous cold for Valentine’s Day weekend (the coldest air they’ve seen this year). The dramatic clashing of temperatures between the arctic and relatively mild maritime air will supply the fuel for the low to rapidly intensify; this will also produce powerful wind gusts to be of hurricane strength (over 120 km/h).
2. The Nor’easter will begin to decrease in speed, but not intensity, once it reaches the Nova Scotia shores and will slowly spin into the Gulf of St. Lawrence – prolonging the event and increasing snowfall totals.
Who will see the worst weather?
As the low deepens off the coast Sunday morning, blizzard conditions are possible from Maine into Boston, where widespread blizzard watches already litter the coastline for forecast snow totals upwards of 40 cm and violent winds. Keep in mind Boston, Massachusetts has already broken their all-time record for most snow in February set back in 2003 (and there’s still half the month to go!)
As the system wreaks havoc on the eastern U.S., our eyes will then quickly shift focus to the Maritimes, specifically Southeast New Brunswick, P.E.I. and Cape Breton, as the low expands its outer reach all the way to the Gaspe Peninsula and into Newfoundland by Sunday afternoon.
With many long-range models in fairly good agreement for a few days now, we have high confidence that strong gusty winds, near-zero visibility and heavy snow are on tap for many. Here’s a general overview and forecast:
Maritimes: Along with snowfall totals of 20-40+ cm, the winds will be relentless with gusts over 110 km/h into P.E.I and Cape Breton, peaking Sunday night, creating near zero visibility and frigid wind chills (should you be outside, which you should not). Gusts of 60-80 km/h will still be remarkable through southern and eastern New Brunswick as well as most of Nova Scotia. Winds will shift to the northwest through the overnight into Monday morning, with strongest gusts over 110 km/h through eastern P.E.I. and Cape Breton yet again. Monday will see the snow clear out, apart from sea-effect snow into P.E.I. and along the northern shores of Nova Scotia.
Newfoundland & Labrador: Winds gusts will exceed 110 km/h through the Avalon and Atlantic coastline and get up to 90 km/h inland Sunday into Monday. Snow will coat the entire province by Sunday evening, with the heaviest amounts focused to the west, south and northern peninsula. Periods of freezing are rain possible for central and eastern regions with snow transitioning over to rain or a rain/snow mix. Heavy snow and hurricane-force wind gusts will be seen over eastern Labrador Monday, with totals topping over 40 cm by Tuesday morning.
Please refer to our preliminary snowfall forecast in Figure 2. Keep in mind this is acts as a general outlook and is subject to change. We have high confidence that these areas will be of greatest impact, while our largest uncertainty arises for southeast Nova Scotia as the region will likely transition over to a rain/snow mix.
The entire low will spin offshore Labrador Monday overnight into Tuesday as the arctic high pressure builds in temporarily from the east with calm but cool conditions. Yet without any hesitation, no doubt to keep forecasters on their toes, another low looks to be in the cards for mid-week next week – this one originating from the Gulf of Mexico, notorious for its ample amount of moisture. Something to keep an eye on so stay tuned for the latest updates and please check your local forecast! Stay safe.