WestJet strike grounded the airline overnight, canceling 300+ flights to 27 US cities

The Sunday morning update: WestJet's 4,400 flight attendants walked out after midnight MT, the airline grounded all Boeing 737 and 787 flights, more than 300 cancellations are stacking up on a Canadian long weekend, 27 US cities are affected with LAX, Las Vegas, and Atlanta as the biggest gateways, WestJet Encore and Delta code-shares still fly, Ottawa has not yet intervened, and JetBlue and Delta posted Northeast weather waivers for this afternoon's forecast storms.

What's happening: WestJet's fleet is grounded

WestJet's flight attendants, represented by CUPE Local 8125, went on strike after the 72-hour strike notice expired just after midnight MT Sunday in Calgary (2:01 AM ET). The airline confirmed the strike and said it cannot operate any scheduled flights on Boeing 737s or 787s.

More than 300 flights have been canceled as of early Sunday, per AP, snarling travel on a long weekend across much of Canada. The airline had been winding down operations since Friday, canceling 81 flights Saturday morning and 276 by Saturday evening, per The Globe and Mail. More cancellations are already queued for Sunday and Monday.

WestJet Encore, the regional affiliate flying 35 Dash 8-Q400s from Calgary and Vancouver, continues operating. Code-share flights operated by airline partners, including Delta, are also unaffected.

Why: the ground-pay dispute

The core fight is over "ground pay," the compensation flight attendants receive for work done before a plane departs and after it lands, including boarding and deplaning. The union says some of that work is unpaid. WestJet says its "credit hour" system combines flight time, ground duties, and delays into a single higher rate credited across the workday.

CEO Alexis von Hoensbroech said the airline offered an hourly rate covering all time before and after flights plus a double-digit wage increase in year one, calling it a "transformative, industry-leading agreement." The union rejected it.

Union president Alia Hussain said WestJet's latest offer didn't go far enough: "We are on strike because we believe we deserve better. We are ready to go back to the table to settle."

This is the same issue that drove Air Canada's flight attendant strike last August, which resulted in thousands of canceled flights before a deal was reached three days in.

How long: the intervention question

The biggest unknown is whether Ottawa will step in. Jobs Minister Patty Hajdu is in Calgary with mediators as negotiations continue, but she has not said whether the government plans to intervene.

Last summer, the government used Section 107 of the Canada Labour Code to direct the labour board to order Air Canada's flight attendants back to work less than 12 hours after their strike began. The union defied that order, forcing Air Canada back to the bargaining table, where a deal was reached three days in. That extralegal precedent now looms over the WestJet standoff.

Prime Minister Mark Carney's office did not answer a direct question about whether Section 107 would be used here. The union has explicitly asked the government not to interfere.

If the strike runs unresolved, cancellations will pile deeper into the long weekend.

What it means for US travelers

WestJet serves 27 destinations in the United States, per Cirium schedule data. Los Angeles (LAX), Las Vegas (LAS), and Atlanta (ATL) are its largest American gateways by departures. Travelers with WestJet-operated flights to or from any US city should expect cancellations through at least Monday.

The airline is allowing all travelers with flights booked through August 4 to make a one-time flight change or cancellation with no fee. Passengers who booked directly with WestJet will be notified by email. Those who booked through a third party or travel agent need to contact them directly.

Under Canada's Air Passenger Protection Regulations, affected passengers should be rescheduled on a WestJet or partner flight within 48 hours, or they can receive a refund. If WestJet cannot reschedule within 48 hours, it is obligated to try rebooking on a competitor, though that may require traveling through a different airport.

WestJet Encore flights on Q400s and code-share flights operated by partner airlines are not affected. If your ticket says "operated by WestJet" on a 737 or 787, it is canceled. If it says "operated by Delta" or another partner, it should still fly.

The Northeast weather watch for this afternoon

Separately from the WestJet strike, JetBlue and Delta have posted weather waivers for the Northeast ahead of forecast thunderstorms this afternoon and evening.

JetBlue's waiver, updated at 2:15 AM ET Sunday, covers flights Sunday August 2 through Monday August 3 to and from JFK, LGA, EWR, DCA, HPN, and ISP. Customers can rebook through Thursday August 6 with no change or cancel fees, as long as the original booking was made before August 1.

Delta's advisory, updated at 10:12 PM ET Saturday, flags forecasted thunderstorms for EWR, HPN, JFK, and LGA.

The FAA's Sunday operations plan, issued at 5:33 AM ET, confirms zero active ground stops anywhere in the country right now but lists ground stop or delay programs as PROBABLE for JFK, LGA, and EWR after 1 PM ET, and a ground stop as PROBABLE for Atlanta after 2 PM ET. Widespread thunderstorms are forecast through the Southeast, Mid-Atlantic, and Northeast. The next FAA planning webinar is at 7:15 AM ET.