Update: SEPTA will suspend all services except Market-Frankford and Broad Street lines after 4 a.m. Saturday morning. 

All SEPTA service with the exception of the Market Frankford and Broad Street Lines to be suspended beginning at 4AM Sat, Jan. 23.

— SEPTA (@SEPTA) January 22, 2016

There is more news coming out hours before the heavy snowfall expected to hit Philadelphia late tonight. The Philadelphia International Airport (PHL) announced that all flights will be canceled on Saturday. 

Airlines have canceled all flights departing and arriving at Philadelphia International Airport on Saturday, January 23.

— PHLAirport (@PHLAirport) January 22, 2016

American, United and Frontier began announcing cancelations last night, and it seems now all other airlines at PHL have followed suit. 

#Jonas is snow joke. We’ve canceled flights across the Northeast US. Check travel options here: https://t.co/kNkPUilgez

— American Airlines (@AmericanAir) January 21, 2016

We are currently canceling flights, and you may check status on our website or the United App. A waiver remains in place for changes.

— United (@united) January 21, 2016

We've cancelled several flights in the Northeast and Mid-Atlantic regions due to #WinterStormJonas See Full List https://t.co/c17wL9LHMr

— Frontier Airlines (@FlyFrontier) January 21, 2016

American and United have announced that they will be offering waivers for cancelations and rescheduled flights. 

The area is expected to get 12 to 18 inches of snow throughout tomorrow according to the National Weather Service. The agency issued a Blizzard warning for Delaware, Eastern Chester, Eastern Montgomery, Lower Bucks and Philadelphia counties early Friday morning. The Mayor's office announced yesterday that the Philadelphia Streets Department had already begun brining streets and getting salt ready for roads over the weekend. A snow emergency will be in effect in Philadelphia starting at 9 p.m. Friday. Gov. Tom Wolf declared a state of emergency yesterday afternoon.