PORTLAND — Leaving a car parked on the street in Portland during a snow storm parking ban can be an expensive proposition.

The towing fee of $70, plus the impound fee of $35 and the $30 ticket totals a whopping $135, not to mention any unpaid parking tickets. Owners have to retrieve their cars at the Ocean Gateway International Marine Terminal.

The city is pushing its Twitter, Facebook and e-mail alerts so people remember to move their cars and avoid the aggravation. Residents can sign up for e-mails at www.portlandmaine.gov, receive tweets from PortlandCitylin at www.twitter.com or go to the city’s Facebook page at Portland-Cityline.

When a parking ban is declared, all cars must be off the street by 10 p.m., usually until 6 a.m. the following day.