Governor Charlie Baker has signed an executive order issuing a state of emergency for Massachusetts. With MBTA service shutting down at 7 p.m. Monday night and Boston parking bans remaining in effect until further notice, Gov. Baker announced Tuesday will be a “partial state snow day.”

Speaking at a press conference shortly before 6 p.m., the governor said that due to historic snowfall – upwards of 6 or 7 feet in Boston – and the work required to remove it, non-emergency workers in Suffolk, Norfolk, Essex and Middlesex counties should stay home Tuesday.

“Mother nature makes the rules,” Gov. Baker said.

The decision to issue the state emergency and partial snow day, the governor said, was based on the announcement from the T that Tuesday service will be suspended. The governor also suggested that the partial snow day would allow removal crews to clear the streets in advance of yet another potential storm Thursday night.