Gov. Dannel P. Malloy announced a statewide travel ban that will go into effect at 5 a.m. Tuesday and declared a state of civil preparedness emergency.

"With snow coming down at rates in excess of three to four inches per hour at points and winds reaching as much at 60 miles per hour, white out conditions will severely limit visibility," Malloy said in a statement late Monday afternoon. "Residents are urged to make safety a priority and to not make any attempt to travel.”

Malloy also announced that he is activating the state's Emergency Operations Center at 5 a.m. Tuesday and has ordered all nonessential first and second shift state employees to stay home from work Tuesday.

In Southeastern Connecticut, the mid-March snowstorm could bring 7 to 12 inches along the coast and 10 to 16 inches through interior parts of the region, said Gary Lessor, meteorologist and the assistant director of The Weather Center at Western Connecticut State University.

Snow is expected to begin falling between 7 a.m. and 10 a.m. Tuesday and begin to mix with sleet around 1 p.m. in coastal areas, said Lessor.

By 2 p.m. Tuesday, precipitation was forecast to turn to sleet in both coastal and inland areas and could even turn to rain along the immediate coastline. The storm would transition back to snow in the evening and taper off between 7 and 9 pm., he said.

There will be minor to moderate coastal flooding at high tide and scattered power outages, he said.

Winds are expected to be between 25 and 35 miles per hour. Gusts could reach as high as 70 miles per hour with most gusts between 45 and 55 MPH, he said.

"Winds are going to be brutal," Lessor said.

Tuesday's high temperatures for the shoreline will be between 35 and 40 degrees, with lows near 20s. Inland New London County will see high temperatures in the low to mid 30s and lows near 20s.

State Department of Transportation Spokesman Kevin Nursick said Monday afternoon the massive statewide storm will mean aggressive snow accumulation of 3 to 4 inches per hour with 50 mile per hour wind gusts and virtually no visibility.

The DOT said it's critical that the public stays off the roads so the department can work to clear the roads.

"Conditions tomorrow during the storm are going to be treacherous," he said Monday afternoon. "No one should be traveling on the roads tomorrow unless it’s an emergency."

The department was working Monday to pre-treat highways and parts of secondary state roads to help roads get down to bare pavement faster when the storm subsides. Nursick expects 634 state trucks and 250 contracted vehicles will be out on the roads Tuesday, along with 15 industrial snow blowers towards the end of the storm.

In the region, Tuesday's referendum on the elementary schools project in East Lyme was canceled due to the weather. The referendum will be rescheduled.

Electric Boat announced on Twitter that the first shift on Tuesday has been canceled at all Connecticut and R.I. locations. The company said employees should monitor local media for an announcement regarding the second shift.

Most offsite outpatient services affiliated with Lawrence + Memorial Hospital, The Westerly Hospital and The William W. Backus Hospital will be closed on Tuesday.

At Backus, all primary care, urgent care and special care offices are closed, and elective surgeries at the main hospital in Norwich have been rescheduled, spokesman Steve Coates said.

At L+M and Westerly, all affiliated physicians’ offices and other outpatient service offices are closed, including the Cancer Center in Waterford, spokesman Mike O’Farrell said. The Pequot Health Center’s emergency department in Groton, however, will remain open.

Elective surgeries at the main hospital in New London will proceed, but outpatient procedures at Pequot Health Center are postponed, O’Farrell said.

Patients are urged to call before coming to appointments scheduled for Wednesday in case of late openings.

Eversource reminded its customers on Monday that they could sign up for outage alerts on its website. They can also report outages on the website or by calling (800) 286-2000. The company said downed wires and emergencies should be reported by calling 911.

Day Staff Writer Judy Benson contributed to this article.

k.drelich@theday.com