Last update: 11:47 a.m.

Large swaths of Montgomery and Prince George's counties went into a second day without power Sunday after a storm lashed the area with severe winds and rain. Gov. Martin O'Malley declared a state of emergency for Maryland.

As of 11:45 a.m. Sunday, 92,155 customers (42 percent) in Prince George's and 188,824 customers (61 percent) in Montgomery County were still without service, according to Pepco.

Mandatory water restrictions remained in place for all Washington Suburban Sanitary Commission (WSSC) customers, residential and commercial, in Montgomery and Prince George’s counties.

Power was restored at two water filtration plants but some pumping stations remained without power, making it difficult for water to move through the distribution system, WSSC said.

State Highway Administration (SHA) crews were on standby overnight to respond to storm-related issues on highways. Drivers were urged to use caution.

“With power outages, not only will signals not be operating, overhead lighting will be dark and pedestrian signals will not operate, so everyone will have to look out for one another,” said SHA Administrator Melinda B. Peters. 

O'Malley Saturday issued a state of emergency, giving the state flexibility to activate the Maryland National Guard and provide assistance to local emergency managers, if necessary.         

O'Malley said President Obama called him Saturday from Camp David, near Thurmont, to check in following Friday’s storms, a local CBS affiliate reported.

The declaration said that more than 840,000 homes were without electricity and it could take up to seven days to fully restore power. It said more than 74 cooling stations have been opened across Maryland.

For full Patch coverage on the storm in Montgomery and Prince George's counties:

• O'Malley Issues State of Emergency Order
• Powerful Storm Leaves Thousands in Dark, Kills One
• Silver Spring Woman Found Dead in Bed Under Fallen Tree
• Montgomery, Prince George's Brace for Next Storm
• Montgomery County Opens Cooling Centers
• Photos: Downed Trees, Power Lines Abound
• Pepco: Power Outages Could Take Days
• Prince George's Responds to Dangerous Heat

--With reporting by Tamika Smith, Ryan McDermott and Laura Thornton