The 5.8 tremor that shook the Washington region last month has prompted elected officials to include earthquakes on the list of potential disasters for which they should be seriously preparing.

At a meeting to discuss the region’s response to the earthquake and two recent tropical weather systems, the Metropolitan Washington Council of Governments determined that elected officials and emergency managers continue to make strides in how they handle public outreach for a major weather event, accident or terrorist attack.

But officials acknowledged that there were few detailed plans for responding to the Aug. 23 earthquake, which briefly frightened millions of people, overloaded cellphone networks and damaged some buildings, including Washington National Cathedral.

“Up until three weeks ago, earthquakes were pretty much at the bottom of the list,” said Tony Alexiou, deputy director of Montgomery County’s Office of Emergency Management and Homeland Security. “Not to say we shouldn’t have a plan, but it’s not as prevalent as preparing for a terrorist attack.”

Alexiou said last month’s quake was the strongest to hit the region in more than 100 years and only the second since at least the 1700s to register at least magnitude 5.0.

But going forward, Alexiou and other COG board members said local governments should further standardize earthquake preparation for first-responders, the public and business leaders. Officials said that the chances of a major earthquake in the Washington area are slim but that the public needs to be better educated on how to respond.

For example, in the minutes after the earthquake, tens of thousands of frightened office workers streamed from their offices into the street. The mass evacuation of high-rise buildings was often facilitated by security managers, but emergency officials say it would have been safer for people to remain indoors.

“If you left the National Cathedral, you might have been hit by something toppling off the top,” Alexiou said.

The quake also caused the federal government and numerous companies to dismiss workers early, leading to an early rush hour that clogged some roadways.

“The earthquake reminded me of September 11, 2001,” said D.C. Council member Phil Mendelson (D-At Large), a COG board vice chairman. “The whole lesson of September 11, 2001, is, ‘Be prepared to respond to the unexpected,’ and for the earthquake, we failed.”

COG will take a look at traffic management in an emergency next month, when Montgomery County Council member Phil Andrews (D-Rockville) reports on how to better prepare for a situation similar to the Jan. 26 snowstorm.

The storm, which dropped six to 10 inches of wet snow during the evening rush, produced gridlock that had some motorists sleeping in their cars until morning.

At Tuesday’s meeting, the board also heard presentations about how Hurricane Irene and Tropical Storm Lee affected the region.

Merni Fitzgerald, head of public affairs for Fairfax County and chairman of COG’s External Affairs Committee, said most local and state governments have greatly improved public outreach through the news media, Twitter, text alerts and Facebook.

Fairfax County, for example, set up an emergency blog that drew 50,000 page views during the earthquake and Hurricane Irene. She said D.C. Mayor Vincent C. Gray (D) also embraced Twitter as a way to communicate with residents during both events.

“It went straight from the mayor to the media and the public,” Fitzgerald said. “That is how communication happens in the 21st century.”

Overall, COG board members were very satisfied with the response to Hurricane Irene, although there were concerns that the public was not informed soon enough about the severity of flash flooding caused last week by remnants of Tropical Storm Lee.

Emergency managers said some areas received nearly twice as much rain as was forecast by the National Weather Service.

Officials said recent weather events reinforce the need for residents to update family disaster plans and emergency kits.

“It’s no longer the one-two punch,” said Frank J. Principi (D-Woodbridge), a member of the Prince William Board of County Supervisors and a COG board vice chairman. “It’s the one-two-three punch, and that is the new reality of what we have to plan for.”