WASHINGTON, March 16 (Reuters) - More than 10,000 U.S.

flights were delayed or canceled Monday amid a series of storms

affecting several major airports along the East Coast and some

other locales.

Because of the risk of high winds and severe thunderstorms,

the Federal Aviation Administration ordered delays at the New

York City area's three airports - New York's LaGuardia and JFK

and Newark airport in New Jersey - as well as at Reagan

Washington National Airport, airports at Charlotte and Atlanta,

and Houston's Bush airport.

Transportation Secretary Sean Duffy said the weather was

impacting flights across the country. A major winter storm was

also snarling flights across the Midwest and Great Lakes

states.

The FAA earlier imposed ground stops at Reagan National,

Chicago O'Hare and at Charlotte before lifting them.

FlightAware, a flight-tracking site, said more than 6,500

U.S. flights had been delayed and more than 3,500 canceled as of

1:30 p.m. EDT (1730 GMT).

American Airlines ( AAL ), Southwest Airlines ( LUV ) and Delta Air Lines ( DAL )

all have about a third of flights delayed or canceled, according

to FlightAware, while United Airlines has 25% of flights delayed

or canceled.

About 40% of flights at Atlanta were canceled or delayed, a

third at Chicago O'Hare and 50% at LaGuardia.

The U.S. government ordered federal employees in the

Washington area to leave offices by 2 p.m. (1800 GMT) because of

weather risks.