March 31--March isn't exactly going out like a lamb in the Chicago area.
Strong-to-severe thunderstorms were expected at times on Thursday as the mercury climbs to near 70 degrees, local meteorologists say.
"It's spring," said Amy Seeley, a meteorologist with the National Weather Service, adding that Thursday's weather wasn't out of the ordinary for the last day of March -- or this time of year, for that matter. "This is a transition time. We tend to get some severe weather this time of year."
O'Hare International Airport experienced departure delays of 16 to 30 minutes Thursday morning due to the forecasted thunderstorms, according to flight-tracking service Flight Aware. Delay times are expected to increase.
As of 9:30 a.m., 54 departing flights were delayed at O'Hare, and four flights were canceled, according to FlightStats.
Aside from light rain showers downtown, most of the Chicago area remained dry Thursday morning, meteorologists said. But south to southwest winds are expected to carry warm, moist air into the Chicago area ahead of a cold front, which will trigger lines of thunderstorms as it moves from west to east late morning and afternoon.
The thunderstorms are expected between 11 a.m. and 4 p.m., according to the weather service. The most severe storms are expected to occur over Northwest Indiana and south of Interstate Highway 55.
The forecast also calls for damaging wind gusts of up to 60 mph, as well as frequent lightning and brief, heavy downpours, according to the weather service. Storms should be over by Thursday night, meteorologists said.
The cold front will pull off to the east Thursday night, followed by much colder air from gusty northwest winds. The cold air will be reinforced by three low-pressure disturbances the next few days, each producing extensive cloudiness and periods of light rain or a rain-snow mix.
On Friday, temperatures will average 4 to 5 degrees below normal into the first part of next week.
meltagouri@chicagotribune.com
