At 5:40PM radar indicated a line of strong thunderstorms stretching across some of Chicago’s south and southwestern suburbs between I-80 and I-88.
Pea sized hail (0.25″) was reported in Yorkville at 5:21PM.
Pea sized hail (0.25″) was also reported in Romeoville at 5:41PM
Pea sized hail (0.25″) was reported in Lemont at 5:42PM
Hail must reach 1″ in diameter for a warning to be issued by the National Weather Service. The 1″ threshold is the point at which hail can begin to cause damage in most cases.
No warnings are in effect, but these storms are being closely monitored at the WGN Weather Center for further intensification.
Below: Radar image at 5:50PM showing the thunderstorm activity stretching from Chicago to Kansas City. A tornado watch is in effect until 11PM for the areas outlined in red.
Showers and thunderstorms continue to march across much of northern Illinois approximating the I-80 corridor. Shortly before 5pm the strongest storms are targeting areas in LaSalle County north of Ottawa. At 4:48 pm pea-size hail was reported from the Mendota area.
Shortly after 4:30 pm radar showed an area of showers and thunderstorms developing into the Chicago area from the southwest. Other thunderstorms were approaching from the west and were currently moving into the Aurora area. These storms are capable of producing hail and gusty winds. Strong south winds 30 to 40 mph with gusts to 50 mph are buffetting the area in advance of the thunderstorms and have helped to boost temperatures into the lower and middle 70s.
At 4:20 pm this afternoon, a thunderstorm dropped 3/4 inch diameter hail in the Tinley Park area near 179th Street and 84th avenue. Thunderstorms continue to move into the south suburbs and are capable of producing hail and strong gusty winds.
Farther south pea-size hail was reported in the Peotone area in Will County at 4:26 pm.
South winds have been increasing in strength across the Chicago metro area throughout the afternoon with gusts reaching 50 mph in some area. The strong winds have ushered in a surge of warmer air that has boosted afternoon temperartures well into the 70s making today one of the warmest Easters in more than 20 years.
Some wind gusts as of 4 pm this afternoon
O’Hare Airport 45 mph
Midway Airport 37 mph
Lansing 41 mph
Waukegan 43 mph
West Chicago 43 mph
Wheeling 48 mph
Gary 37 mph
Kenosha 44 mph
The Storm Prediction Center in Norman, Oklahoma has issued as tornado watch for areas west of Chicago in northwest and west-central Illinois. The tornado watch will be in effect until 11 pm CDT tonight and extends from extreme eastern Kansas across most of northern Missouri into Illinois. In addition to tornadoes, there is a threat of large hail to 2.5 inches in diameter along with wind gusts 70 mph. Severe thunderstorm warnings are currently posted for areas near the Quad Cities.
With south winds gusting above 40 mph this afternoon, temperatures across Illinois have soared into the upper 60s and 70s and dew points have been steadily increasing, priming the atmosphere for the first severe weather outbreak of the slow-starting 2010 season.
Thunderstorms are developing southwest of Chicago near Pontiac and are moving on a track that will take them across the southern suburbs late this afternoon. While this batch of storms is not expected to be severe, they could produce small hail and gusty winds.
A line of rapidly developing thunderstorms was located near the Mississippi River in western Illinois. One of these storms produced nickle sized (0.88″) hail in Burlington, Iowa at 11:30AM.
At 12:30PM, small hail was reported with a thunderstorm in Stockton, Illinois. Stockton is located in JoDaviess County, 125 miles west of Downtown Chicago.
If this line of showers and thunderstorms continues to develop, it may begin to affect portions of the Chicago area by 3PM.