WEATHER SNAP SHOTS: October 2005 Archives

Lake Michigan waterspout off Foster Avenue Beach and the Montrose Avenue Pier along Chicago's lakefront Thursday morning

This waterspout was captured by Ryan Szekeres out over Lake Michigan at 11 a.m. Thursday morning. Unusually chilly air over the lake's comparatively warm water contributed to the instability (the steep decline of temperature with height in place at the time of this vortex's formation) behind the waterspout's formation. Lake water temperatures off Chicago at the time averaged 57-degrees while readings just a mile aloft were only 27-degrees---a nearly 30-degree temperature drop! It's at least the second time in a week that a waterpout has been spotted off the Chicago shoreline.
--Tom Skilling

Photographed Monday morning (Adler Planetarium in the foreground)

Photo courtesy of George Holman and Kami Chin

Patrick Skach, our Oak Brook weather observer, has provided us dramatic evidence of impressive lightning damage produced by Sunday afternoon and evening's rash of late season thunderstorms. While generating much needed rainfall in significant sections of the drought ravaged Chicago metro area--0.94" at O'Hare and 1.54" at Oak Brook as examples--these thunderstorms also unleashed a barrage of cloud to ground lightning strokes which had an explosive effect upon contact with trees with which they had contact. Lightning heats tree sap so quickly that much of the liquid which comprises the sap is transformed to steam which takes up more volume than the liquid from which it is produced. The result? Trees struck by lightning are literally blown apart.
-Tom Skilling

Photos by Patrick Skach - Oak Brook 10-02-2005 3:05pm Strike