This second-to-last weekend of meteorological summer promises Chicagoans warm
and muggy weather with many rain-free hours. But the atmosphere is saturated with
moisture -- nearly 2 inches of it. With converging winds predicted this afternoon in
advance of an approaching cold front -- a set-up which generates a build-up of
moisture known as dew point pooling -- thunderstorm development is likely.
The manner in which Friday's thundery rains hit the area -- fast and, in terms of areal
coverage, selectively -- is instructive. Portions of the Chicago metro area may see
gusty downpours Saturday while other areas end up largely rain-free.
DESPITE LACK OF 90S, SUMMER RANKS AMONG WARMEST 33% HERE SINCE 1871
With only nine days left in meterological summer, Chicago's 72.5-degree average
temperature since June 1 ranks 46th warmest since 1871; that's among the warmest 33
percent of all years on record.
The relatively warm summer has occurred despite the lack of 90-degree-plus
temperatures. To date, only three 90s have occurred at the official observation site at
O'Hare Inernational Airport. A typical year sees 17 such days there.
--Tom Skilling, Chief Meteorologist, WGN-TV/Chicago Tribune
