Chicago's beaches open Friday but cool temperatures riding northeast winds will
hardly have area residents dashing for chilly lake waters. Lake Michigan is 1 degree
cooler than a year ago and at its chilliest levels in four years. But huge changes are
under way that have air masses across North America on the move. Powerful winds--
clocked as high 105 m.p.h. at the 4,900-foot level of Yucca Mountain and 63 m.p.h.
at White Sands, N.M., sent record triple-digit heat in the Southwest packing
Wednesday, whipping visibility-reducing dust into the air. Visibilities near El Paso
dropped to near zero in blowing dust while 50 to 60 m.p.h. gusts at San Simon, Ariz.
made it impossible to see much more than 100 feet.
SUNDAY'S HIGH TEMPERATURES HEADED WELL INTO THE 80s
A sharp temperature rebound, driven by 30 m.p.h. southerly winds and
compressional warming produced as air sinks and compresses beneath the nose
(leading edge) of a powerful jet stream set the stage for a stunning turnaround
Sunday. Readings surge to 85 degrees—the warmest of 2008 and the highest here
since 87 degrees Oct. 8.
