Near 80-degree heat arrives just before storms

The year's warmest air yet is to send temperatures surging toward 80 degrees in all
but immediate lakeshore areas Thursday—and across most of the Chicago metro area
ahead of thunderstorms Friday. It’s a warm surge expected to send daytime readings
15 to 20 degrees above normal. Not even Wednesday's easterly winds off Lake
Michigan’s numbingly cold low 50-degree waters managed to thwart 70-degree
readings in all but shoreline locations. Midway's 73-degree high marked the seventh
reading of 2008 to top 70 degrees: O’Hare’s 74-degree maximum was its sixth.
The extreme dryness of Wednesday’s air no doubt contributed to the strong warming,
because dry air warms more quickly than moist air. At mid-afternoon, O'Hare's
relative humidity sank to an astoundingly low 17 percent—the driest in an April here
in a quarter-century!

HAIL AND TWISTERS WALLOP PLAINS
Powerhouse thunderstorms pounded seven states Wednesday. More than 200 reports
of severe weather—80 percent of them involving hail—had been filed by nightfall. Ten
tornado touchdowns were recorded. Hail up to 4.5” in diameter (softball size)
pounded Lamesa, Texas.