With March in its final week, North America's atmosphere has lurched
into an energetic state-a situation predicted to continue over the
coming two weeks. It's a setup that leads to a cooler and wetter than
normal overall weather pattern. Winds are significantly calmer here
Thursday than in recent days, but barometric pressures are in a dive
across the Plains-a wind-generating development. Winter weather
advisories posted late Wednesday in 15 states include blizzard watches
in sections of Texas, Oklahoma and Colorado. The terrain in those states
slopes upward from east to west, and that's why the howling 40+ m.p.h.
east winds predicted to develop there are to cool as they blow into
these states' higher elevations. This "upslope cooling" is likely to
ring much of the copious moisture flooding into the region from the Gulf
and may generate 12-inch-plus snow accumulations.
Windy storm is Chicago-bound
The windy storm is to sink from Colorado into Texas then take an
ominous turn to the northeast, tracking across central Illinois and
lower Michigan. Cold, wind-driven rain is due in Chicago for the start
of weekend, beginning as some spotty sprinkles late Friday and becoming
steadier overnight. There are early indications the temperatures within
this storm may support a mix of wet snow in far northwest sections of
the Chicago area and a swath of accumulating snow from western Missouri
into east Iowa, northwest Illinois and sections of Wisconsin later
Saturday and Saturday night. Chicago wind gusts may top 40 m.p.h. at the
height of the storm Saturday afternoon and evening.
