Forecast updated 3:45pm EST - 30 Sep 2011
Surface analysis of today's 12Z GFS run at 0Z (8pm) tonight depicts the low
pressure that has plauged the Midwest for more than a week starting to move
Eastward. This in turn is expected to be followed by much colder temperatures
in the area as winds begin to be predominantly from the North.
12Z GFS: Mean sea level pressure & 1000 mb-500 mb thickness at 0Z Saturday
With strong northerly flow settting up by Saturday, lake effect rain
will be a possibility along the southern shore of Lake Michigan with water
temperatures remaining near 63 F. Also with 850 mb temperatures forecasted
to be either at or below 0 C by the 12Z NAM, high temperatures around the region
will only get into the mid-50's on Saturday.
12Z NAM: 850 mb heights, temperature, and wind at 18Z Saturday
By Sunday afternoon, the system remains over the Northeast as
it begins to stall out. This will keep the best precipitation chances across
that region. Meanwhile a region of high pressure continues to build in across
Midwest at the surface, bringing with it dry but still cool conditions.
today's short-range forecast graphic was produced by Ryan Meiszberg