Eastern IA to dodge the bullet on this one...
Iowa City:
Light snow will start at 11PM tonight and continue through the mid-morning hours on Friday. Expect a total accumulation of 1 inch.
Cedar Rapids:
Light snow or flurries will start at 12AM Friday. Expect little more then a dusting of accumulation.
Discussion:
Shallow arctic air mass has moved over areas north of a Shreveport, LA to Evansville, IN line by 12Z. H925 front was analyzed roughly 70mi north of SFC front while H85 front was located 150 mi further N along a Wichita Falls, TX to Peoria, IL line. UA and WV loop analysis indicated numerous disturbances lifting NE along the east side of the upper trough and a developing closed circulation over the TX panhandle. First of two primary disturbances is lifting out of WI, while upstream system is strengthening over ERN OK. WRF takes H85 low along a path through Springfield, MO at 6Z Friday, through St. Louis at 12Z and Ft. Wayne, IN at 18Z. The GFS suggests a similar track but with a timing of 4 to 6 hrs slower during the overnight into early morning period Friday. Concerning the precipitation FCST in ERN IA, the GFS brings the NWRN edge of QPF between 30 and 50 miles further N and W then the WRF. Expect that a dry flow near the SFC will result in a sharp cutoff in precipitation totals from SE to NW, so that over a 50 mile distance snowfall totals go from nothing to 6 inches or more.
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