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Area forecast discussion 
National Weather Service Lincoln Illinois
1122 PM CST sun Mar 1 2015

issued at 900 PM CST sun Mar 1 2015

Skies are partly to mostly cloudy still as high cirrus moves over
the area and lower clouds continue to move to the east, out of
the area. Believe skies will become mostly clear overnight. This
could have an effect on overnight lows. Based on these items, will
be making some small adjustments to overnight forecast. Update to
come out shortly.


Short term...(tonight)
issued at 255 PM CST sun Mar 1 2015

A couple more hours of a light wintry mix are possible south of
I-70 late this afternoon/early this evening as our current storm
system pulls away from the area. Otherwise, quiet weather is
expected for the rest of the night as a large area of high pressure
builds in from the northwest. The high will help provide some
clearing tonight as well as cooler conditions than seen last night.
A decent radiational cooling setup, along with fresh snow pack,
should allow temperatures to fall into the teens in most areas, with
some single digit readings possible across our far northern counties.


Long term...(monday through sunday)
issued at 255 PM CST sun Mar 1 2015

The surface high will quickly depart the area by late Monday. This
will allow deep southwesterly flow to develop across the area Monday
night into Tuesday ahead of our next storm system. While the overall
expectations with this next system have not changed much, the models
have still exhibited some differences and run-to-run variation in
the details. While many earlier runs progged the approach of a
large/well phased upper-level trof, recent runs are not as phased.
This lack of phasing is having two impacts on the local forecast
problem. First, temperatures are now likely to stay a little cooler
on Tuesday, but should still climb above freezing by mid-late
morning. Second, the lingering split in the in the upper-level flow
will also limit the transport of deeper moisture into the area. The
upshot is that the risk of freezing rain may linger a bit longer
Tuesday morning, but overall rainfall amounts and/or potential ice
accumulation should be lower.

Expect sleet and freezing rain to develop across the area after
midnight Monday night/Tuesday morning, with the precipitation
changing to all rain by mid-morning Tuesday. Then, the cold front
associated with the storm system will swing through the area, from
northwest to southeast, Tuesday afternoon and evening. This frontal
passage will quickly bring the precipitation to an end, but there
may be a brief changeover to snow before ending. No significant snow
accumulation is anticipated.

While the frontal boundary should be well south of the Ohio River
valley by late Tuesday night, some guidance still suggests waves
riding along the boundary may be able to push some light snow back
into the the southeast portion of the forecast area Wednesday into
Wednesday night. While this snowfall should be light in the event it
occurs, confidence in its probability of occurrence is low. While
the overall trend for Wednesday had been drier, occasional model
runs keep tossing some snowfall back our way. Hopefully better model
agreement/consistency will be seen with this threat soon.

Another area of high pressure, accompanied by a shot of very cold
air, will build across the region for Wednesday night into Thursday
night, supporting widespread single digit low temperatures, and high
temperatures struggling to reach 20 degrees. However, southerly
return flow will develop on Friday, which should help temperatures
recover to near normal levels for early March by the weekend.


Aviation...(for the 06z tafs through 06z Monday night)
issued at 1122 PM CST sun Mar 1 2015

Thin high cirrus will remain over all taf sites overnight and into
early tomorrow morning. Then models showing mid clouds around
10-12kft advecting into the area and covering all taf sites during
the around noon. These mid clouds look to hang around through the
afternoon and into the evening hours. Based on BUFKIT data, clouds
should lower just ahead of the pcpn expected to arrive in west
central Illinois after midnight tomorrow night, which appears to
be just after taf valid time. Winds will be westerly overnight and
then become light and variable tomorrow through tomorrow night.


Ilx watches/warnings/advisories...


short term...Bak
long term...Bak

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