Area Forecast Discussion
Issued by NWS Central Illinois

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FXUS63 KILX 080817

Area Forecast Discussion
National Weather Service Lincoln IL
217 AM CST Fri Dec 8 2017

.SHORT TERM...(Today and tonight)
ISSUED AT 217 AM CST Fri Dec 8 2017

Clipper type system was located over far northern Manitoba early
this morning, and will quickly drop southward through the day. The
shorter range models are in good agreement with this feature
reaching northwest Wisconsin by early evening, with a cold front
swinging across central Illinois late in the night. Focus for the
snow with this feature remains largely in the post-midnight time
frame, with around a half inch accumulation possible along and
north of I-74. Latest European model suggests a half inch possible
as far south as Springfield and Mattoon, while the NAM bypasses
central Illinois entirely. Will lean a little more toward the GFS
solution, but something to keep an eye on.

Ahead of this feature, southwest winds and a decent amount of
sunshine will lead to some milder temperatures. Highs in the mid-
upper 30s should be common over the forecast area.


.LONG TERM...(Saturday through Thursday)
ISSUED AT 217 AM CST Fri Dec 8 2017

A little bit of light snow and flurries will linger early
Saturday, but the front will quickly depart. This will mark the
start of an extended period of mainly dry conditions. Clipper
systems Monday night and Thursday largely stay to our north. Both
the GFS and ECMWF models suggest at one time or another, the
potential for fast moving streaks of light precipitation, as fast
moving waves race through the northwest flow. Such streaks are
difficult to peg this far out, though.

The Arctic air will remain entrenched across Ontario and Quebec
during the period, but periodic shortwaves will drag lobes of
colder air southward. Saturday, and Monday night through Tuesday,
look to be the colder parts of the forecast period. Outside of
these times, highs should recover into the 40s in many areas.


.AVIATION...(For the 06Z TAFS through 06Z Friday night)
Issued at 1147 PM CST Thu Dec 7 2017

VFR conditions will prevail at all TAF sites next 24hrs. Clear
skies will prevail overnight and into the early morning hours.
However, scattered mid clouds around 8kft will slowly advect into
the area, starting at PIA around 15-16z, then CMI around 20z.
SPI/DEC/CMI will see the scattered mid clouds early evening. As
the next clipper approaches from the northwest, it will arrive at
PIA first with cigs around 5kft starting around 04z and then at
BMI around 05z. Could be some light flurries with those lower
cigs, but not going to add as most of the precip should remain
north and northeast of the TAF sites. CMI will see the lower cigs,
but not until after 06z tomorrow night. Winds will be westerly
overnight but then become southwest ahead of the approaching
clipper. Wind speeds during the day will be 10-13kts at all sites.




SHORT TERM...Geelhart
LONG TERM...Geelhart
AVIATION...Auten is the U.S. government's official web portal to all federal, state and local government web resources and services.