Area Forecast Discussion
Issued by NWS Central Illinois

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FXUS63 KILX 240550

Area Forecast Discussion
National Weather Service Lincoln IL
1250 AM CDT Wed May 24 2017

Issued at 905 PM CDT Tue May 23 2017

As an upper level low drops southward through Iowa this evening
bands of showers continue to wrap around the low pushing eastward
through central IL. Several funnel cloud reports have come from
areas where surface boundaries generated enough surface
convergence and vorticity across central IL this evening, as well
as a few brief touchdowns from weak landspout tornados. This
should all be ending as daytime heating ends this evening. Current
radar imagery is showing a weakening trend in shower activity.
Nevertheless, light showers will be possible through the night,
especially near and east of I-57. Only minor updates needed this


.SHORT TERM...(This evening through Wednesday)
ISSUED AT 301 PM CDT Tue May 23 2017

An upper level system will continue to drop south into the TN
valley by tomorrow afternoon. With this cyclonic flow remaining
over the area tonight and tomorrow, scattered showers will
continue over the entire CWA the next 24-36hrs. Isolated
thunderstorms could be possible this evening, but lack of sunshine
this afternoon is keeping instability down. Tomorrow looks like a
better chance of isolated storms, but in the east during the early
afternoon and then the whole area for the late afternoon. Temps
remained on the cool side today and expect the same tomorrow given
the continued cloud cover and precip. So looking for highs
tomorrow only in the mid 60s. Overnight lows will drop into the
50s with the warmest temps of mid to upper 50s in east and
southeast IL.

.LONG TERM...(Wednesday night through Tuesday)
ISSUED AT 301 PM CDT Tue May 23 2017

As the upper level system begins to lift north into the OH valley,
the chance of precip across the CWA will diminish and push
eastward through Thursday. Isolated storms will be possible, but
precip will mostly be light rain and rain showers Wed night and
Thur. Temps will remain cool Wed night with Thur highs warming
slightly with west central IL reaching into the low to mid 70s.

There will be a break in the precip Thur night and early Fri
morning, but this will be short-lived as sfc wave begins to move
into the area Friday afternoon, bringing another around of showers
and thunderstorms to central and southeast IL. Then the low
pressure area of the system will move into central IL and across
the state Sat through Sun. Additional showers and storms will be
associated with this system Sat with things beginning to diminish
Sunday afternoon through evening. This unsettled pattern will
continue into Memorial Day but dry conditions are currently
expected Monday night into Tuesday.

Temps will finally warm back back up for the holiday weekend.


.AVIATION...(For the 06Z TAFS through 06Z Wednesday night)
Issued at 1243 AM CDT Wed May 24 2017

Complicated sky tonight under cyclonic flow and a broad upper
level trough. Mid and high clouds broken on sat imagery...with
patches of IFR underneath without too much in the way of reason.
Obs are in the IFR category in the eastern portions of Central IL,
but the category does not hold up just over the border into IN.
HRRR develops a band of IFR cigs from Pontiac down into
Bloomington later this evening...but is not initializing well. 24
hrs ago the guidance/models were far more pessimistic with the
cigs. Given that trend...have tweaked here and there for general
improvement. Showers continue with mostly northerly flow...a
little variable at times overnight.




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