Area Forecast Discussion
Issued by NWS Central Illinois

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FXUS63 KILX 260121

Area Forecast Discussion
National Weather Service Lincoln IL
821 PM CDT TUE OCT 25 2016

Issued at 821 PM CDT Tue Oct 25 2016

Elevated instability along a warm frontal zone near 850 mb aloft
is triggering scattered showers and isolated thunderstorms from
around this Illinois River near Beardstown northwestward this
evening...with this region drifting NNE-ward. Models suggest this
instability should affect areas possibly as far eastward as I-55
with some showers possible from around I-72 northward. Have made
adjustments to forecast to address this feature.
Otherwise...expect lows overnight up several degrees from last
night...with the warmest temperatures over west central IL only
reaching the lower 50s as an approaching low shifts winds to
southerly advecting warmer air into the region. Elsewhere across
central and southeast Illinois...upper 40s look on track.


.SHORT TERM...(This evening through Wednesday)
ISSUED AT 249 PM CDT Tue Oct 25 2016

Shortwave moving off the Rockies at this time will move east
overnight. Resulting surface low is expected to track across Iowa
and northern Illinois on Wednesday. Low level jet ramps up tonight
over the Midwest and all guidance is showing moderate low level
moisture convergence over northern portions of the area on the
850mb baroclinic zone. Expect there will be isolated to widely
scattered showers in this region chance PoPs should
cover this well. Temperatures should bottom out warmer than this
morning`s lows...especially over west central Illinois where wind
will be turning further toward the south.

Surface low moves across northern Illinois Wednesday dragging a
cold front along behind it. Elevated instability around 300 J/kg ahead
of the front should be enough for an isolated thunderstorm or two,
but it`ll primarily be just a rainy day ahead of the front. Have
high chance to likely PoPs for showers and a few storms. Clouds
and rain will likely keep temperatures in the 60s across most of
the area.

.LONG TERM...(Wednesday night through Tuesday)
ISSUED AT 249 PM CDT Tue Oct 25 2016
Rain should be ending on Wednesday evening as the front moves out.
Northwest flow will bring in somewhat cooler air for Thursday, but
a ridge aloft will quickly build back over the region Thursday
night and Friday. The surface ridge will move east of the region
and low level southerly flow will redevelop over the area
resulting in breezy and warm conditions for Friday and Saturday.
Expect temperatures to be well above normal in the 70s both days.
Another front will move through the area on Sunday, but current
thinking is that there will not be enough moisture return ahead of
it to produce precip. Additionally, the ridge aloft builds back in
behind the shortwave almost immediately so any cool down will be


.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 643 PM CDT Tue Oct 25 2016

Warm frontal zone of storm system approaching from the west will
bring a few showers to KSPI-KBMI northward through evening...then
this area of showers is expected to shift northward for much of
the night. Nevertheless...VFR conditions expected to prevail
during this time period. By Wednesday morning...rain and a few
thunderstorms will spread east into the area from Iowa...likely
bringing ceilings and visibilities down into MVFR range. Winds
east around 10 kts through the night...becoming south 10-15G20KT
by around 18Z.


.ILX Watches/Warnings/Advisories...


LONG TERM...Carney
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