Area Forecast Discussion
Issued by NWS Central Illinois

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FXUS63 KILX 300400
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
1100 PM CDT THU SEP 29 2016

.UPDATE...
Issued at 833 PM CDT Thu Sep 29 2016

Large upper low continues to spin over southern Kentucky early
this evening and is forecast to only slowly drift north over the
next 24 hours. Meanwhile, several weak disturbances were rotating
west around the northern periphery of the upper low and tracking
into our area bringing scattered showers. One such feature was
seen over eastern Indiana early this evening and is expected to
affect parts of east central through central Illinois later
tonight with another round of showers. This pattern will hold over
our area through at least the start of the weekend with the upper
low finally getting nudged to our north by Sunday. The current
forecast has a good handle on the evening and overnight trends
with only minor adjustments made to the POPs and temperatures
this evening. As a result, no ZFP update will be needed at this
time.

&&

.SHORT TERM...(This evening through Friday)
ISSUED AT 237 PM CDT Thu Sep 29 2016

Pesky upper low has drifted south of the Ohio River this afternoon,
and is progged to wobble along the Indiana/Kentucky border through
Friday. Periods of showers will continue to rotate around the low
into our area, and will be most numerous on Friday. Have maintained
the mention of isolated thunder for Friday afternoon, with edge of
the 500 mb cold pool edging back into eastern Illinois as the low
drifts northwest. With no real change in the air mass, temperatures
will remain cooler than normal, with highs tomorrow in the upper
60s.

.LONG TERM...(Friday night through Thursday)
ISSUED AT 237 PM CDT Thu Sep 29 2016

A 562 mb 500 mb cut-off low centered over southern Indiana today is
expected to wobble slowly WNW through Saturday before finally
drifting northeastward late in the weekend into early next week as a
deep upper low carves into the western U.S. Until the Midwest low
drifts off to the northeast...bands of showers and isolated
afternoon thunderstorms will wrap around the low into central IL.
Model forecast soundings only indicate weak amounts of instability
during mainly the afternoon and early evening periods Friday through
Saturday evening indicating a chance for lightning...but
predominantly there should be minimal lightning activity.

Temperatures will follow a warming trend Saturday through Wednesday
as high pressure builds into the area, with highs in the  upper 60s
Saturday steadily increasing to upper 70s to around 80 Wednesday.
Following a cold front likely to arrive Thursday, temperatures will
begin to cool again...with highs in the mid 70s expected Thursday.
Lows won`t change as noticeably with clearing skies allowing better
nighttime cooling despite a warming air mass. Expect lows Saturday
morning through Wednesday morning generally in the mid 50s.

&&

.AVIATION...(For the 06Z TAFS through 06Z Friday night)
Issued at 1100 PM CDT Thu Sep 29 2016

Upper low to our south will continue to dominate the weather
across the forecast area with a wide variation in cigs with
mostly VFR conditions at the present time, which will deteriorate
to low MVFR to IFR conditions Friday morning. One band of rain
was located over far eastern Illinois, tracking west-southwest and
looks like it will affect BMI and CMI. Another wave was seen over
eastern Indiana and that too was tracking back to the west and
will bring in more rain and low cigs to the area, especially
during the morning and early afternoon hours of Friday. Forecast
soundings Friday afternoon continue to suggest some lifting of the
cigs to MVFR or low VFR after 20z as the second wave shifts away
from our area. Any improvement in cigs looks to be short lived as
model forecast soundings depict cigs going back to IFR again
Friday night. Surface winds will remain out of the northeast at 10
to 15 kts with an occasional gust up to 20 kts at times, especially
around the bands of showers that move across the area.

&&

.ILX Watches/Warnings/Advisories...
NONE.
&&

$$

UPDATE...Smith
SHORT TERM...Geelhart
LONG TERM...Onton
AVIATION...Smith


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