Area Forecast Discussion
Issued by NWS Central Illinois

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FXUS63 KILX 190454
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
1154 PM CDT Wed Apr 18 2018

.UPDATE...
Issued at 849 PM CDT Wed Apr 18 2018

Going forecast was generally in good shape. Wrap around
clouds/showers in the wake of today`s low pressure system will
continue to clip the far northern portion of the forecast area
over the next few hours. Surface reports beneath the radar returns
expected to impact the local area have been snow, rain, or
drizzle. As the low-level thermal profile cools over the next few
hours, through both nocturnal cooling and cold air advection, any
lingering precipitation will change to snow before ending.
Forecast soundings suggest cloud ice may be lost by late tonight,
but don`t expect precipitation to still be falling at that point.
So, the risk of any freezing drizzle/light freezing rain appears
quite low.

Main adjustments were to PoPs, pushing the risk of measurable
precipitation a little further north and fine-tuning the timing.
Otherwise, only a few tweaks were needed to the hourly trends
overnight.

&&

.SHORT TERM...(This evening through Thursday)
ISSUED AT 235 PM CDT Wed Apr 18 2018

Surface low has now moved into extreme east central Illinois near
Paris, and winds are picking up behind it. 2 pm observations
showing gusts to 42 mph in Taylorville and 41 mph in Effingham.
Wind advisory was issued earlier for the areas south of I-70 for
gusts to around 45 mph, and will need to monitor for any
northward expansion in the short term. Still looks like the
strongest of the winds will be through sunset, though gusts to 30
mph will linger much of the night over areas south of I-72.

Further north, aside from a few showers earlier, conditions have
been mostly dry today. As the upper low continues to slowly
move into northeast Iowa, an associated wave rotating around it is
pushing rain and snow showers southward toward the Missouri
border. Areas along and north of I-74 are most likely to be
impacted by precipitation this late afternoon through about
midnight, as the low opens up and starts to move quicker. Rain
will change to snow by about mid evening, with another dusting
possible on mainly grassy surfaces.

High pressure behind this system will result in a clearing trend
on Thursday. Temperatures will be below normal, but still reach
the 50-55 degree range.

.LONG TERM...(Thursday night through Wednesday)
ISSUED AT 235 PM CDT Wed Apr 18 2018

Tonight`s snow should hopefully be the last we see of it for the
season (finally!), as dry conditions prevail through early next
week. By the time the next system arrives toward Tuesday, a
gradual warming trend will have taken place for several days, and
highs return to the 60s early next week.

A couple storm systems will be worth watching during this period.
The upper low currently off the northern California coast will
strengthen as it moves into the 4-corners region late this week.
Longer range model guidance is in good agreement with this
feature taking a more southeast track during the weekend, which
should keep us dry. Regarding early next week, there is less
agreement with an upper wave digging southward from central
Canada. The GFS is much more progressive, with the European
solution about 24 hours slower, and the Canadian solution cuts off
the low over the Plains. With no real confidence this far out,
will mainly keep PoP`s in the silent 20 range.

&&

.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
Issued at 1152 PM CDT Wed Apr 18 2018

MVFR CIGs will prevail across the central Illinois terminals into
Thursday morning on the back side of an area of low pressure.
Scattered flurries are possible across KPIA, KBMI, and KCMI for
the next few hours, but the remaining local terminals should stay
dry. Gusty northwest winds will prevail into the overnight hours,
but will gradually subside by late tonight. The CIGs should
scatter out from north to south Thursday morning, resulting in VFR
conditions for the balance of the TAF valid time.

&&

.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

UPDATE...Bak
SHORT TERM...Geelhart
LONG TERM...Geelhart
AVIATION...Bak



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