Area Forecast Discussion
Issued by NWS Central Illinois

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FXUS63 KILX 190520

Area Forecast Discussion
National Weather Service Lincoln IL
1120 PM CST Sat Nov 18 2017

Issued at 849 PM CST Sat Nov 18 2017

Today`s cold front has now pushed well southeast of the state with
clearing skies taking place over most of the central IL forecast
area already, although some additional patches of low cloudiness
are still poised upstream in northern IL and WI to move in later
this evening and overnight. No major impacts from these cloud
features as no precipitation is expected. Brisk northwest winds
15-20 mph continue with some gusts as high as 35 mph. These will
slowly diminish overnight as the recent low pressure center moves
farther northeastward into New England and high pressure over the
southern Plains edges eastward, diminishing pressure gradients.
Nevertheless, NW winds will still be around 10 to 15 mph by dawn.
Cold air is also poised upstream in the upper Midwest, which will
steadily decrease temperatures overnight into the mid 20s to
lower 30s. Updates this evening are just of minor wind and cloud
cover trends.


.SHORT TERM...(This evening through Sunday)
ISSUED AT 242 PM CST Sat Nov 18 2017

Blustery evening in the wake of todays precipitation. Strong winds
just off the surface and the pressure gradient behind the cold
front are both contributing to winds out of the NW sustained in
excess of 20 mph, gusting 30 to 40mph. Holding on to the advisory
through the evening hours as some gusts are still kicking up to
over 40mph in the advisory area. Some lingering rain/snow showers
moving into eastern IL should be over shortly after sunset.
Colder air moving into the region will drop quickly before
midnight. Although the ground is warm, some elevated
surfaces/bridges with residual water left from today may get
slick once temps drop below freezing. Temperatures are expected
to drop into the 20s by early morning. Tomorrow, expecting plenty
of sun as high pressure starts to build back into the region.
However, temperatures will only climb into the mid to upper 30s
with winds becoming more westerly by sunset.

.LONG TERM...(Sunday night through Saturday)
ISSUED AT 242 PM CST Sat Nov 18 2017

Temps drop into the 20s again on Sun night, though a couple
degrees warmer than tonight as winds come around to the
south/southwest. Temps begin to warm briefly for Monday with
southerly flow as midlevel ridge shifts into the Mississippi River
Valley. Quasi zonal flow starts to shift to a more amplified
pattern as the next system moves into the Upper Midwest/Great
Lakes for Tuesday. Cold front remains dry for now, but the last
run has broken off a large piece of the energy, dropping a closed
upper low into the southeastern CONUS. Watching Tues
night/Wednesday for changes in the forecast potential for
showers in the Midwest between the two waves. Not enough
support/moisture in the models just yet. Lows dropping into the
20s Tues night and Wed night in response to the airmass shift.


.AVIATION...(For the 06Z TAFS through 06Z Sunday night)
Issued at 1020 PM CST Sat Nov 18 2017

Periods of MVFR cigs over central IL terminals overnight, then
becoming VFR by Sunday morning as high pressure moves into the
area. Winds NW around 15 kts with gusts over 20 kts initially,
decreasing slowly overnight. Further decrease in wind speeds to
under 12 kts by mid-day Sunday, while turning westerly.




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