Area Forecast Discussion
Issued by NWS Central Illinois

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FXUS63 KILX 130152

Area Forecast Discussion
National Weather Service Lincoln IL
852 PM CDT Mon Mar 12 2018

Issued at 845 PM CDT Mon Mar 12 2018

Cloud band sinking south into north central and northeast Illinois
this evening continues to slowly dissipate, and we expect that
trend to continue for the remainder of the evening. Just north
of Lake Superior, another upper level wave was seen on the water
vapor loop tracking south and that feature will bring more clouds
into the area on Tuesday along with the possibility for a few
flurries or sprinkles, especially during the afternoon hours.
After a cold night tonight, unseasonably cool weather will once
again be the story for Tuesday with afternoon temperatures having
a tough time getting out of the 30s. Have made only minor
adjustments to the hourly temperature and wind grids for this
evening, otherwise, the rest of the forecast is in good shape. No
ZFP update will be needed this evening.


.SHORT TERM...(This evening through Tuesday)
ISSUED AT 320 PM CDT Mon Mar 12 2018

Large scale trough over the Great Lakes region is producing
northwest flow over central IL with a series of embedded weak
disturbances bringing a threat of flurries and sprinkles over the
upcoming day. Initially a disturbance this afternoon is producing
enough lift just northeast of Danville for some echoes on radar,
however observations in NW Indiana are indicating none of this is
reaching the ground in the relatively dry air. A stronger shortwave
is developing over Ontario and set to reach northeast Illinois
Tuesday morning. This should produce a chance of flurries from about
Bloomington to Effingham eastward. The Dry air mass will cause most
showers to reach the ground as light snow through evaporational
cooling processes despite ambient temperatures reaching up toward
40 degrees. For lows tonight, expect mid 20s, somewhat mitigated by
a steady light NW wind. For highs Tuesday, expect temperatures
ranging from 37-38 along I-72 to 41 from Jacksonville to

.LONG TERM...(Tuesday night through Monday)
ISSUED AT 320 PM CDT Mon Mar 12 2018

Heights will gradually build over central IL Wednesday and Thursday
as a mid-continent ridge shifts eastward and brings a warmer
southwest flow over Illinois. This should bring highs back to the
upper 40s Wednesday and low to mid 50s Thursday.

A frontal boundary setting up from the Plains across southern IL and
a disturbance moving along the boundary could bring a chance of
showers Friday into Saturday. With cool dry air north of the
boundary, some of this could be snow at the cooler times of day, but
not expecting any significant amounts at this time.

Another stronger wave looks to head through the region late Sunday
night into Monday. Details are highly uncertain as evidenced by
large model discrepancies, but pattern looks to support a potential
for thunder especially for southern Illinois, so have included a
slight chance of thunder with the afternoon forecast package. Expect
highs rising from the upper 40s Friday to around 60 by Sunday,
possibly cooling a bit by Monday.


.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 610 PM CDT Mon Mar 12 2018

VFR conditions are expected this forecast period. The lower
base cumulus/stratocumulus deck over our north and east late
this afternoon should gradually dissipate with the loss of
daytime heating. As another shortwave dives south into the
lower Great Lakes on Tuesday, lower VFR cigs are expected
to develop during the morning and be with us into the afternoon
hours and possibly produce a few flurries, especially across
our eastern TAF sites. Northwest winds are expected tonight at
around 10 kts and from 12 to 17 kts on Tuesday with a few gusts
up to 23 kts at times.




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