Area Forecast Discussion
Issued by NWS Central Illinois

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FXUS63 KILX 221729

Area Forecast Discussion
National Weather Service Lincoln IL
1229 PM CDT Fri Sep 22 2017

Issued at 1048 AM CDT Fri Sep 22 2017

Hot and muggy weather across the Midwest continues as high
pressure dominates the eastern half of the US. Southerly winds
and plenty of sunshine will keep the hot conditions in place
through the first weekend of autumn. Some minor cu development
possible today, otherwise it is a very quiet forecast. No major
updates to the forecast anticipated at this time.


.SHORT TERM...(Today and tonight)
ISSUED AT 207 AM CDT Fri Sep 22 2017

Main story for this first day of fall remains with the heat.
An upper level ridge remains firmly in place over the Midwest
this morning, and 850 mb temperatures are above the 90th
percentile for this time of year. Temperatures likely to again
reach into the 92-94 degree range in much of the forecast area,
with a few record highs possible. Cu-rule suggests some scattered
cumulus development over mainly the east half of the forecast
area. Several of the high-resolution models are hinting at some
isolated showers forming in this area by early afternoon. However,
given the strength of the ridge and little in the way of forcing,
will keep the forecast dry for now.

.LONG TERM...(Saturday through Thursday)
ISSUED AT 207 AM CDT Fri Sep 22 2017

No real change in the forecast philosophy through this period.
Through early next week, the strong upper ridge over the eastern
U.S. remains the driving force, with high temperatures remaining
in near record territory in the lower 90s. Temperatures start
easing off a bit on Tuesday with more cloud cover, but I would not
be surprised to see that day trending upward as well.

Upper pattern finally starts to break down around midweek, as a
strong shortwave ejects northeast out of the Rockies into the
upper Mississippi Valley. Main question remains with the speed of
the cold front passing through Illinois. The ECMWF fades out any
associated rainfall as it passes Tuesday evening, while the GFS
keeps showers going with a Wednesday passage. The Canadian model
is the odd one out, holding the ridge much longer until Thursday.
In any event, rain chances are not especially high, but the
highlight will be a significant cooldown.


.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
Issued at 1229 PM CDT Fri Sep 22 2017

VFR throughout forecast. Southerly winds dominate...with some
more variability in CMI/DEC/BMI under less of a pressure gradient.
Few cu today, dissipating at sunset, then few/sct cirrus. Winds
still light and southerly overnight, though some variability will
remain possible as the inversion sets up. Some patchy visibility
drops will also be possible as have been for the last few nights,
but nothing widespread expected, and certainly not enough to drop
flight category.


Issued at 200 AM CDT Fri Sep 22 2017

Record highs through the weekend:

Location         Fri       Sat       Sun
--------       -------   -------   -------
Bloomington    94/1930   92/1937   94/1933
Champaign      95/1891   94/1891   94/1891
Charleston     95/2005   93/2010   93/1933
Decatur        94/2005   92/2007   93/1933
Galesburg      92/1988   89/1937   90/2007
Olney          96/2010   94/1960   94/2010
Peoria         93/1930   92/1937   92/2007
Springfield    95/2005   93/2007   93/2007




SHORT TERM...Geelhart
LONG TERM...Geelhart
CLIMATE...Geelhart is the U.S. government's official web portal to all federal, state and local government web resources and services.