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Area forecast discussion
National Weather Service Lincoln Illinois
559 am CDT Sat Sep 23 2017

Short term...(today and tonight)
issued at 330 am CDT Sat Sep 23 2017

The late season heat wave will continue a few more day across
central and southeast Illinois with high temperatures reaching close to
record levels. Below in the climate section are record highs for
today, Sunday and Monday for 10 of our larger cities in our cwa,
which are mostly in the lower 90s.

A 588-590 dm 500 mb subtropical ridge from Texas NE across Illinois and
into the eastern Great Lakes, will continue the Summer like heat
wave through Monday (and over southeast Illinois thru tue) as 592 dm
500 mb high over PA by 18z/Sunday and ridges back into Illinois into
early next week.

Patchy fog possible over eastern Illinois until mid morning, otherwise
another hot day ahead with partly to mostly sunny skies. Highs of
90-95f today with afternoon heat indices in the 90s. A weak
disturbance that brought isolated convection to parts of in and
east central Illinois yesterday afternoon and early evening appears to
shift west of I-57 today and this area will likely see more
cumulus clouds this afternoon. Most models keep our County Warning Area dry today,
though hrrr shows isolated qpf western County Warning Area into mid afternoon but
this model is also showing qpf currently where we have nearly
clear skies. Fair weather expected tonight as diurnally driven
cumulus clouds dissipate this evening. Lows mostly in the mid
60s, with some upper 60s over the Illinois River valley.

Long term...(sunday through saturday)
issued at 330 am CDT Sat Sep 23 2017

The heat wave will likely continue through Monday with highs in
the lower 90s, except upper 80s Monday northern County Warning Area from Peoria
and Bloomington north. Dry conditions expected through most of County Warning Area
through Tue morning, though do have slight chance of convection
far NW County Warning Area Tue morning as a cold front moves into far NW Illinois. This
front will bring 20-30% chance of showers and thunderstorms over
the Illinois River valley Tue afternoon mainly from I-55 NW. Highs Tue
range from lower 80s by Galesburg to near 90f from I-57 east. The
cold front to sweep thru rest of County Warning Area during Tue night though lift
will be weak and pops are either slight or none going into Wed.
Much cooler air Ushers in on Wed behind cold front with highs
ranging from lower 70s NW of Illinois River, to the lower 80s se of
I-70. Dry and seasonable temperatures expected Wed night thru
Saturday. Highs Thu in the low to mid 70s, and cooler upper 60s
and lower 70s Fri/Sat as a broad upper level trof digs south
across the Great Lakes and into the Ohio/Tennessee River valleys.


Aviation...(for the 12z tafs through 12z Sunday morning)
issued at 559 am CDT Sat Sep 23 2017

VFR conditions are expected to prevail through 12z/7 am Sunday
with strong upper level high pressure ridge (589 dm 500 mb high in
se Iowa/wi) staying nearby through Sunday morning. Light fog
possible in eastern Illinois by cmi with vsbys possibly briefing getting
as low as 5-6 miles thru 14z. Few to scattered cumulus clouds of
4-7k ft to develop by 15z and dissipate around sunset/00z. 1020
mb surface high pressure ridge over the eastern Great Lakes and
ridging back into Illinois to also remain nearby and keep winds fairly
light next 24 hours. Wind direction mainly southeast at 4-8 kts.


issued at 330 am CDT Sat Sep 23 2017

Record highs today through monday:

Location today Sunday Monday
Sep 23 Sep 24 Sep 25
-------- ------- ------- -------
Bloomington... 92/1937 94/1933 93/2007
Champaign..... 94/1891 94/1891 96/1891
Charleston.... 93/2010 93/1933 91/2016
Danville...... 91/2010 92/1939 94/1897
Decatur....... 92/2007 93/1933 91/1939
Galesburg..... 89/1937 90/2007 90/2007
Olney......... 94/1960 94/2010 92/2007
Peoria........ 92/1937 92/2007 92/1891
Springfield... 93/2007 93/2007 94/1891
Lincoln....... 92/1937 93/1935 92/1920


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