377
FXUS63 KILX 101450
AFDILX

Area Forecast Discussion...Updated
National Weather Service Lincoln IL
950 AM CDT Mon Jun 10 2024

.KEY MESSAGES...

- Summer-like temperatures return Wednesday through early next
  week. Heat indices will climb into the 90s to near 100 on
  Thursday and again on Sunday into early next week.

- Our next chance (30-50%) for showers and storms will be Thursday
  into Thursday night as a cold front drops through the area. A
  few of these storms could be strong to severe.

&&

.UPDATE...
Issued at 950 AM CDT Mon Jun 10 2024

A broken stratus deck is shifting SE across the area this morning,
but should eventually transition to scattered Cu by early
afternoon. Minor edits were made to the sky cover forecast to
better capture the current conditions. Otherwise, no forecast
changes were necessary at this time. With high temperatures in the
low to mid 70s today, and a warm up to above normal temps
expected late this week into the extended forecast, today will
wind up being one of the coolest days in June.

Erwin

&&

.DISCUSSION...
Issued at 216 AM CDT Mon Jun 10 2024

An upper shortwave trough is noted on water vapor imagery over
Wisconsin early this morning. A weak front associated with this wave
is stretched from northern Illinois northwestward into southern
Minnesota. This front will continue to sag south today, bringing a
period of low stratus to the area to start the day. The cloud cover
will hold temperatures down a bit, with highs looking to only reach
the low to middle 70s. Surface ridging nosing in from the west will
push the front south of the area later this afternoon, parting way
to mostly clear skies going into tonight. The surface high will
center itself from the middle Mississippi Valley into the lower
Great Lakes Region overnight, allowing winds to become light.
Efficient radiational cooling will send temperatures as low as the
middle 40s to low 50s. Although this is pretty chilly for June
standards, we will still be a good 5-10 degrees warmer than record
lows for June 11.

By the middle of the week, upper ridging over the western CONUS will
spill eastward into the central US as a few upper waves work to
flatten it out. Flow aloft will become more zonal as mid-level
heights rise overhead. Temperatures will return back to summer-like
values on Wednesday, with even warmer and more humid conditions
building by the end of the week into the weekend as another upper
ridge over the southwest US gets kicked eastward. Temperatures
will range from the upper 80s to middle 90s Thursday through early
next week. Lower dewpoints behind a cold front will bring some
brief relief from the humidity on Friday and Saturday, but
otherwise expect heat indices to range from the 90s to near 100
Thursday through early next week.

Precipitation chances look to return later this week as an upper
wave "ridge rider" works through the Great Lakes Region Thursday
night into Friday. A cold front tied to this wave will approach
central Illinois area later in the day on Thursday, bringing our
next chance (30-50%) for showers and storms. Forecast guidance shows
instability ahead of the front becoming moderately strong (up to
2500 J/kg) with favorable wind shear with the arrival of the front.
The potential for a few strong to severe storms exists, with the
highest probabilities being west of the Illinois River.

Precipitation chances outside of the frontal passage Thursday night
become more uncertain going into the weekend, though occasional
upper waves could bring additional chances for precipitation.

NMA

&&

.AVIATION...  (For the 12z TAFs through 12z Tuesday Morning)
Issued at 535 AM CDT Mon Jun 10 2024

Low stratus associated tied to a frontal boundary is sinking south
across the region this morning. Cloud heights are generally between
3-5k ft, though there are a few <3k ft observations upstream. A
brief period of MVFR ceilings would be most likely at CMI and BMI
between 13-17Z. Clouds scatter out by this afternoon as high
pressure approaches from the west. Northwest winds could gust as
high as 15-20 kts behind the front this afternoon, then turn light
and variable overnight.

NMA

&&

.ILX WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$