Beckemeyer, Illinois Weather Forecast Discussion

619
FXUS63 KLSX 121923
AFDLSX
Area Forecast Discussion
National Weather Service Saint Louis MO
223 PM CDT Fri Sep 12 2025
.KEY MESSAGES...
-Above normal temperatures will continue through at least Wednesday.
-Daily chances for spotty afternoon showers and thunderstorms
 starts Saturday and extends through at least Wednesday.
&&
.SHORT TERM...  (Through Late Saturday Night)
Issued at 211 PM CDT Fri Sep 12 2025
As of 2PM temperatures have warmed into the upper 80s to low 90s
areawide under the influence of a building mid-level ridge, low-
level warm air advection, and abundant sunshine. A shortwave
disturbance is expected to move along the northern periphery of
the ridge this evening, and while the weak forcing and dry low
level air will largely mitigate any rainfall, I cannot rule out a
few sprinkles across northeast Missouri and west-central Illinois.
By Saturday the mid-level ridge will be squarely over the mid-
Mississippi Valley, with 850 mb temperatures pushing above the 90th
climatological percentile for this time of year. Combined with
plenty of sunshine, this will result in one of the hottest days of
the period with highs pushing the mid to upper 90s. Instability will
be able to form underneath the ridge, with the HREF is depicting
up to 1000-1500 J/kg of MUCAPE during the afternoon. Within the
low-level warm air advection regime, convective inhibition will
be at a minimum, particularly during the afternoon. Combined with
steep low-level lapse rates, widely isolated showers and
thunderstorms are possible during the afternoon Saturday, despite
the building mid-level ridge.
Delia
&&
.LONG TERM...  (Sunday through Next Friday)
Issued at 211 PM CDT Fri Sep 12 2025
Sunday through Wednesday of next week will feel like nearly a carbon
copy of Saturday as the mid-level ridge persists across the central
CONUS as a part of an Omega Block. Sunday`s temperatures will peak
once again in the mid to upper 90s areawide, a little warmer than 24
hours ago as the signal for high clouds has dissipated. The mid-
level ridge will shift eastward over the week, and high temperatures
will cool a few degrees but remain in the 90s through at least
Wednesday. Each day isolated afternoon showers and perhaps a
thunderstorm will develop across the region. While the location of
where this rain forms is uncertain, confidence is high that amounts
will not be enough to make a significant impact in the hot and dry
conditions gripping the region.
As the mid-level ridge tips to the northeast by mid-week, a mid-
level trough will slide into the Upper Plains, helping to break the
Omega Block. The evolution of this feature and its impacts remain
uncertain, though all global ensemble members depict the trough. The
interquartile spread for high temperatures depicts a clear cooling
trend for the end of next week and next weekend, the details of
which are wrapped up in the uncertainty of the trough.
Delia
&&
.AVIATION...  (For the 18z TAFs through 18z Saturday Afternoon)
Issued at 1143 AM CDT Fri Sep 12 2025
VFR flight conditions will continue through the period under
largely dry conditions. Isolated afternoon showers and perhaps
even a thunderstorm are expected Saturday afternoon area wide,
though confidence in where these pop up is far too low to include
a mention in the TAFs at this time (15% chance). Winds will shift
from southeasterly to southwesterly by tomorrow morning.
Delia
&&
.CLIMATE...
Issued at 218 PM CDT Wed Sep 10 2025
Record daily highs Friday 9/12 through Monday 9/15:
9/12 | 9/13 | 9/14 | 9/15
STL   98    100    101    101
COU  100     99    104    101
UIN   99    100     99    100
Delia
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...None.
IL...None.
&&
$$
WFO LSX

NWS LSX Office Area Forecast Discussion