Leider Park, Illinois Weather Forecast Discussion

794
FXUS63 KLOT 301850
AFDLOT
Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
150 PM CDT Tue Sep 30 2025
.KEY MESSAGES...
- Dry and unseasonably warm daytime conditions through the
  weekend.
&&
.DISCUSSION...
Issued at 150 PM CDT Tue Sep 30 2025
An upper level ridge axis remains over the western Great Lakes
this afternoon. Southerly winds on the west side of the ridge
is pulling moisture from the Gulf northward for an impressive
cloud shield spanning the eastern Great Plains. A shortwave
trough over the Colorado front range will move northeastward
tonight and Wednesday. The trough will weaken and phase with the
longer wave pattern aloft, but it will help nudge the ridge axis
southeastward toward the Ohio River basin. Cloud cover is
expected to increase as the trough moves closer. Winds will
slowly become more southeasterly on Wednesday before switching
to the southwest into Thursday. Temperatures will remain in the
80s south of Interstate 80 tomorrow, but the southeasterly
winds are expected to keep far northeastern Illinois in the
70s.
Wide spread 80s return on Thursday. An upper level ridge will
try to build back over the area for high pressure to grow once
again. Temperatures on Friday and Saturday will increase back
into the mid to upper 80s and with southwest winds, even the
city of Chicago will be in the low to mid 80s. With finer fuels
being dry, there is a limited risk for fire weather concerns
toward the end of the week. Luckily the winds should be light
enough through the work week, but with the gradient flow
increasing over the weekend it is possible forecasted wind
gusts are being underrepresented in models which may increase
the fire danger, particularly for more interior locations away
from Chicago.
Models are still suggesting an upper level trough will move over
the Great Plains early next week which will send a cold front
toward the area increasing precip chances with it. However,
models are still not showing great agreement in the overall
pattern. For now, there was no need to change the PoPs that the
NBM provided knowing the lower confidence in timing. The set up
does not look conducive for severe weather and cool air
advection behind the front should knock temperatures back down
to more seasonable conditions by the middle of next week.
DK
&&
.AVIATION /18Z TAFS THROUGH 00Z THURSDAY/...
Issued at 1214 PM CDT Tue Sep 30 2025
No major forecast concerns for the terminals as high pressure
continues to vacation overhead. East-northeast winds around 5-10
kts will persist through tonight before speeds increase
Wednesday afternoon. While the strongest winds may hold off
until just after the conclusion of the 30-hour TAFs, a few 18-20
kt gusts cannot be ruled out Wednesday afternoon. Otherwise,
VFR conditions but with increasing cirrus tonight into
Wednesday.
Yack
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...None.
IN...None.
LM...None.
&&
$$
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NWS LOT Office Area Forecast Discussion