970
FXUS63 KILX 301841
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
141 PM CDT Tue Sep 30 2025

.KEY MESSAGES...

- Well above normal temperatures and dry weather will continue
  into this weekend.

- Elevated fire weather conditions will develop Saturday through
  Monday, as south winds increase across the Midwest.

&&

.DISCUSSION...
Issued at 141 PM CDT Tue Sep 30 2025

Midday surface map indicated 1035 mb high pressure centered near
James Bay. A ridge axis extended southwest just west of central
IL and down into TX. Winds have been more notable than recent
days from a slightly tightened pressure gradient and deeper
mixing. Northeast winds around 10 mph were common with a few gusts
to 20 mph. Isodrosotherms showed a pool over very dry low level
air to our east where dew points in the lower 30s to lower 40s
covered central to eastern Indiana. This drier air will advect
west into our region tonight and with this in mind have lowered
mins to the low end of guidance in the mid 50s.

Still little change noted in the synoptic pattern through the end
of this week. Omega block remains centered over the central CONUS,
anchored by deep upper lows off the west and east coasts of
Canada. Thus our dry and hot weather pattern will continue for
several more days. The low RH airmass will promote large diurnal
temperature ranges highs generally in the upper 80s and lows in
the 50s to lower 60s through this weekend. As we head into this
weekend we begin to see some changes in the upper flow pattern,
when the closed low off the Pacific coast begins to open,
allowing troughing to advance across the western US. This will
begin to weaken the upper ridge and also introduce a tighter MSLP
gradient to the central US.

Beginning Saturday and persisting through early next week,
guidance points to south winds gusting 15-25 mph each afternoon.
Normally this would not be impactful, but given the worsening
drought conditions, low RH airmass, dry fine fuels, and active
harvesting taking place, ingredients for elevated fire danger and
farm field fires will be in place. In fact, the Hot-Dry-Windy
Index (HDWI) using the GEFS, shows max daily values rising above
the 75th percentile this weekend, based on a 30-year climatology.
So we will likely be increasing our messaging for elevated fire
danger as this weekend approaches.

As far as relief from the hot and dry pattern, global ensembles
offer a glimmer of hope as we get into the early to middle
portions of next week. By this time the upper ridge becomes
flattened, potentially opening the region to a weak frontal
passage and somewhat cooler air. However, prospects for
significant rainfall are very low with the NBM and LREF showing
only a 10-20% chance of over 0.25" QPF through Tuesday.

25

&&

.AVIATION...  (For the 18z TAFs through 18z Wednesday Afternoon)
Issued at 1149 AM CDT Tue Sep 30 2025

Another set of VFR TAFs with FEW-SCT diurnal cu and cirrus through
the forecast. Northeast winds around 10 kt, with a few gusts near
20 kt this afternoon will become light this evening.

25

&&

.CLIMATE...
Issued at 605 PM CDT Mon Sep 29 2025

Record high temperatures through Wednesday:

Location      Tuesday    Wednesday
--------     ----------  ---------
Bloomington   98 (1953)  92 (1897)
Champaign     91 (1971)  92 (1897)
Charleston    92 (1933)  94 (2019)
Decatur       94 (1922)  93 (1897)
Lincoln       93 (1952)  91 (2019)
Olney         93 (1952)  94 (1952)
Peoria        91 (1933)  89 (1937)
Springfield   92 (1971)  91 (2019)


&&

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

$$