661
FXUS63 KILX 121125
AFDILX

Area Forecast Discussion...Updated Aviation
National Weather Service Lincoln IL
525 AM CST Wed Nov 12 2025

.KEY MESSAGES...

- Mostly dry with steadily warming temperatures through Saturday,
  when highs are expected to reach the low to mid 70s.

- It will be breezy again today, with northwest winds gusting
  20-30 mph. Winds become lighter on Thursday.

&&

.DISCUSSION...
Issued at 232 AM CST Wed Nov 12 2025

*** THROUGH TONIGHT ***

A relatively uneventful forecast through the rest of the work
week. Skies early Wed AM were mostly clear, aside from a narrow
ribbon of cirrus clouds streaming in from the northwest. Central
IL is situated between sfc high pressure over the Gulf Coast and
sfc low pressure just north of the Great Lakes, resulting in
persistent westerly winds. While not quite as breezy as yesterday,
modest west- northwesterly flow is expected today, with gusts of
20-25 mph. Dewpoints in the upper 20s/low 30s will result in
afternoon RH around 30%, so there is once again there are some
minor concerns about elevated fire risk today.

A NW flow regime remains in place aloft over the central CONUS,
with troughing out east and ridging out west. A weak impulse
embedded within the NW flow is expected to produce increasing
cloud cover this evening, with the HREF starting to spread clouds
in from the west around 4-5PM (22-23z). Sky cover then increases
to partly/mostly cloudy between about 6 PM and midnight, which
will complicate viewing of any potential auroral displays tomorrow
night. An additional coronal mass ejection (CME) occurred earlier
this week, and forecasts from the Space Weather Prediction Center
indicate aurora displays are possible at times this
evening/tonight. The best bet for aurora enthusiasts would be to
look in the early evening, right as it is getting dark, and hope
that significant cloud cover hasn`t moved in yet. To be clear,
this suggestion is based purely on the cloud cover forecast, it`s
difficult to forecast exactly when the aurora itself would be
visible as far south as central IL.

*** REST OF THE PERIOD ***

The rest of the work week and into the weekend will feature mostly
dry conditions and increasing warmth as an amplified upper ridge
slowly shifts towards the region. There is still a low chance (10-
15%) of light rain south of I-70 early Fri AM due to LLJ forcing,
but this forcing seems to be focused just southeast of the ILX
CWA (PoPs increase to 30% east of the I-69 corridor in Indiana).

The temperature forecast remains on track, with highs near 60
today and Thurs, then near 70 on Fri, and into the low/mid 70s on
Sat. The record highs for Nov 15 (Sat) at our official climate
sites are 79F in Lincoln, 78F in Springfield, and 74F in Peoria.
Peoria stands the best chance of approaching record territory,
although the NBM does give Springfield and Lincoln a 5-10% chance
of reaching their record temps. Breezy southwest winds will
accompany the warmer temps, with ensembles indicating gusts of
20-30 mph on Sat.

Over the past several days, we`ve been monitoring the evolution of
a potential weekend system. Initially, it looked like a phased
wave ejection would occur over the weekend, but models yesterday
started to indicate the southern wave would close off over the
southern US. That trend has continued in the latest guidance, so
confidence in the forecast evolution is starting to increase. The
current forecast evolution, with a northern stream low passing by
well north of the area while a cut-off low meanders over the SW
CONUS, suggests a cold frontal passage Sat evening. Ens mean PWAT
values ahead of the front are between 0.50-1", which is above
average for mid-November, but guidance keeps the frontal passage
dry (less than a 15% chance of measurable rain). Following that
frontal passage, an expansive sfc high pressure nudges in, keeping
the area dry Sun with temps cooling back towards seasonable
values (highs in the 50s). As for the expected cut-off low over
the SW CONUS, the timing of its eventual ejection onto the Plains
remains uncertain. Presumably, this disturbance would eventually
offer a chance of rain to IL, although it seemingly trends slower
with each passing forecast cycle. For now, the latest NBM trends
PoPs upward over the course of the day Mon, peaking at 50-60% Mon
night.

Erwin

&&

.AVIATION...  (For the 12z TAFs through 12z Thursday Morning)
Issued at 524 AM CST Wed Nov 12 2025

No meaningful changes were needed to the TAFs with this update.
VFR conditions will continue through the period, with increasing
upper level cloud cover after 22-23z today. Northwesterly winds
will become gusty today, with peak gusts of 20-25 kts from mid-
morning through late afternoon. No precipitation is expected.

Erwin

&&

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

$$