Bloomington, Illinois 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

148
FXUS63 KILX 261749
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
1249 PM CDT Thu Mar 26 2026

.KEY MESSAGES...

- An Enhanced Risk (level 3 of 5) for severe weather exists east
  and north of a Havana-Springfield-Mattoon line late this
  afternoon and evening. Damaging wind gusts in excess of 75
  mph, hail greater than 2 inches in diameter, and tornadoes
  (EF2+ strength) are possible.

- Large temperature swings are in store starting tonight.
  Readings will soar to record warm levels in the middle to
  upper 80s, nearing 90, today...then will plunge into the
  middle to upper 20s by early Saturday morning.

&&

.DISCUSSION...
Issued at 240 AM CDT Thu Mar 26 2026

As an 850 mb warm front lifts across central IL this morning,
there are some showers and thunderstorms that are moving
through. Before the cold front arrives today, we will be
flirting with near 90 temperatures. Then the cold front will
bring strong to severe storms, potential excessive rainfall, and
a sharp drop off in temperatures this evening. After this
system, we should be dry through Sunday afternoon before rain
chances return.

There a 40-70% chance of greater than 85 degrees south of I-74, from
the HREF. The probabilities increase to 70-100% as you get southwest
of a Macomb to Taylorville line. We are looking at blowing away the
record highs today, and maybe even record monthly highs, as the
records are around 78-85 degrees. (See climate section for locations
and records)

SPC has central IL a slight/enhanced risk (level 2/3 of 5) for
severe weather for today. All hazards are in play, large
(potentially 2+ inch) hail, damaging winds (potentially 75+ mph
gusts), and a few tornadoes. SPC suggests that if there is a
tornado, there is the chance for it to be of EF2 or greater
strength. Timing looks to have the storms developing just north of
the forecast area around 21-23z, initially being discrete. Then the
storms will eventually transition to linear later in the evening.
They would exit to the south by 08-10z Friday morning. The severe
risk, however, will not be around that whole time, as we lose the
daytime heating. As the line moves towards southeastern/southern IL,
the severe threat will diminish towards midnight. Showers and
thunderstorms would continue into early tomorrow morning as it
completes its pass through southeastern IL.

The environment appears primed for this afternoon but will have to
fight a cap initially, but as the front approaches, the cap will
erode. There is a signal that the storms could potentially develop
along or behind the front. If they develop behind the front, we
would more likely be dealing with elevated storms, with more focus
on the very large hail (2+ inch) risk. The tornado risk will be with
any storms that latch onto the boundary. The HREF shows SBCAPE
values of 1500-2000 J/kg, with 40-50 knots of shear. Lapse rates
sound alarm bells for significant hail sizes with insane values of 8-
8.3 C/km as seen on forecast soundings. For the wind risk, the
forecast soundings have an "inverted-v" profile with DCAPE values
1000-1400 J/kg. Then the PWATs, which are around 1.4-1.6, and the
long skinny CAPE profile suggest that these storms could be
efficient rain producers. The WPC maintained a marginal risk for
excessive rainfall for today.

Behind the front, lows tonight will dip down into the mid 30s to low
40s. Highs on Friday won`t be much warmer, with values in the upper
40s to low 50s. As of now, there is a 30-50% chance that
temperatures will get back above 80 degrees southwest of a Avon to
Taylorville line by next Monday.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1249 PM CDT Thu Mar 26 2026

CAMs continue to suggest rapid convective development near or
just northeast of the I-74 corridor between 21z and 23z.
HRRR/RRFS have consistently shown cells firing northeast of
KPIA, then tracking E/SE into Indiana by around 00z. Based on
the latest data, have maintained the PROB30 group for thunder at
KPIA between 21z and 23z, but have gone with TEMPO severe
thunder/hail at both KBMI and KCMI. Once this initial cluster of
storms exits, additional convection will develop along/north of
an advancing cold front during the evening. With all models
showing storms becoming widespread, have opted to go with
predominant thunder at all terminals...with the thunder ending
from north to south between 05z and 07z. Winds will initially be
SW with gusts of around 25kt this afternoon, then will switch to
NE and gust 30-35kt behind the cold front this evening into the
overnight hours. After FROPA, MVFR ceilings will overspread the
area...with HRRR/NAM forecast soundings showing the low clouds
persisting through midday Friday.

&&

.CLIMATE...
Issued at 125 AM CDT Wed Mar 25 2026

Forecast temperatures on Thursday may exceed March records in
some areas.

               Mar 26 Record              March Record
Charleston....   84 (1907)          89 (3/24/1929 and 3/22/2026)
Decatur.......   83 (1907)          89 (3/24/1929)
Jacksonville..   83 (1950)          91 (3/21/1907)
Lincoln.......   83 (1991)          86 (3/29/1985 and 3/30/1986)
Normal........   83 (2007)          88 (3/21/1907)
Olney.........   85 (1907)          89 (3/24/1910 and 3/24/1929)
Peoria........   82 (1907/1991)     87 (3/21/1907)
Springfield...   81 (1991)          91 (3/21/1907)
Urbana........   81 (1907)          85 (3/21/1907 and 3/24/1910)

&&

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

&&

$$

KEY MESSAGES...Barnes
DISCUSSION...Copple
AVIATION...Copple
CLIMATE...Geelhart