Crystal Lake, Illinois 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

812
FXUS63 KDVN 261711
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
1211 PM CDT Thu Mar 26 2026

.KEY MESSAGES...

- A very sharp backdoor cold front will continue to sweep
  southward through our area through the afternoon and evening.

- Showers and storms remain possible along and just behind this
  front, with severe weather possible, especially in our
  southern areas.

- Blustery weather will be in place this evening through Friday
  evening as cold weather spreads over the region, followed by
  another significant warm up, with rain chances in the extended
  forecast.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 206 AM CDT Thu Mar 26 2026

A shortwave is forecast to move from the northern Plains into
the Great Lakes this evening and drive a cold front southward
across the area as a surface low moves along the front this
afternoon. Models have trended faster with the frontal passage
through the area for today with the cold front surging across
the area with the front moving into the Highway 20 corridor
around 10 AM to Interstate 80 by 1 PM then exiting into
northern Missouri and central Illinois by 7 PM this evening.
Winds will be southwesterly ahead of the front with gusts up to
25 MPH then turn to the north behind the front then northeast
with gusts up to 30 to 35 MPH. High temperatures for today may
occur during the morning hours north of Interstate 80 with
temperatures falling during the late afternoon south of
Interstate 80. High temperatures today are forecast to range
from the mid 60s along the Highway 20 corridor to the upper 80s
in far northeast Missouri and west central Illinois. These
temperatures result in near record high temperatures at
Burlington (84, 1981).

The faster timing of the front is increasing confidence that
storm development will be limited to along the front or behind
it with strong lift associated with the surging cold front.
Models have a very limited window for surface based CAPE and
model soundings continue to show an inversion or elevated warm
layer in place through the day today. Think that this indicates
storms will be elevated with the primary threat for large hail
with any supercells that develop. 0 to 6 km shear vectors are
parallel to the front favoring storms that will grow upscale
into lines of storms and produce damaging winds. Isolated
tornadoes are also possible. Both the latest HRRR and 4 KM NAM
Nest runs favor thunderstorm development later this afternoon
near 7 PM mainly south of Interstate 80 in the vicinity of the
front with rain showers farther to the north. A thunderstorm
threat is expected to linger south of a Fairfield to Galesburg
line through 10 PM. The Storm Prediction Center has moved the
Enhanced Risk of severe storms to the east of Bureau and Putnam
Counties. There is a Marginal (level 1 out of 5) Risk south of a
Williamsburg to Maquoketa to Rockford Illinois. There is a
Slight (level 2 out of 5) Risk of severe storms east of a line
from Kirksville to Mount Pleasant to Moline to Prophetstown
Illinois.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
Issued at 206 AM CDT Thu Mar 26 2026

There is little change in the forecast during the long term
period, and included the previous long term discussion with
some minor edits.

Friday still appearing to be a blustery post-frontal day with
temperatures in the 40s and the areas south of I-80 lucky to breach
50 degrees. Wind gusts up to 30 MPH are possible through the
day.

Then a re-bounding western upper high and strengthening thermal
ridge to our southwest will build northeastward again starting
another warming trend across the area Saturday and especially into
the end of the longer range. Ensembles continue to bring a piece of
ridge-riding wave energy with some moisture return to produce the
next round of showers and thunderstorms Monday night into Tuesday.
Along with this chance their may be the potential for stronger
storms again. Then even longer range guidance continues to show an
active pattern evolving if the western CONUS upper trof can get
established.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1207 PM CDT Thu Mar 26 2026

VFR conditions expected to persist into early evening. A cold
front is moving south through the area, with winds increasing to
strong levels up to 35 kts from the northeast already at KDBQ
and soon at KCID. The winds could be rather variable at KBRL
until the cold front moves through toward early afternoon and
Moline just saw this front pass to the south at 17Z. The rest of
this afternoon and evening behind the front, gusty from the
N/NE a period of gusts 30+ kt. Spotty showers are expected this
afternoon north of I-80 and will increase this afternoon/evening
behind the cold front for a period of time. There is also a
chance for thunderstorms (30%) near KMLI and especially KBRL
(60%) around 00z through 04z with MVFR to local IFR conditions
(mainly for visibility). Hail will also be possible with the
strongest activity. Guidance varies on extent of low clouds
overnight/early Friday morning, but there is some potential for
bands of MVFR ceilings aided by strengthening NE flow off Lake
Michigan.

&&

.DVN WATCHES/WARNINGS/ADVISORIES...
IA...None.
IL...None.
MO...None.

&&

$$

SHORT TERM...Cousins
LONG TERM...12
AVIATION...Ervin