Crystal Lake, Illinois 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

331
FXUS63 KDVN 011810
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
1210 PM CST Sun Nov 1 2026

.KEY MESSAGES...

- A large storm system will move through the Midwest the first
  half of the week. Behind the system, spotty rain showers will
  be possible for the second half of the work week.

- Although cooler, temperatures will continue to average above
  normal for early November.

&&

.SHORT TERM /THROUGH MONDAY/...
Issued at 1153 PM CDT Sat Oct 31 2026

Weak disturbances will keep plenty of clouds around today along with
sprinkles or small areas of rain showers. The cloud cover and rain
will help suppress temperatures (similar to Saturday) but still
above normal for early November.

Clouds will further increase and lower tonight as moisture from the
developing storm system begins moving into the area.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
Issued at 1153 PM CDT Sat Oct 31 2026

Monday through Wednesday
Assessment...high (>80%) confidence on a storm system bringing
some rain to the area along with warmer than normal temperatures.

Although there are differences between the global models, they have
been consistent in taking the center of the significant system well
to the west of the area. The net result will be much warmer than
normal temperatures for the area along with windy conditions.
Periodic rounds of rain will be seen with the best chances being
Monday night into Tuesday.

The overall timing for the best chances for rain also agrees with
the surge of moisture from the Pacific along with some from the
Gulf. The model PWATs with the moisture surge are 1.5+ inches which
would exceed the local sounding climatology. Such moisture also
yields a high probability of locally heavy rainfall, especially with
any thunderstorms.

Thunderstorms will be possible since we`ll be in the warm sector of
the storm. The signal for strong to severe storms is mixed but
various ML runs suggests a severe potential in the Plains. Back in
eastern Iowa the signal is being lost in the overall background
noise.

Once the main cold front and a secondary low sweep through the area
on Wednesday, spotty showers and sprinkles will be possible the
second half of the work week.

Temperatures through the entire week will average above normal for
early November.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1155 AM CST Sun Nov 1 2026

Ceilings will deteriorate later this evening into tonight first
to MVFR and then IFR between 09-12Z/Mon. Not much rain is anticipated,
aside from isolated showers overnight and the potential for
some drizzle Monday AM. The IFR ceilings are expected to last
through Monday morning with southeast winds increasing to 15-25
kts.

&&

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

&&

$$

SHORT TERM...08
LONG TERM...08
AVIATION...Uttech