Crystal Lake, Illinois 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

193
FXUS63 KDVN 202342
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
542 PM CST Sat Dec 20 2025

.KEY MESSAGES...

-  We will see temperatures gradually increase daily as we head
   towards the middle of next week, with 50s/60s for much of the
   area by the middle of the upcoming holiday week.

-  Aside from low-end chances for precipitation in the middle of
   next week, we will largely remain dry through much of the
   extended forecast.

&&

.SHORT TERM /THROUGH SUNDAY NIGHT/...
Issued at 145 PM CST Sat Dec 20 2025

High pressure will build in tonight bringing clear skies,
decreasing winds, and chilly temperatures in the single digits
and teens. The quiet weather will continue through Sunday with
dry conditions and seasonable temperatures in the 20s/30s for
highs.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
Issued at 145 PM CST Sat Dec 20 2025

We remain on track for a largely quiet long term, with upper level
zonal flow dominating the region. Westerly flow will be locked
overhead, with waves passing along the northern CONUS. With each of
these waves, we will get some llvl wind shifts, which will bring
through periods of southerly flow. These bouts of southerly flow
will result in a gradual increase in temperatures through the next
week. In fact, temperatures are forecast to trend well above normal
through this timeframe, with widespread upper 40s and 50s throughout
the area. Guidance continues to favor the warmest temperatures
moving in on Christmas Day. While this is still a week out and much
can change, current forecast shows temperatures approaching the low
60s south of the Interstate 80 corridor on Christmas. For reference,
high temperatures during this time of the year are generally in the
low-mid 30s. If these temperatures are to hold true, we will be
approaching record temperature territory. Christmas Day, the
Euro ensemble favors 50s working their way up to the Interstate
80 corridor with 40-60% favorability. The NBM has been trending
on the warmer side with near 60 degrees up to I-80 and even
mid/upper 60s across the far south.

This timeframe is expected to remain mostly dry, aside from a few
chances for light precipitation. Have opted to stick with the mostly
dry conditions given by the NBM, as confidence remains low on the
overall chances. Although, long term guidance is starting to show
some chances for light precipitation in the middle of next week.
Currently this is a weak signal, with light rain possible as a wave
passes overhead. Otherwise, precipitation chances remain <25%
for much of the extended. With systems passing through the north
and leaving us in persistent southerly flow, will see moisture
work into the mid-upper levels, resulting in periods of passing
clouds. Otherwise, seasonal breeziness will be seen.

&&

.AVIATION /00Z TAFS THROUGH 00Z MONDAY/...
Issued at 542 PM CST Sat Dec 20 2025

VFR conditions are expected throughout the TAF period, largely
under clear skies. This evening, the main focus will be on winds
and potential for low-level wind shear at both DBQ and MLI. If
wind gusts continue at DBQ, then mechanical turbulence will be
more common than wind shear. However, confidence is slightly
higher for wind shear at MLI where wind gusts have ceased.
Winds will gradually weaken overnight into Sunday morning as a
high pressure system approaches the area, eventually turning
more south-southeasterly late in the TAF period.

&&

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

&&

$$

SHORT TERM...Uttech
LONG TERM...Gunkel/Uttech
AVIATION...Schultz