Romeoville, Illinois 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

732
FXUS63 KDVN 021736
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
1136 AM CST Mon Feb 2 2026

.KEY MESSAGES...

-  A seasonable day today with a mix of clouds and sun, then a
   weak clipper may bring some areas of light snow across the
   region tonight.

- Temperatures will hover around seasonal values, with a few
  fluctuations, through mid week. Then high temperatures may
  warm above normal by late week.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 247 AM CST Mon Feb 2 2026

Today...First challenge of the day will be if the extensive deck of
stratocu acrs the area can erode like most models suggest they will.
There will be some subsidence fields this morning into afternoon
between passing waves in broad scale northwesterlies bi-secting the
CONUS from NW-to-SE, but there is also a nice inversion aloft from
just below H85 MB to H7 MB that could act as a trapping agent. Time
of year also favors cloud persistence, and for now will delay quite
a bit the clearing that the models induce as the morning progresses.
Wouldn`t be surprised if the clouds hold tough for much of the area
for much of the day. If clouds hang on they will be a high temp
buster from the advertised low to mid 20s in the northern DVN CWA,
to the low 30s in the south. High temps also dependent on extent of
mixing depth up into the base of the inversion, and with sunshine
and a deeper mix, much more of the area would attain at least some
low 30s today. Incoming sfc ridge P-gradient to keep northwesterly
sfc winds going of 10-15 MPH, then trending light an variable by
this evening as the ride arrives.

Tonight...Current water vapor loop indicating another upstream vort
max/wave acrs north central MT ATTM. This feature will look to
clipper it`s way down acrs the area by Tue morning. Limited moisture
and some top-down saturation needing to occur for this feature to
produce precip, but latest fcst soundings and vertical profiles
suggest in some narrow low to mid layer F-gen bands that
Condensation P-Defs lower enough for some light snow tonight, aided
by seeder feeder process with a multi layer saturation deck
squeezing the dry layer from aloft. The narrow banded nature of the
lift and saturation with adequate ice nuclei for snow flakes a
challenge to where these snow fields may occur, but a near term
ensemble blend targets a rather narrow swath along and north of the
I-80 corridor. Will broaden the low chances to much of the CWA north
of I-80 with ongoing uncertainty for now, and allow the day shift
to fine tune and raise POPs if needed.  In areas that receive snow,
it looks like another light event of a dusting to a few tenths in
localized swaths. Like earlier this Sunday evening, the fcst
soundings show a few areas that may be more conducive to light
freezing drizzle as opposed to ice nuclei if the seeder feeders miss
or arn`t adequate enough and the lower cloud deck can maintain.
Again this process too uncertain to mention in the grids just yet.
Low temps tonight held up in the teens.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
Issued at 247 AM CST Mon Feb 2 2026

The long-term period still looks mostly dry, despite a few near by
passes by clipper systems especially by Thursday night. The primary
limiting factor appears to be a lack of moisture, so measurable
precip appears more difficult to come by. After the weak system
tonight, A larger system grazes our northeastern areas Thursday
night into Friday morning. NBM again only has 10-20% chances of
precip for our far northeastern CWA, so not much coverage for that
system either as many of the latest 00z run models have trended even
further northeast with the main storm track. With all of this said,
it appears likely that most of the CWA will remain dry for the week.

With little to no precip chances, the bigger story for this week
will be a trend towards warmer temperatures for the latter portions
of the week. Large-scale ridging along with a Rex Block pattern is
progged to develop across the western CONUS, which will support
thermal ridging over our region, although to what degree looks
uncertain at this time as the ECMWF ensemble mean 850 mb
temperatures are at least a few degrees warmer compared to the GEFS
ensembles. The LREF exceedance probabilities of high temperatures at
the freezing mark or warmer increases to 60 to 90% for Thursday and
Friday. Those that have been looking for some relief from our recent
stretch of cold, the end of next week looks to provide that relief
in a big way. Some folks across our south may see highs in the lower
40s! But the other shoe may drop behind the passing clipper with a
temp cool draw from the north in time for the weekend, especially if
the GFS ensembles get there way.

&&

.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 1136 AM CST Mon Feb 2 2026

A mix of MVFR to some patchy VFR continue over the area late
this morning. Latest satellite imagery shows some breaking up of
the stratocu deck, mainly for areas along and north of
Interstate 80. Some MVFR conditions could continue for an hour
or two at DBQ and MLI before eventually going FEW to SCT.
A thicker MVFR deck persists along our south, including BRL, so
we will continue MVFR ceilings there for several more hours, but
uncertainty remains on when these ceilings will break up.

This evening, a clipper system is expected to move across our
northern areas. However, due to limited moisture, any
precipitation that occurs will be light snow. For now, will only
include a PROB30 group for DBQ as chances remain very low to the
south of there. MVFR conditions may materialize with this snow.
There may be some patchy freezing drizzle in the wake of the
clipper, but confidence remains quite low in this occurring.

&&

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

&&

$$

SHORT TERM...12
LONG TERM...12/Schultz
AVIATION...Schultz