Romeoville, Illinois 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

150
FXUS63 KDVN 300716
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
216 AM CDT Mon Jun 30 2025

.KEY MESSAGES...

- Scattered storms expected this afternoon through very early
  evening.

- The pattern looks less active for much of the week.

&&

.SHORT TERM /THROUGH WEDNESDAY NIGHT/...
Issued at 215 AM CDT Mon Jun 30 2025

Today will be warm and humid, but will see gradual dry advection
this afternoon, and with that, heat stress should be quite a bit
lower then recent days.   The main question today will be whether
storms will be widespread or isolated. A short wave associated with
the slow moving cold approaching the CWA will move through during
the afternoon hours today. This is favorable timing, but with very
weak flow at lower levels, it`s hard to find a strong focus for
storm development today.  The front itself is quite diffuse. We are
probably best off looking to the west this morning, timing the storm
movement and outflows, and using that short term forecasting to
determine storm placement this afternoon. As you can imagine in such
a chaotic weak flow environment, models are incredibly diverse on
outcomes today.  The 00Z NAM/NAMNEST move a strong cluster through
the I-80 corridor today, while the HRRR is consistently south and
mainly dry, NSSL-WRF widespread, and of course the GFS/EC remain
unfocused and non convective.  Though storms could be strong due to
favorable afternoon CAPE and well above normal PWAT values, I`m
inclined to hold pops to the chance range today, given the
uncertainties (30-50%). This will focus the higher pops of the day
to the afternoon hours, mainly in the south and east 1/2 of the CWA,
which is generally where SPC is showing a Marginal (level 1) risk
for severe storms.   By early evening, any storms remaining should
be quickly exiting the eastern counties.

Today`s highs with cloud cover issues at times, are expecte to be in
the lower to mid 80s, with dew point values falling from the lower
70s to mid 60s by evening.

Tonight, a pleasant evening is in store for outdoor activies as dew
points continue to fall, and temperatures eventually settle back to
the lower to mid 60s.

Wednesday, a pleasant summer day is forecast, with mid to upper 80s
highs, plenty of sunshine, and moderate humidity.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
Issued at 215 AM CDT Mon Jun 30 2025

Thursday, July 4th/Friday and the weekend ahead continue to look
warm, with a gradual increase in thunderstorm chances over the
weekend. The heat could be near advisory levels, but the signal for
high dew point air is not too strong at this point. Highs in the
upper 80s to lower 90s seem on track, with lows in the lower 70s.


&&

.AVIATION /06Z TAFS THROUGH 06Z TUESDAY/...
Issued at 1213 AM CDT Mon Jun 30 2025

Light winds and VFR conditions will last most of the night
tonight, with cirrus clouds helping keep fog from becoming
widespread. However, some MVFR fog is expected towards the
sunrise time period, and any clear areas may see shallow dense
fog formation. For now, areas north of Highway 20 in Iowa are
favored for this fog. A cold front will slowly move through
during the morning hours Monday, and an upper level disturbance
could bring scattered thunderstorms to the area this afternoon,
with the highest chances (30%) along and south of Interstate 80
this afternoon.

&&

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

&&

$$

SHORT TERM...Ervin
LONG TERM...Ervin
AVIATION...Ervin