193
FXUS63 KDVN 040840
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
340 AM CDT Fri Jul 4 2025

.KEY MESSAGES...

- The Fourth of July holiday will be hot and humid with
  temperatures in the upper 80s to lower 90s and heat indices
  between 95 and 100.

- Scattered showers and thunderstorms return for Saturday into
  Saturday night (40-70%), a few of which could be strong to
  severe.

- There are occasional chances for showers and storms through
  next week, but with plenty of dry periods expected.

&&

.SHORT TERM /THROUGH SATURDAY NIGHT/...
Issued at 315 AM CDT Fri Jul 4 2025

Through This Morning: WPC surface analysis had a quasi-
stationary boundary draped from central Minnesota into western
and southern Wisconsin, separating muggy conditions with
dewpoints in the upper 60s to lower 70s to the southwest from a
drier air mass to the northeast where dewpoints were in the 50s
(across portions of central to northern Wisconsin). Weak warm
air and moisture advection via WSW 850-700mb flow in a
conditionally unstable air mass (MUCAPE 1500-2500 J/kg) has led
to scattered slow moving storms north of the outlook area
overnight, which have now congealed into a more organized
cluster near and ESE of La Crosse. A cold pool/outflow boundary
shown on radar is gradually sinking to the south and could kick
of a few scattered showers and storms across the northeast
counties early this AM, mainly near and east of Dubuque. Latest
rain/storm chances are between 20-40% in this area with low
confidence on the current activity reaching our area before
dissipating.

Rest of Today: The main story for the Fourth of July will be
hot and humid conditions as a mid to upper level ridge remains
anchored over the region and low-level flow continues out of the
south. Highs will once again reach the upper 80s to lower 90s
with dewpoints in the mid 60s to near 70, yielding peak heat
indices in the mid 90s to near 100 degrees. Currently do not
have widespread near 100 degree values in the forecast so not
planning on a heat headline. There`s a low chance (<10% for an
isolated shower or storm to pop up during peak heating today.
However, did not include in the forecast due to the low potential
and low confidence.

Saturday: A shortwave trough is forecast to move through the
Upper Mississippi Valley region, with the attendant surface low
tracking across central Minnesota into northern Wisconsin and
the U.P. This will keep eastern Iowa and northwest Illinois in
the warm and humid air mass as a weak cold front approaches from
the west late in the day. Scattered showers and storms are
expected to increase in coverage, especially during the late
afternoon and evening hours with forecast soundings showing
the erosion of SBCIN. SPC has a Marginal Risk (Level 1 of 5)
for severe storms across the northwest half of the area with
the primary threats localized damaging winds and locally heavy
rainfall. Forecast PWATs between 2 to 2.25" will be supportive
of torrential downpours which could lead to localized flash
flooding in urban areas or in locations that get hit by repeated
rounds of storms. Shower and storm chances will continue through
the overnight as the surface front will be slow to work through
the area from NW to SE.

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
Issued at 315 AM CDT Fri Jul 4 2025

Zonal flow aloft is forecast to dominant the weather pattern
into next week, leading to seasonable July temperatures and
humidity levels. There are occasional chances for scattered
showers and thunderstorms with the next best chance coming in
later Tuesday into Wednesday (30-50%).

&&

.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 1230 AM CDT Fri Jul 4 2025

VFR is expected to prevail overnight into Friday with scattered
shower and storm chances focused to the north and northeast of
the outlook area. S to SSW winds will increase Friday AM and
persist through the afternoon, occasionally gusting near 20 kts.

&&

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

&&

$$

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