846
FXUS63 KDVN 042332
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
632 PM CDT Fri Jul 4 2025

.KEY MESSAGES...

- Hot and humid conditions continue this afternoon into the evening
  hours, otherwise remaining dry for Independence Day

- Scattered to widespread showers and thunderstorms return for Saturday
  into Saturday night (50-80%), a few of which could become
  strong to severe

- Occasional chances of showers and storms remain in the picture
  through next week, but with plenty of dry periods interspersed

&&

.SHORT TERM /THROUGH SATURDAY NIGHT/...
Issued at 219 PM CDT Fri Jul 4 2025

Hot and muggy conditions remains the main focus for Independence Day
today, thanks to plenty of sunshine over the area and dew point
temperatures in the lower 70s due to rich southerly moisture
returns/evapotranspiration across the central CONUS. As of 2 PM this
afternoon, measured heat indices have reached the middle to upper
90s for most locations, which should eventually improve around/after
sunset. With several Independence Day events ongoing/planned later
today across the area, make sure to take precautions if spending
time outdoors.

* Drink plenty of water! Beverages with electrolytes can also help
  protect against heat stress.

* Wear lightweight, loose-fitting, and light-colored clothing.

* Take regular breaks in the shade!

One thing we have lesser concerns about are thunderstorms as CAMs
continue to indicate largely dry conditions through the evening
hours. We can`t rule out a very isolated shower or storm during peak
heating today, but chances of this are very low (<10%).

Saturday looks to be more active in terms of storms as a mid-level
shortwave trough and attendant cold front approaches the region from
the northwest. The afternoon and evening hours will be the period to
watch for during peak heating with an uncapped environment, with the
potential for some of the storms to become strong to severe.
Analysis of the convective parameter space indicates that damaging
winds will be the primary threat due to copious PWAT values in
excess of 2 inches (near the maximum for the DVN 06.00z sounding
climatology per SPC), but also with steep low-level lapse rates in
place, which should combine to result in the threat for some locally
strong wet microbursts. As such, SPC has maintained a Marginal Risk
(level 1 of 5) for severe storms for most of the CWA, save for the
far easter areas. Storms look to come in a few waves, with the first
having more scattered coverage during the afternoon along a pre-
frontal trough, and a second more widespread round as the cold front
moves through. Storms should begin to diminish after midnight
Saturday night/Sunday morning.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
Issued at 219 PM CDT Fri Jul 4 2025

Sunday and Monday look to be largely dry in the wake of the frontal
passage, but there are some low to medium chances (20-40%) of
lingering showers and storms across our southeast in the morning
hours Sunday in closer proximity to the front. The remainder of the
period through the day Monday is more likely to stay dry. Looking
ahead, a series of mid-level impulses look to sweep through the area
Monday night through Thursday. Timing of each wave remains
uncertain, so lower confidence on the shower and storm chances this
far out.

After the cold front moves through late Saturday, a period of more
seasonal temperatures are expected, with highs warming to the middle
to upper 80s Sunday through Thursday next week.

&&

.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 625 PM CDT Fri Jul 4 2025

Satellite imagery shows diurnal CU across eastern Iowa and
northern Illinois that will dissipate with sunset. Otherwise
expect VFR conditions through 15z/05. Density altitudes may
approach 3 kft after 18z/05. Diurnal convection in the form of
SHRA/TSRA is expected to develop anytime after 17z/05 but is
expected to remain isolated to scattered (20-30% coverage).
After 00z/06 a more robust line of TSRA associated with the
cold front will start moving into eastern Iowa.

&&

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

&&

$$

SHORT TERM...Schultz
LONG TERM...Schultz
AVIATION...08