700
FXUS63 KDVN 052320
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
620 PM CDT Sat Jul 5 2025

.KEY MESSAGES...

- Scattered to widespread showers and thunderstorms are forecast this
  afternoon into tonight (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 SUNDAY/...
Issued at 231 PM CDT Sat Jul 5 2025

A more active day remains on tap today, with increasing chances of
showers and storms (50-80%) this afternoon lingering into tonight.
The culprit is a mid-level shortwave trough and attendant cold front
that is approaching the region from the northwest. Some isolated
strong to severe storms are possible. 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).
Additionally, steep low-level lapse rates will be in place, which
should combine with the high PWATs 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 southeastern areas. Storms look to come in two
waves, with the first having more scattered coverage this 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 tonight. With the anomalously high PWATs and high freezing
levels around 16,500 ft per the 05.12z DVN RAOB, these conditions
are supportive of torrential downpours due to efficient warm rain
processes. Therefore, a secondary risk today is localized flash
flooding with urban areas most at risk. Latest HREF ensemble QPF PMM
values indicate total rainfall through tonight between 0.5 to 1.5
inches for a large portion of the area, with some isolated areas
around 2 inches possible.

Any lingering showers and storms around midnight tonight are
expected to gradually diminish thereafter per the latest suite of
CAMs. The bulk of the forcing with the front will remain to our
south and east on Sunday, but a few isolated showers and storms
can`t be ruled out with a mid-level trough continuing to exit the
area. Theta-e values will be lower, and with a lack of deep-layer
shear and weaker low-level lapse rates, strong storms are not
anticipated. Temperatures on Sunday will be more seasonal compared
to the last few days, with highs warming to the lower to middle
80s.

&&

.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
Issued at 231 PM CDT Sat Jul 5 2025

Zonal flow aloft will be the norm for next week, which will help
maintain seasonable July temperatures and humidity levels. Next week
will continue to have periodic chances of showers and storms,
particularly for Tuesday through Friday, as a series of mid-level
shortwaves look to sweep through the area, but widespread rainfall
is not anticipated. Confidence remains generally low this far out on
the timing of these systems with 20-40% chances of showers and
storms per the NBM. Despite the lower confidence, there are some
signals in the various extended machine learning output for the
potential for isolated strong to severe storms Tuesday through
Friday, so something to be mindful of as we go through the upcoming
week.

&&

.AVIATION /00Z TAFS THROUGH 00Z MONDAY/...
Issued at 555 PM CDT Sat Jul 5 2025

A line of showers and thunderstorms is crossing the
Iowa/Illinois state line at present. This line will move east
of all TAF sites shortly, allowing for primarily VFR
conditions this evening. Winds remain southwesterly to westerly
during this time. Isolated showers or thunderstorms remain
possible through the remainder of the evening, but confidence on
aviation impacts remains low. Another line of thunderstorms is
expected from the west between 03Z to 07Z. Reductions in
visibility to MVFR or even IFR due to heavy rain are possible,
along with lightning and brief gusty winds. Once, this line
moves through, a northwesterly wind shift and MVFR ceilings fill
in behind it. These MVFR ceilings may fall to IFR, but
confidence remains low on this outcome. Otherwise, skies lift to
VFR and winds become northerly during Sunday afternoon.

&&

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

&&

$$

SHORT TERM...Schultz
LONG TERM...Schultz
AVIATION...NWS