151
FXUS63 KDVN 162348
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
648 PM CDT Wed Jul 16 2025

...06z Aviation Update...

.KEY MESSAGES...

- Cooler and less humid Thursday and Friday, before active
  weather returns this weekend.

- Heavy rainfall remains possible over the weekend and early
  next week, as is often the case as a heat dome builds into
  the region.

- Extreme heat likely next week, with probabilities of heat
  index values greater than 100 degrees Tuesday in the 40-70%
  range.

&&

.SHORT TERM /THROUGH THURSDAY/...
Issued at 219 PM CDT Wed Jul 16 2025

Today`s storms have fired in our eastern counties, more or less
where they were most likely to do so, but the entire wave and low
pressure arrived roughly 3 hours early today. Thus, rather than an
afternoon and evening event, this event is already concluded at 2
PM.

Though very warm moist air was over our CWA, the effective boundary
shifting winds from south to southwest/west is already through our
eastern counties, and behind it, dew point values are lowering
steadily through the upper 60s to lower 70s. Looking farther
upstream, northern Iowa already has fallen to the upper 50s to lower
60s, which should advect southeastward into our area this evening
and overnight.

A much cooler, comfortable day is forecast Thursday, with highs in
the lower to mid 70s. Clouds should be in place much of the day
Thursday, with cloudy skies slowly thinning out late in the day.
Models continue to suggest a elevated shower/storm band over
Missouri may occasionally brush through the southern counties
tonight into Thursday. While that is possible, the surface boundary
in Missouri is well south of our border counties, and should be the
focus for storms tonight. Pops remain below 50 percent for any rain
in southern areas tonight into Thursday.

&&

.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
Issued at 219 PM CDT Wed Jul 16 2025

Friday...continued cool temps and less humid conditions is
forecast. Dry conditions will then prevail through Friday as a
surface high builds into the upper Midwest. Clouds will keep
temperatures in the 60s/70s each day, especially on Thursday.

Friday Night-Monday...active zonal flow with upper high across the
southeastern CONUS retrograding west to bring a series of waves
through the forecast area. There will be periods of dry weather, but
the risk for afternoon storms appears highest Saturday and Sunday.
Humidity will once again be on the rise each day with dewpoints in
the upper 60s/low 70s. Heavy rainfall will be possible with any
storms given high PWAT. NSSL ML severe probs also suggest at
least a Marginal risk for severe storms each day. Stay tuned.

Tuesday Onward...a classic MCS summer-like pattern is forecast with
the 12z ensemble 500mb height cluster analysis showing a 594dm high
in all solutions just to our south and an active storm track across
the Dakotas and upper Midwest. This will bring very warm and humid
conditions to the CWA (highest confidence Tue/Wed) and near daily
chances for storms in the extended. Extreme heat remains a concern
next week and beyond per CPC 8-14 Day Temp Hazards Map. The A/C
units will continue to get a workout this summer.

&&

.AVIATION /00Z TAFS THROUGH 00Z FRIDAY/...
Issued at 643 PM CDT Wed Jul 16 2025

Isolated light showers or sprinkles will continue to move acrs
the VCNTY of CID and DBQ through at least mid evening, but will
not restrict VSBY below VFR and won`t mention in the TAFs. Post-
frontal VFR to MVFR stratocu will continue through the night,
with a lower deck of 2000 FT AGL or even 1800 FT AGL possible
after midnight into early Thu morning. A low chance for
overrunning showers or even a thunderstorm to make it into the
southern VCNTY of BRL after 08-09z or so late tonight and have
used a PROB30 for now as a placeholder. Gusty west to northwest
sfc winds will decrease to 8-12 KTs overnight with a continued
veering to the north by dawn Thu. A MVFR cloud deck Thu morning
will diurnally lift to VFR levels by Thu afternoon.

&&

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

&&

$$

SHORT TERM...Ervin
LONG TERM...Ervin/Gross
AVIATION...12