609
FXUS63 KDVN 171110
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
610 AM CDT Thu Jul 17 2025

.KEY MESSAGES...

- Cooler and less humid today and Friday.

- Active weather returns Friday night and through the weekend.
  There are Marginal (level 1 of 5) Risks for severe weather
  Friday Night through Saturday. Damaging wind and heavy
  rainfall will be the primary risks.

- Ring of fire pattern to continue into next week, with building
  heat and periodic chances of storms.

- Extreme heat likely next week beginning Tuesday and possibly
  lasting through Friday, with 50-80% probabilities of heat
  index values greater than 100 degrees.

&&

.SHORT TERM /THROUGH FRIDAY/...
Issued at 305 AM CDT Thu Jul 17 2025

Morning satellite loops and radar mosaics show an active area
of storms from northern KS into northern MO. These storms were
occurring along and north of an 850mb boundary supported by 2
weak shortwaves moving along the northern periphery of the 591
dm upper high and strong upper divergence evident by SPC
mesoanalysis. Closer to home, low stratus was making its way
south into the northwest portions of the CWA. At the surface,
cooler dewpoints in the upper 50s were also starting to make
their way south across IA!

Today/Tonight...latest CAMs and radar/observational trends keep
the aforementioned storms to move along the far southern
portion of the CWA or just to our south early this morning.
Have lowered PoPs to slight chance with the entire area seeing
a dry forecast after 13z. At the same time, CAA clouds will drop
south with cooler dewpoints advecting into the region. This
will result in a much welcomed less humid day today, with
afternoon highs only in the 70s! However, if clouds scatter out
faster than forecast, then these readings may be a bit low. In
any case, temperatures will be cooler than in recent days.
Tonight, continued clearing skies and low level easterly flow
will allow temps to drop into the upper 50s to low 60s
overnight.

Friday...slightly warmer temperatures and humidity levels will
be seen, as surface high drifts over the Great Lakes while a
weak surface low develops over western NE. Afternoon highs to
top out in the lower 80s.

&&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
Issued at 305 AM CDT Thu Jul 17 2025

Friday Night-Monday...active zonal flow with upper high across
the southeastern CONUS retrograding west. This will bring a
series of waves through the forecast area during this period.
Latest 00z guidance suggests a potential MCS may develop Friday
night over the northern Plains and track east towards the CWA
Saturday morning. At the same time, a strengthening LLJ may
allow for additional development ahead of this feature overnight
per the 00z RRFS model. As a result, SPC has a Day 2 Marginal
(level 1 of 5) risk for severe weather west of a Manchester to
Iowa City line. Damaging wind, heavy rain, and lightning will
be the primary threats with this activity. Ring of fire
pattern reloads once again Saturday afternoon and evening with
more storms in or near the CWA. A very unstable atmosphere
characterized by SBCAPEs over 2500 J/Kg, PWs over 2", and
strengthening westerlies to support another severe risk. SPC has
another Day 3 Marginal (level 1 of 5) risk for severe weather
for Saturday across all but the far northern counties. Some 00z
model solutions and NSSL ML guidance suggest the severe risk may
be even higher Saturday, but uncertainties in previous day`s
convection and EML strength preclude a higher risk at this time.
Another concern that will need to be watched closely is the
heavy rain potential and subsequent river rises. Rain rates over
2"/hr are possible and if storms train over the same area, then
flash flooding may occur. There is a large QPF footprint as
indicated by WPC and all ensemble solutions (GEFS, GEPS, ECE)
through this weekend. High probabilities (50-80%) of at least 1"
of rain is shown, allowing for renewed rises on area rivers and
streams. Stay weather aware this weekend!

Tuesday Onward...a strong upper level ridge will build into the
central CONUS pushing the active storm track further north into
the upper Midwest. This unfortunately will allow heat and
humidity to return in earnest with extreme heat becoming more
and more likely. The probabilities of heat indices over 100
degrees has now increased into the 50-80% category Tuesday and
Wednesday across much of the area. In addition, over 60% of all
the members of the GEFS/GEPS/ECE show 100+ degree values at MLI
Tuesday-Thursday. If that were not enough, CPC has a moderate
to high risk of hazardous temps July 24th-25th. Heat headlines
will eventually be needed next week for this.

&&

.AVIATION /12Z TAFS THROUGH 12Z FRIDAY/...
Issued at 610 AM CDT Thu Jul 17 2025

A mix of mostly MVFR to IFR ceilings were seen across the area
early this morning in the wake of a cold front that swept
through the area yesterday evening, along with some light
drizzle under IFR ceilings. Ceilings are expected to gradually
lift and scatter out with time this morning into the early
afternoon to VFR across the area. Uncertainty remains on just
how quickly the ceilings will improve, but confidence in
eventual VFR conditions remains high. Northerly winds around 10
knots this morning will gradually become more easterly this
evening and tonight.

&&

.CLIMATE...
Issued at 309 AM CDT Thu Jul 17 2025

The Climate Prediction Center (CPC) 8-14 day temperature
outlook has 80-90% combined probabilities of near/above normal
temperatures for the July 24th-30th period for the entire CWA.
Normal highs for this period are in the middle 80s and normal
lows are in the middle 60s. In addition, there is a 60-70%
combined probability of near/above normal precipitation along
and north of Hwy 20 for this same period. Active and warm
weather will be the rule for the rest of July.

&&

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

&&

$$

SHORT TERM...Gross
LONG TERM...Ervin/Gross
AVIATION...Schultz
CLIMATE...Gross