456
FXUS63 KDVN 102337
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
637 PM CDT Mon Aug 10 2026

.KEY MESSAGES...

- There is a chance of severe storms this afternoon/evening
  mainly east of the Mississippi where there is a slight, level
  2 out of 5, risk of severe storms. The primary risk is
  damaging winds. Brief tornadoes are a secondary risk.

- A QLCS, likely severe, will impact areas along/north of I-80
  Tuesday morning. Damaging wind is the primary risk with a
  secondary risk of brief spin-up tornadoes. Much of the area is
  in a slight to enhanced, levels 2 and 3 out of 5, risk for
  Tuesday.

- A heat advisory has been issued for areas along/south of an
  Ottumwa, IA to Galesburg, IL line. Depending upon storm
  evolution Tuesday, this headline may need to be extended
  further north.

&&

.SHORT TERM /THROUGH TUESDAY NIGHT/...
Issued at 157 PM CDT Mon Aug 10 2026

A convectively induced vort max continues to move east across Iowa
and will generate diurnal showers and storms along/east of the
Mississippi through the evening. With a boundary present and high
CAPE values building in the atmosphere, isolated to scattered severe
storms will be possible with the primary risk being damaging winds.
Brief spin-up tornadoes are a secondary risk.

Once storms dissipate this evening a period of quiet but very muggy
conditions will be seen until an approaching storm complex arrives
around sunrise Tuesday.

Tuesday morning will be interesting.

Data so far indicates that the Tuesday morning storm complex will
likely be a QLCS. Damaging winds, potentially over 70 mph, will
be the primary risk. A secondary risk will be brief spin-up
tornadoes. Right now areas along/north of I-80 appear to have the
higher risk of severe storms.

A fairly significant cold pool should be generated from the storm
complex which may bring some relief to the very humid conditions
across the northern half of the area Tuesday. However, the cold pool
and associated outflow boundary will then provide the focus for
potential diurnal storm development Tuesday afternoon.

Further south, hot and humid conditions will be seen. A heat
advisory has been issued for areas along/south of an Ottumwa, IA to
Galesburg, IL line. Depending upon how the Tuesday morning storms
develop/evolve, the heat headline may or may not need to be extended
further north.

If diurnal storms develop Tuesday afternoon they will dissipate
shortly after sunset leaving another muggy night for the area.

There are questions regarding late Tuesday night as another
disturbance moves around the edge of the heat dome. This disturbance
could initiate another storm complex that arrives in the area around
sunrise Wednesday.

&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
Issued at 255 AM CDT Mon Aug 10 2026

Tuesday...May initially be active if the Monday night-Tue morning
shortwave and MCS verifies, but after that feature exits the rest of
Tue and Tue night may be mainly dry or at risk for only an isolated
storm. Current NBM loaded temps and DPTs are hot and very humid for
Tuesday and easily supportive of heat headlines. But again there is
much uncertainty on convective trends, and cloud debris/storm
outflow interfering with the ambient temps and how much afternoon
time there would be for recovery. Will still message the potential
but make heat headline issuance a day by day process for now.

Wednesday through Sunday...Medium range ensembles and upper jet
patterns show the main upper ridge bulge trying to press it`s way
eastward acrs the southern plains and low to mid MS RVR Valley mid
to late week. This process may try to shunt the main storm track
more off just to the north of the local area, or if it stalls some
keep us in the bullseye of continued daily ring of fire late week
and even into the weekend. The temperature battle will continue as
well with LLVL baroclinicity and thermal ribbon wavering acrs the
region for high heat or not so bad depending on the daily flux. Will
keep the idea if this pattern holds, there could be quite a bit of
rainfall build up over the week from the west central plains, acrs
IA/IL and over to the eastern OH RVR Valley. It`s still early, but
currently Thu night looks like a potentail heavy rainfall MCS night
in the area especially south of I-80.

&&

.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 637 PM CDT Mon Aug 10 2026

Mostly VFR conditions were observed over the area early this
evening, with some isolated MVFR ceilings seen near DBQ.
Speaking of DBQ, there may be some isolated storms this evening
there, but confidence is pretty low on them occurring, given
the spread among the models, so used a PROB30 group there.

The main focus for this TAF set remains on a thunderstorm
complex that`s expected to move through the northern portions of
the area near/after sunrise Tuesday morning. DBQ and CID are
likely to be impacted by this complex, and the storms could be
pretty strong, possibly packing winds to around 40 to 50 knots.
With this said, we`ve opted for TEMPO groups to highlight the
most likely timing of the storms. If this storm moves overhead,
expect IFR to possibly LIFR conditions (mainly from visibility
reductions) for a time. Once the storms move out, the remainder
of the TAF period should be dry, with southerly flow around 5
to 10 knots.

&&

.DVN WATCHES/WARNINGS/ADVISORIES...
IA...Heat Advisory from noon to 8 PM CDT Tuesday for IAZ087>089-098-
     099.
IL...Heat Advisory from noon to 8 PM CDT Tuesday for ILZ025-026-034-
     035.
MO...Heat Advisory from noon to 8 PM CDT Tuesday for MOZ009-010.

&&

$$

SHORT TERM...08
LONG TERM...12
AVIATION...Schultz