621
FXUS63 KDVN 222328
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
628 PM CDT Tue Jul 22 2025

.KEY MESSAGES...

- Heat Advisory remains in effect for portions of the area
  through 7 PM this evening. The Extreme Heat Watch has been
  transitioned to an Advisory for Wednesday into Thursday.

- An active weather pattern is likely to continue through much
  of the forecast period with alternating rounds of heat,
  humidity, and storm chances.

&&

.SHORT TERM /THROUGH WEDNESDAY NIGHT/...
Issued at 300 PM CDT Tue Jul 22 2025

Tonight...Resultant MCV from last night`s central plains MCC very
evident in satellite imagery swirling slowly north to northeast acrs
southwest into central IA ATTM. Will keep low POPs in the west and
north this afternoon into the evening in case this feature kicks up
an isolated shower or storm. Ambient shear profiles are weak, but as
the MCV clips the far western CWA, it will be interacting with very
high/extreme SBCAPEs of 4000-6000 J/kg. So if it can enhance the
shear profiles a little bit, can`t rule out a rambunctious storm with
localized very heavy rain and winds this evening. SPC`s Marginal
Risk still seems still in line for this potential. Otherwise most
areas too stay dry into Wed morning with lows in the mid to upper
70s.

Wednesday...Thrust of thermal ridge axis up acrs the area day, with
more sun than today to help the heat cause, and no storms expected
through 00z at least. +22 to +23c H85 MB temps in place would
support high temps in the upper 90s to around 100 degrees if we
didn`t have all the humidity in place. So taking the high sfc DPTs
into affect, will advertise mainly low to mid 90s. But with more sun
and sfc DPTs in the mid to upper 70s, we still easily attain Heat
Advisory criteria and will transition the ongoing Extreme Heat Watch
to an Advisory which matches up nicely with neighboring offices.

Wednesday night...Much of the night to be dry and warm with lows in
the mid to upper 70s. But there may be an approaching short wave
out of the central and northern MO RVR Valley that may have an
associated front with it and then possibly produce some late night-
early Thu morning storms. Again some POPs advertised for this
scenario.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
Issued at 300 PM CDT Tue Jul 22 2025

Thursday...The general trend is for a thermal ridge-riding wave
rolling over and just east of the MO RVR Valley to continue to try
and produce sctrd showers and thunderstorms from central IA Wed
night into the local CWA Thu morning, if just in a weakening
fashion. Then the question will be how much this morning activity
hangs on or takes time to decay allowing for lingering debris to
temper the heat potential for headline extension, as well as
insatiability for renewed afternoon and evening convection to develop.
A lot of uncertainty here with these potential factors, but will
have to account with POPs and the heat for headline considerations.
A frontal system potentially undulating acrs the area will also
complicate things and eventual scenarios. If not much activity re-
invigorates earlier in the afternoon or evening, then the good ole`
nocturnal LLJ may combine with the passing short wave aloft to make
for a more active convective window later Thursday evening and
overnight.

Friday through Monday...With the frontal boundary potentially being
quasi-stationary and undulating acrs the local area, will have to
keep POPs going Friday, and the clouds/debris/precip to keep ambient
temps down some and thus no need for a heat headline for now.
Remnants out of Friday may get acted upon by nocturnal LLJ induction
and thus more storms or even an MCS may fire either in or near the
local area Friday night. Would think marginal severe weather
potential and heavy rainfall would be concerns with this activity if
it occurs. Then longer range ensembles suggest more of the same
pattern with the local area lying adjacent to the ring of fire with
alternating bouts of heat and storms into early next week.

&&

.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 628 PM CDT Tue Jul 22 2025

Mostly VFR conditions are expected through the TAF period. This
evening, some isolated thunderstorms are possible, especially
for CID and BRL where the leading edge of a subtle surface low
is present. Confidence in coverage is quite low, so decided to
use PROB30 groups at this time. However, we can`t rule out IFR
conditions if any storms go directly over the terminals. Also,
late tonight into early Wednesday AM, some MVFR to IFR ceilings
are possible for DBQ where higher low-level moisture appears to
be most supportive. VFR conditions are expected by mid-morning
through the afternoon hours as drier air filters in.

&&

.DVN WATCHES/WARNINGS/ADVISORIES...
IA...Heat Advisory from 10 AM Wednesday to 7 PM CDT Thursday for
     IAZ040>042-051>054-063>068-076>078-087>089-098-099.
     Heat Advisory until 7 PM CDT this evening for IAZ051-052-
     063>065-067-068-076>078-087>089-098-099.
IL...Heat Advisory from 10 AM Wednesday to 7 PM CDT Thursday for
     ILZ001-002-007-009-015>018-024>026-034-035.
     Heat Advisory until 7 PM CDT this evening for ILZ015>018-
     024>026-034-035.
MO...Heat Advisory from 10 AM Wednesday to 7 PM CDT Thursday for
     MOZ009-010.
     Heat Advisory until 7 PM CDT this evening for MOZ009-010.

&&

$$

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

NWS DVN Office Area Forecast Discussion