643
FXUS63 KDVN 080550
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
1250 AM CDT Tue Jul 8 2025

...06z Aviation Update...

.KEY MESSAGES...

- A few periods of showers and storms remain in the forecast,
  mainly for this afternoon through Tuesday, and again Thursday
  night through Friday. Severe weather potential remains low at
  this time.

- Seasonal temperatures and humidity levels will continue this
  week.

&&

.SHORT TERM /THROUGH WEDNESDAY/...
Issued at 219 PM CDT Mon Jul 7 2025

Isolated to scattered showers and storms have developed early this
afternoon, mainly along and just east of the Highway 218 corridor.
So far, thunderstorms have remain isolated and haven`t reached
severe levels, but lightning and a brief heavy downpour remain the
main hazards with these. A weak mid-level shortwave has helped to
spark off this activity. Otherwise, partly to mostly sunny skies
will be common elsewhere.

Late tonight through Tuesday looks to be more active as a more
robust mid-level trough and attendant cold front approaches the
area. We will have to watch the current activity over South Dakota
as that is expected to eventually approach our region late tonight,
albeit in a decaying fashion. Other than some locally heavy rainfall
and gusty winds, strong to severe storms are not anticipated.
Chances of showers/storms are around 20-40%.

Tuesday will have relatively higher chances (40-60%) of storms,
especially in the afternoon. Analysis of the convective parameter
space indicates ample instability, with MLCAPE values around 1000-
2000 J/kg, but with very weak deep-layer shear once again. Low-level
lapse rates appear to be somewhat steep - around 6.5 to 7.5 C/km -
coupled with higher PWAT values (1.7 to 2.0 inches). With this said,
although SPC has kept our region out of any convective outlooks (we
remain on the northern cusp of a Marginal Risk to the south), there
appears to be some support for some locally gusty winds in any
storms that develop. Temperatures will be a little cooler due to
more cloud cover, with most areas reaching the low to mid 80s.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
Issued at 219 PM CDT Mon Jul 7 2025

Tuesday night through Thursday: we should enter a period of largely
dry conditions, thanks to an upper-level ridge building across the
central Plains region. This should help keep any mid-level impulses
at bay for a time. Seasonal conditions should continue these days,
with highs warming to the middle to upper 80s for both Wednesday and
Thursday, along with seasonal humidity.

Thursday night and Friday: the next mid-level shortwave sweeps
through the area during this time, leading to another round of
showers and storms potential across the area (40-60% chances).
Unlike the last few rounds of strong to severe storms, Friday looks
to have stronger deep-layer shear and stronger flow in place, along
with abundant instability. The various extended machine learning
output continues to highlight the potential for at least isolated
strong to severe storms, so something to keep an eye on as we get
closer to the end of the week.

An early look at the upcoming weekend indicates a slight cooldown
for Saturday in the wake of Friday`s fropa, with highs in the lower
80s for most, and perhaps some lingering shower and storm chances
Saturday morning. Sunday appears likely to remain dry, with
continued seasonal temperatures.

&&

.AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/...
Issued at 1245 AM CDT Tue Jul 8 2025

Generally a VFR period into Tue morning with some ACCAS and
stratocu around as the main MCS plunges southward to the west of
the area. But there is a chance for isolated to wdly sctrd
showers or a thunderstorm to pop up overnight into early morning
on the eastern flank of the MCS. A better chance for sctrd
storms popping up may be from midday into the afternoon on
remnant boundary and outflow from the overnight system in the
heating of the day, especially along and east of the MS RVR.
Have included some PROB30 windows for this potential. Otherwise,
just VFR debris clouds and light variable sfc wind regime. There
might be a south to southwesterly direction to the winds for
much of the day before expected veering off to the northwest Tue
evening.

&&

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

&&

$$

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