Grandview, Iowa Weather Forecast Discussion

095
FXUS63 KDVN 190843
AFDDVN
Area Forecast Discussion
National Weather Service Quad Cities IA IL
343 AM CDT Fri Sep 19 2025
.KEY MESSAGES...
- On and off showers and isolated thunderstorms are expected
  through the weekend, and possibly through mid-week next week
&&
.SHORT TERM /THROUGH TONIGHT/...
Issued at 342 AM CDT Fri Sep 19 2025
An unsettled weather pattern will continue at least through the
weekend, if not through mid-week next week, as a series of troughs
translates through the region. Early this morning, we continue to
see an area of light to moderate showers over the western CWA ahead
of a mid-level trough evident on GOES-East mid-level water vapor
satellite imagery over central Missouri, which will continue to lift
to the east-northeast. This activity has been primarily showers,
with only some isolated thunderstorms embedded thanks to a lack of
robust instability (MUCAPE values are only around a few hundred
J/kg). The better forcing will shift off to the east today,
resulting in a weakening trend of these showers after sunrise this
morning. However, the attendant upper low will approach our region
through SD into northwestern Iowa, bringing another impulse to
support additional chances (20-50%) of showers and storms this
afternoon and evening, with the highest chances north of Highway 30.
This agrees with the 19.00z HREF ensemble 1-hr probability of
convection. Strong to severe convection isn`t expected, due to a
lack of deep-layer shear and modest instability of 500-1500 J/kg of
SBCAPE per the HREF, and SPC has our region in a general
thunderstorm risk. In terms of temperatures today, I went slightly
cooler than the NBM due to AM rainfall and abundant cloud cover
helping to start us off on the cooler side. Highs are forecast in
the middle 70s northwest to the lower 80s to the east.
The aforementioned upper low will traverse over the IA/MN border
tonight, leading to a continued chance of showers and perhaps an
isolated storm (20-40% chance). Overnight lows are expected to dip
to the upper 50s to lower 60s.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
Issued at 342 AM CDT Fri Sep 19 2025
We will continue to see daily chances (20-50%) of showers and
occasional thunderstorms as the large-scale weather pattern is
progged to continue to feature a series of shortwave troughs moving
through the central CONUS region. Any storms that develop are
expected to be your garden variety storms (not likely to become
strong to severe) due to a lack of robust deep-layer shear, but
modest instability will be enough to generate some storms at times.
NBM exceedance probabilities of a quarter inch or more of rainfall
in a 24 hour period is generally between 20 to 40%, so it`s possible
that some locations could see some wetting rainfall, which should
alleviate the worsening drought conditions over the area. Again,
these showers/storms should be hit-and-miss in our region - it won`t
be a complete washout through Thursday.
In terms of temperatures, there doesn`t appear to be too much of a
change over the next several days, with highs maintained in the
upper 70s to lower 80s for most locations. A slight cooldown is
possible for Wednesday and Thursday as winds shift more
northeasterly as opposed to southerly, with the NBM indicating highs
in the lower to middle 70s for both days.
&&
.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 1253 AM CDT Fri Sep 19 2025
Chances of primarily showers will continue over most of the area
early this morning - most likely for the BRL, CID, and DBQ
terminals where we have TEMPO groups in the respective TAFs. As
of TAF issuance, we are monitoring an area light to moderate
showers over southeastern Iowa into northeastern Missouri, which
is lifting northward. Lightning activity has been quite scarce
due to a lack of instability, so have leaned heavily towards
SHRA than TSRA. Some MVFR visibility reductions are possible
with these showers, with ceilings remaining VFR. Some MVFR fog
is possible in the wake of these showers, but otherwise, VFR
conditions should prevail outside of the showers. Another round
of showers and isolated storms are possible this evening, but
confidence remains low on coverage. Winds will turn southerly
after sunrise this morning, generally around 5 to 10 knots.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...None.
IL...None.
MO...None.
&&
$$
SHORT TERM...Schultz
LONG TERM...Schultz
AVIATION...Schultz

NWS DVN Office Area Forecast Discussion