Iowa City, Iowa 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

306
FXUS63 KDVN 081105
AFDDVN

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

...12z Aviation Update...

.KEY MESSAGES...

-  Isolated to scattered showers and thunderstorms today,
   Wednesday looking to be a lull day, and more storms possible
   later Thursday especially in the west. Shortwave driving
   more storms Friday and Friday night, then not as active for
   the weekend. The severe weather potential remains low at this
   time, but will have to watch for stronger storm potential
   Thursday night in the west and especially on Friday CWA-wide.

- Seasonal temperatures and humidity levels will continue this
  week and into the weekend.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 315 AM CDT Tue Jul 8 2025

Today...The current MCS propagating south-southeastward down the MO
RVR Valley will probably scrape/move acrs portions of the
southwestern DVN CWA in an weakening mode, but still may produce
wind gusts to 35 MPH and lighting as it encounters a lobe of higher D-
CAPE acrs southeast IA into MO through 6-7 AM or so. A couple of
MCV`s evident in both RADAR and satellite imagery, with the one
spiraling currently just southeast of the DSM area having the
potential to kick up more isolated to sctrd convection into the
western and northern DVN CWA this morning. Otherwise may have to
wait to midday and afternoon with the main upper wave approaching
combining with some diurnal instability build up for more sctrd
storms to fire on remnant LLVL boundaries/thermal discontinuity.
This afternoon activity will look to be more favorable along and east
of the MS RVR.

Some uncertainty on extent of lingering convective debris and
ambient clouds tempering heat up potential and thus extent of usable
CAPE for stronger storms or more coverage. But shear profiles are
weak as low to mid level lapse rates, so it may be just pulse type
billow ups and then drops with local outflow winds of 35-45 MPH.
Locally heavy rainfall also if PWAT`s of 2 inches or higher maintain.
High temps a challenge today as well with weak sfc flow, questions
on extent of convective debris hanging on and ongoing humid
conditions. Will let the 50% NBM values ride for now, but see a
scenario that they may be a bit warm in spots.

Tonight...An isolated shower or storm possible, but most spots to go
dry into Wed morning. Lows in the 60s, with patchy fog possible
especially shallow in nature over fields and in river valleys.

&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
Issued at 315 AM CDT Tue Jul 8 2025

Wednesday and Thursday...Wed a lull day with influence of both sfc
and upper ridging, but can`t rule out an isolated storm of shower in
the ongoing buoyancy regime of mid summer. Seasonable temps Wed.
Looking at the medium range ensembles, Thursday is more uncertain.
Broadening upper ridge will look to spill another shortwave toward
the area, and the models are varying from a nocturnal elevated warm
air advection(WAA)wing of sctrd storms making it into the area from
the west Thu night, to a full blown MCS propagating into the fcst
area by Thu afternoon and evening. Extent of passing ridge and
preferred mass field placement prefer the sctrd nocturnal convection
scenario with better storm prospects as you head west.

Friday...The same ensembles showing a more organized digging
shortwave for Friday and Friday night, and this may be the day with
more dynamic/kinematic support for strong to severe storms and even
mCS development in or near the local area. Likely POPs warranted for
this period.

Saturday through Monday...Depending on the progressive nature of
the Friday wave, Saturday may be another lull day with summer
typical temps, sun and humidity. That may linger into Sunday before
ensemble timing brings another short wave aloft, embedded on
southern fringe of more progressive zonal steering flow acrs the
northern quarter of the CONUS, for shower/storm chances by
Monday.

&&

.AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/...
Issued at 556 AM CDT Tue Jul 8 2025

Isolated showers and thunderstorms will move east to northeast
acrs the area through late morning as a remnant circulation
from the decaying MCS off to the west continues to move across
the area. Thus most of the area to be VFR with light south to
southwest sfc winds, with passing bouts of MVFR to IFR with the
showers/storms if they can get into the VCNTY. Then there will
be another chance for sctrd storms popping up 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
afternoon/early evening potential. Otherwise, again just VFR
debris clouds and light variable sfc wind regime through
tonight. There may be a south to southwesterly direction to the
winds for much of the day(instead of variable) before expected
veering off to the northwest this evening. There will be a low
chance 20-40% of at least MVFR fog late tonight, especially acrs
portions of NW IL.

&&

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

&&

$$

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