318
FXUS63 KDVN 141856
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
156 PM CDT Mon Jul 14 2025

.KEY MESSAGES...

- There are periodic chances of showers and storms in the
  forecast for late Tuesday through Saturday, with the highest
  chances coming Wednesday afternoon and evening (40-70%).

- There is a Marginal (level 1 out of 5) Risk for severe storms
  and heavy rainfall on Wednesday

- Flooding is occurring or expected to occur on some area river;
  please see he hydrology action below for more details.

&&

.SHORT TERM /THROUGH TUESDAY/...
Issued at 121 PM CDT Mon Jul 14 2025

Currently, high pressure has shifted to the east of the area
with a surface low and frontal boundary to our south across
Missouri and Illinois near Interstate 70. Diurnally driven
cumulus have developed across the area. Temperatures at 1 PM
were in the lower 80s with dewpoints in the upper 60s and lower
70s.

Zonal flow across the region with southwesterly flow aloft to
our south from the Southern Plains into the lower Ohio River
Valley. High pressure is forecast to shift to the east tonight
with quiet weather across the area. Low temperatures on Tuesday
morning are forecast to be in the mid to upper 60s across the
area. This will allow a shortwave to pass to our south during
the day on Tuesday. There will be very weak shear with some
instability across the area during the afternoon as this
shortwave passes to our south and east and may spread showers
and thunderstorms into west central Illinois, possibly as far
north as Interstate 80. High temperatures on Tuesday will be in
the upper 80s. Heat indices on Tuesday will be in the 90s.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
Issued at 121 PM CDT Mon Jul 14 2025

Periodic chances of showers and storms will be with us for late
Tuesday through Saturday, particularly for mid-week (chances as high
as 40-70% for Wednesday PM). Overall, ensemble guidance suggests
zonal flow will be the norm, depicted well in the 14.00z LREF 500 mb
height cluster analysis. A few mid-level impulses embedded within
the zonal flow will support more active conditions starting late
Tuesday. The bulk of our attention for this week remains on
Wednesday, which looks to be our next chances for strong to severe
storms. A few key features we will keep an eye on is the potential
for an MCV to move across the area on Wednesday which can be
seen in the 14.00z RRFS. Additionally, a surface cold front is
progged to quickly follow behind the MCV, which could also
provide forcing for thunderstorms. Instability should be
adequate for storms as MLCAPE values a progged around 1000-2000
J/kg, along with strengthening kinematics but generally meager
deep-layer shear (around 20 to 30 knots). With this said, along
with a continued signal in the various ML output for severe
convection on Wednesday, SPC has introduced a Marginal Risk
(level 1 of 5) for most of our CWA. How things evolve Wednesday
will greatly depend on how convection develops for locations
upstream over the Plains. A warm and humid air mass is forecast
to be in place across the area on Wednesday with heat indices
approaching 100 in far southeast Iowa, northeast Missouri, and
west central Illinois ahead of storms on Wednesday. In addition
to the severe threat, there is a marginal (level 1 out of 5)
risk for excessive rainfall during the day on Wednesday. Stay
tuned to the forecast over the next few days!

The active period appears likely to continue into the end of the
week as strong upper-level ridging develops over the southeastern
CONUS region, which could act to stall the aforementioned cold
front/baroclinic zone over the Corn Belt region. Temperatures will
remain slightly warmer for Tuesday and Wednesday before the cold
front arrives, with highs in the middle to upper 80s each day,
gradually cooling off after Wednesday.

&&

.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 1226 PM CDT Mon Jul 14 2025

High pressure is forecast to sit across Michigan through the TAF
period with eastern Iowa TAF sites on its western edge. This
will bring VFR conditions through the period. Winds will be
south to southeasterly during the day with speeds of 5 to 10
knots with light and variable winds overnight.

&&

.HYDROLOGY...
Issued at 1226 PM CDT Mon Jul 14 2025

The flood warning for the Skunk River at Sigourney has been
canceled as the river has crested near action stage and has
started to slowly fall. There have been no other forecast
changes with flood warnings remaining in effect for the Iowa
River at Marengo as well as the Mississippi River at Gladstone
and Burlington. A flood watch remains in effect for the
Wapsipinicon River at DeWitt. Within bank rises continue on
several area rivers.

&&

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

&&

$$

SHORT TERM...Cousins
LONG TERM...Schultz
AVIATION...Cousins
HYDROLOGY...Cousins