Severe Thunderstorm Warning 244, NWS Quad Cities, IA

Area Forecast Discussion
National Weather Service Quad Cities IA IL
620 PM CDT Sun Aug 9 2026

.KEY MESSAGES...

- Chances for storms this evening for portions of the area, as
  the battle between heat and convection continues (and will
  continue through at least mid week). Daily severe storm risks
  also continue with high instability possibly through at least
  Tuesday.

- A Heat Advisory is in effect today for the southern half of
  the area with heat indices near 100 or higher. Depending on
  clouds and storms, Monday may be just as hot.

- Cooler temperatures may occur later in the week and into next
  weekend if the warm dome of air can get shunted off to the
  southwest.

&&

.SHORT TERM /THROUGH MONDAY NIGHT/...
Issued at 244 PM CDT Sun Aug 9 2026

Following showers and isolated storms this morning, skies have
mostly cleared, as seen on visible satellite imagery. This, combined
with strong WAA into the region, has helped us to quickly become hot
and humid this afternoon. As of early this afternoon, a warm front
is draped along the Interstate 80 and Interstate 88 corridors, with
gusty winds south of the boundary allowing for some relief amidst
forecast heat indices in the low 90s to near 100 degrees. A Heat
Advisory is in effect until 8 PM this evening for areas along and
south of Interstate 80.

The notable forecast challenge this evening is the potential for
thunderstorms. Overall, the chances for thunderstorms has decreased
due to a cap that extends from 850-700 mb. Still, a low chance (20-
40%) of thunderstorms is possible from 7 to 11 PM this evening,
primarily east of the Mississippi River and along and south of
Interstate 80. If storms are able to develop, there is sufficient
shear and instability to support supercells capable of all severe
hazards.

Heat and humidity will continue on Monday as the warm front remains
draped across the area. While the NBM maintains a 40-80%
probability of exceeding heat indices of 100 degrees south of
Interstate 80, there is some uncertainty due to the potential
for showers and storms as another disturbance passes through the
flow. As such, any heat headline decisions have been left to
the midnight shift.

With the passage of another vort max on Monday, chances for storms
appear most likely in the afternoon and evening. However, capping
may once again limit any storms in our CWA, leading to development
just to our east in northeast Illinois. If storms are able to
develop, a similar setup to today would be in place, leading to
storms capable of all severe hazards.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
Issued at 300 AM CDT Sun Aug 9 2026

Tuesday through Saturday...With the flattening ridge transition, the
local area may be under the battle zone of the LLVL thermal gradient
and upper level short wave propagation path for almost daily chance
of showers and storms for much of the week and even into the
weekend. This deep summer-like MCS-track for much of the week from
the central plains over to the southern GRT LKS and OH RVR Valley
may add up to quite a bit of rainfall by Friday. At least temps look
cooler by late week and into the weekend as well, with a day or two
possibly held down in the 70s with cloud cover and east winds.

&&

.AVIATION /00Z TAFS THROUGH 00Z MONDAY/...
Issued at 616 PM CDT Sun Aug 9 2026

A warm front is lifting northward through the area as of the
start of the period this evening. Thus far, the atmosphere
remains capped off from seeing storms developing along this
front, while farther east and north, near Lake Michigan, storms
are ongoing, and will be into the night, we appear more likely
to remain dry in eastern Iowa and far western Illinois. Some
MVFR cigs are scattered around the area, and may become more
numerous overnight, mainly in northeast Iowa, including DBQ and
CID. Tomorrow, a hot and humid day is expected, with light east
to south winds, and mainly VFR conditions after 15Z. A low
chance for thunderstorm redevelopment is possible in the
afternoon and evening Monday, but coverage is very uncertain,
below 30% in these outer periods, and we will leave it out of
TAFs at this issuance.

&&

.DVN WATCHES/WARNINGS/ADVISORIES...
IA...Heat Advisory until 8 PM CDT this evening for IAZ063>065-067-
     068-076>078-087>089-098-099.
IL...Heat Advisory until 8 PM CDT this evening for ILZ015-016-
     024>026-034-035.
MO...Heat Advisory until 8 PM CDT this evening for MOZ009-010.

&&

SHORT TERM...Ellingworth
LONG TERM...12
AVIATION...Ervin

Hazardous Weather Outlook
National Weather Service Quad Cities IA IL
458 AM CDT Sun Aug 9 2026

IAZ040>042-051>054-063>068-076>078-087>089-098-099-ILZ001-002-007-
009-015>018-024>026-034-035-MOZ009-010-101100-
Buchanan-Delaware-Dubuque-Benton-Linn-Jones-Jackson-Iowa-Johnson-
Cedar-Clinton-Muscatine-Scott-Keokuk-Washington-Louisa-Jefferson-
Henry IA-Des Moines-Van Buren-Lee-Jo Daviess-Stephenson-Carroll-
Whiteside-Rock Island-Henry IL-Bureau-Putnam-Mercer-Henderson-
Warren-Hancock-McDonough-Scotland-Clark-
458 AM CDT Sun Aug 9 2026

This Hazardous Weather Outlook is for portions of north central
Illinois...northwest Illinois...west central Illinois...east
central Iowa...northeast Iowa...southeast Iowa and northeast
Missouri.

.DAY ONE...TODAY AND TONIGHT

Several rounds of thunderstorms are possible today and into this
evening. There is a chance for severe storms especially from late
morning into the afternoon. Damaging winds will be the primary
threat, but large hail and a few tornadoes are also possible. The
Storm Prediction Center has placed much of the OutLook Area in a
Slight(Level 2 of 5) Risk for severe weather today. Locally heavy
rainfall and flash flooding will also be possible in areas with
repeated storm activity.

Dangerous heat and humidity will develop along and south of the
Interstate 80 corridor by this afternoon with heat indices
surpassing the 100 degree mark. A Heat Advisory has been issued
for these areas for this afternoon and evening. Thunderstorms and
clouds may temporarily interrupt the heat at times today.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

Rounds of strong to severe storms will again be possible Monday
and Tuesday as the area continues to lay under an active storm
track. Marginal and Slight Risks for severe weather are in effect
for the Outlook Area for both days.

Depending on cloud cover and areas of rain, dangerous heat may
occur again on Monday and Tuesday with heat index readings
approaching or exceeding 100 degrees. Areas most likely for this
heat will be along and south of the Interstate 80 corridor.

.SPOTTER INFORMATION STATEMENT...

There is a good chance that spotter activation will be needed
today.

12

Preliminary Local Storm Report
National Weather Service Quad Cities IA IL
528 PM CDT Sun Aug 9 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0756 PM     Tstm Wnd Dmg     Rubio                   41.22N 91.94W
08/07/2026                   Washington         IA   Emergency Mngr

            Delayed Report. Several trees blown down,
            many tree branches damaged in Rubio. A car
            port was flipped over. Shingles damaged at
            same residence. Damaged occurred coincident
            with heavy rain and hail. Time estimated
            from radar data.

&&

AE