Severe Thunderstorm Warning 201, NWS Quad Cities, IA

Area Forecast Discussion
National Weather Service Quad Cities IA IL
226 PM CDT Wed Jun 24 2026

.KEY MESSAGES...

- Isolated to low end scattered (10-30%) strong to severe storms
  are possible through sunset. The area at risk is mainly east
  of the Mississippi and north of I-80. Hail looks to be the
  primary risk but a localized damaging wind or an isolated
  tornado cannot be fully ruled out.

- A pattern change this weekend will bring heat and humidity to
  the area. The probability of heat headlines next week has
  increased to over 50%.

&&

.SHORT TERM /THROUGH THURSDAY/...
Issued at 224 PM CDT Wed Jun 24 2026

Satellite through early afternoon shows mainly diurnal cumulus
across the area. Better cumulus is located across southwest
Wisconsin where lapse rates are steeper and the better radar returns
are located.

The cool front with a pre-frontal trof will slowly move through the
area this afternoon/tonight. CAMs are struggling with the weak
forcing but suggest isolated to low end scattered (10-30%)
developing along the pre-frontal trof and cold front this afternoon
evening.

The steep lapse rates and fairly straight hodographs suggest the
primary risk this afternoon/evening is hail but a localized damaging
wind and isolated tornado cannot be ruled out.

Based on progged destabilization, areas mainly east of the
Mississippi and north of I-80 are favored for strong to severe
storms through sunset.

Storms will dissipate with sunset leaving mainly dry conditions
overnight,

&&

.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
Issued at 224 PM CDT Wed Jun 24 2026

Thursday night through Saturday night
Assessment...low to medium (25-40%) confidence on rain

Another system will pass mainly south of the area Thursday night
into Friday. Some solutions are further north. However, there is a
large area ahead of the system with dry easterly flow. Thus there is
a reasonably good chance the system will be either; 1) forced
further south or 2) have a very sharp northern gradient to any rain.

Based on the AIGFS and ECMWF-AIFS and some ML progs, areas north of
I-80 look to remain dry Thursday night and Friday. Along and south
of I-80 there will be a risk of rain but the better chances still
look to be south of an Ottumwa, IA to Galesburg, IL line. Even in
this area, rainfall amounts will be around 0.10 inches.

Sunday through Wednesday
Assessment...a certainty (>95%) of hot and humid conditions

The heat and humidity will tease the southwest half of the area on
Sunday as dew points rise. The model consensus is probably raising
dew points too quickly on Sunday, but, dew points of 65 to 70 are
very reasonable.

Sunday night through Monday will be dry as the main storm track is
well north of the area. Dew points of 70 to 75 are likely to be seen
which will push heat indices above 100. The current probability of
heat headlines for Monday is over 50 percent now.

Monday night into Tuesday the heat and humidity will continue with a
33-40% chance that heat headlines will be needed. However, a system
in the Plains will develop a nocturnal storm complex that will track
generally east northeast.

Data suggests a majority of the area will remain dry as the upper
high in the Ohio Valley looks to remain in place through Tuesday.
Parts of the far north and northwest have a 20-25% probability of
seeing some rain if outflow from the storm complex can initiate some
isolated convection.

Tuesday night into Wednesday becomes more of a question. The upper
high over the Ohio Valley is progged to move closer to the east
coast by several solutions. IF correct, this would help weaken the
western parts of the heat dome and potentially allow the organized
storm track to shift further south.

With several solutions indicating a shifting of the upper high
toward the east coast, the model consensus does have a southward
shift to the organized storm track. The net result is 20-30% rain
chances late Tuesday night into Wednesday.

PWATS in the model solutions continue to be 1.5 inches or higher.
Thus if storms do develop and move across the area, heavy rain can
be expected.

&&

.AVIATION /18Z TAFS THROUGH 18Z THURSDAY/...
Issued at 1220 PM CDT Wed Jun 24 2026

Cool front progged to move through eastern Iowa and northern
Illinois through 12z/25. Stronger winds aloft to allow 10-30%
coverage of diurnal convection 20z/24 through 02z/25.
Probability of a SHRA/TSRA impacting a TAF site is around 10%.
However, if it occurs the impacts could be significant. Thus
PROB30 have been included for each TAF site.

&&

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

&&

SHORT TERM...08
LONG TERM...08
AVIATION...08

Hazardous Weather Outlook...UPDATED
National Weather Service Quad Cities IA IL
836 AM CDT Wed Jun 24 2026

IAZ040>042-051>054-063>068-076>078-087>089-098-099-ILZ001-002-007-
009-015>018-024>026-034-035-MOZ009-010-251345-
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-
836 AM CDT Wed Jun 24 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

Thunderstorms are expected this afternoon and evening, especially
north of Interstate 80. A couple of severe storms are possible
with the primary risks being hail and damaging winds. The Storm
Prediction Center has a Slight, (level 2 out of 5) risk for severe
storms east of the Mississippi and north of Interstate 80. A
Marginal (level 1 out of 5) risk for severe storms east of a line
from Independence, Iowa to Aledo, Illinois.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

Heat and humidity will overspread the area Sunday through Tuesday.
Heat indices of 100 or higher are possible, especially Monday and
Tuesday.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is possible this afternoon and evening.