Severe Thunderstorm Warning 287, NWS Quad Cities, IA

Area Forecast Discussion
National Weather Service Quad Cities IA IL
640 PM CDT Tue Sep 8 2026

.KEY MESSAGES...

- A storm system passing through the Upper Midwest will bring widespread
  showers and storms to the area tonight into Wednesday
  morning. Severe storms and heavy rainfall with the potential
  for some localized flash flooding will be possible in eastern
  Iowa.

- Quiet cooler weather Thursday into Friday, as high pressure passes
  overhead.

- Another stretch of potentially active weather this weekend
  into the next work week, bringing daily chances of
  precipitation for some.

&&

.SHORT TERM /THROUGH WEDNESDAY NIGHT/...
Issued at 245 PM CDT Tue Sep 8 2026

This afternoon's water vapor imagery showing tonight's and Wed
weather maker wave acrs southwest MT, and also showing large long
fetch baroclinic leaf from southwest of the CA Baja to western
Quebec. This as well as LLJ feed off the western Gulf will make for
a moist atmospheric column tonight with 2+ inch PWATs still on track
acrs the region into Wed morning. The current activity from NE into
northern IA will look to get revved up by a increasing SW LLJ of 35-
45 KTs and increasing effective shear profiles of at least 35 KTs as
the evening and night progress. This and MLCAPEs of 1000-1500 J/kg
may make for some strong to marginally severe storms as they flame
up in the area or move in from the west as maturing bows, with the
already advertised damaging winds being the primary threat. But
marginal mid level lapse rates of only 6 C/km and signs in the fcst
soundings of developing llvl inversions overnight may limit the wind
cause especially late.

Storm outflows may gush out well ahead of the main sfc front tonight
into Wed morning, setting the focus of repeated storm development
and then training along these outflow boundaries or even the
incoming main front itself, if the fcst shear profiles and
orientation are correct. This potential utilizing the high PWAT feed
supports the advertised threat for some swaths of high rainfall(1-3+
inches) and localized flash flooding especially in urban environments
such as Cedar Rapids. Some uncertainty remains on the eventual
primary axis north-south lay out of the main convective zone in the
latest CAMs and coarser models, but ensembles are pointing to more
of the Along and north of I-80 to Hwy 30 corridor for longer
duration storms and rains making it the more likely axis for heavy
rainfall. Low temps tonight in the upper 60s to low 70s, with some
patchy fog at least temporarily possible in rain lulls along with
light and variable sfc wind trends along boundaries.

Wednesday and Wednesday night...The post frontal rains will continue
through at least midday, with a slow southward frontal migration as
the day progresses. Thus could see high temps held down in the upper
70s to low 80s acrs much of the area. Flattening steering flow aloft
and additional short wave shuffle may keep additional over-running
showers going in the southern CWA Thu night. With a light post-
frontal sfc wind regime looking to be on tap, if there will be any
cloud thinning or clearing in the north late Wed night into Thu
morning, may have to keep some fog in mind especially acrs heavy
rainfall areas if they occur in the northern CWA.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
Issued at 245 PM CDT Tue Sep 8 2026

Thursday and Friday...A couple of decent looking days look in store
with bouts of both sfc and upper ridging allowing for dry and near
seasonable conditions.

Saturday through Monday...The latest  suite of medium range models
continue to suggest flattening flow again embedded with passing
short wave and associated sfc fronts making for a potentially active
period.  First in line may be Saturday with a sfc front getting
swept through the area off a passing LLVL cyclone along the
US/Canadian border. Then maybe a short lull for Sunday before signs
of a digging longer wave trof acrs the western high plains arching
steering flow in a southwesterly fashion toward the upper midwest.
This could make for another unsettles period for Sunday night into
early next week if this pattern verifies.

&&

.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 620 PM CDT Tue Sep 8 2026

A stormy night is ahead of us, bringing impactful weather to all
terminals. A complex of strong to severe storms is currently
located over central Iowa, tracking east over the next few
hours. This complex will near CID between 01-03z, reaching MLI
between 03-05z. After this initial surge of storms, we expect
widespread showers and storms to develop throughout the area for
the remainder of the night. DBQ will be the more questionable
area on how long and persistent the storm coverage is, but
should be the quickest for storms to move out of Wednesday AM.
This initial complex of storms will bring the potential for
strong to severe wind gusts and hail, but there remains some
uncertainty on the severe threat after 03z. With all
showers/storms, we can expect vis reductions to 3-5 SM with
lower possible in the strongest storms. Otherwise, cigs largely
look to remain MVFR-VFR throughout the night. After 12z
Wednesday, we will see the coverage of showers/storms decrease
from north to south through the area. At this time, the overall
chances for storms will be decreasing, largely becoming
stratiform rain or showers.

Winds will start the TAF period light and largely out of the
south. Over the next few hours, these storms and their
associated outflow boundaries will result in variable winds
that will remain through much of tonight. After 12z Wednesday,
winds will be light and out of the southwest, becoming
northwesterly after the cold front passes through the area later
in the day.

&&

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

&&

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

Hazardous Weather Outlook
National Weather Service Quad Cities IA IL
307 PM CDT Tue Sep 8 2026

IAZ040>042-051>054-063>068-076>078-087>089-098-099-ILZ001-002-007-
009-015>018-024>026-034-035-MOZ009-010-091100-
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-
307 PM CDT Tue Sep 8 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...THIS AFTERNOON AND TONIGHT

Thunderstorms will develop and move into the area this evening and
especially overnight. These storms will bring a risk of heavy
rain, flash flooding and isolated to scattered severe weather
to areas mainly across eastern Iowa. The primary storm concerns
are damaging wind and flooding rain. Areas of repeated storm
activity may produce swaths of 1 to 3 inches to localized areas.
Again this may produce some flash flooding especially in urban
areas.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

Isolated thunderstorms are possible area-wide Wednesday morning
and will move southward across the area through Wednesday
afternoon.  More thunderstorms will be possible on Saturday.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed this evening through Wednesday
morning.

12

Special Weather Statement
National Weather Service Quad Cities IA/IL
752 PM CDT Tue Sep 8 2026

IAZ051-063-076-090145-
Keokuk IA-Iowa IA-Benton IA-
752 PM CDT Tue Sep 8 2026

...Strong thunderstorms will impact portions of western Keokuk, Iowa
and southern Benton Counties through 845 PM CDT...

At 751 PM CDT, Doppler radar was tracking strong thunderstorms along
a line extending from Brooklyn to 9 miles southeast of Pella.
Movement was east at 30 mph.

HAZARD...Wind gusts up to 50 mph.

SOURCE...Radar indicated.

IMPACT...Strong winds could break small tree limbs and blow around
         unsecured objects.

Locations impacted include...
Marengo, Sigourney, Williamsburg, Belle Plaine, Walford, North
English, Victor, Hedrick, Blairstown, What Cheer, Norway, Delta,
Ladora, Keswick, South English, Parnell, Millersburg, Luzerne,
Hayesville, and Amana.

This includes Interstate 80 in Iowa between mile markers 205 and 225.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

Torrential rainfall is occurring and may lead to localized flooding.
Do not drive your vehicle through flooded roadways.

Frequent cloud to ground lightning is occurring with these storms.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

These storms may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

&&

LAT...LON 4151 9241 4151 9230 4196 9230 4194 9183
      4180 9183 4116 9228 4117 9241
TIME...MOT...LOC 0051Z 274DEG 26KT 4174 9242 4129 9282

MAX HAIL SIZE...<0.75 IN
MAX WIND GUST...50 MPH

DC