Severe Thunderstorm Warning 219, NWS St. Louis, MO

867 
WWUS53 KLSX 210142
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
842 PM CDT Mon Jul 20 2026

ILC001-009-210215-
/O.CON.KLSX.SV.W.0219.000000T0000Z-260721T0215Z/
Adams IL-Brown IL-
842 PM CDT Mon Jul 20 2026

...SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 915 PM CDT FOR
EASTERN ADAMS AND BROWN COUNTIES...

At 842 PM CDT, a severe thunderstorm was located 10 miles northeast
of Clayton, or 23 miles northeast of Quincy Regional Airport, moving
southeast at 55 mph.

HAZARD...70 mph wind gusts and small hail.

SOURCE...Radar indicated.

IMPACT...Expect considerable tree damage. Damage is likely to mobile
         homes, roofs, and outbuildings.

Locations impacted include...
  Lima, Woodville, Loraine, Mendon, La Prairie, Coatsburg, Golden,
  Camp Point, Columbus, Quincy Regional Airport, Burton, Clayton,
  Adams, Liberty, Mound Station, Mount Sterling, Buckhorn, Ripley,
  Versailles and La Grange.

This includes the following State Parks...
Siloam Springs State Park.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Anyone outdoors should move to shelter inside a well-built structure
and stay away from windows. This storm is capable of producing
widespread damaging winds.

&&

LAT...LON 3984 9122 4020 9139 4019 9091 4010 9091
      4010 9070 4009 9071 4008 9069 4008 9067
      4005 9067 4002 9063 4003 9061 4002 9062
      4000 9060 3998 9061 3999 9052 3998 9051
      3997 9051 3988 9058 3984 9057
TIME...MOT...LOC 0135Z 321DEG 46KT 4023 9094

THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...70 MPH

$$

Elmore

923 
WWUS53 KLSX 210153
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
853 PM CDT Mon Jul 20 2026

ILC001-009-210215-
/O.CON.KLSX.SV.W.0219.000000T0000Z-260721T0215Z/
Adams IL-Brown IL-
853 PM CDT Mon Jul 20 2026

...SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 915 PM CDT FOR
EASTERN ADAMS AND BROWN COUNTIES...

At 853 PM CDT, a severe thunderstorm was located near Mount Sterling,
or 24 miles east of Quincy Regional Airport, moving southeast at 55
mph.

HAZARD...70 mph wind gusts and small hail.

SOURCE...Radar indicated.

IMPACT...Expect considerable tree damage. Damage is likely to mobile
         homes, roofs, and outbuildings.

Locations impacted include...
  Woodville, Loraine, Chatton, La Prairie, Coatsburg, Paloma, Golden,
  Camp Point, Columbus, Clayton, Liberty, Mound Station, Kellerville,
  Mount Sterling, Buckhorn, Ripley, Coopertown, Versailles and La
  Grange.

This includes the following State Parks...
Siloam Springs State Park.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Anyone outdoors should move to shelter inside a well-built structure
and stay away from windows. This storm is capable of producing
widespread damaging winds.

&&

LAT...LON 3984 9113 4020 9130 4019 9091 4010 9091
      4010 9070 4009 9071 4008 9069 4008 9067
      4005 9067 4002 9063 4003 9061 4002 9062
      4000 9060 3998 9061 3999 9052 3998 9051
      3997 9051 3988 9058 3984 9057
TIME...MOT...LOC 0142Z 321DEG 46KT 4015 9086

THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...70 MPH

$$

Elmore

245 
WWUS53 KLSX 210201
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
901 PM CDT Mon Jul 20 2026

ILC001-009-210215-
/O.CON.KLSX.SV.W.0219.000000T0000Z-260721T0215Z/
Adams IL-Brown IL-
901 PM CDT Mon Jul 20 2026

...SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 915 PM CDT FOR
NORTHEASTERN ADAMS AND BROWN COUNTIES...

At 901 PM CDT, a severe thunderstorm was located 5 miles east of
Mount Sterling, or 25 miles north of Pittsfield, moving southeast at
55 mph.

HAZARD...70 mph wind gusts and small hail.

SOURCE...Radar indicated.

IMPACT...Expect considerable tree damage. Damage is likely to mobile
         homes, roofs, and outbuildings.

Locations impacted include...
  Chatton, La Prairie, Golden, Camp Point, Clayton, Mound Station,
  Kellerville, Mount Sterling, Buckhorn, Ripley, Coopertown,
  Versailles and La Grange.

This includes the following State Parks...
Siloam Springs State Park.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Anyone outdoors should move to shelter inside a well-built structure
and stay away from windows. This storm is capable of producing
widespread damaging winds.

&&

LAT...LON 3984 9098 4020 9113 4019 9091 4010 9091
      4010 9070 4009 9071 4008 9069 4008 9067
      4005 9067 4002 9063 4003 9061 4002 9062
      4000 9060 3998 9061 3999 9052 3997 9051
      3988 9058 3984 9057
TIME...MOT...LOC 0153Z 321DEG 46KT 4005 9076

THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...70 MPH

$$

Elmore

608 
WWUS53 KLSX 210208
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
908 PM CDT Mon Jul 20 2026

ILC001-210218-
/O.CAN.KLSX.SV.W.0219.000000T0000Z-260721T0215Z/
Adams IL-
908 PM CDT Mon Jul 20 2026

...SEVERE THUNDERSTORM WARNING IS CANCELLED FOR NORTHEASTERN ADAMS
COUNTY...

The storm which prompted the warning has moved out of the area.
Therefore, the warning has been cancelled. However, gusty winds are
still possible with this thunderstorm.

&&

LAT...LON 4010 9070 4009 9071 4008 9069 4008 9067
      4005 9068 4005 9067 4002 9063 4003 9061
      4002 9062 4000 9060 3998 9061 3998 9052
      3999 9053 3998 9051 3988 9058 3984 9057
      3984 9092 4010 9091
TIME...MOT...LOC 0201Z 322DEG 46KT 3997 9067

$$


ILC009-210215-
/O.CON.KLSX.SV.W.0219.000000T0000Z-260721T0215Z/
Brown IL-
908 PM CDT Mon Jul 20 2026

...SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 915 PM CDT FOR
BROWN COUNTY...

At 908 PM CDT, a severe thunderstorm was located 10 miles southeast
of Mount Sterling, or 22 miles northeast of Pittsfield, moving
southeast at 55 mph.

HAZARD...60 mph wind gusts and small hail.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

Locations impacted include...
  Mound Station, Mount Sterling, Buckhorn, Ripley, Coopertown,
  Versailles and La Grange.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Seek shelter inside a well-built structure and stay away from
windows. This storm is capable of producing damaging winds.

&&

LAT...LON 4010 9070 4009 9071 4008 9069 4008 9067
      4005 9068 4005 9067 4002 9063 4003 9061
      4002 9062 4000 9060 3998 9061 3998 9052
      3999 9053 3998 9051 3988 9058 3984 9057
      3984 9092 4010 9091
TIME...MOT...LOC 0201Z 322DEG 46KT 3997 9067

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Elmore

Area Forecast Discussion
National Weather Service St Louis MO
653 PM CDT Mon Jul 20 2026

.KEY MESSAGES...

- Widely scattered showers and thunderstorms this afternoon will
  diminish this evening after sunset. Another round of scattered
  thunderstorms is possible tonight. A few storms may produce
  wind gusts of 50-60 mph across parts of northeast Missouri and
  west central Illinois.

- A cold front will move through the area on Tuesday. There is a
  chance for thunderstorms with the front, mainly in the
  afternoon across southeast Missouri and southern Illinois.

- Cooler and less humid air will move into the area behind the
  front, with highs only in the low to mid 80s on Wednesday and
  Thursday.

&&

.SHORT TERM /THROUGH TUESDAY/...
Issued at 338 PM CDT Mon Jul 20 2026

Warm and humid conditions continue across the area this afternoon
across much of the area.  A weak cold front moved across much of
Illinois and stalled near the Mississippi River last night.  This
front is now moving slowly back to the northeast, and the warm moist
airmass is building back into Illinois behind it. Scattered
thunderstorms over the eastern Ozarks will dissipate this evening as
daytime heating wanes.  Storms arent showing much organization and
deep layer shear is only around 20kts.  However the RAP is showing
MLCAPE values in excess of 3000 J/Kg so an isolated strong wind gust
cant be ruled out.

Another much stronger cold front will move from the Upper Midwest
through the Mid Mississippi Valley on Tuesday, and this will break
our most recent stretch of hot weather.  Additional thunderstorm
development is expected ahead of the front tonight across Iowa,
though it is unclear how widespread and how strong the storms will
be by the time they reach our forecast area.  Forecast soundings are
showing a fairly deep dry layer in the low levels, and subsequently
a great deal of CINH.  Both the RAP and GFS therefore show very
little QPF with this front, and even the HRRR only shows widely
scattered convection as the front moves through.  However, CAPE
values will continue in the 2500-3000 J/Kg range ahead of the front
early Tuesday morning, with around 40kts of deep layer shear, so any
storms that can punch through that CINH could become severe, most
likely in far southeast Missouri into south central Illinois Tuesday
afternoon.

&&

.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
Issued at 338 PM CDT Mon Jul 20 2026

A deep long wave trough over the eastern U.S. will allow a much
cooler Canadian high pressure system to dig into the Mississippi
Valley Tuesday night and Wednesday.  Temperatures are expected to be
much cooler in the low to mid 80s in most locations Wednesday and
Thursday as high pressure moves from the Midwest into the Ohio
Valley.  Medium range guidance is moving a short wave trough from
the Great Plains into the Mid Mississippi Valley Thursday into
Friday.  There are some timing and amplitude differences with this
wave, however guidance suggests the low level reflection of the wave
will generate a low level jet Thursday night into Friday which will
produce precip that persists through much of Friday into Friday
night.  Clouds and precip on Friday look to suppress temperatures ,
and highs may not even reach 80s.  Warmer weather spreads east from
the Great Plains through the weekend into early next week as the
long wave pattern shifts east and the upper ridge builds back into
the Mississippi Valley.

&&

.AVIATION /00Z TAFS THROUGH 06Z WEDNESDAY/...
Issued at 652 PM CDT Mon Jul 20 2026

A cluster of strong thunderstorms is currently located across
southeastern Iowa with southeastward progression into west-central
Illinois expected over the next few hours. Confidence remains low on
the evolution of this thunderstorm cluster with about a 30% chance
of KUIN being impacted. As a result, have added mention of -TSRA
from 02-04z this evening to cover the potential. A second round of
convection is forecast to slide southward out of Iowa later this
evening into the overnight hours. Currently, this round also has
about a 30-50% chance of impacting KUIN around 09-12z with low
confidence regarding the southern extent of these storms. There is
currently only a 15-20% chance that convection from this second
round makes it south into central/east-central Missouri early
tomorrow morning (around 12z), which is why no mention was included
at this time for other terminals. A weak cold front will push
through the area (north to south) overnight into the morning
bringing northerly surface winds along with the potential for some
MVFR visibilities from smoke/haze. Northwesterly winds become gusty
tomorrow with gusts up to 20-25 kts across the region before winds
begin to weaken after sunset tomorrow night.

&&

.LSX WATCHES/WARNINGS/ADVISORIES...
MO...Heat Advisory until 7 PM CDT Tuesday for MOZ041-047>051-
     059>065-072>075-084-085-099.
     Heat Advisory until 8 PM CDT this evening for MOZ018-019-026-
     027-034>036-042-052.
IL...Air Quality Alert until midnight CDT tonight for ILZ058>060-
     064-065-069-070-074-079-095>102.
     Heat Advisory until 7 PM CDT Tuesday for ILZ069-074-079-
     100>102.
     Heat Advisory until 8 PM CDT this evening for ILZ095-097-098.

&&

SHORT TERM...Carney
LONG TERM...Carney
AVIATION...Peine