Severe Thunderstorm Warning 43, NWS St. Louis, MO

303 
WWUS53 KLSX 140821
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
321 AM CDT Tue Apr 14 2026

MOC103-140831-
/O.CAN.KLSX.SV.W.0043.000000T0000Z-260414T0900Z/
Knox MO-
321 AM CDT Tue Apr 14 2026

...SEVERE THUNDERSTORM WARNING IS CANCELLED FOR SOUTHEASTERN KNOX
COUNTY...

The storm which prompted the warning has moved out of the area.
Therefore, the warning has been cancelled.

&&

LAT...LON 4018 9195 4023 9193 4025 9150 4024 9151
      4013 9151 4006 9149 4004 9149 3995 9144
      3995 9195
TIME...MOT...LOC 0805Z 243DEG 27KT 4003 9192

$$


MOC111-140900-
/O.CON.KLSX.SV.W.0043.000000T0000Z-260414T0900Z/
Lewis MO-
321 AM CDT Tue Apr 14 2026

...SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 4 AM CDT FOR
LEWIS COUNTY...

At 321 AM CDT, a severe thunderstorm was located over Lewistown, or
16 miles west of Canton, moving northeast at 25 mph.

HAZARD...60 mph wind gusts and quarter size hail.

SOURCE...Radar indicated.

IMPACT...Hail damage to vehicles is expected. Expect wind damage to
         roofs, siding, and trees.

Locations impacted include...
  Steffenville, La Belle, Lewistown, Ewing, Maywood, Monticello, La
  Grange and Canton.

This includes the following State Parks...
Wakonda State Park.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4018 9195 4023 9193 4025 9150 4024 9151
      4013 9151 4006 9149 4004 9149 3995 9144
      3995 9195
TIME...MOT...LOC 0805Z 239DEG 23KT 4003 9194

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

$$

Carney

003 
WWUS53 KLSX 140839
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
339 AM CDT Tue Apr 14 2026

MOC111-140900-
/O.CON.KLSX.SV.W.0043.000000T0000Z-260414T0900Z/
Lewis MO-
339 AM CDT Tue Apr 14 2026

...SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 4 AM CDT FOR
LEWIS COUNTY...

At 339 AM CDT, a severe thunderstorm was located 8 miles northeast of
Ewing, or 7 miles west of Canton, moving east at 30 mph.

HAZARD...60 mph wind gusts and quarter size hail.

SOURCE...Radar indicated.

IMPACT...Hail damage to vehicles is expected. Expect wind damage to
         roofs, siding, and trees.

Locations impacted include...
  Lewistown, Ewing, Monticello, La Grange and Canton.

This includes the following State Parks...
Wakonda State Park.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4016 9192 4023 9188 4025 9152 4025 9150
      4024 9151 4013 9151 4008 9150 4006 9149
      4004 9149 4000 9147 3998 9147 3998 9146
      3995 9144 3999 9188
TIME...MOT...LOC 0821Z 251DEG 25KT 4008 9181

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

$$

Carney

660 
WWUS53 KLSX 140857
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
357 AM CDT Tue Apr 14 2026

MOC111-140907-
/O.EXP.KLSX.SV.W.0043.000000T0000Z-260414T0900Z/
Lewis MO-
357 AM CDT Tue Apr 14 2026

...SEVERE THUNDERSTORM WARNING WILL EXPIRE AT 4 AM CDT FOR LEWIS
COUNTY...

The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning will be allowed to expire. However, small
hail, gusty winds, and heavy rain are still possible with this
thunderstorm.

&&

LAT...LON 4016 9192 4023 9188 4025 9152 4025 9150
      4024 9151 4013 9151 4008 9150 4006 9149
      4004 9149 4000 9147 3998 9147 3998 9146
      3995 9144 3999 9188
TIME...MOT...LOC 0839Z 251DEG 25KT 4012 9165

$$

Carney

Area Forecast Discussion
National Weather Service Saint Louis MO
257 AM CDT Tue Apr 14 2026

.KEY MESSAGES...

- Warm and humid conditions continue through most of this week.
  The best chances for thunderstorms, some potentially severe,
  are tonight and Wednesday.

- A strong cold front brings seasonably cool temperatures for the
  weekend.

&&

.SHORT TERM...  (Through Late Wednesday Afternoon)
Issued at 256 AM CDT Tue Apr 14 2026

The overall weather pattern across the US consists of surface high
pressure near the southeast US coastline with a rich plume of Gulf
moisture (60+ dewpoints) circulating around this high from central
Texas northeast to the Chicago area. The western edge of this
moisture plume is bounded by a dryline, oscillating back and forth
each day with daytime heating and the passage of shortwave troughs
aloft. The northern extent is bounded by a quasi-stationary
front/trough stretching from Nebraska to Michigan. Looking aloft,
upper level ridging is centered over the Gulf with a trough over the
Southwest US moving from around Las Vegas to the Four Corners during
the day today. Between the Gulf ridge and the Southwest US trough
exists a southwesterly jet with embedded shortwave troughs. The rich
low level moisture on the edge of the upper level ridge has led to
an axis of instability within which multiple patches of
thunderstorms will continue to generate over the coming days.
Seasonably strong mid level flow combines with the instability to
produce conditions favorable for supercell thunderstorms and
occasional convective clusters where thunderstorms form.

Zooming in on our forecast area, although instability maximizes this
afternoon with daytime heating (temperatures nearing 90!), the
influence of the ridge aloft is expected to maintain capping through
much of the day, inhibiting convective development. We'll be in
between disturbances to our northeast and southwest leading to a
local minimum in convective potential. The primary focus for
development will be more toward the periphery of the ridge and along
the surface boundaries: the warm/stationary front to the north and
the dryline to the west. High resolution guidance is in good
agreement that convection will be suppressed locally during the day
today. That said, if we are able to get any local areas of lift
along a local convergence zone or in an area of locally maximized
low level moisture (reducing capping), then a storm or two could
develop. The environment is primed for supercell thunderstorms if
this occurs, with large hail and damaging winds the main threats.
The better chance for thunderstorms locally will be from leftover
storms which formed to our west tracking into our area during the
late evening or overnight hours. While wind shear will still be
sufficient for organized thunderstorms, surface based instability
will be on a downward diurnal trend by the time any such activity
reaches our area, limiting the severe weather potential.

On Wednesday the southwest trough opens up and lifts northeast
through the Plains. This leads to greater mid level lift supporting
more widespread showers and thunderstorms across the instability
axis including through our region. While we continue to see moderate
to strong mid level flow sufficient for storm organization, more
widespread cloud cover is expected to limit the development of
surface based instability to just patches of stronger instability
where cloud cover is less extensive. As a result, our confidence in
the timing and location of the severe weather threat on Wednesday is
lower, though the threat is likely to favor the afternoon hours when
the potential for surface based instability is greatest during the
heat of the day. We may not have greater clarity on these points
until Wednesday morning when the effects of morning clouds and
showers can be a bit better known.

Kimble

&&

.LONG TERM...  (Wednesday Night through Monday)
Issued at 256 AM CDT Tue Apr 14 2026

The passage of the trough Wednesday into Wednesday night will also
shove the front southeastward, pulling in some slightly drier air
and shifting the instability axis southeastward. Showers and storms
may still be ongoing Thursday morning, with the focus for convective
activity shifting toward the Ohio Valley with time. Most of our area
sees gradually clearing skies with continued warm temperatures near
80 degrees.

While ridging briefly builds back in behind Wednesday's departing
trough, a stronger trough will be moving out of the Pacific
Northwest and into the Plains on Friday. We'll see moisture return
northward ahead of this approaching trough setting up the potential
for another round of severe thunderstorms. Where that severe weather
threat materializes depends on the speed of the front. At the
moment, timing of the front favors a greater severe thunderstorm
threat to our west as the front moves through our area mostly during
the overnight Friday night into the first half of the day on
Saturday. However, if the front speeds up a bit, this could shift
the threat more into our area. Alternatively, if it slows down a
bit, then another threat could develop during peak heating on
Saturday. At this stage it's too soon to have much confidence in a
severe weather threat locally given the current expected frontal
timing, but it's a time period to watch for any changes that could
shift the threat into our area.

The air mass behind this front is MUCH cooler than what we've been
dealing with as of late. This air mass has origins in the Arctic
which is still cold this time of year. There remains some
uncertainty in how cold it will be by the time it reaches our area,
but there is strong confidence that we'll see at least one day of
below normal temperatures. NBM interquartile range for high
temperatures on Sunday is around 10 degrees, with the warmer end of
that range right around normal for mid April while the cooler end is
several degrees below normal. Dewpoints also drop into the 20s
suggesting that if we were to get a clear, calm night that
temperatures could approach levels where a frost or freeze could
develop. At this time, NBM probability of 32 degrees or colder is
only 5 to 15 percent across the region as the likelihood of seeing
the clear, calm conditions necessary to realize this air mass's full
potential is low. We will begin to warm back up again early next
week as amplified ridging rather quickly replaces this weekend's
trough.

Kimble

&&

.AVIATION...  (For the 06z TAFs through 06z Tuesday Night)
Issued at 1102 PM CDT Mon Apr 13 2026

A complex of showers and thunderstorms has track from eastern
Kansas into central Missouri late this evening. The activity is
expected to make it into KCOU just before midnight and near KJEF
around 06z. The strongest thunderstorms have produced wind gusts
up to 70 mph to the west of the TAF sites, though general
weakening is expected with eastward movement. Locally heavy rain
and gusty winds are possible with these thunderstorms, through
approximately 08z.

Thunderstorms should continue to weaken as they approach the
Mississippi River late tonight. Cloud base remain above VFR level
for the most part with localize, briefing dips to MVFR under the
strongest cells. MVFR will become less likely as thunderstorms
remain elevated and weaken overnight. Gusty conditions are
expected to continue much of the time, being more prevalent during
the daylight hours after diurnal mixing resumes late Tuesday
morning. Isolated to widely scattered showers are possible Tuesday
afternoon, but will be hit-or-miss. This was not included in the
prevailing group with the high degree of uncertainty at any given
terminal. Chances for rain increase late Tuesday night with
showers and an isolated thunderstorm. However, widespread
thunderstorms are not expected with VFR persisting through the end
of the period.

Maples

&&

.LSX WATCHES/WARNINGS/ADVISORIES...
MO...None.
IL...None.
&&

WFO LSX

Hazardous Weather Outlook
National Weather Service St Louis MO
226 PM CDT Mon Apr 13 2026

ILZ058>060-064-065-069-070-074-079-095>102-MOZ018-019-026-027-
034>036-041-042-047>052-059>065-072>075-084-085-099-141930-
Greene IL-Macoupin IL-Montgomery IL-Bond IL-Fayette IL-Clinton IL-
Marion IL-Washington IL-Randolph IL-Adams IL-Brown IL-Pike IL-
Calhoun IL-Jersey IL-Madison IL-Saint Clair IL-Monroe IL-Knox MO-
Lewis MO-Shelby MO-Marion MO-Monroe MO-Ralls MO-Pike MO-Boone MO-
Audrain MO-Moniteau MO-Cole MO-Osage MO-Callaway MO-Montgomery MO-
Lincoln MO-Gasconade MO-Warren MO-Saint Charles MO-Franklin MO-
Saint Louis MO-Saint Louis City MO-Jefferson MO-Crawford MO-
Washington MO-Saint Francois MO-Sainte Genevieve MO-Iron MO-
Madison MO-Reynolds MO-
226 PM CDT Mon Apr 13 2026

This Hazardous Weather Outlook is for portions of eastern and
central Missouri as well as west central and southwest Illinois.

.DAY ONE...Tonight.

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

There is a chance of thunderstorms each day through Saturday night.

Severe thunderstorms are possible Tuesday night and again Wednesday
afternoon into Wednesday evening.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

Jaja