Severe Thunderstorm Warning 187, NWS St. Louis, MO

709 
WWUS53 KLSX 172300
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
600 PM CDT Wed Jun 17 2026

MOC163-173-172330-
/O.CON.KLSX.SV.W.0187.000000T0000Z-260617T2330Z/
Pike MO-Ralls MO-
600 PM CDT Wed Jun 17 2026

...SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 630 PM CDT FOR
WESTERN PIKE AND SOUTHWESTERN RALLS COUNTIES IN NORTHEASTERN
MISSOURI...

At 600 PM CDT, a severe thunderstorm was located near Spencerburg, or
9 miles north of Vandalia, moving east at 40 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...
  Center, Spencerburg, Frankford, Curryville, Bowling Green, St.
  Clement, Ashley and Tarrants.

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.

Tornadoes can develop quickly from severe thunderstorms. Seek shelter
immediately in an interior room on the lowest floor of a well-built
structure.

A Tornado Watch remains in effect until 1000 PM CDT Wednesday for a
portion of northeast Missouri.

&&

LAT...LON 3937 9164 3957 9163 3951 9108 3950 9107
      3923 9115 3923 9118 3922 9118 3930 9143
      3932 9144 3932 9150
TIME...MOT...LOC 2250Z 282DEG 36KT 3946 9157

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

$$

Elmore

013 
WWUS53 KLSX 172304
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
604 PM CDT Wed Jun 17 2026

MOC163-173-172330-
/O.CON.KLSX.SV.W.0187.000000T0000Z-260617T2330Z/
Pike MO-Ralls MO-
604 PM CDT Wed Jun 17 2026

...SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 630 PM CDT FOR
WESTERN PIKE AND SOUTHWESTERN RALLS COUNTIES IN NORTHEASTERN
MISSOURI...

At 604 PM CDT, a severe thunderstorm was located over Spencerburg, or
10 miles northeast of Vandalia, moving east at 40 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...
  Center, Spencerburg, Frankford, Curryville, Bowling Green, St.
  Clement, Ashley and Tarrants.

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.

A Tornado Watch remains in effect until 1000 PM CDT Wednesday for a
portion of northeast Missouri.

&&

LAT...LON 3936 9160 3956 9159 3951 9108 3950 9107
      3923 9115 3923 9118 3922 9118 3930 9143
      3932 9144 3932 9150
TIME...MOT...LOC 2300Z 283DEG 36KT 3944 9145

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

$$

Elmore

729 
WWUS53 KLSX 172311
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
611 PM CDT Wed Jun 17 2026

MOC163-173-172321-
/O.CAN.KLSX.SV.W.0187.000000T0000Z-260617T2330Z/
Pike MO-Ralls MO-
611 PM CDT Wed Jun 17 2026

...SEVERE THUNDERSTORM WARNING IS CANCELLED FOR WESTERN PIKE AND
SOUTHWESTERN RALLS COUNTIES IN NORTHEASTERN MISSOURI...

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 has been cancelled. However, small hail and
gusty winds are still possible with this thunderstorm.

A Tornado Watch remains in effect until 1000 PM CDT Wednesday for a
portion of northeast Missouri.

&&

LAT...LON 3936 9160 3956 9159 3951 9108 3950 9107
      3923 9115 3923 9118 3922 9118 3930 9143
      3932 9144 3932 9150
TIME...MOT...LOC 2304Z 283DEG 36KT 3943 9140

$$

Elmore

Area Forecast Discussion
National Weather Service Saint Louis MO
207 PM CDT Wed Jun 17 2026

.KEY MESSAGES...

- Severe thunderstorms move southeast across the region this
  evening, ending during the early overnight hours.

- Tonight's cold front brings cooler and drier conditions for the
  rest of the week. Rain chances return this weekend.

&&

.SHORT TERM...  (Through Late Thursday Night)
Issued at 206 PM CDT Wed Jun 17 2026

Strong southwest flow has brought in a warm, humid air mass just
ahead of an advancing cold front. This is leading to a rapidly
destabilizing environment this afternoon with thunderstorms expected
ahead of the front. Unusually strong wind shear will lead to strong
potential for storms to organize into supercells capable of large
hail, damaging winds, and tornadoes. Very high precipitable water
values near 2 inches suggest very heavy rainfall rates are likely,
though quick storm motions should minimize the duration in any one
location. Low level wind flow out of the southwest ahead of the
front minimizes the effective convergence along it, so storm
coverage may be initially isolated. In addition, shear vectors
oriented across the boundary suggest storms should remain more
discreet with less potential for a more organized cold pool driven
MCS. A locally greater tornado threat may exist in the vicinity of
the remnant outflow boundary laid down by this morning's storms
across Illinois. Near this boundary convergence will be stronger
along with the potential for locally greater low level wind shear.
Storm coverage is expected to decrease after sunset with the front
bringing in a drier and cooler air mass behind it.

Guidance consensus is that the front settles just south of our area
on Thursday, with lingering showers or thunderstorms similarly
staying just to our south. However, some of these could drift into
the southern periphery of our forecast area. Otherwise, additional
very light, low topped showers may develop behind the cold front as
low level lapse rates maximize tomorrow afternoon. However, an
inversion aloft will limit the depth of these showers, so the impact
will be quite minor from just a few sprinkles. Otherwise maximum
temperatures will be about 10F cooler on Thursday compared to today,
with dewpoints similarly lower by about 10F.

Kimble

&&

.LONG TERM...  (Friday through Next Wednesday)
Issued at 206 PM CDT Wed Jun 17 2026

The trough driving today's action digs out a rather broad low
amplitude trough over the eastern US for the rest of the week, with
similarly low amplitude ridging over the western US. This puts us in
northwesterly flow which favors subsidence aloft and surface high
pressure, although a few weak cold fronts can also occur. So our
forecast for the next several days favors cooler and drier
conditions.

As ridging gradually pushes east toward the Rocky Mountains,
moisture return begins across the Plains later this week. By
Saturday a shortwave trough rounding the top of the ridge triggers a
round of showers and storms in Nebraska and Kansas, the remnants of
which push ESE toward our area Saturday night. This represents our
next best chance of rain. Models vary on how the shortwave trough
and associated features progress, in part due to the convection
associated with it. If this shortwave is a bit slower and the
moisture return makes it northward into our area then we could
develop a local severe weather threat on Sunday. However, confidence
remains low on this due to variance in the guidance on the track and
timing of this wave. Either way, this Saturday night into Sunday
period represents our best chance of rain locally within this 7-day
forecast. Among the long range ensemble guidance, up to 40 percent
of members bring precipitable water values up above 2 inches, so a
locally heavy rain threat will exist. A flash flood threat could
materialize if mesoscale features can align to produce training or
prolonged thunderstorm activity. After Sunday's wave trends favor
drier and mild conditions again under renewed northwest flow.

Kimble

&&

.AVIATION...  (For the 18z TAFs through 18z Thursday Afternoon)
Issued at 1218 PM CDT Wed Jun 17 2026

Strong southwest winds are expected today with gusts occasionally
near 40KT in spots. Thunderstorms are expected to initiate early
this afternoon in northern Missouri, tracking southeast ahead of a
cold front. These storms could be locally severe. Winds shift to
the WNW and slacken behind the front this evening.

Kimble

&&

.LSX WATCHES/WARNINGS/ADVISORIES...
MO...Wind Advisory until 8 PM CDT this evening for Franklin MO-
     Gasconade MO-Jefferson MO-Lincoln MO-Madison MO-Saint
     Charles MO-Saint Francois MO-Saint Louis City MO-Saint
     Louis MO-Sainte Genevieve MO-Warren MO.

     Wind Advisory until 6 PM CDT this evening for Audrain MO-Boone
     MO-Callaway MO-Cole MO-Knox MO-Lewis MO-Marion MO-Moniteau
     MO-Monroe MO-Montgomery MO-Osage MO-Pike MO-Ralls MO-Shelby
     MO.

IL...Wind Advisory until 8 PM CDT this evening for Bond IL-Calhoun IL-
     Clinton IL-Fayette IL-Greene IL-Jersey IL-Macoupin IL-
     Madison IL-Marion IL-Monroe IL-Montgomery IL-Randolph IL-
     Saint Clair IL-Washington IL.

     Wind Advisory until 6 PM CDT this evening for Adams IL-Brown IL-
     Pike IL.

&&

WFO LSX

Preliminary Local Storm Report
National Weather Service St Louis MO
518 PM CDT Wed Jun 17 2026

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

0308 PM     Non-Tstm Wnd Dmg Sandoval                38.62N 89.12W
06/17/2026                   Marion             IL   Emergency Mngr

            Non-convective high winds snapped a power
            pole in Sandoval. The wires landed on a
            church and burned the structure to the
            ground. Ignition time not certain.

&&

LSJ

Preliminary Local Storm Report
National Weather Service St Louis MO
519 PM CDT Wed Jun 17 2026

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

0308 PM     Non-Tstm Wnd Dmg Centralia               38.53N 89.13W
06/17/2026                   Marion             IL   Emergency Mngr

            Non-convective wind gusts blew over multiple
            power lines in Centralia.

&&

LSJ

Preliminary Local Storm Report
National Weather Service St Louis MO
534 PM CDT Wed Jun 17 2026

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

0531 PM     Non-Tstm Wnd Dmg Iuka                    38.62N 88.79W
06/17/2026                   Marion             IL   Emergency Mngr

            Power lines downed on a house. The house is
            smoking.

&&

LSJ