Severe Thunderstorm Warning 37, NWS St. Louis, MO

911 
WWUS53 KLSX 220135
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
835 PM CDT Fri Mar 21 2025

ILC001-220145-
/O.CAN.KLSX.SV.W.0037.000000T0000Z-250322T0200Z/
Adams IL-
835 PM CDT Fri Mar 21 2025

...SEVERE THUNDERSTORM WARNING IS CANCELLED FOR EAST CENTRAL ADAMS 
COUNTY...

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

&&

LAT...LON 4003 9063 4002 9063 4003 9061 4002 9062
      4001 9062 4000 9060 3998 9061 3999 9052
      3998 9051 3997 9051 3995 9053 3992 9054
      3990 9055 3989 9057 3988 9058 3985 9058
      3984 9057 3985 9091 3984 9092 4001 9091
TIME...MOT...LOC 0121Z 269DEG 49KT 3991 9097

$$


ILC009-220200-
/O.CON.KLSX.SV.W.0037.000000T0000Z-250322T0200Z/
Brown IL-
835 PM CDT Fri Mar 21 2025

...SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 9 PM CDT FOR 
BROWN COUNTY...

At 835 PM CDT, a severe thunderstorm was located 5 miles south of 
Mount Sterling, or 21 miles north of Pittsfield, moving east at 55 
mph.

HAZARD...60 mph wind gusts.

SOURCE...Emergency management reported.

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

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

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Seek shelter inside a well-built structure and stay away from 
windows. This storm has produced damaging winds.

&&

LAT...LON 4003 9063 4002 9063 4003 9061 4002 9062
      4001 9062 4000 9060 3998 9061 3999 9052
      3998 9051 3997 9051 3995 9053 3992 9054
      3990 9055 3989 9057 3988 9058 3985 9058
      3984 9057 3985 9091 3984 9092 4001 9091
TIME...MOT...LOC 0121Z 269DEG 49KT 3991 9097

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.00 IN
WIND THREAT...OBSERVED
MAX WIND GUST...60 MPH

$$

Carney

430 
WWUS53 KLSX 220150
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
850 PM CDT Fri Mar 21 2025

ILC009-220200-
/O.EXP.KLSX.SV.W.0037.000000T0000Z-250322T0200Z/
Brown IL-
850 PM CDT Fri Mar 21 2025

...SEVERE THUNDERSTORM WARNING WILL EXPIRE AT 9 PM CDT FOR BROWN 
COUNTY...

The storm which prompted the warning has moved out of the area. 
Therefore, the warning will be allowed to expire.

&&

LAT...LON 4003 9063 4002 9063 4003 9061 4002 9062
      4001 9062 4000 9060 3998 9061 3999 9052
      3998 9051 3997 9051 3995 9053 3992 9054
      3990 9055 3989 9057 3988 9058 3985 9058
      3984 9057 3985 9091 3984 9092 4001 9091
TIME...MOT...LOC 0135Z 269DEG 49KT 3991 9073

$$

Carney

Area Forecast Discussion...Updated Aviation
National Weather Service Saint Louis MO
647 PM CDT Fri Mar 21 2025

.KEY MESSAGES...

- A Red Flag Warning for Critical Fire Danger now includes most
  of the area until 7 pm. Strong winds, low relative humidity, and
  dry vegetation will favor erratic and rapid fire growth.

- Isolated showers and thunderstorms with gusty winds are
  possible this evening, mainly north of I-70.

- Widespread showers and thunderstorms are expected Saturday into
  Sunday morning, with greatest coverage and highest rainfall
  amounts (0.25 to locally 1") near the I-70 corridor. A few
  thunderstorms could be strong to severe with marginally severe
  hail west of the Mississippi River.

&&

.SHORT TERM...  (Through Late Saturday Night)
Issued at 249 PM CDT Fri Mar 21 2025

Favorable low-level southwesterly flow downsloped off the Ozark
Plateau, limited moisture return, deep BL mixing, and mild
temperatures in the 60s F, have all contributed to Critical Fire
Danger/Red Flag conditions at times this afternoon, which has
expanded further northward than previously anticipated into
northeastern MO/west-central IL. These conditions should improve as
an upper-level trough forces a series of cold fronts through the CWA
this evening, with low-level CAA and moisture increasing. Following
the second cold front, 20 to 30 percent of HREF membership have
isolated to scattered showers and thunderstorms entering areas north
of I-70 this evening within weak low-level moisture convergence and
steep lapse rates. In opportunities to mix down 40 kt winds at the
top of the mixed layer, a brief period of gusty winds of 35 to 45
mph are possible with both passage of the second front and with any
of these showers and thunderstorms. The potential gusty winds is
greatest in northeastern MO/west-central IL where the greatest,
albeit modest, MUCAPE up to 150 J/kg is indicated in some short-term
model guidance.

On Saturday, upper-level ridging and an attendant passing surface
pressure ridge will keep post-frontal CAA brief, giving way to low-
level southerly WAA by afternoon along/west of the Mississippi
River. Dry conditions and increasing late-day upper-level clouds
will allow for strong insolation CWA, but the varying WAA will to
temperatures ranging from the 60s F along/west of the Mississippi
River to the 50s F in south-central IL.

Pfahler

&&

.LONG TERM...  (Sunday through Next Friday)
Issued at 249 PM CDT Fri Mar 21 2025

As another upper-level trough reaches the Upper Mississippi River
Valley Saturday night, it will lead to increasing showers and
thunderstorms in response to strong low-level WAA and moisture
transport within a 50 to 60 kt low-level jet. Thunderstorms could be
organized into supercells at times, especially west of the
Mississippi River, where most short-term model guidance generate
MUCAPE of 750 to 1250 J/kg as a plume of steep mid-level lapse rates
arrives among 35 to 50 kt of effective deep-layer wind shear. With a
stable BL and virtually no SBCAPE/MLCAPE, these thunderstorms will
likely be elevated and pose a threat of marginally severe hail.
However, if instability trends higher, larger hail cannot be ruled
out. Coverage of showers and thunderstorms is forecast to be
greatest early Sunday morning as additional showers and
thunderstorms arrive along/ahead of a cold front before they end
from west to east later in the morning. With the longest duration
and greatest coverage suggested to exist generally near the I-70
corridor, probabilities of total rainfall 0.25 and 0.50" in ensemble
model guidance are highest in those areas at 60 to 80 percent and 40
to 50 percent, respectively. Since large-scale forcing will be much
weaker by afternoon along with instability, it is not clear how much
additional showers and thunderstorms will develop along the cold
front as it departs southeastern MO/southwestern IL during the
afternoon. With clouds decreasing and the post-frontal airmass
modified Pacific in nature, high temperatures will remain above
average, in the 60s to around 70 F.

Upper-level northwesterly flow will prevail through most of next
week, traversed by one or more swift shortwave troughs, with 30 to
50 percent of ensemble model guidance containing light showers
around Tuesday with the strong shortwave trough. However, largely
dry conditions are expected otherwise with moisture return limited
in this pattern. A front/baroclinic zone will also oscillate across
the region, making northward progress gradually through the week as
longwave troughing slowly departs the Great Lakes and more of the
CWA can be exposed to WAA. In the NBM this evolution translates to
the interquartile temperature range spanning approximately 10 F, but
with an underlying warming trend progressively above average.

Global model guidance diverge by the end of the week, but signal
upper-level troughing across the central CONUS with an increasing
chance of showers and thunderstorms.

Pfahler

&&

.AVIATION...  (For the 00z TAFs through 00z Saturday Evening)
Issued at 641 PM CDT Fri Mar 21 2025

VFR flight conditions are expected to prevail through the period.
Strong and gusty winds will continue this evening and into the
early overnight hours, particularly across northeast Missouri and
west central Illinois as two fronts move through the area. The
first will shift the wind from the southwest to the west
northwest, and then the second will turn the wind further to the
northwest later tonight. Scattered showers and a few thunderstorms
will affect mostly northeast Missouri and west central Illinois
this evening. Wind gusts to 35-45kts are possible with the
strongest storms, and visibility could briefly fall to MVFR in
moderate rain. Winds will gradually diminish overnight and then
turn to the south and southeast late Saturday morning into the
afternoon.

Carney

&&

.LSX WATCHES/WARNINGS/ADVISORIES...
MO...Red Flag Warning until 7 PM CDT this evening for Audrain MO-
     Boone MO-Callaway MO-Cole MO-Crawford MO-Dent MO-Franklin
     MO-Gasconade MO-Iron MO-Jefferson MO-Knox MO-Lewis MO-
     Lincoln MO-Madison MO-Marion MO-Moniteau MO-Monroe MO-
     Montgomery MO-Osage MO-Pike MO-Ralls MO-Reynolds MO-Saint
     Charles MO-Saint Francois MO-Saint Louis City MO-Saint
     Louis MO-Sainte Genevieve MO-Shelby MO-Warren MO-Washington
     MO.

IL...Red Flag Warning until 7 PM CDT this evening for Adams IL-Bond
     IL-Brown IL-Calhoun IL-Clinton IL-Greene IL-Jersey IL-
     Macoupin IL-Madison IL-Monroe IL-Montgomery IL-Pike IL-
     Randolph IL-Saint Clair IL-Washington IL.

&&

WFO LSX

Hazardous Weather Outlook
National Weather Service St Louis MO
652 PM CDT Fri Mar 21 2025

ILZ058>060-064-065-069-070-074-079-095>102-MOZ018-019-026-027-
034>036-041-042-047>052-059>065-072>075-084-085-099-230000-
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-
652 PM CDT Fri Mar 21 2025

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

.DAY ONE...Tonight.

There is a slight chance of thunderstorms with gusty winds in
northeastern Missouri and west-central Illinois this evening.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday.

There is a chance of thunderstorms Saturday night into Sunday across
much of the area. A few of these thunderstorms could be strong to
severe west of the Mississippi River with marginally severe hail.

There is a slight chance of thunderstorms Thursday.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

Carney

Preliminary Local Storm Report
National Weather Service St Louis MO
807 PM CDT Fri Mar 21 2025

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

0750 PM     Non-Tstm Wnd Gst Canton                  40.13N 91.52W
03/21/2025  M45 MPH          Lewis              MO   Fire Dept/Rescue

            Sustained winds measured of 38 mph Power
            outages also reported near Lewistown.

&&

Britt

Preliminary Local Storm Report
National Weather Service St Louis MO
819 PM CDT Fri Mar 21 2025

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

0800 PM     Tstm Wnd Dmg     1 NW Quincy             39.95N 91.41W
03/21/2025                   Adams              IL   Broadcast Media

            Downed utility pole at 3rd and Cedar.
            Estimated 60 mph winds downtown and on the
            southside of Quincy.

&&

Britt