Severe Thunderstorm Warning 377, NWS St. Louis, MO

138 
WWUS53 KLSX 161242
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
642 AM CST Mon Dec 16 2024

MOC123-186-187-161315-
/O.CON.KLSX.SV.W.0377.000000T0000Z-241216T1315Z/
Madison MO-Sainte Genevieve MO-Saint Francois MO-
642 AM CST Mon Dec 16 2024

...SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 715 AM CST 
FOR NORTHEASTERN MADISON, SOUTH CENTRAL SAINTE GENEVIEVE AND 
SOUTHEASTERN SAINT FRANCOIS COUNTIES IN SOUTHEASTERN MISSOURI...

At 642 AM CST, severe thunderstorms were located along a line from 9 
miles southwest of St. Mary to over Marquand, or along a line from 
13 miles south of Ste. Genevieve to 9 miles southeast of 
Fredericktown, moving east at 45 mph.

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

SOURCE...Radar indicated.

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

This severe thunderstorm will be near...
  Womac around 635 AM CST.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Seek shelter inside a well-built structure and stay away from 
windows. These storms are capable of producing damaging winds.

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

&&

LAT...LON 3764 9025 3775 9019 3776 9004 3767 9011
      3764 9015 3760 9015 3754 9014 3749 9014
      3749 9023 3761 9025
TIME...MOT...LOC 1227Z 252DEG 37KT 3774 9025 3759 9030 3742 9037

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

$$

Jaja

728 
WWUS53 KLSX 161249
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
649 AM CST Mon Dec 16 2024

MOC123-186-187-161259-
/O.CAN.KLSX.SV.W.0377.000000T0000Z-241216T1315Z/
Madison MO-Sainte Genevieve MO-Saint Francois MO-
649 AM CST Mon Dec 16 2024

...SEVERE THUNDERSTORM WARNING IS CANCELLED FOR NORTHEASTERN 
MADISON, SOUTH CENTRAL SAINTE GENEVIEVE AND SOUTHEASTERN SAINT 
FRANCOIS COUNTIES IN SOUTHEASTERN MISSOURI...

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

&&

LAT...LON 3764 9025 3775 9019 3776 9004 3767 9011
      3764 9015 3760 9015 3754 9014 3749 9014
      3749 9023 3761 9025
TIME...MOT...LOC 1242Z 252DEG 37KT 3778 9006 3763 9010 3747 9018

$$

Jaja

Area Forecast Discussion...Updated Aviation
National Weather Service Saint Louis MO
515 AM CST Mon Dec 16 2024

.KEY MESSAGES...

- Showers and a few thunderstorms will be found mainly across
southeast Missouri and southwest Illinois this morning.

- There is another chance of rain on Tuesday night and Wednesday
  with the best chance (60-70%) across southeast Missouri and
  southwest Illinois.

- Dry and cooler weather is expected late this week into the weekend.

&&

.SHORT TERM...  (Through Late Tuesday Afternoon)
Issued at 322 AM CST Mon Dec 16 2024

Latest radar trends continue to show showers expanding across
southern Missouri and southern Illinois in a strong band of low
level moisture convergence ahead of the mid-level trough over the
Plains. Isolated thunderstorms are embedded within these bands of
showers as the latest SPC mesoanalysis is showing MUCAPES of 500-
1000+ J/kg with deep layer shear of 20 to 30 knots.  Recent runs of
the CAMS continue to show that rain will expand across areas south
of I-44 in MO and south of I-70 in IL before the forcing associated
with the low level jet will move southeast of the CWA later this
morning. Until then, there could be some stronger storms that could
produce some small hail and heavier downpours.  While most of the
area will not see as much rainfall as Saturday's system, the HREF
LPMM is showing up to 1" of rainfall over the far southern part of
the CWA. The HREF has the upper trough moving east of the CWA by
late this afternoon with a shortwave ridge moving across the area on
Tuesday. This will keep the area dry this afternoon through
tomorrow.

The cold front that is currently entering the western part of
Missouri will move through the CWA later today.  There will be a
large spread in highs today with 60s over the southeast half of the
CWA compared to around 50 degrees over northeast Missouri.  A
surface high will move across Missouri and Illinois tonight causing
light winds and clear skies allowing temperatures to fall back into
the lower 30s. Winds will turn out of the southeast ahead of the
next system on Tuesday under a partly sunny sky causing highs to
climb back into the lower to mid 50s.

Britt

&&

.LONG TERM...  (Tuesday Night through Sunday)
Issued at 322 AM CST Mon Dec 16 2024

Model guidance has been consistent with the next trough moving
across the Midwest Tuesday night into Wednesday.   The LREF
continues to show that its highest number of ensemble members
showing precipitation on Tuesday night will once again be over
the southeast half of the CWA. Temperatures will fall toward
freezing late on Tuesday night over the northern CWA which could
lead to some snow mixing in with the rain before it ends, but less
than 10 percent of the LREF members are showing a chance of snow
at UIN which lowers confidence in this potential.

A trough will move from the Northern High Plains on Wednesday night
into the Great Lakes on Thursday night.  The latest track keeps
chances out of the CWA on Thursday night with the number of LREF
members producing precipitation at UIN or SPI at less than 10
percent.  The dry weather looks like it will continue into the
weekend as an upper ridge will be building into the area.

Two cold fronts will move through the area this week, one associated
with the first upper trough on Tuesday night and Wednesday and the
second with the clipper on Thursday night.  Both fronts will bring
cooler air with high temperatures behind the first front on
Wednesday and Thursday in the 40s and highs behind the second front
Friday into the weekend in the 30s.

Britt

&&

.AVIATION...  (For the 12z TAFs through 12z Tuesday Morning)
Issued at 457 AM CST Mon Dec 16 2024

Area of light rain that is affecting STL/CPS/SUS will move out
early in the period. MVFR ceilings and visibilities that are
affecting the airports will move out of the airports this morning
with generally scattered clouds by this afternoon. Winds will turn
out of the southwest to west this morning with gusts to 20 knots
during the afternoon before decreasing between 00-02Z.

Britt

&&

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

WFO LSX

Hazardous Weather Outlook
National Weather Service St Louis MO
345 AM CST Mon Dec 16 2024

ILZ058>060-064-065-069-070-074-079-095>102-MOZ018-019-026-027-
034>036-041-042-047>052-059>065-072>075-084-085-099-170945-
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-
345 AM CST Mon Dec 16 2024

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

.DAY ONE...Today and tonight.

There is a chance of thunderstorms through this morning, mainly
across southeast Missouri and southwest Illinois.

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

The chance for thunderstorms Tuesday night and Wednesday morning
across parts of southeast Missouri and southwest Illinois.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

Britt