Alert archive / Missouri / Severe Thunderstorm Warnings in 2023

Severe Thunderstorm Warning 329, NWS St. Louis, MO

August 3, 20234 counties in Missouri

NWS St. Louis, MO issued this severe thunderstorm warning at Aug 3, 2023, 4:52 AM CDT for 4 counties in Missouri. It was in force for 38 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Aug 3, 2023, 4:52 AM CDT (09:52 UTC)
Expired: Aug 3, 2023, 5:30 AM CDT
In force: 38 min
Issued by: NWS St. Louis, MO
Area: Storm-based polygon
Hail: 0.88 in
Wind: 60.0 mph

Counties Crawford County, MO, Franklin County, MO, Jefferson County, MO, Washington County, MO

The radar

The St Louis radar (KLSX), 65 km from the middle of the area, began a volume at 09:53 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Springfield, MO (KSGF), launched 00:00Z, 9.9 hours before the alert went out and 287 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 3933 J/kg
Mixed-layer CIN: -5 J/kg
Mixed-layer LCL: 1617 m above ground
0-6 km bulk shear: 25 kt
0-1 km storm-relative helicity: 66 m²/s²
0-3 km storm-relative helicity: 235 m²/s²
Significant tornado parameter: 0.7
Supercell composite: 12.8

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS St. Louis, MO wrote its last area forecast discussion before this severe thunderstorm warning went out at Aug 3, 3:32 AM CDT, 1 hour 20 minutes earlier.

Area forecast discussion, Aug 3, 3:32 AM CDT, 1 hour 20 minutes before

Area Forecast Discussion
National Weather Service Saint Louis MO
332 AM CDT Thu Aug 3 2023

.SHORT TERM...  (Through Late Friday Afternoon)
Issued at 322 AM CDT Thu Aug 3 2023

Key Message:

Ongoing training of storms early this morning with activity
extending as far west as north central Kansas. So will keep Flood
Watch going through 15z today with widespread 1-3" rainfall
totals still expected in the flash flood watch area, with a few
locations already in excess of 6" (Southern Moniteau/Cole
counties) as of 08z Thursday. The heaviest rain will be in a NW-SE
axis from near Columbia to Farmington.

(Today - Friday)

With the low level jet (25-35kt) veering to the west, it will become
parallel to the mean 850-300mb flow, so this favors a continued
upwind propagation and cell training for a while longer. Then
between 12z and 15z, the low level jet will veer to the northwest
and weaken with activity quickly tapering off.

Even with rain tapering off, the effective front will linger across
southern portions of Missouri through the rest of the day. North of
this boundary, the latest HREF ensemble run has surface based CAPEs
between 1500-3000 J/kg and mean PWs around 2 inches. So plenty of
instability and moisture across the region, thus expect scattered
showers and storms will develop by late afternoon for portions of
central and southeast Missouri. The rest of the forecast area should
remain dry.

By tonight, some of the latest CAMs indicate that another MCS will
develop over south central and southeast Missouri. However, the
majority of the CAMs do not develop an MCS or have one develop
further to our southeast. Also, even with PMM/LPMM qpf values
indicating isolated 1-2" amounts of rain in southern portions of the
forecast area tonight, the latest HREF has more of a spread when it
comes to QPF amounts, so confidence is low on another heavy rain
event for portions of our area at this time. Will need to keep eye
out on the later model runs to see if adjustments need to be made
and/or possible flood watch for tonight.

On Friday, even though mean surface based CAPE values will be a bit
lower (1000-1500 J/kg) with mean PWs less than 2 inches as well as a
lingering frontal boundary across region, only expect a low end
chance of showers and storms once again due to weaker mid and upper
level flow.

Highs today and Friday will be near normal while lows tonight will
be a bit above normal in the upper 60s to mid 70s.

Byrd

.LONG TERM...  (Friday Night through Wednesday)
Issued at 322 AM CDT Thu Aug 3 2023

No major changes as the latest deterministic as well as ensembles
keep chances of showers and storms through the weekend, as
several shortwaves slide along the zonal flow aloft. However, with
weaker mid level flow and little to no low level jet each night,
precipitation chances will be on the lower side.

Otherwise, after near normal temperatures on Saturday and Sunday,
cooler than normal temperatures through the work week. This is due
to an upper level ridge building over the western CONUS once again
putting our area in northwest flow aloft.

Byrd
&&

.AVIATION...  (For the 00z TAFs through 00z Thursday Evening)
Issued at 715 PM CDT Wed Aug 2 2023

Active TAF period with showers and storms already developing
across the forecast area. For KUIN, MVFR/IFR ceilings through the
majority of the forecast period with showers and some storms
through at least 10z Thursday. For the rest of TAF sites, VFR
flight conditions will lower to MVFR with onset of heavier
precipitation after 02z Thursday. For KCOU and KJEF, rain will
taper off after 09z Thursday. In the meantime, rain will persist
over St. Louis metro area TAFs from 02z to 15z Thursday. As for
winds, they will remain from the northeast to southeast.

Byrd
&&

.PRELIMINARY POINT TEMPS/POPS...
Saint Louis     86  74  87  74 /  40  20  20  40
Quincy          84  70  86  71 /  10  10   5  40
Columbia        85  72  88  72 /  20  30  30  50
Jefferson City  88  73  90  74 /  20  40  30  50
Salem           84  69  88  70 /  60  20  20  20
Farmington      89  70  89  71 /  70  40  30  30

&&

.LSX WATCHES/WARNINGS/ADVISORIES...
MO...Flood Watch until 10 AM CDT this morning for Audrain MO-Boone MO-
     Callaway MO-Cole MO-Crawford MO-Franklin MO-Gasconade MO-
     Iron MO-Jefferson MO-Lincoln MO-Madison MO-Moniteau MO-
     Montgomery MO-Osage MO-Reynolds MO-Saint Charles MO-Saint
     Francois MO-Saint Louis City MO-Saint Louis MO-Sainte
     Genevieve MO-Warren MO-Washington MO.

IL...Flood Watch until 10 AM CDT this morning for Calhoun IL-Clinton
     IL-Jersey IL-Madison IL-Marion IL-Monroe IL-Randolph IL-
     Saint Clair IL-Washington IL.

&&

WFO LSX

Hazardous weather outlook, Aug 3, 3:50 AM CDT, 1 hour 2 minutes before

Hazardous Weather Outlook
National Weather Service St Louis MO
350 AM CDT Thu Aug 3 2023

ILZ058>060-064-065-069-070-074-079-095>102-MOZ018-019-026-027-
034>036-041-042-047>052-059>065-072>075-084-085-099-041200-
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-
350 AM CDT Thu Aug 3 2023

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.

Flash Flood Watch is in effect for parts of Missouri and Illinois
through mid morning as thunderstorms producing heavy rainfall rates
will persist.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

Thunderstorms are possible each day through Monday. There is another
chance of thunderstorms on Wednesday.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will likely be needed.

Byrd

In the hours before

Local storm report, Aug 3, 12:08 AM CDT, 4 hours 44 minutes before

Preliminary Local Storm Report
National Weather Service St Louis MO
1208 AM CDT Thu Aug 3 2023

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

1049 PM     Tstm Wnd Dmg     1 E Park Hills          37.85N 90.51W
08/02/2023                   St. Francois       MO   Law Enforcement

            County dispatch reported several trees down
            in Park Hills. Time estimated from radar.

&&

AE

Local storm report, Aug 3, 12:19 AM CDT, 4 hours 33 minutes before

Preliminary Local Storm Report
National Weather Service St Louis MO
1219 AM CDT Thu Aug 3 2023

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

1130 PM     Tstm Wnd Dmg     Fredericktown           37.56N 90.29W
08/02/2023                   Madison            MO   Broadcast Media

            Broadcast media relayed reports of downed
            trees and power outages in Fredericktown.
            Time estimated from radar.

&&

AE

Local storm report, Aug 3, 12:26 AM CDT, 4 hours 26 minutes before

Preliminary Local Storm Report
National Weather Service St Louis MO
1226 AM CDT Thu Aug 3 2023

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

1038 PM     Tstm Wnd Dmg     4 NNW Frankclay         37.91N 90.63W
08/02/2023                   St. Francois       MO   Law Enforcement

            Several trees down in Terre Du Lac, with
            reports of trees on houses. Time estimated
            from radar.

&&

AE

Local storm report, Aug 3, 1:56 AM CDT, 2 hours 56 minutes before

Preliminary Local Storm Report
National Weather Service St Louis MO
156 AM CDT Thu Aug 3 2023

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

1039 AM     Tstm Wnd Dmg     Leadwood                37.86N 90.59W
08/02/2023                   St. Francois       MO   Public

            Large trees down. Time estimated by RADAR.

&&

Carney

Local storm report, Aug 3, 2:00 AM CDT, 2 hours 52 minutes before

Preliminary Local Storm Report
National Weather Service St Louis MO
200 AM CDT Thu Aug 3 2023

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

1041 AM     Tstm Wnd Dmg     Bonne Terre             37.92N 90.55W
08/02/2023                   St. Francois       MO   County Official

            Tree down on garage. Garage collapsed. Time
            estimated by RADAR.

&&

Carney

Local storm report, Aug 3, 4:00 AM CDT, 52 minutes before

Preliminary Local Storm Report
National Weather Service St Louis MO
400 AM CDT Thu Aug 3 2023

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

0330 AM     Tstm Wnd Dmg     New Bloomfield          38.72N 92.08W
08/03/2023                   Callaway           MO   Law Enforcement

            Water over roadways in and around New
            Bloomfield, including State Highway J, and
            MM. State Highway Y had 6 inches of flowing
            water over it.

&&

Carney

The office that day

Everything else NWS St. Louis, MO issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 2, 7:36 PM CDT	Severe Thunderstorm Warning	LSX	Callaway, Cole, Moniteau	39 min
Aug 2, 8:07 PM CDT	Areal Flood Advisory	LSX	Cole, Moniteau	2 hr
Aug 2, 8:10 PM CDT	Severe Thunderstorm Warning Considerable damage threat	LSX	Cole, Osage	65 min
Aug 2, 8:29 PM CDT	Flash Flood Warning	LSX	Callaway, Cole, Moniteau, Osage	4 hr
Aug 2, 8:30 PM CDT	Tornado Warning	LSX	Moniteau	16 min
Aug 2, 9:28 PM CDT	Areal Flood Advisory	LSX	Franklin, Gasconade	23 min
Aug 2, 9:42 PM CDT	Severe Thunderstorm Warning	LSX	Crawford, Gasconade	63 min
Aug 2, 9:51 PM CDT	Flash Flood Warning	LSX	Franklin, Gasconade	3 hr
Aug 2, 9:59 PM CDT	Severe Thunderstorm Warning	LSX	Washington	61 min
Aug 2, 10:21 PM CDT	Areal Flood Advisory	LSX	Crawford, Washington	3 hr
Aug 2, 10:29 PM CDT	Severe Thunderstorm Warning	LSX	Iron, Madison, Reynolds, Sainte Genevieve, Saint Francois	61 min
Aug 2, 10:41 PM CDT	Severe Thunderstorm Warning Considerable damage threat	LSX	Washington	49 min
Aug 2, 10:45 PM CDT	River Flood Warning	LSX	Franklin	3 days
Aug 2, 11:18 PM CDT	Severe Thunderstorm Warning Considerable damage threat	LSX	Madison	57 min
Aug 2, 11:25 PM CDT	Severe Thunderstorm Warning	LSX	Cole, Moniteau	38 min
Aug 3, 12:03 AM CDT	Severe Thunderstorm Warning	LSX	Iron, Reynolds	57 min
Aug 3, 12:13 AM CDT	Flash Flood Warning Considerable damage threat	LSX	Cole, Moniteau	4 hr
Aug 3, 12:26 AM CDT	Severe Thunderstorm Warning	LSX	Iron, Reynolds	49 min
Aug 3, 1:33 AM CDT	Flash Flood Warning	LSX	Boone, Callaway, Franklin, Gasconade, Moniteau, Osage	4 hr
Aug 3, 1:46 AM CDT	Severe Thunderstorm Warning	LSX	Callaway, Osage	22 min
Aug 3, 3:05 AM CDT	Flash Flood Warning Considerable damage threat	LSX	Boone, Callaway, Moniteau, Osage	6 hr
Aug 3, 6:56 AM CDT	River Flood Warning	LSX	Crawford, Washington	5 hr
Aug 3, 8:51 AM CDT	Flash Flood Warning	LSX	Madison, Sainte Genevieve, Saint Francois	4 hr
Aug 3, 10:36 AM CDT	River Flood Warning	LSX	Cole	35 hr
Aug 3, 10:36 AM CDT	River Flood Warning	LSX	Osage	11 hr
Aug 3, 10:40 AM CDT	River Flood Warning	LSX	Jefferson	4 days
Aug 3, 10:40 AM CDT	River Flood Warning	LSX	Jefferson, Saint Louis	4 days
Aug 3, 12:24 AM CDT	Flash Flood Warning	LSX	Bond, Fayette, Marion	6 hr

Nearby

Severe Thunderstorm Warnings in Missouri, 2023 Every severe thunderstorm warning in 2023

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.