Alert archive / Missouri / Severe Thunderstorm Warnings in 1993

Severe Thunderstorm Warning 121, NWS St. Louis, MO

July 20, 1993Jefferson County, Missouri

NWS St. Louis, MO issued this severe thunderstorm warning at Jul 20, 1993, 5:20 PM CDT for Jefferson County, Missouri. It was in force for 55 min.

The area

The counties it named.

The facts

Issued: Jul 20, 1993, 5:20 PM CDT (22:20 UTC)
Expired: Jul 20, 1993, 6:15 PM CDT
In force: 55 min
Issued by: NWS St. Louis, MO
Area: Whole counties

County Jefferson County, MO

The radar

The St Louis radar (KLSX), 50 km from the middle of the area, began a volume at 22:23 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

Paducah/Barkley, KY (KPAH), launched 12:00Z, 10.3 hours before the alert went out and 209 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: 1217 J/kg
Mixed-layer CIN: -8 J/kg
Mixed-layer LCL: 689 m above ground
0-6 km bulk shear: 16 kt
0-1 km storm-relative helicity: -32 m²/s²
0-3 km storm-relative helicity: -32 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

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.

In the hours before

Special weather statement, Jul 20, 3:43 PM CDT, 1 hour 37 minutes before

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Special weather statement, Jul 20, 3:44 PM CDT, 1 hour 36 minutes before

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Special weather statement, Jul 20, 4:45 PM CDT, 35 minutes before

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Special weather statement, Jul 20, 4:45 PM CDT, 35 minutes before

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Special weather statement, Jul 20, 5:10 PM CDT, 10 minutes before

MOZ010-011-014-202300-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE COLUMBIA MO
510 PM CDT TUE JUL 20 1993

...A SEVERE THUNDERSTORM WATCH CONTINUES IN EFFECT UNTIL 900 PM CDT
FOR THE EAST AND SOUTH SECTIONS OF CENTRAL MISSOURI...

AT 505 PM CDT WEATHER RADAR SHOWED THUNDERSTORMS WITH VERY HEAVY
SHOWERS OVER EAST AND SOUTH MISSOURI.  THE BAND WAS ABOUT 25 MILES WIDE
AND EAST OF A LINE EXTENDING FROM 55 MILES EAST OF COLUMBIA TO 55 MILES
SOUTHEAST OF COLUMBIA...AROUND SULLIVAN...TO JUST SOUTH OF FT. LEONARD
WOOD.  THE THUNDERSTORMS WERE MOVING TO THE EAST AND SOUTHEAST AROUND
25 MILES AN HOUR AND NO LONGER PRESENT A THREAT OF SEVERE WEATHER TO
CENTRAL MISSOURI.

NO SEVERE WEATHER WAS REPORTED OR INDICATED BY RADAR IN CENTRAL
MISSOURI DURING THE LAST HOUR.

LB/GS

Special weather statement, Jul 20, 5:10 PM CDT, 10 minutes before

MOZ010-011-014-202300-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE COLUMBIA MO
510 PM CDT TUE JUL 20 1993

...A SEVERE THUNDERSTORM WATCH CONTINUES IN EFFECT UNTIL 900 PM CDT
FOR THE EAST AND SOUTH SECTIONS OF CENTRAL MISSOURI...

AT 505 PM CDT WEATHER RADAR SHOWED THUNDERSTORMS WITH VERY HEAVY
SHOWERS OVER EAST AND SOUTH MISSOURI.  THE BAND WAS ABOUT 25 MILES WIDE
AND EAST OF A LINE EXTENDING FROM 55 MILES EAST OF COLUMBIA TO 55 MILES
SOUTHEAST OF COLUMBIA...AROUND SULLIVAN...TO JUST SOUTH OF FT. LEONARD
WOOD.  THE THUNDERSTORMS WERE MOVING TO THE EAST AND SOUTHEAST AROUND
25 MILES AN HOUR AND NO LONGER PRESENT A THREAT OF SEVERE WEATHER TO
CENTRAL MISSOURI.

NO SEVERE WEATHER WAS REPORTED OR INDICATED BY RADAR IN CENTRAL
MISSOURI DURING THE LAST HOUR.

LB/GS

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 20, 3:11 PM CDT	Severe Thunderstorm Warning	LSX	Ralls	49 min
Jul 20, 3:26 PM CDT	Severe Thunderstorm Warning	LSX	Pike	64 min
Jul 20, 4:08 PM CDT	Severe Thunderstorm Warning	LSX	Lincoln	52 min
Jul 20, 4:18 PM CDT	Severe Thunderstorm Warning	LSX	Franklin, Warren	57 min
Jul 20, 4:41 PM CDT	Severe Thunderstorm Warning	LSX	Saint Charles	64 min
Jul 20, 5:07 PM CDT	Severe Thunderstorm Warning	LSX	Saint Louis, City of Saint Louis	53 min
Jul 20, 5:40 PM CDT	Severe Thunderstorm Warning	LSX	Iron, Washington	65 min
Jul 20, 5:45 PM CDT	Flash Flood Warning	LSX	Franklin, Jefferson, Saint Charles, Saint Louis	2 hr
Jul 20, 5:45 PM CDT	Flash Flood Warning	LSX	City of Saint Louis	2 hr
Jul 20, 6:20 PM CDT	Severe Thunderstorm Warning	LSX	Sainte Genevieve, Saint Francois	55 min
Jul 20, 5:57 PM CDT	Severe Thunderstorm Warning	LSX	Monroe, Saint Clair	63 min
Jul 20, 6:20 PM CDT	Severe Thunderstorm Warning	LSX	Randolph	55 min

Nearby

Severe Thunderstorm Warnings in Missouri, 1993 Every severe thunderstorm warning in 1993

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.