Alert archive / Missouri / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 57, NWS St. Louis, MO

May 17, 1997Washington County, Missouri

NWS St. Louis, MO issued this severe thunderstorm warning at May 17, 1997, 8:21 PM CDT for Washington County, Missouri. It was in force for 69 min. 3 reports came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued: May 17, 1997, 8:21 PM CDT (01:21 UTC)
Expired: May 17, 1997, 9:30 PM CDT
In force: 69 min
Issued by: NWS St. Louis, MO
Area: Whole counties

County Washington County, MO

The radar

The St Louis radar (KLSX), 84 km from the middle of the area, began a volume at 01:23 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.

What was reported inside it

Time	Report	Where	Remark
May 17, 8:30 PM CDT	Hail 0.75	Irondale, MO	Skywarn spotters reported 3/4 inch hail.
May 17, 8:45 PM CDT	Hail 0.75	Potosi, MO	Skywarn spotters reported 3/4 inch hail.
May 17, 8:50 PM CDT	Hail 1	Potosi, MO	Skywarn spotters reported 1 inch hail.

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

The nearest sounding before it

Springfield, MO (KSGF), launched 00:00Z, 1.4 hours before the alert went out and 284 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: 1784 J/kg
Mixed-layer CIN: -24 J/kg
Mixed-layer LCL: 1565 m above ground
0-6 km bulk shear: 28 kt
0-1 km storm-relative helicity: 49 m²/s²
0-3 km storm-relative helicity: 180 m²/s²
Significant tornado parameter: 0.2
Supercell composite: 4.1

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

254 
WUUS1 KSTL 180124 RRA
SVRSTL
MOC221-180230-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
821 PM CDT SAT MAY 17 1997
 
THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL  930 PM CDT
FOR PEOPLE IN THE FOLLOWING LOCATION...
 
IN EAST CENTRAL MISSOURI
 
   ...SOUTHERN WASHINGTON COUNTY
 
AT 820 PM...THE ST LOUIS DOPPLER RADAR INDICATED A SEVERE STORM JUST
WEST OF POTOSI...THIS STORM WAS MOVING TO THE EAST AT 20 MPH.
THIS SEVERE STORM WILL HIT THE CITY OF SPRINGTOWN AND MINERAL POINT BY 8
 ALSO THIS STORM WILL PRODUCE LARGE HAIL AND STRONG WIND UP TO 55 MPH.
 
 
THIS STORM HAS A HISTORY OF DAMAGING HAIL. STAY INSIDE AND AWAY
FROM WINDOWS.
 
SEEK SHELTER IN A STURDY BUILDING. REMEMBER SEVERE THUNDERSTORMS
OFTEN PRODUCE TORNADOES WITH LITTLE OR NO ADVANCE WARNING.
 
VA/TS

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, May 17, 2:53 PM CDT, 5 hours 28 minutes before

MOZ042-041-050-010-048-072-062-059-084-018-019-065-052-085-027-047-
051-034-049-036-035-099-061-075-074-063-064-009-026-060-073-ILZ095-
064-096-098-069-065-058-099-059-100-070-102-060-097-079-101-074-
181100-

SEVERE WEATHER OUTLOOK   ...UPDATED...
NATIONAL WEATHER SERVICE ST LOUIS MO
245 PM CDT SAT MAY 17 1997

THIS OUTLOOK COVERS THE COUNTY WARNING AREA OF THE NATIONAL WEATHER
SERVICE FORECAST OFFICE IN ST. LOUIS. AREAS INCLUDED ARE PARTS OF
CENTRAL...NORTHEAST AND EAST CENTRAL MISSOURI...AND SOUTHWEST
ILLINOIS.

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORM DEVELOPMENT THIS
AFTERNOON AND TONIGHT FOR PORTIONS OF NORTHEAST AND CENTRAL MISSOURI.
THE AFFECTED REGION IS AN AREA GENERALLY NORTH AND WEST OF A LINE FROM
BURLINGTON IOWA TO FORT LEONARD WOOD MISSOURI TO JOPLIN MISSOURI.

SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP OVER NORTH CENTRAL
AND EASTERN KANSAS THIS AFTERNOON AND MOVE EAST THIS EVENING AND
TONIGHT. SOME OF THESE STORMS COULD BECOME SEVERE AS CONDITIONS
BECOME FAVORABLE FOR LARGE HAIL AND STRONG SURFACE WINDS. SKYWARN
OPERATIONS MAY BECOME NECESSARY BY EVENING. SPOTTERS SHOULD KEEP
ADVISED OF WEATHER CONDITIONS IN CASE SKYWARN ACTIVATION WOULD BE
NEEDED.

THERE IS A CHANCE FOR MODERATE TO STRONG THUNDERSTORMS OVER THE
REST OF THE STATE TO THE SOUTH AND EAST OF THE SLIGHT RISK AREA.

THERE WILL BE AN EVEN BETTER CHANCE FOR LOCALLY SEVERE STORMS
SUNDAY OVER MUCH OF MISSOURI.

BECHTOLD
!...UPDATED TO EXTEND AREA OF SLIGHT RISK FURTHER SOUTH AND EAST...

The office that day

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

Issued	Product	Office	Counties	Lasted
May 17, 8:48 PM CDT	Severe Thunderstorm Warning	LSX	Saint Francois	57 min
May 17, 9:03 PM CDT	Severe Thunderstorm Warning	LSX	Iron	42 min
May 17, 9:44 PM CDT	Severe Thunderstorm Warning	LSX	Crawford	31 min
May 17, 9:49 PM CDT	Tornado Warning	LSX	Crawford	26 min
May 17, 10:05 PM CDT	Severe Thunderstorm Warning	LSX	Washington	40 min
May 17, 10:13 PM CDT	Severe Thunderstorm Warning	LSX	Crawford	47 min
May 18, 12:15 AM CDT	Severe Thunderstorm Warning	LSX	Franklin	45 min
May 18, 7:11 AM CDT	Severe Thunderstorm Warning	LSX	Knox	49 min
May 18, 7:42 AM CDT	Severe Thunderstorm Warning	LSX	Clark	48 min

Nearby

Severe Thunderstorm Warnings in Missouri, 1997 Every severe thunderstorm warning in 1997

Sources

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