Alert archive / Missouri / Tornado Warnings in 1999

Tornado Warning 21, NWS St. Louis, MO

April 8, 1999Gasconade County, Missouri

NWS St. Louis, MO issued this tornado warning at Apr 8, 1999, 7:12 PM CDT for Gasconade County, Missouri. It was in force for 48 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
Apr 8, 1999, 7:12 PM CDT (00:12 UTC)
Expired
Apr 8, 1999, 8:00 PM CDT
In force
48 min
Issued by
NWS St. Louis, MO
Area
Whole counties

County Gasconade County, MO

The radar

The St Louis radar (KLSX), 77 km from the middle of the area, began a volume at 00:15 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Apr 8, 5:15 PM CDTTornado WatchSPC4 hr

The nearest sounding before it

Springfield, MO (KSGF), launched 00:00Z, 0.2 hours before the alert went out and 265 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-pSkew-T log-p diagram, Springfield, MO at 00:00Z on 1999-04-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 737 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Springfield, MO at 00:00Z on 1999-04-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 453 square meters per square second.1939587897117136Sfc1 km3 km6 km9 kmRMLM
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
737 J/kg
Mixed-layer CIN
-8 J/kg
Mixed-layer LCL
937 m above ground
0-6 km bulk shear
83 kt
0-1 km storm-relative helicity
453 m²/s²
0-3 km storm-relative helicity
582 m²/s²
Significant tornado parameter
2.5
Supercell composite
13.2

Open this sounding in Storm Lab

The text

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

999 
WFUS1 KSTL 090013 RRA
TORSTL
MOC073-090100-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
712 PM CDT THU APR 8 1999

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A

* TORNADO WARNING FOR...
  NORTHERN GASCONADE COUNTY IN EASTERN MISSOURI

* UNTIL 800 PM CDT

* AT 712 PM CDT... NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  A TORNADO JUST NORTH OF LINN... MOVING NORTHEAST AT 50 MPH.

* LOCATIONS IN THE PATH...
  SWISS
  BAY
  HERMANN



THIS IS A DANGEROUS SITUATION IF IN THE PATH...TAKE COVER NOW
MOVE TO A BASEMENT IF AVAILABLE. IF NOT...STAY ON THE LOWEST LEVEL
AND GO TO A SMALL INTERIOR ROOM. MOBILE HOMES AND AUTOMOBILESHOULD
BE ABANDONED IN FAVOR OF A STRONG STRUCTURE. AS A LAST RESORT...
MOVE TO A DITCH OR CULVERT AND COVER YOUR HEAD.

TS/RP

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 8, 7:20 PM CDTTornado WarningLSXAudrain, Montgomery50 min
Apr 8, 7:33 PM CDTTornado WarningLSXFranklin, Warren47 min
Apr 8, 7:42 PM CDTTornado WarningLSXPike48 min
Apr 8, 8:15 PM CDTTornado WarningLSXGasconade50 min
Apr 8, 8:36 PM CDTSevere Thunderstorm WarningLSXFranklin49 min

Nearby

Tornado Warnings in Missouri, 1999Every tornado warning in 1999Tornadoes in 1999

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.