Alert archive / Illinois / Tornado Warnings in 1999

Tornado Warning 46, NWS St. Louis, MO

August 12, 1999Brown County, Illinois

NWS St. Louis, MO issued this tornado warning at Aug 12, 1999, 7:48 PM CDT for Brown County, Illinois. It was in force for 47 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: Aug 12, 1999, 7:48 PM CDT (00:48 UTC)
Expired: Aug 12, 1999, 8:35 PM CDT
In force: 47 min
Issued by: NWS St. Louis, MO
Area: Whole counties

County Brown County, IL

What was reported inside it

Time	Report	Where
Aug 12, 8:02 PM CDT	Tornado F1	Mt Sterling, IL
Aug 12, 8:12 PM CDT	Thunderstorm Wind 60	Cooperstown, IL
Aug 12, 8:15 PM CDT	Thunderstorm Wind 60	La Grange, IL

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 watch it was issued in

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

Issued	Product	Office	Lasted
Aug 12, 6:45 PM CDT	Tornado Watch	SPC	5 hr

The nearest sounding before it

Lincoln, IL (KILX), launched 00:00Z, 0.8 hours before the alert went out and 184 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: 1165 J/kg
Mixed-layer CIN: -260 J/kg
Mixed-layer LCL: 1321 m above ground
0-6 km bulk shear: 46 kt
0-1 km storm-relative helicity: 322 m²/s²
0-3 km storm-relative helicity: 437 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.5

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KSTL 130047 RRA
TORSTL
ILC009-130135-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
748 PM CDT THU AUG 12 1999

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A

* TORNADO WARNING FOR...
  BROWN COUNTY IN WEST CENTRAL ILLINOIS

* UNTIL 835 PM CDT

* AT 745 PM CDT... NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  A TORNADO BETWEEN BUCKHORN AND MT. STERLING... MOVING EAST AT 20
  MPH.

* LOCATIONS IN THE PATH...
  MT. STERLING



IF YOU ARE IN THE PATH OF THIS STORM...SEEK SHELTER NOW! A
BASEMENT OFFERS THE BEST PROTECTION. IF NOT AVAILABLE...MOVE TO
THE LOWEST FLOOR AND SEEK SHELTER IN A SMALL INTERIOR ROOM. STAY
AWAY FROM OUTSIDE WALLS AND WINDOWS. MOBILE HOMES SHOULD BE
ABANDONED IN FAVOR OF A MORE SUBSTANTIAL STRUCTURE. DO NOT TRY TO
OUTRUN A TORNADO IN A VEHICLE

PEDIGO/RP

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 12, 7:19 PM CDT	Severe Thunderstorm Warning	LSX	Brown	26 min
Aug 12, 7:46 PM CDT	Severe Thunderstorm Warning	LSX	Brown	44 min
Aug 12, 8:07 PM CDT	Tornado Warning	LSX	Pike	48 min
Aug 12, 10:51 PM CDT	Severe Thunderstorm Warning	LSX	Calhoun	49 min
Aug 12, 11:00 PM CDT	Severe Thunderstorm Warning	LSX	Jersey	50 min
Aug 13, 12:19 AM CDT	Severe Thunderstorm Warning	LSX	Calhoun, Jersey	46 min
Aug 13, 12:21 AM CDT	Severe Thunderstorm Warning	LSX	Madison	49 min

Nearby

Tornado Warnings in Illinois, 1999 Every tornado warning in 1999 Tornadoes 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.