Alert archive / Illinois / Tornado Warnings in 1999

Tornado Warning 47, NWS St. Louis, MO

August 12, 1999Pike County, Illinois

NWS St. Louis, MO issued this tornado warning at Aug 12, 1999, 8:07 PM CDT for Pike County, Illinois. It was in force for 48 min. 1 report 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, 8:07 PM CDT (01:07 UTC)
Expired
Aug 12, 1999, 8:55 PM CDT
In force
48 min
Issued by
NWS St. Louis, MO
Area
Whole counties

County Pike County, IL

The radar

The St Louis radar (KLSX), 104 km from the middle of the area, began a volume at 01:07 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

TimeReportWhereRemark
Aug 12, 8:13 PM CDTTornado F0Chambersburg, 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.

IssuedProductOfficeLasted
Aug 12, 6:45 PM CDTTornado WatchSPC5 hr

The nearest sounding before it

Lincoln, IL (KILX), launched 00:00Z, 1.1 hours before the alert went out and 204 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, Lincoln, IL at 00:00Z on 1999-08-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1165 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Lincoln, IL at 00:00Z on 1999-08-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 322 square meters per square second.193958Sfc1 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
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 130106 RRA
TORSTL
ILC149-130155-

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

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A

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

* UNTIL 855 PM CDT

* AT 806 PM... NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  TORNADO 6 MILES NORTH OF GRIGGSVILLE... MOVING EAST NORTHEAST AT
  25 MPH.

* LOCATIONS IN THE PATH...
  CHAMBERSBURG
  PERRY

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 AJND WINDOWS. MOBILE HOMES SHOULD BE
ABANDONED IN FAVOR OF A MORE SUBSTANTIAL STRUCTURE. DO NOT TRY TO
OUTRUN A TORNADO IN A VEHICLE

GLASS/RP

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 12, 7:19 PM CDTSevere Thunderstorm WarningLSXBrown26 min
Aug 12, 7:46 PM CDTSevere Thunderstorm WarningLSXBrown44 min
Aug 12, 7:48 PM CDTTornado WarningLSXBrown47 min
Aug 12, 10:51 PM CDTSevere Thunderstorm WarningLSXCalhoun49 min
Aug 12, 11:00 PM CDTSevere Thunderstorm WarningLSXJersey50 min
Aug 13, 12:19 AM CDTSevere Thunderstorm WarningLSXCalhoun, Jersey46 min
Aug 13, 12:21 AM CDTSevere Thunderstorm WarningLSXMadison49 min

Nearby

Tornado Warnings in Illinois, 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.