Alert archive / Illinois / Severe Thunderstorm Warnings in 1987

Severe Thunderstorm Warning 2, NWS St. Louis, MO

January 7, 1987Madison County, Saint Clair County, Illinois

NWS St. Louis, MO issued this severe thunderstorm warning at Jan 7, 1987, 4:58 PM CST for Madison County, Saint Clair County, Illinois. It was in force for 32 min.

The area

The counties it named.

The facts

Issued
Jan 7, 1987, 4:58 PM CST (22:58 UTC)
Expired
Jan 7, 1987, 5:30 PM CST
In force
32 min
Issued by
NWS St. Louis, MO
Area
Whole counties

Counties Madison County, IL, Saint Clair County, IL

The radar

The WSR-88D network and its archive begin in 1991, so there is no radar volume for this alert.

The nearest sounding before it

Salem-Leckrone, IL (KSLO), launched 12:00Z, 11.0 hours before the alert went out and 88 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, Salem-Leckrone, IL at 12:00Z on 1987-01-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 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, Salem-Leckrone, IL at 12:00Z on 1987-01-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -91 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
812 m above ground
0-6 km bulk shear
77 kt
0-1 km storm-relative helicity
-91 m²/s²
0-3 km storm-relative helicity
24 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.

The office that day

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

IssuedProductOfficeCountiesLasted
Jan 7, 4:03 PM CSTSevere Thunderstorm WarningLSXMadison42 min

Nearby

Severe Thunderstorm Warnings in Illinois, 1987Every severe thunderstorm warning in 1987

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.