Alert archive / Illinois / Severe Thunderstorm Warnings in 1994

Severe Thunderstorm Warning 73, NWS Lincoln, IL

July 21, 1994DeKalb County, Illinois

NWS Lincoln, IL issued this severe thunderstorm warning at Jul 21, 1994, 5:54 PM CDT for DeKalb County, Illinois. It was in force for 31 min.

The area

The counties it named.

The facts

Issued
Jul 21, 1994, 5:54 PM CDT (22:54 UTC)
Expired
Jul 21, 1994, 6:25 PM CDT
In force
31 min
Issued by
NWS Lincoln, IL
Area
Whole counties

County DeKalb County, IL

The nearest sounding before it

Green Bay/Straub, WI (KGRB), launched 12:00Z, 10.9 hours before the alert went out and 293 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, Green Bay/Straub, WI at 12:00Z on 1994-07-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 439 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, Green Bay/Straub, WI at 12:00Z on 1994-07-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 14 square meters per square second.19395878Sfc1 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
439 J/kg
Mixed-layer CIN
-54 J/kg
Mixed-layer LCL
998 m above ground
0-6 km bulk shear
40 kt
0-1 km storm-relative helicity
14 m²/s²
0-3 km storm-relative helicity
36 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

000 
WUUS1 KRFD 212254 RRA
SVRRFD
ILC037-212345-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING 
NATIONAL WEATHER SERVICE ROCKFORD IL
554 PM CDT THU JUL 21 1994

THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM 
WARNING EFFECTIVE UNTIL 645 PM CDT FOR PEOPLE IN THE FOLLOWING 
COUNTY

   IN THE NORTH CENTRAL PART OF ILLINOIS
      SOUTHERN DEKALB

AT 550 PM RADAR INDICATED A SEVERE THUNDERSTORM ON THE DEKALB-
LA SALLE COUNTY LINE IN THE VICINITY OF SOMONAUK. THE CELL WAS
MOVING TO THE NORTHEAST AT 30 MPH.

SOME COMMUNITIES THAT WILL BE AFFECTED BY THIS SEVERE THUNDERSTORM...
SOMONAUK...SANDWICH...HINCKLEY

IF YOU ARE IN THE PATH OF THIS STORM...MOVE OUT OF AREAS THAT ARE
PRONE TO FLOODING AND TAKE SHELTER.  DAMAGING WINDS...LARGE HAIL
AND VERY HEAVY RAIN IS IMMINENT! REMEMBER...SEVERE THUNDERSTORMS
CAN ALSO PRODUCE TORNADOES WITH LITTLE OR NO WARNING!

REHWALD

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, Jul 21, 5:19 PM CDT, 35 minutes before
ILZ029-031-037-212320-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE PEORIA IL
519 PM CDT THU JUL 21 1994

...THUNDERSTORMS WILL CONTINUE TO PUSH THROUGH CENTRAL ILLINOIS...

A SMALL AREA OF THUNDERSTORMS...THAT EXTENDED FROM ABOUT WASHINGTON
THROUGH PEKIN TO GLASFORD...IS EXPECTED TO MOVE EAST NORTHEAST INTO
WOODFORD COUNTY EARLY THIS EVENING. THE STORMS WILL BE ALONG AND SOUTH
OF HIGHWAY 24 IN WOODFORD COUNTY BY 615 PM. PERIODS OF HEAVY RAIN CAN
BE EXPECTED WITH THESE THUNDERSTORMS.

MILLER
Special weather statement, Jul 21, 5:22 PM CDT, 32 minutes before
ILZ029-031-037-212320-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE PEORIA IL
519 PM CDT THU JUL 21 1994

...THUNDERSTORMS WILL CONTINUE TO PUSH THROUGH CENTRAL ILLINOIS...

A SMALL AREA OF THUNDERSTORMS...THAT EXTENDED FROM ABOUT WASHINGTON
THROUGH PEKIN TO GLASFORD...IS EXPECTED TO MOVE EAST NORTHEAST INTO
WOODFORD COUNTY EARLY THIS EVENING. THE STORMS WILL BE ALONG AND SOUTH
OF HIGHWAY 24 IN WOODFORD COUNTY BY 615 PM. PERIODS OF HEAVY RAI2N CAN
BE EXPECTED WITH THESE THUNDERSTORMS.

MILLER

The office that day

Everything else NWS Lincoln, IL issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 21, 6:13 PM CDTSevere Thunderstorm WarningILXMcLean57 min

Nearby

Severe Thunderstorm Warnings in Illinois, 1994Every severe thunderstorm warning in 1994

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.