Alert archive / Illinois / Severe Thunderstorm Warnings in 1991

Severe Thunderstorm Warning 55, NWS Lincoln, IL

May 31, 1991DeKalb County, Illinois

NWS Lincoln, IL issued this severe thunderstorm warning at May 31, 1991, 3:39 PM CDT for DeKalb County, Illinois. It was in force for 61 min.

The area

The counties it named.

The facts

Issued: May 31, 1991, 3:39 PM CDT (20:39 UTC)
Expired: May 31, 1991, 4:40 PM CDT
In force: 61 min
Issued by: NWS Lincoln, IL
Area: Whole counties

County DeKalb County, IL

The nearest sounding before it

Dayton/James M C, OH (KDAY), launched 12:00Z, 8.7 hours before the alert went out and 443 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: 281 J/kg
Mixed-layer CIN: -24 J/kg
Mixed-layer LCL: 665 m above ground
0-6 km bulk shear: 33 kt
0-1 km storm-relative helicity: 43 m²/s²
0-3 km storm-relative helicity: 77 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.3

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.

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, May 31, 12:11 PM CDT, 3 hours 28 minutes before

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Special weather statement, May 31, 12:16 PM CDT, 3 hours 23 minutes before

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Special weather statement, May 31, 1:00 PM CDT, 2 hours 39 minutes before

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Special weather statement, May 31, 2:36 PM CDT, 1 hour 3 minutes before

ILZ005-312030-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE PEORIA IL
235 PM CDT FRI MAY 31 1991

...STRONG THUNDERTORMS APPROACHING NORTHWEST ILLINOIS...

AT 230 PM...RADAR INDICATED NO THUNDERSTORMS IN BUREAU COUNTY. HOWEVER...
STRONG THUNDERSTORMS WERE MOVING TOWARD NORTHWEST PARTS OF THE STATE
ABOUT 25 MILES WEST OF THE QUAD CITIES. THE STORMS WERE MOVING EAST
AROUND 30 MPH. THESE STORMS WILL APPROACH WESTERN PARTS OF BUREAU COUNTY
AROUND 430 PM...IF THEY KEEP MOVING AT THE SAME SPEED AND INTENSITY.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT FOR NORTHWEST AND NORTHERN
ILLINOIS...INCLUDING BUREAU COUNTY...UNTIL 500 PM CDT. HAIL...DAMAGING
WINDS AND DEADLY LIGHTNING ARE POSSIBLE WITH THE THUNDERSTORMS IN THIS
AREA. A FLASH FLOOD WATCH IS ALSO IN EFFECT FOR THESE AREAS THIS AFTERNOON
AND TONIGHT FOR THE POSSIBILITY OF FLASH FLOOD PRODUCING HEAVY RAIN IN
ALREADY SATURATED LOCATIONS.
                                          MILLER

The office that day

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

Issued	Product	Office	Counties	Lasted
May 30, 7:15 PM CDT	Severe Thunderstorm Warning	ILX	McDonough, Schuyler	60 min
May 30, 7:26 PM CDT	Severe Thunderstorm Warning	ILX	DeKalb, Lee	49 min
May 31, 3:39 PM CDT	Severe Thunderstorm Warning	ILX	Boone	51 min
May 31, 4:16 PM CDT	Severe Thunderstorm Warning	ILX	Bureau	59 min
May 31, 6:39 PM CDT	Severe Thunderstorm Warning	ILX	Fulton, Peoria, Tazewell	51 min

Nearby

Severe Thunderstorm Warnings in Illinois, 1991 Every severe thunderstorm warning in 1991

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.