Alert archive / Illinois / Tornado Warnings in 1991

Tornado Warning 25, NWS Lincoln, IL

May 17, 1991Mason County, Illinois

NWS Lincoln, IL issued this tornado warning at May 17, 1991, 11:09 PM CDT for Mason County, Illinois. It was in force for 66 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
May 17, 1991, 11:09 PM CDT (04:09 UTC)
Expired
May 18, 1991, 12:15 AM CDT
In force
66 min
Issued by
NWS Lincoln, IL
Area
Whole counties

County Mason County, IL

What was reported inside it

TimeReportWhereRemark
May 17, 11:35 PM CDTHail 1Mason, 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. Storm Data before 1996 records only tornadoes, thunderstorm wind and hail.

The nearest sounding before it

Paducah/Barkley, KY (KPAH), launched 00:00Z, 4.2 hours before the alert went out and 368 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, Paducah/Barkley, KY at 00:00Z on 1991-05-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1491 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Paducah/Barkley, KY at 00:00Z on 1991-05-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 145 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
1491 J/kg
Mixed-layer CIN
-208 J/kg
Mixed-layer LCL
1263 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
145 m²/s²
0-3 km storm-relative helicity
192 m²/s²
Significant tornado parameter
0.0
Supercell composite
2.6

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KPIA 180409
TORPIA
ILC125-180515-

BULLETIN - IMMEDIATE BROADCAST REQUESTED/EBS ACTIVATION REQUESTED 
TORNADO WARNING 
NATIONAL WEATHER SERVICE PEORIA IL
1109 PM CDT FRI MAY 17 1991

THE NATIONAL WEATHER SERVICE HAS ISSUED A TORNADO WARNING 
EFFECTIVE UNTIL 1215 AM CDT FOR PEOPLE IN THE FOLLOWING COUNTY

   IN THE CENTRAL PART OF ILLINOIS
      MASON

AT 1105 PM A TORNADO WAS INDICATED BY RADAR IN WESTERN MASON
COUNTY ILLINOIS BETWEEN THE CITIES OF BATH AND HAVANA MOVING
EAST AT 25 MPH.

TOWNS IN THE PATH OF THE TORNADO ARE EASTON AND MASON CITY.

IF YOU ARE IN THE PATH OF THIS TORNADO...GO TO A BASEMENT SHELTER
IF AVAILABLE...OTHERWISE TO A CENTRAL INTERIOR ROOM ON THE LOWEST
FLOOR.  ABANDON CARS AND MOBILE HOMES FOR A REINFORCED BUILDING.

THIS IS A DANGEROUS STORM.  TAKE COVER IMMEDIATELY.

ATTN ISP 9

STUMETZ

What forecasters said that day

The local office's own words before this tornado 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 17, 5:19 PM CDT, 5 hours 50 minutes before
ILZ005>007-009-172315-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE PEORIA IL
515 PM CDT FRI MAY 17 1991

...TORNADO WATCH IN EFFECT FOR MUCH OF WEST CENTRAL ILLINOIS TILL 9 PM CDT...

AT 510 PM...RADAR INDICATED A STRONG THUNDERSTORM IN SOUTHERN HENRY COUNTY
NEAR THE TOWN OF ALPHA. THIS STORM IS MOVING EAST NORTHEAST AT AROUND
30 MPH. THIS WILL AFFECT THE NORTHWEST PORTIONS OF BUREAU COUNTY BY 6 PM. TOWNS
THAT WILL BE AFFECTED BY THIS STORM ARE THOMAS...NEW BEDFORD AND MANLIUS.

ANOTHER STORM LOCATED 30 MILES SOUTHWEST OF BURLINGTON WILL CROSS THE
MISSISSIPPI RIVER AROUND 6 PM AFFECTING NORTHERN HENDERSON AND WARREN
COUNTIES.

THESE ARE STRONG STORMS WITH HEAVY RAIN FALL...LARGE HADIL AND POSSIBLE
TORNADOES.

MOGGED
Special weather statement, May 17, 6:05 PM CDT, 5 hours 4 minutes before
ILZ009-010-180000-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SPRINGFIELD IL
6 00 PM CDT FRI MAY 17 1991

...TORNADO WATCH UNTIL 9 PM CDT FOR PORTIONS OF CENTRAL AND EASTERN
   ILLINOIS...

AT 600 PM CDT WEATHER RADAR INDICATED SHOWERS AND THUNDERSTORMS
EXTENDING FROM NORTHEASTERN DOUGLAS COUNTY NEAR NEWMAN...EASTWARD ALONG
THE VERMILION...EDGAR COUNTY LINES.  THE CELLS CONTINUED TO DEVELOP IN
THESE AREAS AND MOVE EASTWARD AT 25 MPH.

THUNDERSTORMS WERE ALSO OVER NORTHWESTERN AND SOUTHWESTERN ILLINOIS.
OTHERWISE...NO THUNDERSTORMS WERE OVER CENTRAL OR EAST CENTRAL ILLINOIS.

TEMPERATURES WILL REMAIN IN THE 80S THIS EVENING...WINDS WILL BE SOUTH
10 TO 20 MPH EXCEPT OVER PORTIONS OuF EAST CENTRAL ILLINOIS...THEY WILL
BE EAST TO NORTHEAST 10 TO 20 MPH...AND TEMPERATURES WILL BE IN THE 70S.
DB
Special weather statement, May 17, 8:01 PM CDT, 3 hours 8 minutes before
ILZ009-010-180200-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SPRINGFIELD IL
8 00 PM CDT FRI MAY 17 1991

...TORNADO WATCH UNTIL 9 PM CDT FOR PORTIONS OF EAST CENTRAL ILLINOIS...
...TORNADO WATCH UNTIL MIDNIGHT FOR MOST OF CENTRAL ILLINOIS...

AT 800 PM CDT NO PRECIPITATION WAS FALLING ACROSS CENTRAL OR EAST
CENTRAL ILLINOIS.

THUNDERSTORMS HAVE BEEN MOVING ACROSS WEST CENTRAL AND NORTHWESTERN
ILLINOIS.  IT IS EXPECTED THESE STORMS WILL 3MOVE OVER PORTIONS OF
CENTRAL ILLINOIS BY MIDNIGHT.

DB
Special weather statement, May 17, 8:59 PM CDT, 2 hours 10 minutes before
ILZ009-010-180300-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SPRINGFIELD IL
9 00 PM CDT FRI MAY 17 1991

...TORNADO WATCH UNTIL MIDNIGHT FOR MOST OF CENTRAL AND PORTIONS
   OF EAST CENTRAL ILLINOIS...

AT 900 PM CDT WEATHER RADARS SHOWS AN AREA OF SHOWERS AND THUNDERSTORMS
NORTH OF A LINE FROM QUINCY TO PEORIA TO 30 MILES SOUTH OF PONTIAC
ILLINOIS. THESE THUNDERSTORMS WAS MOVING EAST AT 20 MPH

THUNDERSTORMS CONTINUE TO MOVE ACROSS WEST CENTRAL AND NORTHWESTERN
ILLINOIS.  IT IS EXPECTED THESE STORMS WILL MOVE OVER PORTIONS OF
CENTRAL ILLINOIS BETWEEN 10 AND 11 PM.

HILLIARD

The office that day

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

IssuedProductOfficeCountiesLasted
May 17, 7:26 PM CDTSevere Thunderstorm WarningILXPutnam64 min
May 17, 7:38 PM CDTSevere Thunderstorm WarningILXMcDonough, Warren67 min
May 17, 7:56 PM CDTSevere Thunderstorm WarningILXMcLean34 min
May 17, 8:11 PM CDTTornado WarningILXFulton, Knox, Peoria64 min
May 17, 8:50 PM CDTTornado WarningILXFulton, Peoria55 min
May 17, 9:24 PM CDTSevere Thunderstorm WarningILXMcLean, Mason, Tazewell, Woodford66 min
May 17, 9:28 PM CDTSevere Thunderstorm WarningILXCass, Menard47 min
May 17, 9:56 PM CDTSevere Thunderstorm WarningILXLogan, Sangamon49 min
May 17, 10:41 PM CDTSevere Thunderstorm WarningILXDeWitt, Macon, Piatt49 min
May 17, 10:48 PM CDTTornado WarningILXMacon42 min
May 17, 11:11 PM CDTSevere Thunderstorm WarningILXChampaign, Douglas49 min
May 17, 11:11 PM CDTSevere Thunderstorm WarningILXColes, Moultrie49 min

Nearby

Tornado Warnings in Illinois, 1991Every tornado warning in 1991Tornadoes 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.