Alert archive / Iowa / Tornado Warnings in 1991

Tornado Warning 9, NWS Quad Cities, IA

May 17, 1991Muscatine County, Iowa; Rock Island County, Illinois

NWS Quad Cities, IA issued this tornado warning at May 17, 1991, 4:48 PM CDT for Muscatine County, Iowa; Rock Island County, Illinois. It was in force for 27 min.

The area

The counties it named.

The facts

Issued
May 17, 1991, 4:48 PM CDT (21:48 UTC)
Expired
May 17, 1991, 5:15 PM CDT
In force
27 min
Issued by
NWS Quad Cities, IA
Area
Whole counties

Counties Muscatine County, IA, Rock Island County, IL

The nearest sounding before it

Green Bay/Straub, WI (KGRB), launched 12:00Z, 9.8 hours before the alert went out and 402 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 1991-05-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1 joules per kilogram.LCLEL10008507005003002001001 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 1991-05-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 6 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
1 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
532 m above ground
0-6 km bulk shear
42 kt
0-1 km storm-relative helicity
6 m²/s²
0-3 km storm-relative helicity
54 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 
TTAA00 KMLI 172148
TORMLI
IAC139-ILC161-172215-

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

THE NATIONAL WEATHER SERVICE HAS ISSUED A TORNADO WARNING 
EFFECTIVE UNTIL 515 PM CDT FOR PEOPLE IN THE FOLLOWING 
COUNTIES

   IN THE EXTREME EAST PART OF IOWA
      EXTREME EASTERN MUSCATINE...

   IN THE NORTHWEST PART OF ILLINOIS
      SOUTHERN ROCK-ISLAND...

AT 440 PM... A TORNADO WAS REPORTED 7 MILES NORTHWEST OF
BUFFALO...WHICH IS 12 MILES WEST OF THE QUAD CITIES.  THE
STORM WAS MOVING NORTHEAST AT 30 MPH.

SOME CITIES/TOWNS IN THE PATH OF THIS STORM INCLUDE... BUFFALO...
 BLUEGRASS...MONTPEIIER...THE QUAD CITY METRO AREA.

THIS IS A DANGEROUS STORM SITUATION.  ACT QUICKLY.  IF YOU ARE
IN THE PATH OF THIS TORNADO MOVE TO A SHELTER BELOW GROUND IF
AVAILABLE.  OTHERWISE...GO TO A SMALL INTERIOR ROOM ON THE LOWEST
FLOOR POSSIBLE.  AVOID WINDOWS.  ABANDON CARS AND MOBILE HOMES
FOR A REINFORCED BUILDING OR GET INTO A DITCH OR CULVERT.

REPORTS OF TORNADOS OR TORNADO DAMAGE SHOULD BE GIVEN TO A LAW
ENFORCEMENT AGENCY FOR RELAY TO THE NATIONAL WEATHER SERVICE.

IF YOU LIVE IN A HOME OR APARTMENT...FIND SHELTER IN THE INNERMOST
PORTION OF THE BUILDING ON THE LOWEST FLOOR.  GET TO A BASEMENT IF
ONE IS AVAILABLE.  AVOID WINDOWS.  PROTECT YOURSELF FROM FLYING
DEBRIS WITH CUSHIONS...BLANKETS...OR PILLOWS.

ATTN ISP 7 AND 1

LAGUE



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, 2:49 PM CDT, 1 hour 59 minutes before
IAZ008-ILZ001-WIZ018-172045-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DUBUQUE IA
255 PM CDT FRI MAY 17 1991

...TORNADO WATCH FOR MUCH OF TRI-STATE AREA UNTIL 900 PM CDT...

AT 250 PM CDT...NO STORMS WERE IN THE TRI-STATE AREA...HOWEVER THERE
WERE STORMS 40 MILES SOUTHWEST AND 60 MILES WEST OF DUBUQUE THAT WERE
MOVING NORTH AT 20 MILES AN HOUR.

SEVERE STORMS MAY DEVELOP ANYWHERE OVER THE TRI-STATE AREA THE REMAINDER
OF THIS AFTERNOON...AND TORNADOES SPAWN FROM SEVERE THUNDERSTORMS SO BE
ON THE LOOKOUT FOR DANGEROUS STORMS AND IF THREATENING WEATHER IS
SIGHTED...TAKE COVER IMMEDIATELY.

GRANT COUNTY AND LAFAYETTE COUNTY IN WISCONSIN...PLUS JO-DAVIES
COUNTY IN ILLINOIS ARE $NOT IN THIS WATCH AT THIS TIME BUT MAY ALSO
RECEIVE SOME SEVERE WEATHER.
KOWALSKI
NNNN
Special weather statement, May 17, 3:14 PM CDT, 1 hour 34 minutes before
IAZ008-ILZ001-WIZ018-172115-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DUBUQUE IA
314 PM CDT FRI MAY 17 1991

...TORNADO WATCH FOR MUCH OF TRI-STATE AREA UNTIL 900 PM CDT...

AT 310 PM CDT...RADAR INDICATED SHOWERS AND THUNDERSTORMS IN THE
SOUTHWEST PART OF THE TRI-STATE AREA...NEAR ANAMOSA AND MONTICELLO IN
JONES COUNTY...30 TO 40 MILES SOUTHWEST OF DUBUQUE.

ELSEWHERE...SHOWERS AND A FEW THUNDERSTORMS WERE LOCATED 40 TO 60
MILES WEST THROUGH SOUTHWEST OF DUBUQUE.

MOVEMENT OF THE STORMS WERE NORTHEAST AT 20 MILES AN HOUR AND WILL
CONTINUE TO MOVE THROUGH JONES COUNTY.

NO SEVERE WEATHER WAS IN THE AREA AT THIS 310 PM CDT.

THE TORNADO WATCH DOES NOT INCLUDE GRANT AND GLAFAYETTE COUNTIES IN
WISCONSIN...OR JO-DAVIES COUNTY IN ILLINOIS AT THIS TIME.
KOWALSKI

NNNN
Special weather statement, May 17, 3:24 PM CDT, 1 hour 24 minutes before
ILZ004-IAZ015-172230-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOLINE IL
320 PM CDT FRI MAY 17 1991

...STRONG THUNDERSTORMS APPROACHING THE BISTATE AREA...

AT 330 PM... RADAR INDICATED AN AREA OF STRONG THUNDERSTORMS
MOVING TOWARD THE IOWA PORTIONS OF THE BISTATE AREA.  THE STORMS
WERE MOVING INTO MUSCATINE AND CEDAR COUNTIES.  THESE STORMS HAVE
A HISTORY OF PRODUCING HAIL...HEAVY RAINS AND STRONG WINDS.  THE
STORMS WERE MOVING NORTHEAST AT 30 MPH.

OTHER STORMS WERE DEVELOPING NEAR KEITHSBURG ILLINOIS.  THESE STORMS
WERE DEVELOPING RAPIDLY AND MOVING NORTHEAST AT 30 MPH.

LAGUE
Special weather statement, May 17, 4:41 PM CDT, 7 minutes before
IAZ008-172245-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DUBUQUE IA
441 PM CDT FRI MAY 17 1991

...TORNADO WATCH FOR IOWA COUNTIES IN TRI-STATE AREA...

AT 435 PM CDT...RADAR INDICATED THUNDERSTORMS OVER THE SOUTHERN PART OF
THE TRI-STATE AREA OVER MUCH OF JACKSON COUNTY.  THE STORMS WERE
PRODUCING HEAVY RAINS AND WERE MOVING EAST NORTHEAST AT 30 MILES AN
HOUR AND WERE LOCATED 10 TO 30 MILES SOUTH OF DUBUQUE.

ELSE WHERE SHOWERS AND THUNDERSTORMS WERE SCATTERED OVER THE REMAINDER
OF THE TRI-STATE AREA.

NO SEVERE WEATHER HAS BEEN REPORTED AS YET OVER THE TRI-STATES...BUT
A TORNADO WATCH REMAINS IN EFFECT AND SEVERE THUNDERSTORMS ALONG WITH
TORNADOES ARE POSSIBLE.

KEEP AN EYE TO THE SKY...AND IF THREATENING WEATHER APPROACHES...TAKE
COVER IMMEDIATELY.
KOWALSKI

NNNN

The office that day

Everything else NWS Quad Cities, IA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 17, 3:46 PM CDTSevere Thunderstorm WarningDVNDelaware59 min
May 17, 3:59 PM CDTTornado WarningDVNMuscatine31 min
May 17, 4:19 PM CDTTornado WarningDVNScott41 min
May 17, 5:02 PM CDTTornado WarningDVNScott28 min
May 17, 6:13 PM CDTSevere Thunderstorm WarningDVNLee62 min
May 17, 6:21 PM CDTFlash Flood WarningDVNScott2 hr
May 17, 5:40 PM CDTSevere Thunderstorm WarningDVNHenry, Rock Island, Whiteside50 min

Nearby

Tornado Warnings in Iowa, 1991Tornado 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; the sounding from the Mesonet's radiosonde archive.