Alert archive / Iowa / Tornado Warnings in 1998

Tornado Warning 19, NWS Omaha, NE

May 21, 1998Pottawattamie County, Iowa

NWS Omaha, NE issued this tornado warning at May 21, 1998, 8:47 PM CDT for Pottawattamie County, Iowa. It was in force for 33 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
May 21, 1998, 8:47 PM CDT (01:47 UTC)
Expired
May 21, 1998, 9:20 PM CDT
In force
33 min
Issued by
NWS Omaha, NE
Area
Whole counties

County Pottawattamie County, IA

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 1.8 hours before the alert went out and 69 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, Omaha, NE at 00:00Z on 1998-05-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 66 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, Omaha, NE at 00:00Z on 1998-05-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 300 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
66 J/kg
Mixed-layer CIN
-295 J/kg
Mixed-layer LCL
905 m above ground
0-6 km bulk shear
59 kt
0-1 km storm-relative helicity
300 m²/s²
0-3 km storm-relative helicity
484 m²/s²
Significant tornado parameter
0.0
Supercell composite
7.6

Open this sounding in Storm Lab

The text

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

442 
WFUS1 KOMA 220149 RRA
TOROMA
IAC155-220220-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
847 PM CDT THU MAY 21 1998

THE NATIONAL WEATHER SERVICE IN OMAHA HAS ISSUED A

* TORNADO WARNING FOR...
  EXTREME NORTHEASTERN POTTAWATTAMIE COUNTY IN SOUTHWESTERN IOWA

* UNTIL 920 PM CDT

* AT 845 PM CDT... NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  A POSSIBLE TORNADO 34 MILES EAST NORTHEAST OF DOWNTOWN OMAHA OR 2
  MILES WEST OF WALNUT MOVING EAST SOUTHEAST AT 25 MPH.  A FUNNEL
  CLOUD WAS REPORTED IN WALNUT IOWA AREA AT 845 PM CDT.

* THE TORNADO IS EXPECTED TO BE NEAR...
  WALNUT                       NOW

PERSONS IN THE WARNED AREA SHOULD TAKE SHELTER IN A BASEMENT IF
AVAILABLE.  OTHERWISE GO TO A SMALL INTERIOR ROOM ON THE LOWEST
FLOOR.  CARS AND MOBILE HOMES SHOULD BE ABANDONED.

MILLER

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 21, 5:05 PM CDT, 3 hours 42 minutes before
NEZ011-012-015>018-030>034-042>045-050>053-065>068-078-088>093-
IAZ043-055-056-069-079-080-090-091-221200-

SEVERE WEATHER OUTLOOK
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
505 PM CDT THU MAY 21 1998

...SEVERE WEATHER OUTLOOK FOR EASTERN NEBRASKA AND SOUTHWEST IOWA...

SPOTTER ACTION...
STORM SPOTTER ACTIVATION MAY BE NEEDED TONIGHT IN EASTERN NEBRASKA
AND SOUTHWEST IOWA.

DISCUSSION...
THUNDERSTORMS WILL BE SCATTERED ACROSS MUCH OF EASTERN NEBRASKA AND
SOUTHWEST IOWA THROUGH TONIGHT.  THE CHANCE OF SEVERE STORMS IS
SLIGHTLY HIGHER SOUTH OF A LINE FROM NELIGH TO TEKAMAH AND HARLAN
IOWA WHERE THE ATMOSPHERE IS MORE UNSTABLE.  THUNDERSTORMS WILL HAVE
POTENTIAL TO PRODUCE DAMAGING WINDS AND HAIL.  SIGNIFICANT RAINFALL
IS ALSO POSSIBLE.
>
A NEARLY STATIONARY FRONT EXTENDS FROM SOUTHERN MISSOURI TO NORTHERN
KANSAS AND EASTERN WYOMING.  VERY MOIST AND UNSTABLE AIR SOUTH OF THE
FRONT WILL CONTINUE TO BE LIFTED NORTH ACROSS NEBRASKA AND SOUTHWEST
IOWA...WHILE UPPER LEVEL DISTURBANCES TRACK OVER THE AREA.

MILLER
Special weather statement, May 21, 5:05 PM CDT, 3 hours 42 minutes before
NEZ011-012-015>018-030>034-042>045-050>053-065>068-078-088>093-
IAZ043-055-056-069-079-080-090-091-221200-

SEVERE WEATHER OUTLOOK
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
505 PM CDT THU MAY 21 1998

...SEVERE WEATHER OUTLOOK FOR EASTERN NEBRASKA AND SOUTHWEST IOWA...

SPOTTER ACTION...
STORM SPOTTER ACTIVATION MAY BE NEEDED TONIGHT IN EASTERN NEBRASKA
AND SOUTHWEST IOWA.

DISCUSSION...
THUNDERSTORMS WILL BE SCATTERED ACROSS MUCH OF EASTERN NEBRASKA AND
SOUTHWEST IOWA THROUGH TONIGHT.  THE CHANCE OF SEVERE STORMS IS
SLIGHTLY HIGHER SOUTH OF A LINE FROM NELIGH TO TEKAMAH AND HARLAN
IOWA WHERE THE ATMOSPHERE IS MORE UNSTABLE.  THUNDERSTORMS WILL HAVE
POTENTIAL TO PRODUCE DAMAGING WINDS AND HAIL.  SIGNIFICANT RAINFALL
IS ALSO POSSIBLE.
>
A NEARLY STATIONARY FRONT EXTENDS FROM SOUTHERN MISSOURI TO NORTHERN
KANSAS AND EASTERN WYOMING.  VERY MOIST AND UNSTABLE AIR SOUTH OF THE
FRONT WILL CONTINUE TO BE LIFTED NORTH ACROSS NEBRASKA AND SOUTHWEST
IOWA...WHILE UPPER LEVEL DISTURBANCES TRACK OVER THE AREA.

MILLER
Local storm report, May 21, 8:28 PM CDT, 19 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
828 PM CDT THU MAY 21 1998

TIME(CDT)  .....CITY LOCATION..... STATE  ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0535 PM    1 S NORFOLK               NE   70 MPH TSTM GUST
05/21/98   MADISON                        WINDOWS BROKEN

0550 PM    NORFOLK                   NE   60 MPH TSTM GUST
05/21/98   MADISON

0558 PM    STANTON                   NE   60 MPH TSTM GUST
05/21/98   STANTON                        TREE LIMBS DOWN

0600 PM    2 W STANTON               NE   70 MPH TSTM GUST
05/21/98   STANTON

0600 PM    10 SW STANTON             NE   70 MPH TSTM GUST
05/21/98   STANTON                        NUMEROUS POWER LINES DOWN

0600 PM    2 S STANTON               NE   70 MPH TSTM GUST
05/21/98   STANTON                        TREES DOWN

0605 PM    2 SE STANTON              NE   .75 INCH HAIL
05/21/98   STANTON

0615 PM    5 E STANTON               NE   70 MPH TSTM GUST
05/21/98   STANTON                        TREE DAMAGE TO HOUSE AND
                                          CAR

0715 PM    CRAIG                     NE   WIND DAMAGE
05/21/98   BURT

0754 PM    2 S BLENCOE               IA   .75 INCH HAIL
05/21/98   MONONA

0801 PM    2 S MAGNOLIA              IA   TORNADO
05/21/98   HARRISON

0806 PM    WOODBINE                  IA   .75 INCH HAIL
05/21/98   HARRISON

0810 PM    4 NE LOGAN                IA   .75 INCH HAIL
05/21/98   HARRISON

0810 PM    WOODBINE                  IA   70 MPH TSTM GUST
05/21/98   HARRISON                       TREE LIMBS DOWN ALL OVER
                                          TOWN

ZAPOTOCNY
Local storm report, May 21, 8:28 PM CDT, 19 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
828 PM CDT THU MAY 21 1998

TIME(CDT)  .....CITY LOCATION..... STATE  ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0535 PM    1 S NORFOLK               NE   70 MPH TSTM GUST
05/21/98   MADISON                        WINDOWS BROKEN

0550 PM    NORFOLK                   NE   60 MPH TSTM GUST
05/21/98   MADISON

0558 PM    STANTON                   NE   60 MPH TSTM GUST
05/21/98   STANTON                        TREE LIMBS DOWN

0600 PM    2 W STANTON               NE   70 MPH TSTM GUST
05/21/98   STANTON

0600 PM    10 SW STANTON             NE   70 MPH TSTM GUST
05/21/98   STANTON                        NUMEROUS POWER LINES DOWN

0600 PM    2 S STANTON               NE   70 MPH TSTM GUST
05/21/98   STANTON                        TREES DOWN

0605 PM    2 SE STANTON              NE   .75 INCH HAIL
05/21/98   STANTON

0615 PM    5 E STANTON               NE   70 MPH TSTM GUST
05/21/98   STANTON                        TREE DAMAGE TO HOUSE AND
                                          CAR

0715 PM    CRAIG                     NE   WIND DAMAGE
05/21/98   BURT

0754 PM    2 S BLENCOE               IA   .75 INCH HAIL
05/21/98   MONONA

0801 PM    2 S MAGNOLIA              IA   TORNADO
05/21/98   HARRISON

0806 PM    WOODBINE                  IA   .75 INCH HAIL
05/21/98   HARRISON

0810 PM    4 NE LOGAN                IA   .75 INCH HAIL
05/21/98   HARRISON

0810 PM    WOODBINE                  IA   70 MPH TSTM GUST
05/21/98   HARRISON                       TREE LIMBS DOWN ALL OVER
                                          TOWN

ZAPOTOCNY

The office that day

Everything else NWS Omaha, NE issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 21, 7:29 PM CDTSevere Thunderstorm WarningOAXHarrison, Monona61 min
May 21, 7:50 PM CDTTornado WarningOAXHarrison, Monona50 min
May 22, 2:36 AM CDTSevere Thunderstorm WarningOAXPage64 min

Nearby

Tornado Warnings in Iowa, 1998Every tornado warning in 1998Tornadoes in 1998

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.