Alert archive / Iowa / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 13, NWS Omaha, NE

May 7, 1997Shelby County, Iowa

NWS Omaha, NE issued this severe thunderstorm warning at May 7, 1997, 3:36 PM CDT for Shelby County, Iowa. It was in force for 64 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 7, 1997, 3:36 PM CDT (20:36 UTC)
Expired
May 7, 1997, 4:40 PM CDT
In force
64 min
Issued by
NWS Omaha, NE
Area
Whole counties

County Shelby County, IA

The radar

The Omaha radar (KOAX), 97 km from the middle of the area, began a volume at 20:36 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
May 7, 2:00 PM CDTSevere Thunderstorm WatchSPC5 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 12:00Z, 8.6 hours before the alert went out and 97 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 12:00Z on 1997-05-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 12:00Z on 1997-05-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 155 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
963 m above ground
0-6 km bulk shear
46 kt
0-1 km storm-relative helicity
155 m²/s²
0-3 km storm-relative helicity
202 m²/s²
Significant tornado parameter
0.0
Supercell composite
5.1

Open this sounding in Storm Lab

The text

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

901 
WUUS1 KOMA 072037 RRA
SVROMA
IAC165-072140-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
336 PM CDT WED MAY 7 1997

* SEVERE THUNDERSTORM WARNING FOR
  SHELBY COUNTY - IN SOUTHWESTERN IOWA

* UNTIL 440 PM CDT
 
* SOME LOCATIONS AFFECTED
  EARLING                      NOW
  WESTPHALIA                   NOW
  CORLEY                       BY AROUND 345 PM CDT
  HARLAN                       BY AROUND 345 PM CDT
  IRWIN                        BY AROUND 355 PM CDT
  JACKSONVILLE                 BY AROUND 400 PM CDT
  BOTNA                        BY AROUND 405 PM CDT
  ELK HORN                     BY AROUND 410 PM CDT

* AT 335 PM CDT...A SEVERE THUNDERSTORM WAS INDICATED BY DOPPLER
  RADAR 37 MILES NORTHEAST OF DOWNTOWN OMAHA OR 5 MILES WEST
  SOUTHWEST OF WESTPHALIA MOVING EAST AT 30 MPH.
 
PEOPLE IN THE WARNED AREA SHOULD GET INTO A REINFORCED SHELTER AND
PREPARE FOR DAMAGING WINDS...LARGE HAIL...VERY HEAVY RAIN...AND
DANGEROUS LIGHTNING.
BYRD

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 7, 10:52 AM CDT, 4 hours 44 minutes before
NEZ011-012-015>018-030>034-042>045-050>053-065>068-078-088>093-
IAZ043-055-056-069-079-080-090-091-081200-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
1055 AM CDT WED MAY 7 1997

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

SPOTTER ACTION...
STORM SPOTTER ACTIVATION MAY BE REQUIRED INTO THIS EVENING OVER EASTERN
NEBRASKA AND WESTERN IOWA.

  DISCUSSION...
THUNDERSTORMS DEVELOPING OVER NORTHEAST NEBRASKA COULD POSSIBLY BECOME
SEVERE EARLY THIS AFTERNOON OVER PARTS OF EAST CENTRAL NEBRASKA AND WEST
CENTRAL IOWA.  THESE STORMS WERE NORTH OF A WARM FRONT THAT WAS ALONG
THE PLATTE RIVER.  OTHER THUNDERSTORM DEVELOPMENT...INCLUDING SOME
POSSIBLY SEVERE...COULD DEVELOP OR MOVE INTO SOUTHEAST NEBRASKA AND
SOUTHWEST IOWA LATER THIS AFTERNOON AS A COLD FRONT ENTERS THE AREA.
THE MAIN THREAT FROM THESE STORMS ARE GUSTY WINDS AND HAIL...ALTHOUGH
SUPERCELL DEVELOPMENT AND A POSSIBLE TORNADO CAN/T PBE RULED OUT.

CHERMOK
Special weather statement, May 7, 10:55 AM CDT, 4 hours 41 minutes before
NEZ011-012-015>018-030>034-042>045-050>053-065>068-078-088>093-
IAZ043-055-056-069-079-080-090-091-081200-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
1055 AM CDT WED MAY 7 1997

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

SPOTTER ACTION...
STORM SPOTTER ACTIVATION MAY BE REQUIRED INTO THIS EVENING OVER EASTERN
NEBRASKA AND WESTERN IOWA.

  DISCUSSION...
THUNDERSTORMS DEVELOPING OVER NORTHEAST NEBRASKA COULD POSSIBLY BECOME
SEVERE EARLY THIS AFTERNOON OVER PARTS OF EAST CENTRAL NEBRASKA AND WEST
CENTRAL IOWA.  THESE STORMS WERE NORTH OF A WARM FRONT THAT WAS ALONG
THE PLATTE RIVER.  OTHER THUNDERSTORM DEVELOPMENT...INCLUDING SOME
POSSIBLY SEVERE...COULD DEVELOP OR MOVE INTO SOUTHEAST NEBRASKA AND
SOUTHWEST IOWA LATER THIS AFTERNOON AS A COLD FRONT ENTERS THE AREA.
THE MAIN THREAT FROM THESE STORMS ARE GUSTY WINDS AND HAIL...ALTHOUGH
SUPERCELL DEVELOPMENT AND A POSSIBLE TORNADO CAN/T BE RULED OUT.

CHERMOK

The office that day

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

IssuedProductOfficeCountiesLasted
May 7, 3:01 PM CDTSevere Thunderstorm WarningOAXPottawattamie64 min
May 7, 4:16 PM CDTSevere Thunderstorm WarningOAXMills, Pottawattamie64 min
May 7, 4:49 PM CDTTornado WarningOAXMills66 min
May 7, 5:58 PM CDTSevere Thunderstorm WarningOAXMontgomery, Page62 min

Nearby

Severe Thunderstorm Warnings in Iowa, 1997Every severe thunderstorm warning in 1997

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; radar from the NEXRAD Level II archive.