Alert archive / Iowa / Severe Thunderstorm Watches in 2000

Severe Thunderstorm Watch 573

July 11, 200029 counties in Iowa; 9 counties in Nebraska; 8 counties in South Dakota

The Storm Prediction Center issued this severe thunderstorm watch at Jul 11, 2000, 7:30 PM CDT for 29 counties in Iowa; 9 counties in Nebraska; 8 counties in South Dakota. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Jul 11, 2000, 7:30 PM CDT (00:30 UTC)
Expired
Jul 12, 2000, 1:00 AM CDT
In force
6 hr
Issued by
the Storm Prediction Center
All 46 counties

Audubon County, IA, Boone County, IA, Buena Vista County, IA, Calhoun County, IA, Carroll County, IA, Cherokee County, IA, Clay County, IA, Crawford County, IA, Dallas County, IA, Dickinson County, IA, Emmet County, IA, Greene County, IA, Guthrie County, IA, Harrison County, IA, Humboldt County, IA, Ida County, IA, Lyon County, IA, Monona County, IA, O'Brien County, IA, Osceola County, IA, Palo Alto County, IA, Plymouth County, IA, Pocahontas County, IA, Polk County, IA, Sac County, IA, Shelby County, IA, Sioux County, IA, Webster County, IA, Woodbury County, IA, Burt County, NE, Cedar County, NE, Cuming County, NE, Dakota County, NE, Dixon County, NE, Dodge County, NE, Thurston County, NE, Washington County, NE, Wayne County, NE, Bon Homme County, SD, Clay County, SD, Douglas County, SD, Hutchinson County, SD, Lincoln County, SD, Turner County, SD, Union County, SD, Yankton County, SD

The radar

The Sioux Falls radar (KFSD), 103 km from the middle of the area, began a volume at 00:32 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.

Warnings issued inside it

23 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
Jul 11, 7:30 PM CDTTornado WarningFSDLincoln30 min
Jul 11, 7:44 PM CDTTornado WarningFSDLincoln, Turner31 min
Jul 11, 7:52 PM CDTSevere Thunderstorm WarningFSDLyon23 min
Jul 11, 8:05 PM CDTSevere Thunderstorm WarningOAXCedar40 min
Jul 11, 8:06 PM CDTSevere Thunderstorm WarningFSDClay, Yankton54 min
Jul 11, 8:18 PM CDTSevere Thunderstorm WarningFSDUnion27 min
Jul 11, 8:35 PM CDTSevere Thunderstorm WarningFSDDixon25 min
Jul 11, 8:36 PM CDTTornado WarningFSDOsceola24 min
Jul 11, 8:52 PM CDTTornado WarningFSDPlymouth23 min
Jul 11, 8:57 PM CDTSevere Thunderstorm WarningFSDDakota, Dixon33 min
Jul 11, 9:21 PM CDTSevere Thunderstorm WarningOAXCedar24 min
Jul 11, 9:28 PM CDTSevere Thunderstorm WarningFSDDixon32 min
Jul 11, 9:40 PM CDTSevere Thunderstorm WarningFSDWoodbury35 min
Jul 11, 9:56 PM CDTSevere Thunderstorm WarningOAXColfax, Cuming49 min
Jul 11, 9:57 PM CDTSevere Thunderstorm WarningFSDDakota, Dixon33 min
Jul 11, 10:03 PM CDTSevere Thunderstorm WarningOAXThurston57 min
Jul 11, 10:04 PM CDTSevere Thunderstorm WarningFSDIda26 min
Jul 11, 10:17 PM CDTSevere Thunderstorm WarningDMXSac28 min
Jul 11, 10:44 PM CDTSevere Thunderstorm WarningOAXMonona31 min
Jul 11, 10:46 PM CDTSevere Thunderstorm WarningDMXCalhoun, Sac44 min
Jul 11, 10:46 PM CDTSevere Thunderstorm WarningOAXCuming, Dodge29 min
Jul 11, 11:01 PM CDTSevere Thunderstorm WarningDMXCarroll44 min
Jul 11, 11:15 PM CDTSevere Thunderstorm WarningOAXDodge, Douglas, Washington45 min

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 0.5 hours before the alert went out and 153 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 2000-07-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3053 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 2000-07-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 36 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
3053 J/kg
Mixed-layer CIN
-9 J/kg
Mixed-layer LCL
1183 m above ground
0-6 km bulk shear
31 kt
0-1 km storm-relative helicity
36 m²/s²
0-3 km storm-relative helicity
53 m²/s²
Significant tornado parameter
0.5
Supercell composite
5.8

Open this sounding in Storm Lab

The text

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

309 
WWUS9 KMKC 120027
SEL3  

SEL3  
MKC WW 120023
IAZ000-NEZ000-SDZ000-120600-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 573
STORM PREDICTION CENTER NORMAN OK
723 PM CDT TUE JUL 11 2000

THE STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

   WESTERN IOWA                               
   EASTERN NEBRASKA                           
   SOUTHEASTERN SOUTH DAKOTA                       

EFFECTIVE THIS TUESDAY NIGHT AND WEDNESDAY MORNING FROM 730 PM
UNTIL 100 AM CDT.

HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 80
MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE SEVERE THUNDERSTORM WATCH AREA IS ALONG AND 95 STATUTE MILES
EAST AND WEST OF A LINE FROM 55 MILES NORTHEAST OF YANKTON SOUTH
DAKOTA TO 70 MILES WEST OF DES MOINES IOWA.

REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE
FAVORABLE FOR SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH AREA. 
PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR THREATENING
WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS AND POSSIBLE
WARNINGS.

OTHER WATCH INFORMATION...  CONTINUE...WW 572...

DISCUSSION...WRN EXTENT OF MN/SD ACTIVITY IS MOVING SEWD AT 35 KT
AND WILL INTERACTING WITH INSTABILITY GRADIENT.  SBCAPE 0F 3000 TO
5000 J/KG IS ALONG AN AXIS ACROSS ERN NEB/WRN IA INDICATING THAT
ACTIVITY WILL MOVE SEWD ALONG WEAK WRM FRONTAL BOUNDARY.


AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 2 INCHES.  EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 70
KNOTS.  A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 600.  MEAN STORM
MOTION VECTOR 29035.


...MCCARTHY

432,0944 413,0931 413,0965 432,0983

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 11, 11:00 PM CDTSevere Thunderstorm WatchSPCAdair, Adams, Cass, Clarke, Decatur, Fremont and 10 more5 hr
Jul 12, 3:15 PM CDTSevere Thunderstorm WatchSPCBanner, Box Butte, Cheyenne, Dawes, Deuel, Garden and 5 more7 hr

Nearby

Severe Thunderstorm Watches in Iowa, 2000Severe Thunderstorm Watches in Nebraska, 2000Severe Thunderstorm Watches in South Dakota, 2000Every severe thunderstorm watch in 2000

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.