Alert archive / Iowa / Severe Thunderstorm Watches in 2005

Severe Thunderstorm Watch 521

June 24, 200543 counties in Iowa; 30 counties in Nebraska; Clay County, Union County, Yankton County, South Dakota

The Storm Prediction Center issued this severe thunderstorm watch at Jun 24, 2005, 9:25 PM CDT for 43 counties in Iowa; 30 counties in Nebraska; Clay County, Union County, Yankton County, South Dakota. It was in force for 8 hr.

The area

The outline as issued.

The facts

Issued
Jun 24, 2005, 9:25 PM CDT (02:25 UTC)
Expired
Jun 25, 2005, 5:00 AM CDT
In force
8 hr
Issued by
the Storm Prediction Center
All 76 counties

Audubon County, IA, Boone County, IA, Bremer County, IA, Buena Vista County, IA, Butler County, IA, Calhoun County, IA, Carroll County, IA, Cerro Gordo County, IA, Cherokee County, IA, Clay County, IA, Crawford County, IA, Dallas County, IA, Floyd County, IA, Franklin County, IA, Greene County, IA, Grundy County, IA, Guthrie County, IA, Hamilton County, IA, Hancock County, IA, Hardin County, IA, Harrison County, IA, Humboldt County, IA, Ida County, IA, Jasper County, IA, Kossuth County, IA, Marshall County, IA, Mitchell County, IA, Monona County, IA, O'Brien County, IA, Palo Alto County, IA, Plymouth County, IA, Pocahontas County, IA, Polk County, IA, Sac County, IA, Shelby County, IA, Sioux County, IA, Story County, IA, Tama County, IA, Webster County, IA, Winnebago County, IA, Woodbury County, IA, Worth County, IA, Wright County, IA, Antelope County, NE, Boone County, NE, Burt County, NE, Butler County, NE, Cedar County, NE, Colfax County, NE, Cuming County, NE, Dakota County, NE, Dixon County, NE, Dodge County, NE, Douglas County, NE, Garfield County, NE, Greeley County, NE, Holt County, NE, Howard County, NE, Knox County, NE, Madison County, NE, Merrick County, NE, Nance County, NE, Pierce County, NE, Platte County, NE, Polk County, NE, Saunders County, NE, Sherman County, NE, Stanton County, NE, Thurston County, NE, Valley County, NE, Washington County, NE, Wayne County, NE, Wheeler County, NE, Clay County, SD, Union County, SD, Yankton County, SD

The radar

The Omaha radar (KOAX), 117 km from the middle of the area, began a volume at 02:27 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

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

IssuedProductOfficeCountiesLasted
Jun 24, 9:30 PM CDTSevere Thunderstorm WarningFSDWoodbury46 min
Jun 24, 9:40 PM CDTSevere Thunderstorm WarningFSDBuena Vista37 min
Jun 24, 9:44 PM CDTSevere Thunderstorm WarningDMXPocahontas51 min
Jun 24, 9:46 PM CDTSevere Thunderstorm WarningOAXCuming18 min
Jun 24, 10:24 PM CDTSevere Thunderstorm WarningDMXSac51 min
Jun 24, 10:26 PM CDTSevere Thunderstorm WarningFSDWoodbury35 min
Jun 24, 10:30 PM CDTSevere Thunderstorm WarningDMXCalhoun45 min
Jun 24, 11:16 PM CDTFlash Flood WarningFSDBuena Vista4 hr
Jun 24, 11:44 PM CDTFlash Flood WarningFSDCherokee4 hr
Jun 25, 12:17 AM CDTSevere Thunderstorm WarningFSDUnion29 min
Jun 25, 1:06 AM CDTFlash Flood WarningDMXWebster6 hr
Jun 25, 2:23 AM CDTFlash Flood WarningFSDPlymouth2 hr
Jun 25, 3:10 AM CDTFlash Flood WarningFSDBuena Vista, Cherokee2 hr

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 2.4 hours before the alert went out and 117 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 2005-06-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2829 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 2005-06-25The 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
2829 J/kg
Mixed-layer CIN
-49 J/kg
Mixed-layer LCL
1743 m above ground
0-6 km bulk shear
29 kt
0-1 km storm-relative helicity
155 m²/s²
0-3 km storm-relative helicity
310 m²/s²
Significant tornado parameter
0.7
Supercell composite
19.2

Open this sounding in Storm Lab

The text

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

000 
WWUS20 KWNS 250223
SEL1  
SPC WW 250223
IAZ000-NEZ000-SDZ000-251000-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 521
NWS STORM PREDICTION CENTER NORMAN OK
925 PM CDT FRI JUN 24 2005

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

       NORTHERN AND CENTRAL IOWA
       NORTHERN AND EASTERN NEBRASKA
       SOUTHEAST SOUTH DAKOTA

EFFECTIVE THIS FRIDAY NIGHT AND SATURDAY MORNING FROM 925 PM UNTIL
500 AM CDT.

HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 65
MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 65
STATUTE MILES NORTH AND SOUTH OF A LINE FROM 10 MILES NORTH
NORTHEAST OF WATERLOO IOWA TO 5 MILES NORTH NORTHWEST OF BURWELL
NEBRASKA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU1).

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. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY DO PRODUCE
TORNADOES.

OTHER WATCH INFORMATION...THIS SEVERE THUNDERSTORM WATCH REPLACES
SEVERE THUNDERSTORM WATCH NUMBER 518. WATCH NUMBER 518 WILL NOT BE
IN EFFECT AFTER 925 PM CDT. CONTINUE...WW 517...WW 520...

DISCUSSION...ELEVATED TSTMS EXPECTED TO INCREASE OVER WW AREA
THROUGH EARLY SATURDAY AS LLJ/MOISTURE TRANSPORT STRENGTHEN ATOP
STALLING FRONTAL ZONE. GREATEST SEVERE THREAT SHOULD BE
HAIL...ALTHOUGH SMALL SCALE BOWING SEGMENTS WITH DAMAGING WIND COULD
ALSO DEVELOP GIVEN UNIDIRECTIONAL CLOUD LAYER WIND AND HIGH PWS.

AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 55
KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM
MOTION VECTOR 25025.


...CORFIDI

414,0921 405,0991 424,0991 433,0921

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 24, 8:42 PM CDTMesoscale DiscussionSPCAdair, Adams, Allamakee, Audubon, Benton, Black Hawk and 74 more33 min
Jun 25, 12:04 AM CDTMesoscale DiscussionSPCAudubon, Black Hawk, Boone, Bremer, Buena Vista, Butler and 40 more86 min
Jun 25, 2:08 AM CDTMesoscale DiscussionSPCCarroll, Crawford, Harrison, Ida, Monona, Sac and 1 more67 min
Jun 25, 3:23 AM CDTMesoscale DiscussionSPCBoone, Calhoun, Carroll, Crawford, Greene, Grundy and 9 more37 min
Jun 25, 3:35 PM CDTMesoscale DiscussionSPCAdair, Audubon, Benton, Black Hawk, Boone, Bremer and 29 more115 min
Jun 25, 6:13 PM CDTMesoscale DiscussionSPCAdair, Adams, Audubon, Buena Vista, Calhoun, Carroll and 26 more3 hr
Jun 24, 7:32 PM CDTMesoscale DiscussionSPCArthur, Banner, Box Butte, Chase, Cherry, Cheyenne and 16 more88 min
Jun 24, 10:10 PM CDTSevere Thunderstorm WatchSPCAdams, Buffalo, Clay, Dawson, Fillmore, Franklin and 11 more7 hr
Jun 24, 11:08 PM CDTMesoscale DiscussionSPCArthur, Blaine, Box Butte, Brown, Chase, Cherry and 21 more67 min
Jun 25, 4:02 PM CDTMesoscale DiscussionSPCChase, Dundy, Hayes, Hitchcock88 min
Jun 25, 5:40 PM CDTMesoscale DiscussionSPCBanner, Box Butte, Cheyenne, Dawes, Garden, Kimball and 4 more95 min
Jun 25, 6:05 PM CDTSevere Thunderstorm WatchSPCArthur, Banner, Box Butte, Cheyenne, Dawes, Deuel and 9 more7 hr

Nearby

Severe Thunderstorm Watches in Iowa, 2005Severe Thunderstorm Watches in Nebraska, 2005Severe Thunderstorm Watches in South Dakota, 2005Every severe thunderstorm watch in 2005

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.