Alert archive / Iowa / Tornado Watches in 2004

Tornado Watch 256

May 22, 20044 states

The Storm Prediction Center issued this tornado watch at May 22, 2004, 10:40 PM CDT for 4 states. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued: May 22, 2004, 10:40 PM CDT (03:40 UTC)
Expired: May 23, 2004, 4:00 AM CDT
In force: 5 hr
Issued by: the Storm Prediction Center

All 77 counties

Adair County, IA, Adams County, IA, Appanoose County, IA, Benton County, IA, Cedar County, IA, Clarke County, IA, Davis County, IA, Decatur County, IA, Delaware County, IA, Fremont County, IA, Henry County, IA, Iowa County, IA, Jasper County, IA, Jefferson County, IA, Johnson County, IA, Jones County, IA, Keokuk County, IA, Linn County, IA, Louisa County, IA, Lucas County, IA, Madison County, IA, Mahaska County, IA, Marion County, IA, Mills County, IA, Monroe County, IA, Montgomery County, IA, Muscatine County, IA, Page County, IA, Polk County, IA, Poweshiek County, IA, Ringgold County, IA, Tama County, IA, Taylor County, IA, Union County, IA, Van Buren County, IA, Wapello County, IA, Warren County, IA, Washington County, IA, Wayne County, IA, Atchison County, KS, Brown County, KS, Clay County, KS, Cloud County, KS, Dickinson County, KS, Doniphan County, KS, Geary County, KS, Jackson County, KS, Marshall County, KS, Nemaha County, KS, Ottawa County, KS, Pottawatomie County, KS, Republic County, KS, Riley County, KS, Saline County, KS, Washington County, KS, Andrew County, MO, Atchison County, MO, Buchanan County, MO, Daviess County, MO, DeKalb County, MO, Gentry County, MO, Grundy County, MO, Harrison County, MO, Holt County, MO, Mercer County, MO, Nodaway County, MO, Putnam County, MO, Schuyler County, MO, Worth County, MO, Gage County, NE, Jefferson County, NE, Johnson County, NE, Nemaha County, NE, Otoe County, NE, Pawnee County, NE, Richardson County, NE, Thayer County, NE

The radar

The Omaha radar (KOAX), 133 km from the middle of the area, began a volume at 03:40 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

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

Issued	Product	Office	Counties	Lasted
May 22, 10:48 PM CDT	Severe Thunderstorm Warning	DMX	Adams, Taylor	57 min
May 22, 10:52 PM CDT	Severe Thunderstorm Warning	OAX	Montgomery	23 min
May 22, 10:54 PM CDT	Tornado Warning	OAX	Gage, Jefferson	66 min
May 22, 10:57 PM CDT	Severe Thunderstorm Warning	DMX	Adair	48 min
May 22, 11:02 PM CDT	Flash Flood Warning	OAX	Gage	6 hr
May 22, 11:03 PM CDT	Severe Thunderstorm Warning	TOP	Cloud, Washington	27 min
May 22, 11:06 PM CDT	Severe Thunderstorm Warning	DVN	Benton	39 min
May 22, 11:09 PM CDT	Severe Thunderstorm Warning	DMX	Madison, Ringgold, Union	51 min
May 22, 11:09 PM CDT	Severe Thunderstorm Warning	OAX	Johnson, Lancaster, Otoe	66 min
May 22, 11:26 PM CDT	Severe Thunderstorm Warning	OAX	Nemaha	64 min
May 22, 11:29 PM CDT	Severe Thunderstorm Warning	TOP	Clay, Cloud, Washington	46 min
May 22, 11:31 PM CDT	Severe Thunderstorm Warning	DMX	Clarke, Decatur	44 min
May 22, 11:36 PM CDT	Severe Thunderstorm Warning	DMX	Polk, Warren	54 min
May 22, 11:36 PM CDT	Severe Thunderstorm Warning	OAX	Fremont, Page	54 min
May 22, 11:38 PM CDT	Severe Thunderstorm Warning	EAX	Atchison	67 min
May 22, 11:51 PM CDT	Severe Thunderstorm Warning	TOP	Clay, Ottawa	39 min
May 22, 11:54 PM CDT	Tornado Warning	DMX	Warren	36 min
May 22, 11:59 PM CDT	Severe Thunderstorm Warning	TOP	Brown, Jackson	46 min
May 23, 12:07 AM CDT	Tornado Warning	DMX	Jasper, Marion	53 min
May 23, 12:13 AM CDT	Severe Thunderstorm Warning	EAX	Nodaway	47 min
May 23, 12:16 AM CDT	Severe Thunderstorm Warning	EAX	Doniphan	59 min
May 23, 12:22 AM CDT	Severe Thunderstorm Warning	DMX	Lucas	23 min
May 23, 12:35 AM CDT	Severe Thunderstorm Warning	DMX	Mahaska, Poweshiek	55 min
May 23, 12:37 AM CDT	Severe Thunderstorm Warning	EAX	Andrew, Buchanan	53 min
May 23, 1:16 AM CDT	Severe Thunderstorm Warning	DVN	Benton, Iowa	59 min
May 23, 1:17 AM CDT	Severe Thunderstorm Warning	EAX	DeKalb, Gentry	58 min
May 23, 1:29 AM CDT	Severe Thunderstorm Warning	EAX	Daviess	61 min
May 23, 1:34 AM CDT	Severe Thunderstorm Warning	EAX	Mercer	56 min
May 23, 1:39 AM CDT	Severe Thunderstorm Warning	DVN	Johnson, Linn	51 min
May 23, 1:45 AM CDT	Severe Thunderstorm Warning	EAX	Grundy, Putnam, Sullivan	60 min
May 23, 2:08 AM CDT	Severe Thunderstorm Warning	DVN	Delaware, Jones	52 min

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, 3.7 hours before the alert went out and 133 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 2882 J/kg
Mixed-layer CIN: -5 J/kg
Mixed-layer LCL: 1091 m above ground
0-6 km bulk shear: 64 kt
0-1 km storm-relative helicity: 51 m²/s²
0-3 km storm-relative helicity: 260 m²/s²
Significant tornado parameter: 4.2
Supercell composite: 16.7

Open this sounding in Storm Lab

The text

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

000 
WWUS20 KWNS 230342
SEL6  
SPC WW 230340
IAZ000-KSZ000-MOZ000-NEZ000-230900-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 256
NWS STORM PREDICTION CENTER NORMAN OK
1040 PM CDT SAT MAY 22 2004

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

       SOUTHERN IOWA
       NORTHEAST KANSAS
       NORTHWEST MISSOURI
       SOUTHEAST NEBRASKA

EFFECTIVE THIS SATURDAY NIGHT AND SUNDAY MORNING FROM 1040 PM
UNTIL 400 AM CDT.

TORNADOES...HAIL TO 3 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS
TO 90 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE TORNADO WATCH AREA IS ALONG AND 60 STATUTE MILES NORTH AND
SOUTH OF A LINE FROM 20 MILES SOUTHWEST OF CONCORDIA KANSAS TO 35
MILES EAST OF CEDAR RAPIDS IOWA.

REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
TORNADOES AND 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...THIS TORNADO WATCH REPLACES TORNADO
WATCH NUMBER 251...TORNADO WATCH NUMBER 253...TORNADO WATCH NUMBER
254. WATCH NUMBER 251 253 254 WILL NOT BE IN EFFECT AFTER 1040 PM
CDT. CONTINUE...WW 255...

DISCUSSION...INTENSE SUPERCELLS WILL CONTINUE AS VERY IMPRESSIVE
SHEAR PROFILES AND UNSTABLE AIR MASS CONTINUES ACROSS MUCH OF WATCH
AREA.  STORMS WILL EVOLVE MORE INTO SHORT LINES/BOWS INCREASING WIND
DAMAGE POTENTIAL.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 3 INCHES. EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 80 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500.
MEAN STORM MOTION VECTOR 25045.


...HALES

401,0975 424,0910 410,0910 382,0975

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 22, 7:11 PM CDT	Mesoscale Discussion	SPC	Adair, Adams, Audubon, Cass, Clarke, Dallas and 15 more	94 min
May 22, 7:23 PM CDT	Mesoscale Discussion	SPC	Adair, Adams, Audubon, Cass, Dallas, Fremont and 9 more	67 min
May 22, 8:58 PM CDT	Mesoscale Discussion	SPC	Adair, Adams, Appanoose, Audubon, Benton, Boone and 49 more	92 min
May 22, 11:33 PM CDT	Mesoscale Discussion	SPC	Adair, Adams, Appanoose, Benton, Cedar, Clarke and 33 more	87 min
May 23, 12:24 AM CDT	Mesoscale Discussion	SPC	Cedar, Clinton, Des Moines, Dubuque, Jackson, Jones and 3 more	66 min
May 23, 12:40 AM CDT	Severe Thunderstorm Watch	SPC	Clinton, Dubuque, Jackson, Scott	5 hr
May 23, 2:21 AM CDT	Mesoscale Discussion	SPC	Appanoose, Buchanan, Cedar, Davis, Delaware, Des Moines and 14 more	54 min
May 23, 4:30 AM CDT	Mesoscale Discussion	SPC	Clinton, Des Moines, Jackson, Lee, Louisa, Muscatine and 1 more	60 min
May 23, 12:25 PM CDT	Mesoscale Discussion	SPC	Cedar, Clinton, Delaware, Des Moines, Dubuque, Henry and 7 more	95 min
May 23, 1:15 PM CDT	Tornado Watch	SPC	Des Moines, Lee	6 hr
May 23, 2:05 PM CDT	Tornado Watch	SPC	Allamakee, Benton, Buchanan, Cedar, Clayton, Clinton and 14 more	8 hr
May 23, 5:10 PM CDT	Mesoscale Discussion	SPC	Clinton, Dubuque, Jackson, Scott	95 min
May 22, 7:49 PM CDT	Mesoscale Discussion	SPC	Barton, Clay, Cloud, Dickinson, Ellsworth, Geary and 14 more	86 min
May 22, 10:09 PM CDT	Mesoscale Discussion	SPC	Barton, Clay, Cloud, Dickinson, Ellsworth, Geary and 13 more	66 min
May 23, 1:21 AM CDT	Mesoscale Discussion	SPC	Atchison, Brown, Dickinson, Doniphan, Douglas, Geary and 13 more	24 min
May 23, 1:40 AM CDT	Severe Thunderstorm Watch	SPC	Adair, Buchanan, Caldwell, Clark, Clinton, Daviess and 11 more	4 hr
May 23, 4:35 PM CDT	Severe Thunderstorm Watch	SPC	Barry, Camden, Christian, Crawford, Dade, Dallas and 24 more	5 hr
May 23, 5:00 PM CDT	Mesoscale Discussion	SPC	Callaway, Cole, Crawford, Franklin, Gasconade, Jefferson and 15 more	2 hr
May 23, 5:30 PM CDT	Tornado Watch	SPC	Jefferson, Saint Charles, Saint Louis, City of Saint Louis	6 hr
May 23, 6:50 PM CDT	Mesoscale Discussion	SPC	Dawes, Sioux	85 min

Nearby

Tornado Watches in Iowa, 2004 Tornado Watches in Kansas, 2004 Tornado Watches in Missouri, 2004 Every tornado watch in 2004

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.