Alert archive / Nebraska / Severe Thunderstorm Watches in 2004

Severe Thunderstorm Watch 621

July 13, 20046 counties in Iowa; 22 counties in Nebraska

The Storm Prediction Center issued this severe thunderstorm watch at Jul 13, 2004, 2:25 PM CDT for 6 counties in Iowa; 22 counties in Nebraska. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued: Jul 13, 2004, 2:25 PM CDT (19:25 UTC)
Expired: Jul 13, 2004, 8:00 PM CDT
In force: 6 hr
Issued by: the Storm Prediction Center

All 28 counties

Fremont County, IA, Harrison County, IA, Mills County, IA, Monona County, IA, Pottawattamie County, IA, Shelby County, IA, Boone County, NE, Burt County, NE, Butler County, NE, Cass County, NE, Colfax County, NE, Cuming County, NE, Dodge County, NE, Douglas County, NE, Hamilton County, NE, Lancaster County, NE, Madison County, NE, Merrick County, NE, Nance County, NE, Otoe County, NE, Platte County, NE, Polk County, NE, Sarpy County, NE, Saunders County, NE, Seward County, NE, Stanton County, NE, Washington County, NE, York County, NE

The radar

The Omaha radar (KOAX), 60 km from the middle of the area, began a volume at 19:27 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

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

Issued	Product	Office	Counties	Lasted
Jul 13, 2:56 PM CDT	Severe Thunderstorm Warning	OAX	Madison	34 min
Jul 13, 3:02 PM CDT	Severe Thunderstorm Warning	OAX	Cuming, Stanton	43 min
Jul 13, 3:30 PM CDT	Severe Thunderstorm Warning	OAX	Madison	45 min
Jul 13, 4:09 PM CDT	Severe Thunderstorm Warning	OAX	Douglas, Sarpy, Saunders	36 min
Jul 13, 4:34 PM CDT	Severe Thunderstorm Warning	OAX	Cass	26 min
Jul 13, 4:59 PM CDT	Severe Thunderstorm Warning	OAX	Fremont	31 min

The nearest sounding before it

Omaha, NE (KOAX), launched 12:00Z, 7.4 hours before the alert went out and 59 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: 1522 J/kg
Mixed-layer CIN: -329 J/kg
Mixed-layer LCL: 1617 m above ground
0-6 km bulk shear: 32 kt
0-1 km storm-relative helicity: 77 m²/s²
0-3 km storm-relative helicity: 68 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

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

000 
WWUS20 KWNS 131924
SEL1  
SPC WW 131925
IAZ000-NEZ000-140100-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 621
NWS STORM PREDICTION CENTER NORMAN OK
225 PM CDT TUE JUL 13 2004

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

       SOUTHWEST IOWA
       EASTERN NEBRASKA

EFFECTIVE THIS TUESDAY AFTERNOON AND EVENING FROM 225 PM UNTIL 800
PM CDT.

HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70
MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE SEVERE THUNDERSTORM WATCH AREA IS ALONG AND 50 STATUTE MILES
NORTH AND SOUTH OF A LINE FROM 45 MILES WEST OF COLUMBUS NEBRASKA
TO 35 MILES EAST OF OMAHA NEBRASKA.

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...CONTINUE...WW 619...WW 620...

DISCUSSION...ELEVATED THUNDERSTORMS DEVELOPING IN NERN NEB N OF
FRONTAL ZONE ACROSS SRN NEB.  WITH AIR MASS SEWD FROM STORMS INTO
SWRN IA VERY UNSTABLE...STORMS EXPECTED TO BECOME SEVERE AS THEY
MOVE ESEWD.  PRIMARY THREAT WILL BE LARGE HAIL...WITH WIND DAMAGE
POTENTIAL INCREASING AS THEY DEVELOP INTO SHORT LINES/BOWS.

AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60
KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 550. MEAN STORM
MOTION VECTOR 29030.


...HALES

420,0981 420,0951 403,0951 404,0981

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 12, 9:15 PM CDT	Severe Thunderstorm Watch	SPC	Adair, Adams, Audubon, Boone, Buena Vista, Calhoun and 32 more	7 hr
Jul 12, 9:19 PM CDT	Mesoscale Discussion	SPC	Clay, Dickinson, Emmet, Hancock, Kossuth, Lyon and 5 more	116 min
Jul 12, 11:19 PM CDT	Mesoscale Discussion	SPC	Adair, Adams, Cass, Decatur, Fremont, Mills and 6 more	116 min
Jul 12, 11:52 PM CDT	Mesoscale Discussion	SPC	Cherokee, Dickinson, Lyon, O'Brien, Osceola, Plymouth and 1 more	53 min
Jul 13, 12:55 AM CDT	Severe Thunderstorm Watch	SPC	Adair, Audubon, Benton, Black Hawk, Boone, Bremer and 52 more	6 hr
Jul 13, 4:21 AM CDT	Mesoscale Discussion	SPC	Allamakee, Benton, Black Hawk, Bremer, Buchanan, Butler and 22 more	54 min
Jul 13, 10:32 AM CDT	Mesoscale Discussion	SPC	Cedar, Clinton, Delaware, Dubuque, Jackson, Johnson and 4 more	118 min
Jul 13, 10:55 AM CDT	Tornado Watch	SPC	Cedar, Clinton, Delaware, Dubuque, Jackson, Jones and 3 more	6 hr
Jul 13, 1:39 PM CDT	Mesoscale Discussion	SPC	Cedar, Clinton, Delaware, Dubuque, Jackson, Jones and 3 more	66 min
Jul 12, 7:45 PM CDT	Mesoscale Discussion	SPC	Boone, Butler, Colfax, Cuming, Dodge, Greeley and 14 more	2 hr
Jul 12, 8:40 PM CDT	Tornado Watch	SPC	Adams, Buffalo, Clay, Franklin, Hall, Hamilton and 10 more	5 hr
Jul 13, 3:27 PM CDT	Mesoscale Discussion	SPC	Arthur, Banner, Box Butte, Chase, Cheyenne, Deuel and 11 more	3 hr
Jul 13, 4:10 PM CDT	Severe Thunderstorm Watch	SPC	Arthur, Banner, Box Butte, Chase, Cheyenne, Dawes and 10 more	6 hr

Nearby

Severe Thunderstorm Watches in Nebraska, 2004 Severe Thunderstorm Watches in Iowa, 2004 Every severe thunderstorm 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.