Alert archive / Nebraska / Tornado Watches in 2005

Tornado Watch 814

September 24, 200511 counties in Iowa; 36 counties in Nebraska; 9 counties in South Dakota

The Storm Prediction Center issued this tornado watch at Sep 24, 2005, 3:55 PM CDT for 11 counties in Iowa; 36 counties in Nebraska; 9 counties in South Dakota. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued: Sep 24, 2005, 3:55 PM CDT (20:55 UTC)
Expired: Sep 24, 2005, 11:00 PM CDT
In force: 7 hr
Issued by: the Storm Prediction Center

All 56 counties

Cherokee County, IA, Harrison County, IA, Ida County, IA, Lyon County, IA, Monona County, IA, O'Brien County, IA, Osceola County, IA, Plymouth County, IA, Pottawattamie County, IA, Sioux County, IA, Woodbury County, IA, Antelope County, NE, Boone County, NE, Boyd County, NE, Buffalo 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, Hall County, NE, Hamilton 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, Sarpy 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, York County, NE, Bon Homme County, SD, Charles Mix County, SD, Clay County, SD, Gregory County, SD, Hutchinson County, SD, Lincoln County, SD, Turner County, SD, Union County, SD, Yankton County, SD

The radar

The Sioux Falls radar (KFSD), 161 km from the middle of the area, began a volume at 20:55 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

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

Issued	Product	Office	Counties	Lasted
Sep 24, 5:38 PM CDT	Severe Thunderstorm Warning	LBF	Garfield	67 min
Sep 24, 6:18 PM CDT	Severe Thunderstorm Warning	LBF	Wheeler	57 min
Sep 24, 7:13 PM CDT	Severe Thunderstorm Warning	LBF	Wheeler	32 min
Sep 24, 7:14 PM CDT	Severe Thunderstorm Warning	OAX	Boone	61 min
Sep 24, 7:52 PM CDT	Severe Thunderstorm Warning	OAX	Antelope	23 min
Sep 24, 9:11 PM CDT	Severe Thunderstorm Warning	FSD	Osceola	49 min
Sep 24, 9:25 PM CDT	Severe Thunderstorm Warning	LBF	Garfield	50 min
Sep 24, 9:37 PM CDT	Severe Thunderstorm Warning	LBF	Holt	53 min
Sep 24, 11:00 PM CDT	Severe Thunderstorm Warning	LBF	Holt	60 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 12:00Z, 8.9 hours before the alert went out and 168 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: 58 J/kg
Mixed-layer CIN: -288 J/kg
Mixed-layer LCL: 569 m above ground
0-6 km bulk shear: 34 kt
0-1 km storm-relative helicity: 332 m²/s²
0-3 km storm-relative helicity: 397 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 5.5

Open this sounding in Storm Lab

The text

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

000 
WWUS20 KWNS 242100
SEL4  
SPC WW 242100
IAZ000-MNZ000-NEZ000-SDZ000-250400-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 814
NWS STORM PREDICTION CENTER NORMAN OK
400 PM CDT SAT SEP 24 2005

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

       WESTERN IOWA
       SOUTHWEST MINNESOTA
       CENTRAL AND EASTERN NEBRASKA
       SOUTHEAST SOUTH DAKOTA

EFFECTIVE THIS SATURDAY AFTERNOON AND EVENING FROM 400 PM UNTIL
1100 PM CDT.

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

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 90 STATUTE MILES
NORTH AND SOUTH OF A LINE FROM 15 MILES NORTHWEST OF BURWELL
NEBRASKA TO 45 MILES EAST OF SIOUX CITY IOWA.  FOR A COMPLETE
DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE UPDATE
(WOUS64 KWNS WOU4).

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 813. WATCH NUMBER 813 WILL NOT BE IN EFFECT AFTER 400
PM CDT. 

DISCUSSION...TSTMS EXPECTED TO FORM IN THE NEXT 1-2 HRS AS LARGE
SCALE FORCING ASSOCIATED WITH APPARENT SHORTWAVE IMPULSE NOW
AFFECTING WRN SD BEGINS TO OVERSPREAD WW REGION.  AMPLE
SHEAR/INSTABILITY PRESENT FOR SUSTAINED SUPERCELLS.  BACKED LOW
LEVEL FLOW ALONG OUTFLOW BNDRY ORIENTED ROUGHLY PARALLEL TO EXPECTED
STORM MOTION MAY ALSO POSE A THREAT FOR TORNADOES.

AVIATION...TORNADOES AND 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 500.
MEAN STORM MOTION VECTOR 26025.


...CORFIDI

431,0992 434,0953 410,0953 403,0992

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Sep 24, 7:14 AM CDT	Mesoscale Discussion	SPC	Buena Vista, Cherokee, Clay, Dickinson, Emmet, Hancock and 10 more	2 hr
Sep 24, 3:26 PM CDT	Mesoscale Discussion	SPC	Buena Vista, Calhoun, Carroll, Cherokee, Clay, Crawford and 13 more	94 min
Sep 24, 1:03 AM CDT	Mesoscale Discussion	SPC	Boyd, Cedar, Dakota, Dixon, Knox, Wayne	57 min
Sep 24, 5:57 PM CDT	Mesoscale Discussion	SPC	Dawson, Dundy, Frontier, Furnas, Gosper, Hayes and 3 more	93 min

Nearby

Tornado Watches in Nebraska, 2005 Tornado Watches in Iowa, 2005 Tornado Watches in South Dakota, 2005 Every tornado 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.