Alert archive / South Dakota / Tornado Watches in 2004
Tornado Watch 612
The Storm Prediction Center issued this tornado watch at Jul 12, 2004, 3:25 PM CDT for 5 counties in Nebraska; 16 counties in South Dakota. It was in force for 6 hr.
The area
The outline as issued.
The facts
- Issued
- Jul 12, 2004, 3:25 PM CDT (20:25 UTC)
- Expired
- Jul 12, 2004, 9:00 PM CDT
- In force
- 6 hr
- Issued by
- the Storm Prediction Center
All 21 counties
Boyd County, NE, Cedar County, NE, Dixon County, NE, Holt County, NE, Knox County, NE, Aurora County, SD, Bon Homme County, SD, Brule County, SD, Charles Mix County, SD, Clay County, SD, Davison County, SD, Douglas County, SD, Gregory County, SD, Hanson County, SD, Hutchinson County, SD, Lincoln County, SD, McCook County, SD, Minnehaha County, SD, Turner County, SD, Union County, SD, Yankton County, SD
The radar
The Sioux Falls radar (KFSD), 140 km from the middle of the area, began a volume at 20:25 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
16 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 12, 3:29 PM CDT | Severe Thunderstorm Warning | FSD | Charles Mix | 31 min |
| Jul 12, 3:35 PM CDT | Severe Thunderstorm Warning | FSD | Gregory | 25 min |
| Jul 12, 4:00 PM CDT | Severe Thunderstorm Warning | LBF | Boyd | 60 min |
| Jul 12, 4:00 PM CDT | Severe Thunderstorm Warning | FSD | Charles Mix, Gregory | 30 min |
| Jul 12, 4:03 PM CDT | Tornado Warning | FSD | Gregory | 27 min |
| Jul 12, 4:08 PM CDT | Tornado Warning | LBF | Boyd | 52 min |
| Jul 12, 4:30 PM CDT | Severe Thunderstorm Warning | FSD | Charles Mix, Gregory | 30 min |
| Jul 12, 4:57 PM CDT | Severe Thunderstorm Warning | LBF | Holt | 63 min |
| Jul 12, 4:58 PM CDT | Tornado Warning | LBF | Boyd | 62 min |
| Jul 12, 5:12 PM CDT | Severe Thunderstorm Warning | FSD | Gregory | 33 min |
| Jul 12, 5:56 PM CDT | Severe Thunderstorm Warning | LBF | Holt | 64 min |
| Jul 12, 5:59 PM CDT | Severe Thunderstorm Warning | LBF | Boyd | 61 min |
| Jul 12, 6:18 PM CDT | Tornado Warning | LBF | Holt | 42 min |
| Jul 12, 6:38 PM CDT | Severe Thunderstorm Warning | FSD | Minnehaha | 22 min |
| Jul 12, 7:00 PM CDT | Severe Thunderstorm Warning | LBF | Holt | 45 min |
| Jul 12, 7:00 PM CDT | Severe Thunderstorm Warning | FSD | Minnehaha | 45 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
Aberdeen, SD (KABR), launched 12:00Z, 8.4 hours before the alert went out and 187 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.
- Mixed-layer CAPE
- 12 J/kg
- Mixed-layer CIN
- -517 J/kg
- Mixed-layer LCL
- 2141 m above ground
- 0-6 km bulk shear
- 55 kt
- 0-1 km storm-relative helicity
- -106 m²/s²
- 0-3 km storm-relative helicity
- 109 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
000
WWUS20 KWNS 122025
SEL2
SPC WW 122025
NEZ000-SDZ000-130200-
URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 612
NWS STORM PREDICTION CENTER NORMAN OK
325 PM CDT MON JUL 12 2004
THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF
NORTHEAST NEBRASKA
SOUTHEAST SOUTH DAKOTA
EFFECTIVE THIS MONDAY AFTERNOON AND EVENING FROM 325 PM UNTIL 900
PM CDT.
TORNADOES...HAIL TO 3 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS
TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.
THE TORNADO WATCH AREA IS ALONG AND 50 STATUTE MILES EITHER SIDE
OF A LINE FROM 45 MILES SOUTH SOUTHWEST OF CHAMBERLAIN SOUTH
DAKOTA TO 45 MILES EAST OF YANKTON SOUTH DAKOTA.
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...CONTINUE...WW 611...
DISCUSSION...STRONG STORMS ARE EXPECTED TO CONTINUE DEVELOPING
WITHIN LOW LEVEL CONVERGENCE ZONE FROM SOUTH CENTRAL SD ESEWD INTO
SERN SD/NERN NEB. AIR MASS HAS BECOME VERY UNSTABLE WITH MLCAPE OF
2500-3500 J/KG. WINDS VEER AND INCREASE WITH HEIGHT RESULTING IN
STRONG DEEP LAYER SHEAR SUPPORTIVE OF SUPERCELL DEVELOPMENT. IN
ADDITION...SRH AND LCL PARAMETERS SUGGEST THREAT FOR POSSIBLE
TORNADOES AS CELLS PROPAGATE EWD AND SEWD INTO THE EVENING HOURS.
AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 3 INCHES. EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 550.
MEAN STORM MOTION VECTOR 28030.
...WEISS
435,0993 433,0962 421,0963 422,0994SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 12, 2:04 PM CDT | Mesoscale Discussion | SPC | Boyd, Keya Paha | 116 min |
| Jul 12, 5:41 PM CDT | Mesoscale Discussion | SPC | Antelope, Boone, Boyd, Cedar, Colfax, Cuming and 16 more | 2 hr |
| Jul 12, 6:20 PM CDT | Tornado Watch | SPC | Antelope, Boone, Burt, Cedar, Colfax, Cuming and 14 more | 7 hr |
| Jul 11, 7:20 PM CDT | Severe Thunderstorm Watch | SPC | Butte, Corson, Dewey, Harding, Meade, Perkins and 2 more | 8 hr |
| Jul 11, 9:54 PM CDT | Mesoscale Discussion | SPC | Aurora, Beadle, Brule, Buffalo, Charles Mix, Davison and 12 more | 3 hr |
| Jul 11, 11:34 PM CDT | Mesoscale Discussion | SPC | Brown, Campbell, Corson, Day, Edmunds, McPherson and 3 more | 116 min |
| Jul 11, 11:50 PM CDT | Severe Thunderstorm Watch | SPC | Campbell, McPherson | 6 hr |
| Jul 12, 1:29 AM CDT | Mesoscale Discussion | SPC | Brown, Campbell, McPherson, Marshall | 91 min |
| Jul 12, 3:13 AM CDT | Mesoscale Discussion | SPC | Brown, Campbell, McPherson | 92 min |
| Jul 12, 8:53 AM CDT | Mesoscale Discussion | SPC | Aurora, Beadle, Brookings, Brown, Brule, Buffalo and 30 more | 2 hr |
| Jul 12, 10:55 AM CDT | Severe Thunderstorm Watch | SPC | Beadle, Brookings, Clark, Codington, Day, Deuel and 4 more | 5 hr |
Nearby
Tornado Watches in South Dakota, 2004Tornado Watches in Nebraska, 2004Every 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.