Alert archive / Nebraska / Tornado Watches in 2004
Tornado Watch 640
The Storm Prediction Center issued this tornado watch at Jul 15, 2004, 3:00 PM CDT for 29 counties in Nebraska; 9 counties in South Dakota. It was in force for 6 hr.
The area
The outline as issued.
The facts
- Issued
- Jul 15, 2004, 3:00 PM CDT (20:00 UTC)
- Expired
- Jul 15, 2004, 9:00 PM CDT
- In force
- 6 hr
- Issued by
- the Storm Prediction Center
All 38 counties
Antelope County, NE, Boone County, NE, Boyd County, NE, Buffalo County, NE, Butler County, NE, Cedar County, NE, Colfax County, NE, Cuming County, NE, Dixon 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, Seward County, NE, Sherman County, NE, Stanton County, NE, Valley County, NE, Wayne County, NE, Wheeler County, NE, York County, NE, Bon Homme County, SD, Charles Mix County, SD, Clay County, SD, Douglas County, SD, Hutchinson County, SD, Lincoln County, SD, Turner County, SD, Union County, SD, Yankton County, SD
The radar
The Omaha radar (KOAX), 165 km from the middle of the area, began a volume at 19:59 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
14 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 15, 5:19 PM CDT | Tornado Warning | FSD | Charles Mix | 26 min |
| Jul 15, 5:45 PM CDT | Tornado Warning | FSD | Charles Mix | 30 min |
| Jul 15, 6:01 PM CDT | Severe Thunderstorm Warning | LBF | Holt | 59 min |
| Jul 15, 6:08 PM CDT | Tornado Warning | OAX | Knox | 52 min |
| Jul 15, 6:33 PM CDT | Tornado Warning | OAX | Antelope | 27 min |
| Jul 15, 6:48 PM CDT | Tornado Warning | LBF | Holt | 27 min |
| Jul 15, 7:03 PM CDT | Tornado Warning | OAX | Antelope, Knox | 42 min |
| Jul 15, 7:04 PM CDT | Tornado Warning | OAX | Antelope, Knox | 41 min |
| Jul 15, 7:06 PM CDT | Tornado Warning | OAX | Antelope, Knox | 39 min |
| Jul 15, 7:14 PM CDT | Tornado Warning | LBF | Holt | 46 min |
| Jul 15, 7:36 PM CDT | Severe Thunderstorm Warning | FSD | Charles Mix | 24 min |
| Jul 15, 7:43 PM CDT | Severe Thunderstorm Warning | FSD | Bon Homme | 47 min |
| Jul 15, 7:46 PM CDT | Tornado Warning | LBF | Wheeler | 44 min |
| Jul 15, 8:29 PM CDT | Severe Thunderstorm Warning | FSD | Bon Homme | 31 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, 8.0 hours before the alert went out and 164 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
- 13 J/kg
- Mixed-layer CIN
- -468 J/kg
- Mixed-layer LCL
- 1009 m above ground
- 0-6 km bulk shear
- 33 kt
- 0-1 km storm-relative helicity
- 48 m²/s²
- 0-3 km storm-relative helicity
- 127 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 151959
SEL0
SPC WW 152000
NEZ000-SDZ000-160200-
URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 640
NWS STORM PREDICTION CENTER NORMAN OK
300 PM CDT THU JUL 15 2004
THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF
EASTERN NEBRASKA
SOUTHEAST SOUTH DAKOTA
EFFECTIVE THIS THURSDAY AFTERNOON AND EVENING FROM 300 PM UNTIL
900 PM CDT.
TORNADOES...HAIL TO 3 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS
TO 80 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.
THE TORNADO WATCH AREA IS ALONG AND 65 STATUTE MILES EAST AND WEST
OF A LINE FROM 50 MILES NORTH NORTHWEST OF YANKTON SOUTH DAKOTA TO
25 MILES SOUTH SOUTHEAST OF GRAND ISLAND NEBRASKA.
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 639...
DISCUSSION...SEVERE THUNDERSTORMS WILL RAPIDLY DEVELOP NEAR
INTERSECTION OF SURFACE TROUGH AND CONVECTIVE OUTFLOW BOUNDARY NEAR
SD/NEB BORDER IN NWRN PORTION OF WATCH. WITH EXTREMELY UNSTABLE
AIRMASS AND 40-50 KT OF SHEAR...CONDITIONS FAVORABLE FOR TORNADIC
SUPERCELLS AND VERY LARGE HAIL. STORMS SHOULD DEVELOP SE/S ACROSS
ERN NEB.
AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 3 INCHES. EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 70 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 600.
MEAN STORM MOTION VECTOR 34030.
...HALES
433,0962 403,0965 403,0992 433,0990SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 14, 7:49 PM CDT | Mesoscale Discussion | SPC | Banner, Box Butte, Cheyenne, Dawes, Deuel, Kimball and 3 more | 86 min |
| Jul 15, 9:32 AM CDT | Mesoscale Discussion | SPC | Dakota, Dixon | 118 min |
| Jul 15, 11:55 AM CDT | Mesoscale Discussion | SPC | Antelope, Boyd, Burt, Butler, Cass, Cedar and 26 more | 2 hr |
| Jul 15, 2:03 PM CDT | Mesoscale Discussion | SPC | Antelope, Blaine, Boone, Boyd, Brown, Cedar and 22 more | 2 hr |
| Jul 15, 2:53 PM CDT | Mesoscale Discussion | SPC | Arthur, Banner, Box Butte, Chase, Cheyenne, Dawes and 12 more | 3 hr |
| Jul 15, 5:04 PM CDT | Mesoscale Discussion | SPC | Dundy | 86 min |
| Jul 15, 6:08 PM CDT | Mesoscale Discussion | SPC | Chase, Dawson, Dundy, Frontier, Furnas, Gosper and 4 more | 97 min |
| Jul 15, 6:25 PM CDT | Severe Thunderstorm Watch | SPC | Adams, Buffalo, Chase, Dawson, Deuel, Dundy and 15 more | 7 hr |
| Jul 14, 10:07 PM CDT | Mesoscale Discussion | SPC | Butte, Custer, Fall River, Harding, Lawrence, Meade and 2 more | 53 min |
| Jul 15, 5:41 PM CDT | Mesoscale Discussion | SPC | Brookings, Clark, Codington, Day, Deuel, Grant and 10 more | 94 min |
| Jul 15, 6:00 PM CDT | Severe Thunderstorm Watch | SPC | Clark, Codington, Day, Deuel, Grant, Hamlin and 2 more | 5 hr |
Nearby
Tornado Watches in Nebraska, 2004Tornado Watches in South Dakota, 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.