Alert archive / South Dakota / Tornado Watches in 2012
Tornado Watch 473
The Storm Prediction Center issued this tornado watch at Jul 5, 2012, 5:55 PM MDT for Carter County, Montana; 12 counties in South Dakota. It was in force for 6 hr.
The area
The outline as issued.
The facts
- Issued
- Jul 5, 2012, 5:55 PM MDT (23:55 UTC)
- Expired
- Jul 6, 2012, 12:00 AM MDT
- In force
- 6 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2.5 in
- Strongest gust expected
- 75 kt
Counties Carter County, MT, Bennett County, SD, Butte County, SD, Custer County, SD, Fall River County, SD, Haakon County, SD, Harding County, SD, Jackson County, SD, Lawrence County, SD, Meade County, SD, Pennington County, SD, Perkins County, SD, Ziebach County, SD
The radar
The Rapid City radar (KUDX), 80 km from the middle of the area, began a volume at 23:55 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.
What SPC expected
The probabilities SPC published with the watch, for the watch area over its life.
- Two or more tornadoes
- 50%
- One or more EF2 to EF5 tornadoes
- 30%
- Ten or more severe wind reports
- 50%
- One or more gusts of 65 knots or more
- 30%
- Ten or more severe hail reports
- 60%
- One or more hailstones of 2 inches or more
- 30%
- Six or more combined severe hail and wind reports
- 95%
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 5, 6:23 PM MDT | Severe Thunderstorm Warning | UNR | Butte | 40 min |
| Jul 5, 7:22 PM MDT | Flash Flood Warning | UNR | Fall River | 4 hr |
| Jul 5, 8:13 PM MDT | Severe Thunderstorm Warning | UNR | Fall River | 47 min |
| Jul 5, 8:38 PM MDT | Severe Thunderstorm Warning | UNR | Custer, Fall River | 52 min |
| Jul 5, 8:57 PM MDT | Severe Thunderstorm Warning | UNR | Butte, Lawrence | 35 min |
| Jul 5, 9:47 PM MDT | Severe Thunderstorm Warning | UNR | Pennington | 28 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
Rapid City, SD (KUNR), launched 12:00Z, 11.9 hours before the alert went out and 84 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 1568 m above ground
- 0-6 km bulk shear
- 15 kt
- 0-1 km storm-relative helicity
- 16 m²/s²
- 0-3 km storm-relative helicity
- 44 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.2
The text
As transmitted, in the capitals the NWS used until 2016.
824
WWUS20 KWNS 052359
SEL3
SPC WW 052359
MTZ000-SDZ000-WYZ000-060600-
URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 473
NWS STORM PREDICTION CENTER NORMAN OK
555 PM MDT THU JUL 5 2012
THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF
FAR SOUTHEAST MONTANA
WESTERN AND WEST CENTRAL SOUTH DAKOTA
FAR NORTHEAST WYOMING
EFFECTIVE THIS THURSDAY AFTERNOON FROM 555 PM UNTIL MIDNIGHT MDT.
TORNADOES...HAIL TO 2.5 INCHES IN DIAMETER...THUNDERSTORM WIND
GUSTS TO 85 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE
AREAS.
THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 65 STATUTE
MILES EAST AND WEST OF A LINE FROM 25 MILES NORTH OF BUFFALO
SOUTH DAKOTA TO 75 MILES SOUTH SOUTHWEST OF PHILIP SOUTH DAKOTA.
FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU3).
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 470...WW 471...WW 472...
DISCUSSION...TSTMS EXPECTED TO CONTINUE STRENGTHENING AND INCREASING
IN EXTENT THROUGH LATE TNGT OVER WRN SD REGION...IN ZONE OF
SUSTAINED/MOISTENING LOW LVL SELY FLOW ASSOCIATED WITH UPR IMPULSE
CROSSING THE NRN RCKYS. PER DISCUSSION IN EARLIER SVR TSTM WATCH
#472...INCREASING UPR LVL DIVERGENCE AND STRENGTHENING LOW TO MID
LVL SHEAR RELATED TO UPR IMPULSE WILL YIELD AN ENVIRONMENT FAVORABLE
FOR LOW LVL MESOCYCLONES AND POSSIBLY TORNADOES...ESPECIALLY WITH
ANY MORE DISCRETE STORMS.
AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 2.5 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 75 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
550. MEAN STORM MOTION VECTOR 21025.
...CORFIDISPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 5, 2:40 PM MDT | Mesoscale Discussion | SPC | Carter | 95 min |
| Jul 5, 4:10 PM MDT | Severe Thunderstorm Watch | SPC | Carter, Powder River | 8 hr |
| Jul 5, 5:37 PM MDT | Mesoscale Discussion | SPC | Carter | 53 min |
| Jul 5, 4:52 PM MDT | Mesoscale Discussion | SPC | Clay, Union, Yankton | 53 min |
Nearby
Tornado Watches in South Dakota, 2012Tornado Watches in Montana, 2012Every tornado watch in 2012
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.