Alert archive / Nebraska / Severe Thunderstorm Watches in 2012
Severe Thunderstorm Watch 554
The Storm Prediction Center issued this severe thunderstorm watch at Aug 3, 2012, 7:11 PM CDT for 20 counties in Nebraska. It was in force for 7 hr.
The area
The outline as issued.
The facts
- Issued
- Aug 3, 2012, 7:11 PM CDT (00:11 UTC)
- Expired
- Aug 4, 2012, 2:00 AM CDT
- In force
- 7 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2 in
- Strongest gust expected
- 60 kt
Counties Antelope County, NE, Blaine County, NE, Boyd County, NE, Brown County, NE, Cedar County, NE, Custer County, NE, Garfield County, NE, Holt County, NE, Hooker County, NE, Keya Paha County, NE, Knox County, NE, Lincoln County, NE, Logan County, NE, Loup County, NE, McPherson County, NE, Pierce County, NE, Rock County, NE, Thomas County, NE, Wayne County, NE, Wheeler County, NE
The radar
The North Platte radar (KLNX), 82 km from the middle of the area, began a volume at 00:13 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
- 20%
- One or more EF2 to EF5 tornadoes
- 5%
- Ten or more severe wind reports
- 70%
- One or more gusts of 65 knots or more
- 30%
- Ten or more severe hail reports
- 70%
- One or more hailstones of 2 inches or more
- 20%
- Six or more combined severe hail and wind reports
- 90%
Warnings issued inside it
10 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 3, 7:33 PM CDT | Severe Thunderstorm Warning | LBF | Blaine, Brown, Cherry, Rock, Thomas | 57 min |
| Aug 3, 7:45 PM CDT | Severe Thunderstorm Warning | LBF | Brown, Holt, Rock | 60 min |
| Aug 3, 8:29 PM CDT | Severe Thunderstorm Warning | LBF | Brown, Holt, Rock | 47 min |
| Aug 3, 8:38 PM CDT | Severe Thunderstorm Warning | LBF | Boyd, Holt | 26 min |
| Aug 3, 9:22 PM CDT | Severe Thunderstorm Warning | LBF | Arthur, Keith, Lincoln, McPherson | 38 min |
| Aug 3, 9:29 PM CDT | Severe Thunderstorm Warning | OAX | Knox | 31 min |
| Aug 3, 10:02 PM CDT | Severe Thunderstorm Warning | LBF | Logan, McPherson | 43 min |
| Aug 3, 10:32 PM CDT | Severe Thunderstorm Warning | LBF | Lincoln | 43 min |
| Aug 3, 11:07 PM CDT | Severe Thunderstorm Warning | LBF | Custer | 53 min |
| Aug 3, 11:58 PM CDT | Severe Thunderstorm Warning | LBF | Custer | 18 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
N. Platte/Lee Bi, NE (KLBF), launched 00:00Z, 0.2 hours before the alert went out and 131 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
- 1191 J/kg
- Mixed-layer CIN
- -104 J/kg
- Mixed-layer LCL
- 2741 m above ground
- 0-6 km bulk shear
- 25 kt
- 0-1 km storm-relative helicity
- 28 m²/s²
- 0-3 km storm-relative helicity
- 69 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 1.7
The text
As transmitted, in the capitals the NWS used until 2016.
370
WWUS20 KWNS 040010
SEL4
SPC WW 040010
NEZ000-040700-
URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 554
NWS STORM PREDICTION CENTER NORMAN OK
715 PM CDT FRI AUG 3 2012
THE NWS STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF
NORTHERN AND CENTRAL NEBRASKA
EFFECTIVE THIS FRIDAY NIGHT AND SATURDAY MORNING FROM 715 PM
UNTIL 200 AM 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 APPROXIMATELY ALONG AND 40
STATUTE MILES NORTH AND SOUTH OF A LINE FROM 35 MILES WEST
NORTHWEST OF NORTH PLATTE NEBRASKA TO 20 MILES EAST SOUTHEAST OF
YANKTON SOUTH DAKOTA. FOR A COMPLETE DEPICTION OF THE WATCH SEE
THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU4).
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 553...
DISCUSSION...THUNDERSTORMS ARE INCREASING ALONG A BOUNDARY EXTENDING
FROM NORTH CENTRAL INTO NORTHEAST NEB. THESE STORMS WILL SAG
SOUTHWARD ACROSS THE WATCH AREA DURING THE NEXT SEVERAL HOURS.
STRONG INSTABILITY...STEEP LOW LEVEL LAPSE RATES...AND SUFFICIENT
VERTICAL SHEAR WILL POSE A RISK OF LARGE HAIL AND DAMAGING WINDS IN
THE STRONGER STORMS.
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 500. MEAN STORM
MOTION VECTOR 30025.
...HARTSPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 3, 7:33 PM CDT | Severe Thunderstorm Watch | SPC | Dakota, Dixon | 6 hr |
| Aug 3, 11:19 PM CDT | Mesoscale Discussion | SPC | Antelope, Blaine, Boone, Cedar, Custer, Garfield and 10 more | 86 min |
Nearby
Severe Thunderstorm Watches in Nebraska, 2012Every severe thunderstorm 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.