Alert archive / Nebraska / Severe Thunderstorm Watches in 2020

Severe Thunderstorm Watch 337

July 7, 202018 counties in Nebraska

The Storm Prediction Center issued this severe thunderstorm watch at Jul 7, 2020, 1:02 AM CDT for 18 counties in Nebraska. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued
Jul 7, 2020, 1:02 AM CDT (06:02 UTC)
Expired
Jul 7, 2020, 5:19 AM CDT
In force
4 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
65 kt

Counties Antelope County, NE, Boyd County, NE, Brown County, NE, Cedar County, NE, Cuming County, NE, Dakota County, NE, Dixon County, NE, Garfield County, NE, Holt County, NE, Keya Paha County, NE, Knox County, NE, Madison County, NE, Pierce County, NE, Rock County, NE, Stanton County, NE, Thurston County, NE, Wayne County, NE, Wheeler County, NE

The radar

The Sioux Falls radar (KFSD), 159 km from the middle of the area, began a volume at 06:01 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
5%
One or more EF2 to EF5 tornadoes
2%
Ten or more severe wind reports
50%
One or more gusts of 65 knots or more
30%
Ten or more severe hail reports
30%
One or more hailstones of 2 inches or more
10%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Jul 7, 1:18 AM CDTSevere Thunderstorm WarningLBFBoyd, Holt, Keya Paha, Rock42 min
Jul 7, 1:51 AM CDTSevere Thunderstorm WarningOAXAntelope, Knox39 min
Jul 7, 1:59 AM CDTSevere Thunderstorm WarningLBFBoyd, Holt, Rock61 min
Jul 7, 2:28 AM CDTSevere Thunderstorm WarningOAXAntelope, Knox47 min
Jul 7, 2:50 AM CDTSevere Thunderstorm WarningOAXAntelope, Cedar, Knox, Pierce25 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, 6.0 hours before the alert went out and 261 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-pSkew-T log-p diagram, N. Platte/Lee Bi, NE at 00:00Z on 2020-07-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 450 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, N. Platte/Lee Bi, NE at 00:00Z on 2020-07-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -10 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
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
450 J/kg
Mixed-layer CIN
-162 J/kg
Mixed-layer LCL
2603 m above ground
0-6 km bulk shear
27 kt
0-1 km storm-relative helicity
-10 m²/s²
0-3 km storm-relative helicity
111 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.1

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 6, 8:22 PM CDTMesoscale DiscussionSPCBoone, Burt, Colfax, Dodge, Madison, Platte53 min
Jul 7, 12:44 AM CDTMesoscale DiscussionSPCAntelope, Boone, Boyd, Brown, Cedar, Holt and 7 more2 hr
Jul 7, 3:24 AM CDTMesoscale DiscussionSPCBurt, Cedar, Colfax, Cuming, Dakota, Dixon and 8 more2 hr
Jul 7, 3:50 PM CDTMesoscale DiscussionSPCBox Butte, Dawes, Morrill, Scotts Bluff, Sioux85 min
Jul 6, 9:07 PM CDTMesoscale DiscussionSPCBennett, Buffalo, Haakon, Hand, Hughes, Hyde and 9 more83 min
Jul 6, 10:47 PM CDTSevere Thunderstorm WatchSPCAurora, Bennett, Bon Homme, Brule, Buffalo, Charles Mix and 18 more4 hr

Nearby

Severe Thunderstorm Watches in Nebraska, 2020Every severe thunderstorm watch in 2020

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.