Alert archive / Nebraska / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 134, NWS Omaha, NE

July 7, 2020Antelope County, Knox County, Nebraska

NWS Omaha, NE issued this severe thunderstorm warning at Jul 7, 2020, 1:51 AM CDT for Antelope County, Knox County, Nebraska. It was in force for 39 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Jul 7, 2020, 1:51 AM CDT (06:51 UTC)
Expired
Jul 7, 2020, 2:30 AM CDT
In force
39 min
Issued by
NWS Omaha, NE
Area
Storm-based polygon
Hail
0.88 in
Wind
65.0 mph

Counties Antelope County, NE, Knox County, NE

The radar

The Sioux Falls radar (KFSD), 166 km from the middle of the area, began a volume at 06:55 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.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Jul 7, 1:02 AM CDTSevere Thunderstorm WatchSPC4 hr

The nearest sounding before it

N. Platte/Lee Bi, NE (KLBF), launched 00:00Z, 6.9 hours before the alert went out and 260 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

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Omaha, NE wrote its last area forecast discussion before this severe thunderstorm warning went out at Jul 6, 6:54 PM CDT, 6 hours 57 minutes earlier.

Area forecast discussion, Jul 6, 6:54 PM CDT, 6 hours 57 minutes before
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Hazardous weather outlook, Jul 6, 3:15 PM CDT, 10 hours 36 minutes before
Hazardous Weather Outlook
National Weather Service Omaha/Valley NE
315 PM CDT Mon Jul 6 2020

IAZ043-055-056-069-079-080-090-091-NEZ011-012-015>018-030>034-
042>045-050>053-065>068-078-088>093-071015-
Monona-Harrison-Shelby-Pottawattamie-Mills-Montgomery-Fremont-
Page-Knox-Cedar-Thurston-Antelope-Pierce-Wayne-Boone-Madison-
Stanton-Cuming-Burt-Platte-Colfax-Dodge-Washington-Butler-
Saunders-Douglas-Sarpy-Seward-Lancaster-Cass-Otoe-Saline-
Jefferson-Gage-Johnson-Nemaha-Pawnee-Richardson-
315 PM CDT Mon Jul 6 2020

This Hazardous Weather Outlook is for portions of southwest
Iowa...west central Iowa...east central Nebraska...northeast
Nebraska and southeast Nebraska.

.DAY ONE...Tonight and Tuesday

A few scattered strong to severe thunderstorms will be possible
over the northern parts of northeast Nebraska from around 5 pm to
9 pm this evening. These storms could produce hail, strong winds
and locally heavy rain.

It then appears that there may be a lull in activity from around
9 pm until after 2 am. After midnight, another area of strong to
possibly severe thunderstorms is expected to move into parts of
northeast Nebraska from the northwest. The main hazard from these
storms is expected to be strong gusty winds. There is a lot of
uncertainty as to how far south these storms could develop.

.DAYS TWO THROUGH SEVEN...Tuesday Night through Monday

Thunderstorms are possible again from Wednesday afternoon through
Wednesday night. Some storms could become severe with large hail,
strong winds and areas of very heavy rain that could cause
localized flooding.

There will continue to be chances for thunderstorms from Thursday
into the weekend, with the highest chances for Thursday into
Thursday night. Later outlooks will address the potential for
severe storms in those periods.

Heat indices over the next several days will average 95 to 100
just about every afternoon.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected to be needed tonight or
Tuesday, but please pass along any reports of severe weather or
heavy rain.

The office that day

Everything else NWS Omaha, NE issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 6, 7:06 PM CDTSpecial Weather StatementOAXThurston24 min
Jul 6, 7:20 PM CDTSevere Thunderstorm WarningOAXAntelope, Madison, Pierce55 min
Jul 6, 7:30 PM CDTSpecial Weather StatementOAXBurt30 min
Jul 6, 8:12 PM CDTSevere Thunderstorm WarningOAXAntelope, Boone, Madison, Platte45 min
Jul 6, 8:51 PM CDTSpecial Weather StatementOAXBoone24 min
Jul 6, 9:10 PM CDTSpecial Weather StatementOAXPlatte35 min
Jul 6, 9:32 PM CDTSpecial Weather StatementOAXPlatte28 min
Jul 6, 9:50 PM CDTSpecial Weather StatementOAXPolk10 min
Jul 6, 10:11 PM CDTSpecial Weather StatementOAXButler34 min
Jul 6, 10:29 PM CDTSpecial Weather StatementOAXButler31 min
Jul 7, 2:28 AM CDTSevere Thunderstorm WarningOAXAntelope, Knox47 min
Jul 7, 2:50 AM CDTSevere Thunderstorm WarningOAXAntelope, Cedar, Knox, Pierce25 min

Nearby

Severe Thunderstorm Warnings in Nebraska, 2020Every severe thunderstorm warning 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.