Alert archive / Nebraska / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 96, NWS Omaha, NE

July 9, 20216 counties in Nebraska

NWS Omaha, NE issued this severe thunderstorm warning at Jul 9, 2021, 11:26 PM CDT for 6 counties in Nebraska. It was in force for 64 min. 2 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Jul 9, 2021, 11:26 PM CDT (04:26 UTC)
Expired: Jul 10, 2021, 12:30 AM CDT
In force: 64 min
Issued by: NWS Omaha, NE
Area: Storm-based polygon
Hail: 0.75 in
Wind: 75.0 mph

Counties Butler County, NE, Gage County, NE, Lancaster County, NE, Saline County, NE, Saunders County, NE, Seward County, NE

The radar

The Omaha radar (KOAX), 90 km from the middle of the area, began a volume at 04:29 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 was reported inside it

Time	Report	Where	Remark
Jul 9, 11:52 PM CDT	TSTM WND DMG	Western, NE	DELAYED REPORT. TIME ESTIMATED FROM RADAR. ROOF TORN OFF OF GRAIN BIN.
Jul 10, 12:08 AM CDT	TSTM WND GST 60	Western, NE

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

Did it verify

Verified. The Iowa Environmental Mesonet's Cow matched 3 storm reports to this severe thunderstorm warning; the first came 26 minutes after it went out.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The watch it was issued in

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

Issued	Product	Office	Lasted
Jul 9, 9:58 PM CDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 4.4 hours before the alert went out and 90 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 2603 J/kg
Mixed-layer CIN: -130 J/kg
Mixed-layer LCL: 1447 m above ground
0-6 km bulk shear: 45 kt
0-1 km storm-relative helicity: 90 m²/s²
0-3 km storm-relative helicity: 186 m²/s²
Significant tornado parameter: 0.6
Supercell composite: 8.1

Open this sounding in Storm Lab

The text

As transmitted.

548 
WUUS53 KOAX 100426
SVROAX
NEC023-067-109-151-155-159-100530-
/O.NEW.KOAX.SV.W.0096.210710T0426Z-210710T0530Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Omaha/Valley Nebraska
1126 PM CDT Fri Jul 9 2021

The National Weather Service in Omaha has issued a

* Severe Thunderstorm Warning for...
  Western Lancaster County in southeastern Nebraska...
  Seward County in southeastern Nebraska...
  Saline County in southeastern Nebraska...
  Southern Butler County in east central Nebraska...
  Southwestern Saunders County in east central Nebraska...
  Northwestern Gage County in southeastern Nebraska...

* Until 1230 AM CDT.

* At 1125 PM CDT, severe thunderstorms were located along a line
  extending from 4 miles east of Rising City to near Grafton, moving
  east at 45 mph.

  HAZARD...75 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...Expect considerable tree damage. Damage is likely to 
           mobile homes, roofs, and outbuildings.

* Severe thunderstorms will be near...
  Rising City around 1130 PM CDT.
  Brainard around 1140 PM CDT.

Other locations in the path of these severe thunderstorms include
Valparaiso, Friend, Weston, Dorchester, Crete and Wilber.

This includes Interstate 80 in Nebraska between mile markers 366 and
395.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

This is a DANGEROUS SITUATION. These storms are producing widespread
wind damage across south central Nebraska. SEEK SHELTER NOW inside a
sturdy structure and stay away from windows!
 
&&

LAT...LON 4035 9737 4120 9737 4121 9672 4087 9676
      4035 9692
TIME...MOT...LOC 0425Z 273DEG 40KT 4122 9722 4058 9770 

HAIL...<.75IN
WIND...75MPH
 
$$

DeWald

3 follow-up statements

685 
WWUS53 KOAX 100443
SVSOAX

Severe Weather Statement
National Weather Service Omaha/Valley Nebraska
1143 PM CDT Fri Jul 9 2021

NEC023-067-109-151-155-159-100530-
/O.CON.KOAX.SV.W.0096.000000T0000Z-210710T0530Z/
Lancaster NE-Seward NE-Saline NE-Butler NE-Saunders NE-Gage NE-
1143 PM CDT Fri Jul 9 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1230 AM CDT
FOR WESTERN LANCASTER...SEWARD...SALINE...SOUTHERN BUTLER...
SOUTHWESTERN SAUNDERS AND NORTHWESTERN GAGE COUNTIES...

At 1143 PM CDT, severe thunderstorms were located along a line
extending from near Brainard to 4 miles south of Ohiowa, moving east
at 50 mph.

HAZARD...75 mph wind gusts and penny size hail.

SOURCE...Radar indicated.

IMPACT...Expect considerable tree damage. Damage is likely to mobile 
         homes, roofs, and outbuildings.

Locations impacted include...
  Brainard, Valparaiso, Weston and De Witt.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

This is a DANGEROUS SITUATION. These storms are producing widespread
wind damage across south central Nebraska. SEEK SHELTER NOW inside a
sturdy structure and stay away from windows.
 
&&

LAT...LON 4035 9737 4120 9737 4121 9672 4087 9676
      4035 9692
TIME...MOT...LOC 0443Z 280DEG 41KT 4121 9697 4036 9743 

HAIL...0.75IN
WIND...75MPH
 
$$

DeWald

560 
WWUS53 KOAX 100506
SVSOAX

Severe Weather Statement
National Weather Service Omaha/Valley Nebraska
1206 AM CDT Sat Jul 10 2021

NEC023-067-109-151-155-159-100530-
/O.CON.KOAX.SV.W.0096.000000T0000Z-210710T0530Z/
Lancaster NE-Seward NE-Saline NE-Butler NE-Saunders NE-Gage NE-
1206 AM CDT Sat Jul 10 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1230 AM CDT
FOR WESTERN LANCASTER...SEWARD...SALINE...SOUTHEASTERN BUTLER...
SOUTHWESTERN SAUNDERS AND NORTHWESTERN GAGE COUNTIES...

At 1206 AM CDT, severe thunderstorms were located along a line
extending from Weston to 5 miles southeast of Western, moving east at
45 mph.

HAZARD...75 mph wind gusts and penny size hail.

SOURCE...Radar indicated.

IMPACT...Expect considerable tree damage. Damage is likely to mobile 
         homes, roofs, and outbuildings.

Locations impacted include...
Northwestern Lincoln, Seward, Crete, Milford, Wilber, Friend,
Dorchester, Valparaiso, De Witt, Beaver Crossing, Brainard, Weston,
Staplehurst, Western, Garland, Pleasant Dale, Dwight, Bee, Ulysses
and Malcolm.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

This is a DANGEROUS SITUATION. These storms are potentially 
producing widespread wind damage across. SEEK SHELTER NOW inside a 
sturdy structure and stay away from windows.
 
&&

LAT...LON 4035 9737 4120 9724 4121 9672 4087 9676
      4035 9692
TIME...MOT...LOC 0506Z 273DEG 37KT 4117 9674 4035 9711 

HAIL...0.75IN
WIND...75MPH
 
$$

DeWald

146 
WWUS53 KOAX 100528
SVSOAX

Severe Weather Statement
National Weather Service Omaha/Valley Nebraska
1228 AM CDT Sat Jul 10 2021

NEC023-067-109-151-155-159-100538-
/O.EXP.KOAX.SV.W.0096.000000T0000Z-210710T0530Z/
Lancaster NE-Seward NE-Saline NE-Butler NE-Saunders NE-Gage NE-
1228 AM CDT Sat Jul 10 2021

...THE SEVERE THUNDERSTORM WARNING FOR WESTERN LANCASTER...SEWARD...
SALINE...SOUTHEASTERN BUTLER...SOUTHWESTERN SAUNDERS AND NORTHWESTERN
GAGE COUNTIES WILL EXPIRE AT 1230 AM CDT...
    
The storms which prompted the warning have moved out of the area.
Therefore, the warning will be allowed to expire.  However heavy rain
is still possible with these thunderstorms.

A Severe Thunderstorm Watch remains in effect until 500 AM CDT for
southeastern and east central Nebraska.

LAT...LON 4035 9737 4120 9724 4121 9672 4087 9676
      4035 9692
TIME...MOT...LOC 0528Z 273DEG 40KT 4116 9641 4034 9679 

$$

DeWald

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 9, 7:22 PM CDT, 4 hours 4 minutes earlier.

Area forecast discussion, Jul 9, 7:22 PM CDT, 4 hours 4 minutes before

Area Forecast Discussion
National Weather Service Omaha/Valley NE
722 PM CDT Fri Jul 9 2021

...Updated Aviation Forecast Discussion...

.DISCUSSION...
Issued at 335 PM CDT Fri Jul 9 2021

Things starting to maybe become a little more clear on how things
will pan out this afternoon/evening, but some key questions still
remain: 1. Where will the warm front set up? 2. Will forcing be
strong enough to break the fairly stout cap over the area (per the
KOAX 19Z sounding)? As of around 2:30 PM, radar/satellite/surface
obs show the warm front from roughly Tekamah, NE, eastward to
near Carroll, IA, and south/southeastward toward Creston, IA.
Difficult to say how much farther northeastward it makes it, as
outflow from a significant hail-producing storm that moved through
the Des Moines metro area could slow its progress a fair amount.
As far as forcing, could see some enhanced convergence with that
outflow, but may need to end up waiting for a strengthening low
level jet early this evening to get anything to go, which seems to
be the idea held by the CAMs, and those still have very little,
if anything, that initiates in the forecast area. That said, if
something does get going, plenty of instability with just over
3000 J/kg of MUCAPE per the KOAX 19Z sounding, and decent shear
would suggest supercells capable of all hazards, especially right
near the warm front where low level shear is likely enhanced. So
while severe storms aren't particularly likely in the forecast
area early this evening, still worth keeping a close eye on, as
potential is there.

Higher confidence that the greater severe weather risk will be
overnight as convection currently going up in SE WY into the NE
panhandle is expected to congeal into an MCS and move eastward
into the area toward 11 PM. Expect a damaging wind and hail threat
with those storms, as plenty of instability will remain in place
overnight. One question with regarding those storms will be cold
pool maintenance, as RAP guidance suggests 0-3 km shear values
generally less than 30 kts ahead of the line, but still should be
sufficient for at least some level of organization.

Main severe storm threat should exit the area by 5 AM or so, but
expect scattered showers and storms to persist through Saturday as
a mid/upper level trough currently over Montana digs into the
area and eventually cuts off. In addition to precip, this will
bring much cooler weather, with highs in the 70s for many both
Saturday and Sunday. Latest guidance suggests the low may stick
around the area a little bit longer than previously thought, which
could lead to continued showers and storms into at least Sunday,
so increased precip chances a bit through the Sunday morning
hours. May end up needing to go higher and possibly into Monday in
future forecasts.

Low should eventually push off toward the Great Lakes, bringing a
return to the mid and upper 80s by Tuesday. However, another bit
of shortwave energy and cold front look to slide through sometime
Tuesday night into Thursday bringing our next chance at precip,
though still some differences on exact timing.

&&

.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 639 PM CDT Fri Jul 9 2021

VFR conditions will continue until 06-07Z when complex of
thunderstorms at this time over the Nebraska Panhandle moves east
into the TAF sites. Wind gusts greater than 30-40 kts can be
expected with these storms as they move quickly west to east. MVFR
and IFR ceilings are likely in these storms. After the lines
passes, other thunderstorms and showers will linger with MVFR
conditions possible in vicinity of the storms.

&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...None.
IA...None.
&&

DISCUSSION...CA
AVIATION...Smith

Hazardous weather outlook, Jul 9, 3:43 PM CDT, 7 hours 43 minutes before

Hazardous Weather Outlook
National Weather Service Omaha/Valley NE
343 PM CDT Fri Jul 9 2021

IAZ043-055-056-069-079-080-090-091-NEZ011-012-015>018-030>034-
042>045-050>053-065>068-078-088>093-101200-
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-
343 PM CDT Fri Jul 9 2021

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 Saturday

Though not likely, a few strong to severe thunderstorms could
develop across extreme southeast Nebraska and southwest Iowa late
this afternoon into this evening. Any storms that do develop in
this area will be capable of producing large hail and damaging
winds. A few tornadoes would also be possible.

A more widespread severe weather episode is possible across
portions of the area later this evening. Strong to severe
thunderstorms are expected to develop across central Nebraska and
spread east through the area from around 10 PM through the early
morning hours Saturday. Large hail and damaging winds will be the
primary hazards with these storms.

Scattered thunderstorms are possible Saturday however severe
storms are not expected.

.DAYS TWO THROUGH SEVEN...Saturday night through Friday

Some lingering non-severe storms are possible into Sunday.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed across portions of southeast
Nebraska and southwest Iowa this evening.

In the hours before

Local storm report, Jul 9, 10:55 PM CDT, 31 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
1055 PM CDT FRI JUL 9 2021

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1055 PM     TSTM WND GST     8 N TILDEN              42.16N 97.80W
07/09/2021  M58 MPH          PIERCE             NE   MESONET

            PWS-KNEMEADO3.

&&

DMP

Local storm report, Jul 9, 11:11 PM CDT, 15 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
1111 PM CDT FRI JUL 9 2021

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1059 PM     TSTM WND DMG     BATTLE CREEK            42.00N 97.60W
07/09/2021                   MADISON            NE   LAW ENFORCEMENT

            LAW ENFORCEMENT RELAYED REPORT OF POWER OUT
            IN BATTLE CREEK.

&&

PF

Local storm report, Jul 9, 11:12 PM CDT, 14 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
1112 PM CDT FRI JUL 9 2021

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1059 PM     TSTM WND DMG     2 WNW MEADOW GROVE      42.04N 97.78W
07/09/2021                   MADISON            NE   LAW ENFORCEMENT

            LAW ENFORCEMENT RELAYED REPORT OF TREES AND
            POWER LINES DOWN ALONG HIGHWAY 275.

&&

PF

Local storm report, Jul 9, 11:13 PM CDT, 13 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
1113 PM CDT FRI JUL 9 2021

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1105 PM     TSTM WND GST     3 SSW NORFOLK           41.99N 97.44W
07/09/2021  M63 MPH          MADISON            NE   ASOS

            ASOS AT NORFOLK AIRPORT MEASURED A PEAK WIND
            GUST OF 63 MPH.

&&

PF

Local storm report, Jul 9, 11:16 PM CDT, 10 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
1116 PM CDT FRI JUL 9 2021

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1101 PM     TSTM WND DMG     3 NNW MEADOW GROVE      42.07N 97.76W
07/09/2021                   MADISON            NE   PUBLIC

            REPORT FROM MPING: TREES UPROOTED OR
            SNAPPED.

&&

PF

Local storm report, Jul 9, 11:18 PM CDT, 8 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
1118 PM CDT FRI JUL 9 2021

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1055 PM     TSTM WND DMG     3 E PIERCE              42.20N 97.47W
07/09/2021                   PIERCE             NE   EMERGENCY MNGR

            TREES DOWN EAST OF PIERCE.

&&

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 9, 9:30 PM CDT	Severe Thunderstorm Warning	OAX	Antelope, Knox, Pierce	45 min
Jul 9, 9:50 PM CDT	Special Weather Statement	OAX	Antelope, Boone	10 min
Jul 9, 10:12 PM CDT	Severe Thunderstorm Warning	OAX	Antelope, Cedar, Knox, Madison, Pierce, Stanton and 1 more	48 min
Jul 9, 10:15 PM CDT	Severe Thunderstorm Warning	OAX	Butler, Colfax, Platte	45 min
Jul 9, 10:52 PM CDT	Severe Thunderstorm Warning	OAX	Burt, Cuming, Thurston	38 min
Jul 9, 10:56 PM CDT	Severe Thunderstorm Warning	OAX	Butler, Colfax, Dodge, Platte, Saunders	64 min
Jul 9, 11:00 PM CDT	Severe Thunderstorm Warning	OAX	Cuming, Madison, Pierce, Stanton, Wayne	45 min
Jul 9, 11:19 PM CDT	Severe Thunderstorm Warning	OAX	Burt, Cuming, Dodge	41 min
Jul 9, 11:38 PM CDT	Severe Thunderstorm Warning	OAX	Burt, Dodge, Douglas, Saunders, Washington	52 min
Jul 9, 11:41 PM CDT	Severe Thunderstorm Warning	OAX	Butler, Colfax, Cuming, Dodge, Platte, Saunders and 1 more	49 min
Jul 9, 11:46 PM CDT	Severe Thunderstorm Warning	OAX	Jefferson	44 min
Jul 9, 11:55 PM CDT	Severe Thunderstorm Warning	OAX	Cass, Douglas, Gage, Johnson, Lancaster, Otoe and 2 more	65 min
Jul 10, 12:11 AM CDT	Severe Thunderstorm Warning	OAX	Gage, Johnson, Pawnee	49 min
Jul 10, 12:26 AM CDT	Severe Thunderstorm Warning	OAX	Dodge, Douglas, Saunders, Washington	19 min
Jul 10, 12:40 AM CDT	Severe Thunderstorm Warning	OAX	Otoe	50 min
Jul 10, 12:42 AM CDT	Severe Thunderstorm Warning	OAX	Dodge, Douglas, Saunders, Washington	18 min
Jul 10, 12:44 AM CDT	Severe Thunderstorm Warning	OAX	Cass, Gage, Johnson, Nemaha, Otoe, Pawnee and 1 more	61 min
Jul 10, 1:31 PM CDT	Special Weather Statement	OAX	Dodge, Douglas, Sarpy, Saunders, Washington	74 min
Jul 10, 1:56 PM CDT	Severe Thunderstorm Warning	OAX	Dodge, Douglas, Sarpy, Saunders, Washington	64 min
Jul 10, 4:18 PM CDT	Special Weather Statement	OAX	Pawnee, Richardson	27 min

Nearby

Severe Thunderstorm Warnings in Nebraska, 2021 Every severe thunderstorm warning in 2021

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.