Alert archive / Nebraska / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 4, NWS Omaha, NE

April 5, 2021Douglas County, Washington County, Nebraska; Harrison County, Pottawattamie County, Iowa

NWS Omaha, NE issued this severe thunderstorm warning at Apr 5, 2021, 1:28 AM CDT for Douglas County, Washington County, Nebraska; Harrison County, Pottawattamie County, Iowa. It was in force for 32 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Apr 5, 2021, 1:28 AM CDT (06:28 UTC)
Expired: Apr 5, 2021, 2:00 AM CDT
In force: 32 min
Issued by: NWS Omaha, NE
Area: Storm-based polygon
Hail: 0.75 in
Wind: 65.0 mph

Counties Harrison County, IA, Pottawattamie County, IA, Douglas County, NE, Washington County, NE

The radar

The Omaha radar (KOAX), 31 km from the middle of the area, began a volume at 06:28 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 nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 6.5 hours before the alert went out and 32 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: 452 J/kg
Mixed-layer CIN: -73 J/kg
Mixed-layer LCL: 3078 m above ground
0-6 km bulk shear: 35 kt
0-1 km storm-relative helicity: 77 m²/s²
0-3 km storm-relative helicity: 150 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.4

Open this sounding in Storm Lab

The text

As transmitted.

838 
WUUS53 KOAX 050628
SVROAX
IAC085-155-NEC055-177-050700-
/O.NEW.KOAX.SV.W.0004.210405T0628Z-210405T0700Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Omaha/Valley Nebraska
128 AM CDT Mon Apr 5 2021

The National Weather Service in Omaha has issued a

* Severe Thunderstorm Warning for...
  Northwestern Pottawattamie County in southwestern Iowa...
  Southern Harrison County in southwestern Iowa...
  Southeastern Washington County in east central Nebraska...
  Northeastern Douglas County in east central Nebraska...

* Until 200 AM CDT.

* At 127 AM CDT, outflow associated with weakening showers was 
  located along a line extending from near Kennard to Omaha to 6 
  miles north of Ralston, moving east at 25 mph.

  HAZARD...65 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...Expect damage to roofs, siding, and trees.

* Locations impacted include...
  Omaha, Fort Calhoun, Kennard, Carter Lake, Crescent, Desoto Bend
  National Wildlife Refuge, Wilson Island State Park and Hitchcock
  Nature Center.

This includes Interstate 29 between mile markers 58 and 68.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4156 9598 4139 9584 4129 9582 4128 9612
      4136 9614 4148 9621
TIME...MOT...LOC 0627Z 262DEG 20KT 4147 9616 4137 9606 4130 9605 

HAIL...<.75IN
WIND...65MPH
 
$$

Mead

1 follow-up statement

833 
WWUS53 KOAX 050656
SVSOAX

Severe Weather Statement
National Weather Service Omaha/Valley Nebraska
156 AM CDT Mon Apr 5 2021

IAC085-155-NEC055-177-050704-
/O.EXP.KOAX.SV.W.0004.000000T0000Z-210405T0700Z/
Pottawattamie IA-Harrison IA-Washington NE-Douglas NE-
156 AM CDT Mon Apr 5 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN POTTAWATTAMIE...
SOUTHERN HARRISON...SOUTHEASTERN WASHINGTON AND NORTHEASTERN DOUGLAS
COUNTIES WILL EXPIRE AT 200 AM CDT...
            
The strong winds which prompted the warning have weakened below 
severe limits, and no longer pose an immediate threat to life or 
property. Therefore, the warning will be allowed to expire.  However 
gusty winds are still possible with the showers moving through the 
area.

LAT...LON 4156 9598 4139 9584 4129 9582 4128 9612
      4136 9614 4148 9621
TIME...MOT...LOC 0654Z 262DEG 20KT 4149 9597 4139 9587 4132 9586 

$$

Mead

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 4, 8:21 PM CDT	Special Weather Statement	OAX	Butler	39 min
Apr 4, 10:44 PM CDT	Special Weather Statement	OAX	Platte	31 min
Apr 4, 11:03 PM CDT	Severe Thunderstorm Warning	OAX	Butler, Colfax, Platte	14 min
Apr 4, 11:47 PM CDT	Special Weather Statement	OAX	Colfax	28 min
Apr 5, 12:24 AM CDT	Severe Thunderstorm Warning	OAX	Dodge, Douglas, Sarpy, Saunders, Washington	36 min
Apr 5, 1:07 AM CDT	Severe Thunderstorm Warning	OAX	Burt, Dodge, Washington	23 min
Apr 5, 2:05 AM CDT	Special Weather Statement	OAX	Colfax, Dodge, Saunders	55 min
Apr 5, 2:08 AM CDT	Special Weather Statement	OAX	Burt	52 min
Apr 5, 2:52 AM CDT	Special Weather Statement	OAX	Dodge, Douglas, Washington	53 min
Apr 5, 3:39 AM CDT	Special Weather Statement	OAX	Harrison, Pottawattamie	51 min
Apr 5, 6:28 AM CDT	Special Weather Statement	OAX	Harrison, Monona, Pottawattamie, Shelby	47 min

Nearby

Severe Thunderstorm Warnings in Nebraska, 2021 Severe Thunderstorm Warnings in Iowa, 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.