Alert archive / Iowa / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 34, NWS Omaha, NE

June 11, 2021Harrison County, Monona County, Iowa; Burt County, Washington County, Nebraska

NWS Omaha, NE issued this severe thunderstorm warning at Jun 11, 2021, 7:50 AM CDT for Harrison County, Monona County, Iowa; Burt County, Washington County, Nebraska. It was in force for 40 min. 1 report 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: Jun 11, 2021, 7:50 AM CDT (12:50 UTC)
Expired: Jun 11, 2021, 8:30 AM CDT
In force: 40 min
Issued by: NWS Omaha, NE
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Harrison County, IA, Monona County, IA, Burt County, NE, Washington County, NE

The radar

The Omaha radar (KOAX), 58 km from the middle of the area, began a volume at 12:52 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
Jun 11, 8:05 AM CDT	TSTM WND DMG	2 Nw Little Sioux, IA	3 TREE LIMBS CRACKED AND BROKEN. WINDS ESTIMATED 50 TO 60 MPH.

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

The watch it was issued in

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

Issued	Product	Office	Lasted
Jun 11, 5:36 AM CDT	Severe Thunderstorm Watch	SPC	5 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 12:00Z, 0.8 hours before the alert went out and 58 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: 2132 J/kg
Mixed-layer CIN: -90 J/kg
Mixed-layer LCL: 899 m above ground
0-6 km bulk shear: 29 kt
0-1 km storm-relative helicity: 81 m²/s²
0-3 km storm-relative helicity: 162 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.7

Open this sounding in Storm Lab

The text

As transmitted.

737 
WUUS53 KOAX 111250
SVROAX
IAC085-133-NEC021-177-111330-
/O.NEW.KOAX.SV.W.0034.210611T1250Z-210611T1330Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Omaha/Valley Nebraska
750 AM CDT Fri Jun 11 2021

The National Weather Service in Omaha has issued a

* Severe Thunderstorm Warning for...
  Eastern Monona County in west central Iowa...
  Western Harrison County in southwestern Iowa...
  Southeastern Burt County in east central Nebraska...
  North central Washington County in east central Nebraska...

* Until 830 AM CDT.

* At 749 AM CDT, severe thunderstorms were located along a line
  extending from 5 miles east of Whiting to 8 miles north of Tekamah
  to near Uehling, moving southeast at 35 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

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

* Severe thunderstorms will be near...
  Tekamah around 755 AM CDT.

Other locations in the path of these severe thunderstorms include
Mondamin, Pisgah, Ute, Moorhead, Blair and Modale.

This includes Interstate 29 between mile markers 82 and 109.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4169 9576 4151 9617 4171 9644 4174 9644
      4174 9647 4190 9619 4217 9603 4208 9569
TIME...MOT...LOC 1249Z 303DEG 30KT 4215 9604 4189 9618 4175 9647 

HAIL...<.75IN
WIND...60MPH
 
$$

Mead

2 follow-up statements

267 
WWUS53 KOAX 111316
SVSOAX

Severe Weather Statement
National Weather Service Omaha/Valley Nebraska
816 AM CDT Fri Jun 11 2021

IAC085-133-NEC021-177-111330-
/O.CON.KOAX.SV.W.0034.000000T0000Z-210611T1330Z/
Monona IA-Harrison IA-Burt NE-Washington NE-
816 AM CDT Fri Jun 11 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 830 AM CDT
FOR EASTERN MONONA...WESTERN HARRISON...SOUTHEASTERN BURT AND NORTH
CENTRAL WASHINGTON COUNTIES...

At 816 AM CDT, severe thunderstorms were located along a line
extending from 4 miles west of Ute to 4 miles south of Pisgah to 7
miles northwest of Blair, moving southeast at 35 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

Locations impacted include...
  Ute and Modale.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4169 9576 4151 9617 4171 9644 4174 9644
      4174 9647 4190 9619 4217 9603 4208 9569
TIME...MOT...LOC 1316Z 303DEG 30KT 4203 9579 4177 9593 4163 9622 

HAIL...<.75IN
WIND...60MPH
 
$$

Mead

399 
WWUS53 KOAX 111326
SVSOAX

Severe Weather Statement
National Weather Service Omaha/Valley Nebraska
826 AM CDT Fri Jun 11 2021

IAC085-133-NEC021-177-111336-
/O.EXP.KOAX.SV.W.0034.000000T0000Z-210611T1330Z/
Monona IA-Harrison IA-Burt NE-Washington NE-
826 AM CDT Fri Jun 11 2021

...THE SEVERE THUNDERSTORM WARNING FOR EASTERN MONONA...WESTERN
HARRISON...SOUTHEASTERN BURT AND NORTH CENTRAL WASHINGTON COUNTIES
WILL EXPIRE AT 830 AM CDT...
            
The storms 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 of 40 to 50 mph are still possible with these thunderstorms.

A Severe Thunderstorm Watch remains in effect until 1100 AM CDT for
southwestern and west central Iowa...and east central Nebraska.

LAT...LON 4169 9576 4151 9617 4171 9644 4174 9644
      4174 9647 4190 9619 4217 9603 4208 9569
TIME...MOT...LOC 1326Z 303DEG 30KT 4199 9571 4173 9585 4159 9614 

$$

Mead

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 11, 7:10 AM CDT	Severe Thunderstorm Warning	OAX	Monona	35 min
Jun 11, 7:34 AM CDT	Severe Thunderstorm Warning	OAX	Monona	26 min
Jun 11, 5:27 AM CDT	Severe Thunderstorm Warning	OAX	Knox	33 min
Jun 11, 5:55 AM CDT	Severe Thunderstorm Warning	OAX	Antelope, Cedar, Knox, Pierce, Wayne	35 min
Jun 11, 6:45 AM CDT	Severe Thunderstorm Warning	OAX	Boone	30 min
Jun 11, 7:24 AM CDT	Severe Thunderstorm Warning	OAX	Platte	36 min
Jun 11, 7:41 AM CDT	Severe Thunderstorm Warning	OAX	Butler, Colfax, Madison, Platte, Stanton	34 min
Jun 11, 8:13 AM CDT	Severe Thunderstorm Warning	OAX	Butler, Colfax, Platte	47 min
Jun 11, 8:55 AM CDT	Special Weather Statement	OAX	Cass, Douglas, Sarpy	35 min
Jun 11, 9:00 AM CDT	Severe Thunderstorm Warning	OAX	Butler, Lancaster, Saunders, Seward	30 min
Jun 11, 10:43 AM CDT	Areal Flood Advisory	OAX	Lancaster	3 hr
Jun 11, 10:51 AM CDT	Severe Thunderstorm Warning	OAX	Johnson, Nemaha, Otoe	39 min
Jun 11, 11:26 AM CDT	Severe Thunderstorm Warning	OAX	Johnson, Nemaha, Richardson	49 min
Jun 11, 11:45 AM CDT	Severe Thunderstorm Warning	OAX	Pawnee, Richardson	45 min
Jun 11, 12:11 PM CDT	Severe Thunderstorm Warning	OAX	Nemaha, Richardson	34 min
Jun 11, 12:19 PM CDT	Severe Thunderstorm Warning	OAX	Pawnee, Richardson	41 min
Jun 11, 12:25 PM CDT	Tornado Warning	OAX	Richardson	16 min

Nearby

Severe Thunderstorm Warnings in Iowa, 2021 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.