Alert archive / Nebraska / Special Weather Statements in 2021

Special Weather Statement, NWS Omaha, NE

July 31, 2021Boone County, Nebraska

NWS Omaha, NE issued this special weather statement at Jul 31, 2021, 12:21 AM CDT for Boone County, Nebraska. It was in force for 54 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: Jul 31, 2021, 12:21 AM CDT (05:21 UTC)
Expired: Jul 31, 2021, 1:15 AM CDT
In force: 54 min
Issued by: NWS Omaha, NE

County Boone County, NE

The radar

The Omaha radar (KOAX), 142 km from the middle of the area, began a volume at 05:25 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, 5.4 hours before the alert went out and 141 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: 2669 J/kg
Mixed-layer CIN: -3 J/kg
Mixed-layer LCL: 967 m above ground
0-6 km bulk shear: 40 kt
0-1 km storm-relative helicity: 52 m²/s²
0-3 km storm-relative helicity: 279 m²/s²
Significant tornado parameter: 3.4
Supercell composite: 19.5

Open this sounding in Storm Lab

The text

As transmitted.

655 
WWUS83 KOAX 310521
SPSOAX

Special Weather Statement
National Weather Service Omaha/Valley Nebraska
1221 AM CDT Sat Jul 31 2021
 
NEZ030-031-042-310615-
Madison NE-Platte NE-Boone NE-
1221 AM CDT Sat Jul 31 2021

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHWESTERN MADISON...
NORTHWESTERN PLATTE AND BOONE COUNTIES UNTIL 115 AM CDT...

At 1221 AM CDT, Doppler radar was tracking strong thunderstorms along
a line extending from 7 miles north of Newman Grove to near Albion to
9 miles north of Wolbach. Movement was southeast at 35 mph.

Pea size hail and wind gusts up to 50 mph will be possible with these
storms.

Locations impacted include...
Albion, Newman Grove, St. Edward, Cedar Rapids, Petersburg, Lindsay,
Humphrey, Primrose, Cornlea, Loretto and The Highway 14 And 56
Junction.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall is also occurring with these storms, and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.

&&

A Severe Thunderstorm Watch remains in effect until 400 AM CDT for
northeastern Nebraska.

LAT...LON 4191 9829 4192 9783 4171 9740 4152 9770
      4153 9788 4151 9789 4150 9809 4148 9810
      4148 9829 4179 9830
TIME...MOT...LOC 0521Z 302DEG 30KT 4185 9783 4171 9807 4153 9834 

$$

CA

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 30, 7:23 PM CDT	Special Weather Statement	OAX	Saunders	37 min
Jul 30, 7:54 PM CDT	Special Weather Statement	OAX	Lancaster	36 min
Jul 30, 8:17 PM CDT	Special Weather Statement	OAX	Lancaster	28 min
Jul 30, 10:30 PM CDT	Severe Thunderstorm Warning	OAX	Nemaha, Otoe	45 min
Jul 31, 1:03 AM CDT	Severe Thunderstorm Warning	OAX	Colfax	32 min
Jul 31, 1:10 AM CDT	Special Weather Statement	OAX	Platte	35 min
Jul 31, 1:33 AM CDT	Special Weather Statement	OAX	Douglas	42 min
Jul 31, 2:06 AM CDT	Special Weather Statement	OAX	Saunders	39 min
Jul 31, 2:35 AM CDT	Special Weather Statement	OAX	Cass, Lancaster	55 min
Jul 30, 8:06 PM CDT	Special Weather Statement	OAX	Pottawattamie	24 min
Jul 30, 8:12 PM CDT	Severe Thunderstorm Warning	OAX	Pottawattamie, Shelby	33 min
Jul 30, 8:42 PM CDT	Severe Thunderstorm Warning	OAX	Mills, Montgomery, Page, Pottawattamie	33 min
Jul 30, 9:03 PM CDT	Severe Thunderstorm Warning	OAX	Fremont, Mills, Page	42 min
Jul 30, 9:13 PM CDT	Severe Thunderstorm Warning	OAX	Montgomery, Page	32 min
Jul 30, 9:39 PM CDT	Severe Thunderstorm Warning	OAX	Fremont, Page	51 min
Jul 30, 10:12 PM CDT	Tornado Warning	OAX	Page	18 min
Jul 31, 2:14 AM CDT	Special Weather Statement	OAX	Pottawattamie	76 min

Nearby

Special Weather Statements in Nebraska, 2021 Every special weather statement 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.