Alert archive / Nebraska / Red Flag Warnings in 2021

Red Flag Warning 8, NWS Omaha, NE

May 1, 20215 counties in Iowa; 19 counties in Nebraska

NWS Omaha, NE issued this red flag warning at May 1, 2021, 10:01 AM CDT for 5 counties in Iowa; 19 counties in Nebraska. It took effect at May 1, 2021, 1:00 PM CDT. It was in force for 7 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
May 1, 2021, 10:01 AM CDT (15:01 UTC)
In effect from
May 1, 2021, 1:00 PM CDT
Expired
May 1, 2021, 8:00 PM CDT
In force
7 hr
Issued by
NWS Omaha, NE
All 24 counties

Harrison County, IA, Mills County, IA, Monona County, IA, Pottawattamie County, IA, Shelby County, IA, Boone County, NE, Burt County, NE, Butler County, NE, Cass County, NE, Colfax County, NE, Cuming County, NE, Dodge County, NE, Douglas County, NE, Lancaster County, NE, Madison County, NE, Platte County, NE, Saline County, NE, Sarpy County, NE, Saunders County, NE, Seward County, NE, Stanton County, NE, Thurston County, NE, Washington County, NE, Wayne County, NE

The radar

The Omaha radar (KOAX), 27 km from the middle of the area, began a volume at 15:02 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 12:00Z, 3.0 hours before the alert went out and 27 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, Omaha, NE at 12:00Z on 2021-05-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Omaha, NE at 12:00Z on 2021-05-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 198 square meters per square second.193958Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
2673 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
198 m²/s²
0-3 km storm-relative helicity
184 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

708 
WWUS83 KOAX 011501
RFWOAX

URGENT - FIRE WEATHER MESSAGE
National Weather Service Omaha/Valley NE
1001 AM CDT Sat May 1 2021

IAZ043-055-056-069-079-NEZ015-018-030>034-042>045-050>053-065>067-
078-020000-
/O.NEW.KOAX.FW.W.0008.210501T1800Z-210502T0000Z/
Monona-Harrison-Shelby-Pottawattamie-Mills-Thurston-Wayne-Boone-
Madison-Stanton-Cuming-Burt-Platte-Colfax-Dodge-Washington-Butler-
Saunders-Douglas-Sarpy-Seward-Lancaster-Cass-Saline-
1001 AM CDT Sat May 1 2021

...RED FLAG WARNING IN EFFECT FROM 1 PM THIS AFTERNOON TO 7 PM
CDT THIS EVENING FOR WIND AND LOW RELATIVE HUMIDITY FOR PORTIONS
OF EASTERN NEBRASKA AND SOUTHWEST IOWA...

The National Weather Service in Omaha/Valley has issued a Red
Flag Warning for wind and low relative humidity, which is in
effect from 1 PM this afternoon to 7 PM CDT this evening.

* Affected Area...In Iowa, Monona, Harrison, Shelby, 
  Pottawattamie and Mills. In Nebraska, Thurston, Wayne, Boone, 
  Madison, Stanton, Cuming, Burt, Platte, Colfax, Dodge, 
  Washington, Butler, Saunders, Douglas, Sarpy, Seward, 
  Lancaster, Cass and Saline.

* Winds...Southwest 20 to 25 mph with gusts up to 40 mph.

* Relative Humidity...As low as 20 percent.

* Impacts...Any fires that develop will likely spread rapidly. 
  Outdoor burning is not recommended.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions
are either occurring now, or will shortly. A combination of
strong winds, low relative humidity and warm temperatures can
contribute to extreme fire behavior.

&&

$$
2 follow-up statements
213 
WWUS83 KOAX 012342
RFWOAX

URGENT - FIRE WEATHER MESSAGE
National Weather Service Omaha/Valley NE
642 PM CDT Sat May 1 2021

IAZ043-055-056-069-079-NEZ015-018-030>034-042>045-050>053-065>067-
078-020100-
/O.EXT.KOAX.FW.W.0008.000000T0000Z-210502T0100Z/
Monona-Harrison-Shelby-Pottawattamie-Mills-Thurston-Wayne-Boone-
Madison-Stanton-Cuming-Burt-Platte-Colfax-Dodge-Washington-Butler-
Saunders-Douglas-Sarpy-Seward-Lancaster-Cass-Saline-
642 PM CDT Sat May 1 2021

...RED FLAG WARNING NOW IN EFFECT UNTIL 8 PM CDT THIS EVENING FOR
WIND AND LOW RELATIVE HUMIDITY FOR PORTIONS OF EASTERN NEBRASKA
AND SOUTHWEST IOWA...

* Affected Area...In Iowa, Monona, Harrison, Shelby, 
  Pottawattamie and Mills. In Nebraska, Thurston, Wayne, Boone, 
  Madison, Stanton, Cuming, Burt, Platte, Colfax, Dodge, 
  Washington, Butler, Saunders, Douglas, Sarpy, Seward, 
  Lancaster, Cass and Saline.

* Winds...Southwest 20 to 25 mph with gusts up to 35 mph.

* Relative Humidity...As low as 16 percent.

* Impacts...Any fires that develop will likely spread rapidly. 
  Outdoor burning is not recommended.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions
are either occurring now, or will shortly. A combination of
strong winds, low relative humidity and warm temperatures can
contribute to extreme fire behavior.

&&

$$
103 
WWUS83 KOAX 020055
RFWOAX

URGENT - FIRE WEATHER MESSAGE
National Weather Service Omaha/Valley NE
755 PM CDT Sat May 1 2021

IAZ043-055-056-069-079-NEZ015-018-030>034-042>045-050>053-065>067-
078-020200-
/O.EXP.KOAX.FW.W.0008.000000T0000Z-210502T0100Z/
Monona-Harrison-Shelby-Pottawattamie-Mills-Thurston-Wayne-Boone-
Madison-Stanton-Cuming-Burt-Platte-Colfax-Dodge-Washington-Butler-
Saunders-Douglas-Sarpy-Seward-Lancaster-Cass-Saline-
755 PM CDT Sat May 1 2021

...RED FLAG WARNING WILL EXPIRE AT 8 PM CDT THIS EVENING FOR WIND
AND LOW RELATIVE HUMIDITY FOR PORTIONS OF EASTERN NEBRASKA AND
SOUTHWEST IOWA...

Winds are not as strong as they were earlier today and relative
humidity values have increased. The Red Flag Warning which was in
effect will be allowed to expire at 8 pm. 

$$

BCM

Nearby

Red Flag Warnings in Nebraska, 2021Red Flag Warnings in Iowa, 2021Every red flag 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.