Alert archive / Iowa / Red Flag Warnings in 2021

Red Flag Warning 7, NWS Sioux Falls, SD

May 1, 2021Dakota County, Dixon County, Nebraska; 10 counties in Iowa; Union County, South Dakota

NWS Sioux Falls, SD issued this red flag warning at May 1, 2021, 3:09 AM CDT for Dakota County, Dixon County, Nebraska; 10 counties in Iowa; Union County, South Dakota. It took effect at May 1, 2021, 1:00 PM CDT. It was in force for 6 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, 3:09 AM CDT (08:09 UTC)
In effect from
May 1, 2021, 1:00 PM CDT
Expired
May 1, 2021, 7:00 PM CDT
In force
6 hr
Issued by
NWS Sioux Falls, SD

Counties Buena Vista County, IA, Cherokee County, IA, Clay County, IA, Dickinson County, IA, Ida County, IA, O'Brien County, IA, Osceola County, IA, Plymouth County, IA, Sioux County, IA, Woodbury County, IA, Dakota County, NE, Dixon County, NE, Union County, SD

The radar

The Sioux Falls radar (KFSD), 110 km from the middle of the area, began a volume at 08:12 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, 8.2 hours before the alert went out and 172 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 00:00Z 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 00:00Z on 2021-05-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 71 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
2917 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
71 m²/s²
0-3 km storm-relative helicity
306 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

396 
WWUS83 KFSD 010809
RFWFSD

URGENT - FIRE WEATHER MESSAGE
National Weather Service Sioux Falls SD
309 AM CDT Sat May 1 2021

IAZ003-013-014-020>022-031-032-011800-
/O.NEW.KFSD.FW.W.0007.210501T1800Z-210502T0000Z/
Dickinson-O'Brien-Clay-Plymouth-Cherokee-Buena Vista-Woodbury-Ida-
309 AM CDT Sat May 1 2021

...RED FLAG WARNING IN EFFECT FROM 1 PM THIS AFTERNOON TO 7 PM
CDT THIS EVENING FOR GUSTY WINDS AND LOW HUMIDITY FOR FIRE 
WEATHER ZONES 003, 013, 014, 020, 021, 022, 031, AND 032...

The National Weather Service in Sioux Falls has issued a Red Flag
Warning, which is in effect from 1 PM this afternoon to 7 PM CDT
this evening. 

* AFFECTED AREA...Fire weather zones 003, 013, 014, 020, 021, 
  022, 031, and 032. 

* WIND...Southwest 15 to 20 mph with gusts around 30 mph.

* 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.

&&

$$
3 follow-up statements
472 
WWUS83 KFSD 011507
RFWFSD

URGENT - FIRE WEATHER MESSAGE
National Weather Service Sioux Falls SD
1007 AM CDT Sat May 1 2021

...RED FLAG WARNING IN EFFECT FROM 1 PM THIS AFTERNOON TO 7 PM CDT
THIS EVENING FOR PORTIONS OF FAR NORTHEAST NEBRASKA, FAR SOUTHEAST
SOUTH DAKOTA, AND MUCH OF NORTHWEST IOWA...

IAZ002-012-NEZ013-014-SDZ071-020000-
/O.EXA.KFSD.FW.W.0007.210501T1800Z-210502T0000Z/
Osceola-Sioux-Dixon-Dakota-Union-
1007 AM CDT Sat May 1 2021

...RED FLAG WARNING IN EFFECT UNTIL 7 PM CDT THIS EVENING FOR
GUSTY WINDS AND LOW HUMIDITY FOR FIRE WEATHER ZONES 002, 012, 
013, 014, AND 071...

The National Weather Service in Sioux Falls has issued a Red Flag
Warning, which is in effect until 7 PM CDT this evening. 

* AFFECTED AREA...Fire weather zones 002, 012, 013, 014, and 071.

* WIND...Southwest 15 to 20 mph with gusts around 30 mph.

* 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.

&&

$$

IAZ003-013-014-020>022-031-032-020000-
/O.CON.KFSD.FW.W.0007.210501T1800Z-210502T0000Z/
Dickinson-O'Brien-Clay-Plymouth-Cherokee-Buena Vista-Woodbury-Ida-
1007 AM CDT Sat May 1 2021

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 7 PM CDT THIS EVENING
FOR GUSTY WINDS AND LOW HUMIDITY FOR FIRE WEATHER ZONES 003, 013,
014, 020, 021, 022, 031, AND 032...

* AFFECTED AREA...Fire weather zones 003, 013, 014, 020, 021, 
  022, 031, and 032. 

* WIND...Southwest 15 to 20 mph with gusts around 30 mph.

* 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.

&&

$$
349 
WWUS83 KFSD 011946
RFWFSD

URGENT - FIRE WEATHER MESSAGE
National Weather Service Sioux Falls SD
246 PM CDT Sat May 1 2021

...RED FLAG WARNING IN EFFECT UNTIL 7 PM CDT THIS EVENING FOR 
PORTIONS OF FAR NORTHEAST NEBRASKA, FAR SOUTHEAST SOUTH DAKOTA, 
AND MUCH OF NORTHWEST IOWA...

IAZ002-003-012>014-020>022-031-032-NEZ013-014-SDZ071-020000-
/O.CON.KFSD.FW.W.0007.000000T0000Z-210502T0000Z/
Osceola-Dickinson-Sioux-O'Brien-Clay-Plymouth-Cherokee-
Buena Vista-Woodbury-Ida-Dixon-Dakota-Union-
246 PM CDT Sat May 1 2021

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 7 PM CDT THIS EVENING
FOR GUSTY WINDS AND VERY LOW HUMIDITY FOR FIRE WEATHER ZONES 002,
003, 012, 013, 013, 014, 014, 020, 021, 022, 031, 032, AND 071...

* AFFECTED AREA...Fire weather zones across portions of far
  southeast South Dakota, far northeast Nebraska, and much of
  northwest Iowa.

* WIND...Southwest 15 to 20 mph with gusts up to 40 mph.

* HUMIDITY...as low as 10 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.

&&

$$
200 
WWUS83 KFSD 020009
RFWFSD

URGENT - FIRE WEATHER MESSAGE
National Weather Service Sioux Falls SD
709 PM CDT Sat May 1 2021

...RED FLAG WARNING FOR LOW HUMIDITY AND STRONG WINDS FOR EXTREME
SOUTHEAST SOUTH DAKOTA...EXTREME NORTHEAST NEBRASKA AND MUCH OF
NORTHWEST IOWA ALLOWED TO EXPIRE...

IAZ002-003-012>014-020>022-031-032-NEZ013-014-SDZ071-020115-
/O.EXP.KFSD.FW.W.0007.000000T0000Z-210502T0000Z/
Osceola-Dickinson-Sioux-O'Brien-Clay-Plymouth-Cherokee-
Buena Vista-Woodbury-Ida-Dixon-Dakota-Union-
709 PM CDT Sat May 1 2021

...RED FLAG WARNING HAS EXPIRED FOR STRONG WINDS AND LOW HUMIDITY
FOR FIRE WEATHER ZONES 002, 003, 012, 013, 013, 014, 014, 020, 
021, 022, 031, 032, AND 071...

Winds will continue to decrease early this evening, and relative
humidity will also slowly recover as temperatures begin to fall.
However, through shortly before sunset, there will still be some
areas of southwest winds gusting 25 to 35 mph and humidity of 15 
to 25 percent, creating continued very high to extreme fire 
danger.

$$

Nearby

Red Flag Warnings in Iowa, 2021Red Flag Warnings in Nebraska, 2021Red Flag Warnings in South Dakota, 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.