Alert archive / South Dakota / Red Flag Warnings in 2021

Red Flag Warning 6, NWS Sioux Falls, SD

April 3, 20215 counties in South Dakota

NWS Sioux Falls, SD issued this red flag warning at Apr 3, 2021, 4:09 AM CDT for 5 counties in South Dakota. It took effect at Apr 3, 2021, 2:00 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
Apr 3, 2021, 4:09 AM CDT (09:09 UTC)
In effect from
Apr 3, 2021, 2:00 PM CDT
Expired
Apr 3, 2021, 9:00 PM CDT
In force
7 hr
Issued by
NWS Sioux Falls, SD

Counties Aurora County, SD, Beadle County, SD, Brule County, SD, Gregory County, SD, Jerauld County, SD

The radar

The Sioux Falls radar (KFSD), 164 km from the middle of the area, began a volume at 09:09 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

Aberdeen, SD (KABR), launched 00:00Z, 9.2 hours before the alert went out and 123 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, Aberdeen, SD at 00:00Z on 2021-04-03Temperature 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, Aberdeen, SD at 00:00Z on 2021-04-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -125 square meters per square second.1939587897Sfc1 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
3292 m above ground
0-6 km bulk shear
50 kt
0-1 km storm-relative helicity
-125 m²/s²
0-3 km storm-relative helicity
-75 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

680 
WWUS83 KFSD 030909
RFWFSD

URGENT - FIRE WEATHER MESSAGE
National Weather Service Sioux Falls SD
409 AM CDT Sat Apr 3 2021

SDZ038-050-052-057-058-031715-
/O.NEW.KFSD.FW.W.0006.210403T1900Z-210404T0200Z/
Beadle-Gregory-Jerauld-Brule-Aurora-
409 AM CDT Sat Apr 3 2021

...RED FLAG WARNING IN EFFECT FROM 2 PM THIS AFTERNOON TO 9 PM
CDT THIS EVENING FOR GUSTY WINDS AND LOW HUMIDITY FOR SOUTH DAKOTA
FIRE WEATHER ZONES 038, 050, 052, 057, 058...

The National Weather Service in Sioux Falls has issued a Red Flag
Warning, which is in effect from 2 PM this afternoon to 9 PM CDT
this evening. 

* AFFECTED AREA...In South Dakota...Fire weather zones 038, 050,
  052, 057, and 058, or generally west of a line from Huron to
  Lake Andes. 

* WIND...South 15 to 20 mph with gusts 25 to 30 mph.

* HUMIDITY...as low as 15 to 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
345 
WWUS83 KFSD 031517
RFWFSD

URGENT - FIRE WEATHER MESSAGE
National Weather Service Sioux Falls SD
1017 AM CDT Sat Apr 3 2021

SDZ038-050-052-057-058-032330-
/O.CON.KFSD.FW.W.0006.210403T1900Z-210404T0200Z/
Beadle-Gregory-Jerauld-Brule-Aurora-
1017 AM CDT Sat Apr 3 2021

...RED FLAG WARNING REMAINS IN EFFECT FROM 2 PM THIS AFTERNOON TO
9 PM CDT THIS EVENING FOR GUSTY WINDS AND LOW HUMIDITY FOR FIRE 
WEATHER ZONES 038, 050, 052, 057, AND 058...

* AFFECTED AREA...In South Dakota...Fire weather zones 038, 050, 
  052, 057, and 058, or generally west of a line from Huron to 
  Lake Andes. 

* WIND...South increasing this afternoon to 15 to 20 mph with
  gusts around 25 mph.

* HUMIDITY...as low as 15 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.

&&

$$
784 
WWUS83 KFSD 032138
RFWFSD

URGENT - FIRE WEATHER MESSAGE
National Weather Service Sioux Falls SD
438 PM CDT Sat Apr 3 2021

SDZ038-050-052-057-058-040200-
/O.CON.KFSD.FW.W.0006.000000T0000Z-210404T0200Z/
Beadle-Gregory-Jerauld-Brule-Aurora-
438 PM CDT Sat Apr 3 2021

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 9 PM CDT THIS EVENING
FOR GUSTY WINDS AND LOW HUMIDITY FOR FIRE WEATHER ZONES 038, 050,
052, 057, AND 058...

* AFFECTED AREA...In South Dakota...Fire weather zones 038, 050, 
  052, 057, and 058, or generally west of a line from Huron to 
  Lake Andes. 

* WIND...South increasing into early evening 14 to 20 mph, with
  frequent gusts around around 25 mph.

* HUMIDITY...as low as 12 to 15 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.

&&

$$
517 
WWUS83 KFSD 040203
RFWFSD

URGENT - FIRE WEATHER MESSAGE
National Weather Service Sioux Falls SD
903 PM CDT Sat Apr 3 2021

SDZ038-050-052-057-058-040315-
/O.EXP.KFSD.FW.W.0006.000000T0000Z-210404T0200Z/
Beadle-Gregory-Jerauld-Brule-Aurora-
903 PM CDT Sat Apr 3 2021

...RED FLAG WARNING HAS EXPIRED FOR GUSTY WINDS AND LOW HUMIDITY
FOR FIRE WEATHER ZONES 038, 050, 052, 057, AND 058...

As of 900 pm CDT, decreasing wind speed and a small increase in 
humidity has ended the critical fire weather threat for the night.
However, with humidity remaining from 20 to 30 percent at mid 
evening, one should continue to exercise caution with any use of 
fire.

$$

Nearby

Red 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.