Alert archive / South Dakota / Red Flag Warnings in 2021

Red Flag Warning 5, NWS Sioux Falls, SD

April 2, 20214 states

NWS Sioux Falls, SD issued this red flag warning at Apr 2, 2021, 10:49 AM CDT for 4 states. It was in force for 9 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 2, 2021, 10:49 AM CDT (15:49 UTC)
Expired
Apr 2, 2021, 8:00 PM CDT
In force
9 hr
Issued by
NWS Sioux Falls, SD
All 33 counties

Buena Vista County, IA, Cherokee County, IA, Clay County, IA, Dickinson County, IA, Ida County, IA, Lyon County, IA, O'Brien County, IA, Osceola County, IA, Plymouth County, IA, Sioux County, IA, Woodbury County, IA, Cottonwood County, MN, Jackson County, MN, Lincoln County, MN, Lyon County, MN, Murray County, MN, Nobles County, MN, Pipestone County, MN, Rock County, MN, Dakota County, NE, Dixon County, NE, Bon Homme County, SD, Brookings County, SD, Clay County, SD, Hutchinson County, SD, Lake County, SD, Lincoln County, SD, McCook County, SD, Minnehaha County, SD, Moody County, SD, Turner County, SD, Union County, SD, Yankton County, SD

The radar

The Sioux Falls radar (KFSD), 44 km from the middle of the area, began a volume at 15:53 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, 3.8 hours before the alert went out and 226 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 2021-04-02Temperature 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 2021-04-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 840 square meters per square second.19395878Sfc1 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
2259 m above ground
0-6 km bulk shear
41 kt
0-1 km storm-relative helicity
840 m²/s²
0-3 km storm-relative helicity
1056 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

244 
WWUS83 KFSD 021549
RFWFSD

URGENT - FIRE WEATHER MESSAGE
National Weather Service Sioux Falls SD
1049 AM CDT Fri Apr 2 2021

IAZ001>003-012>014-020>022-031-032-MNZ071-072-080-081-089-090-097-
098-NEZ013-014-SDZ040-055-056-061-062-065>071-030000-
/O.NEW.KFSD.FW.W.0005.210402T1549Z-210403T0100Z/
Lyon-Osceola-Dickinson-Sioux-O'Brien-Clay-Plymouth-Cherokee-
Buena Vista-Woodbury-Ida-Lincoln-Murray-Cottonwood-Nobles-Jackson-
Pipestone-Rock-Dixon-Dakota-Brookings-Lake-Moody-McCook-Minnehaha-
Hutchinson-Turner-Bon Homme-Yankton-Union-
1049 AM CDT Fri Apr 2 2021

...RED FLAG WARNING IN EFFECT UNTIL 8 PM CDT THIS EVENING FOR
STRONG WINDS AND LOW RELATIVE HUMIDITIES FOR FIRE WEATHER ZONES 
001, 002, 003, 012, 013, 013, 014, 014, 020, 021, 022, 031, 032, 
040, 055, 056, 061, 062, 065, 066, 067, 068, 069, 070, 071, 071, 
072, 080, 081, 089, 090, 097, AND 098...

The National Weather Service in Sioux Falls has issued a Red Flag
Warning, which is in effect until 8 PM CDT this evening. 

* AFFECTED AREA...Southwest Minnesota, northwest Iowa, northeast
  Nebraska and far eastern South Dakota.

* WIND...South 20 to 30 mph with gusts of 40 to 45 mph.

* HUMIDITY...lowest humidity 20 to 25 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
086 
WWUS83 KFSD 022137
RFWFSD

URGENT - FIRE WEATHER MESSAGE
National Weather Service Sioux Falls SD
437 PM CDT Fri Apr 2 2021

IAZ001>003-012>014-020>022-031-032-MNZ071-072-080-081-089-090-097-
098-NEZ013-014-SDZ040-055-056-061-062-065>071-030100-
/O.CON.KFSD.FW.W.0005.000000T0000Z-210403T0100Z/
Lyon-Osceola-Dickinson-Sioux-O'Brien-Clay-Plymouth-Cherokee-
Buena Vista-Woodbury-Ida-Lincoln-Murray-Cottonwood-Nobles-Jackson-
Pipestone-Rock-Dixon-Dakota-Brookings-Lake-Moody-McCook-Minnehaha-
Hutchinson-Turner-Bon Homme-Yankton-Union-
437 PM CDT Fri Apr 2 2021

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 8 PM CDT THIS EVENING
FOR STRONG WIND AND LOW RELATIVE HUMIDITY FOR FIRE WEATHER ZONES 
001, 002, 003, 012, 013, 013, 014, 014, 020, 021, 022, 031, 032, 
040, 055, 056, 061, 062, 065, 066, 067, 068, 069, 070, 071, 071, 
072, 080, 081, 089, 090, 097, AND 098...

* AFFECTED AREA...Southwest Minnesota, northwest Iowa, northeast 
  Nebraska and far eastern South Dakota. 

* WIND...South 20 to 30 mph with gusts of 40 to 45 mph.

* HUMIDITY...lowest humidity 15 to 22 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.

&&

$$
731 
WWUS83 KFSD 030112
RFWFSD

URGENT - FIRE WEATHER MESSAGE
National Weather Service Sioux Falls SD
812 PM CDT Fri Apr 2 2021

IAZ001>003-012>014-020>022-031-032-MNZ071-072-080-081-089-090-097-
098-NEZ013-014-SDZ040-055-056-061-062-065>071-030215-
/O.EXP.KFSD.FW.W.0005.000000T0000Z-210403T0100Z/
Lyon-Osceola-Dickinson-Sioux-O'Brien-Clay-Plymouth-Cherokee-
Buena Vista-Woodbury-Ida-Lincoln-Murray-Cottonwood-Nobles-Jackson-
Pipestone-Rock-Dixon-Dakota-Brookings-Lake-Moody-McCook-Minnehaha-
Hutchinson-Turner-Bon Homme-Yankton-Union-
812 PM CDT Fri Apr 2 2021

...RED FLAG WARNING HAS EXPIRED FOR STRONG WIND AND LOW HUMIDITY 
FOR FIRE WEATHER ZONES 001, 002, 003, 012, 013, 013, 014, 014, 
020, 021, 022, 031, 032, 040, 055, 056, 061, 062, 065, 066, 067, 
068, 069, 070, 071, 071, 072, 080, 081, 089, 090, 097, AND 098...

Strong winds have diminished to under 20 mph as of 8 pm CDT, with
a slight recovery in humidity to around 25 to 35 percent. 
Continue to use caution in dealing with fire, as even with lesser 
wind, the low humidity values will lead to erratic fire behavior.

$$

Nearby

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