Alert archive / South Dakota / Red Flag Warnings in 2021

Red Flag Warning 9, NWS Aberdeen, SD

April 4, 20216 counties in South Dakota

NWS Aberdeen, SD issued this red flag warning at Apr 4, 2021, 3:54 AM CDT for 6 counties in South Dakota. It took effect at Apr 4, 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
Apr 4, 2021, 3:54 AM CDT (08:54 UTC)
In effect from
Apr 4, 2021, 1:00 PM CDT
Expired
Apr 4, 2021, 7:00 PM CDT
In force
6 hr
Issued by
NWS Aberdeen, SD

Counties Campbell County, SD, Corson County, SD, Dewey County, SD, Edmunds County, SD, McPherson County, SD, Walworth County, SD

The radar

The Aberdeen radar (KABR), 132 km from the middle of the area, began a volume at 08:55 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

Bismarck Municip, ND (KBIS), launched 00:00Z, 8.9 hours before the alert went out and 144 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, Bismarck Municip, ND at 00:00Z on 2021-04-04Temperature 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, Bismarck Municip, ND at 00:00Z on 2021-04-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 7 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
4012 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
7 m²/s²
0-3 km storm-relative helicity
83 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

807 
WWUS83 KABR 040854
RFWABR

URGENT - FIRE WEATHER MESSAGE
National Weather Service Aberdeen SD
354 AM CDT Sun Apr 4 2021

SDZ003>005-009-010-015-041700-
/O.NEW.KABR.FW.W.0009.210404T1800Z-210405T0000Z/
Corson-Campbell-McPherson-Walworth-Edmunds-Dewey-
354 AM CDT Sun Apr 4 2021 /254 AM MDT Sun Apr 4 2021/

...RED FLAG WARNING IN EFFECT FROM 1 PM CDT /NOON MDT/ THIS
AFTERNOON TO 7 PM CDT /6 PM MDT/ THIS EVENING FOR WIND AND LOW
RELATIVE HUMIDITY FOR NORTH CENTRAL SD...

The National Weather Service in Aberdeen has issued a Red Flag
Warning for wind and low relative humidity, which is in effect
from 1 PM CDT /noon MDT/ this afternoon to 7 PM CDT /6 PM MDT/
this evening.

* AFFECTED AREA...In South Dakota, Corson, Campbell, McPherson, 
  Walworth, Edmunds and Dewey.

* WINDS...Southeast 15 to 20 mph with gusts up to 30 mph.

* RELATIVE HUMIDITY...As low as 12 percent.

* IMPACTS...The combination of gusty winds and low relative 
  humidity will produce critical fire weather conditions. Any 
  fires will spread rapidly and become difficult to control and 
  suppress.

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
830 
WWUS83 KABR 041606
RFWABR

URGENT - FIRE WEATHER MESSAGE
National Weather Service Aberdeen SD
1106 AM CDT Sun Apr 4 2021

SDZ003>005-009-010-015-050000-
/O.CON.KABR.FW.W.0009.210404T1800Z-210405T0000Z/
Corson-Campbell-McPherson-Walworth-Edmunds-Dewey-
1106 AM CDT Sun Apr 4 2021 /1006 AM MDT Sun Apr 4 2021/

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 7 PM CDT /6 PM MDT/
THIS EVENING FOR WIND AND LOW RELATIVE HUMIDITY FOR NORTH CENTRAL
SD...

* AFFECTED AREA...In South Dakota, Corson, Campbell, McPherson, 
  Walworth, Edmunds and Dewey.

* WINDS...Southeast 10 to 20 mph with gusts up to 30 mph.

* RELATIVE HUMIDITY...10 to 20 percent.

* IMPACTS...The combination of gusty winds and low relative 
  humidity will produce critical fire weather conditions. Any 
  fires will spread rapidly and become difficult to control and 
  suppress.

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.

&&

$$
TMT
225 
WWUS83 KABR 042358
RFWABR

URGENT - FIRE WEATHER MESSAGE
National Weather Service Aberdeen SD
658 PM CDT Sun Apr 4 2021

SDZ003>005-009-010-015-050100-
/O.EXP.KABR.FW.W.0009.000000T0000Z-210405T0000Z/
Corson-Campbell-McPherson-Walworth-Edmunds-Dewey-
658 PM CDT Sun Apr 4 2021 /558 PM MDT Sun Apr 4 2021/

...RED FLAG WARNING WILL EXPIRE AT 7 PM CDT /6 PM MDT/ THIS
EVENING FOR WIND AND LOW RELATIVE HUMIDITY FOR NORTH CENTRAL SD...

As the temperatures cool, the relative humidity will rise across
the area, thus the Red Flag Warning will be allowed to expire.

$$

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.