Alert archive / South Dakota / Red Flag Warnings in 2021

Red Flag Warning 19, NWS Aberdeen, SD

August 17, 202110 counties in South Dakota

NWS Aberdeen, SD issued this red flag warning at Aug 17, 2021, 2:39 AM CDT for 10 counties in South Dakota. It took effect at Aug 17, 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
Aug 17, 2021, 2:39 AM CDT (07:39 UTC)
In effect from
Aug 17, 2021, 1:00 PM CDT
Expired
Aug 17, 2021, 8:00 PM CDT
In force
7 hr
Issued by
NWS Aberdeen, SD

Counties Campbell County, SD, Corson County, SD, Dewey County, SD, Hughes County, SD, Jones County, SD, Lyman County, SD, Potter County, SD, Stanley County, SD, Sully County, SD, Walworth County, SD

The radar

The Aberdeen radar (KABR), 166 km from the middle of the area, began a volume at 07:40 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, 7.7 hours before the alert went out and 154 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 2021-08-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2413 joules per kilogram.LCLLFCEL10008507005003002001001 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 2021-08-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 181 square meters per square second.1939Sfc1 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
2413 J/kg
Mixed-layer CIN
-160 J/kg
Mixed-layer LCL
1716 m above ground
0-6 km bulk shear
27 kt
0-1 km storm-relative helicity
181 m²/s²
0-3 km storm-relative helicity
240 m²/s²
Significant tornado parameter
0.1
Supercell composite
4.0

Open this sounding in Storm Lab

The text

As transmitted.

990 
WWUS83 KABR 170739
RFWABR

URGENT - FIRE WEATHER MESSAGE
National Weather Service Aberdeen SD
239 AM CDT Tue Aug 17 2021

SDZ003-004-009-015-016-033>035-045-048-171545-
/O.UPG.KABR.FW.A.0009.210817T1800Z-210818T0100Z/
/O.NEW.KABR.FW.W.0019.210817T1800Z-210818T0100Z/
Corson-Campbell-Walworth-Dewey-Potter-Stanley-Sully-Hughes-Jones-
Lyman-
239 AM CDT Tue Aug 17 2021 /139 AM MDT Tue Aug 17 2021/

...RED FLAG WARNING IN EFFECT FROM 1 PM CDT /NOON MDT/ THIS
AFTERNOON TO 8 PM CDT /7 PM MDT/ THIS EVENING FOR WIND AND LOW
RELATIVE HUMIDITY FOR CENTRAL AND NORTH CENTRAL SOUTH DAKOTA...

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 8 PM CDT /7 PM MDT/
this evening. The Fire Weather Watch is no longer in effect.

* AFFECTED AREA...In South Dakota, Corson, Campbell, Walworth, 
  Dewey, Potter, Stanley, Sully, Hughes, Jones and Lyman.

* WINDS...Southeast 15 to 20 mph with gusts up to 35 mph.

* RELATIVE HUMIDITY...As low as 18 percent.

* IMPACTS...These conditions are supportive of rapid fire growth.

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.

&&

$$

Dorn
2 follow-up statements
774 
WWUS83 KABR 171450
RFWABR

URGENT - FIRE WEATHER MESSAGE
National Weather Service Aberdeen SD
950 AM CDT Tue Aug 17 2021

SDZ003-004-009-015-016-033>035-045-048-180100-
/O.CON.KABR.FW.W.0019.210817T1800Z-210818T0100Z/
Corson-Campbell-Walworth-Dewey-Potter-Stanley-Sully-Hughes-Jones-
Lyman-
950 AM CDT Tue Aug 17 2021 /850 AM MDT Tue Aug 17 2021/

...RED FLAG WARNING REMAINS IN EFFECT FROM 1 PM CDT /NOON MDT/
THIS AFTERNOON TO 8 PM CDT /7 PM MDT/ THIS EVENING FOR WIND AND
LOW RELATIVE HUMIDITY FOR CENTRAL AND NORTH CENTRAL SOUTH
DAKOTA...

* AFFECTED AREA...In South Dakota, Corson, Campbell, Walworth, 
  Dewey, Potter, Stanley, Sully, Hughes, Jones and Lyman.

* WINDS...Southeast 15 to 25 mph with gusts up to 35 mph.

* RELATIVE HUMIDITY...As low as 19 percent.

* IMPACTS...These conditions are supportive of rapid fire growth.

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.

&&

$$
761 
WWUS83 KABR 180101
RFWABR

URGENT - FIRE WEATHER MESSAGE
National Weather Service Aberdeen SD
801 PM CDT Tue Aug 17 2021

SDZ003-004-009-015-016-033>035-045-048-180215-
/O.EXP.KABR.FW.W.0019.000000T0000Z-210818T0100Z/
Corson-Campbell-Walworth-Dewey-Potter-Stanley-Sully-Hughes-Jones-
Lyman-
801 PM CDT Tue Aug 17 2021 /701 PM MDT Tue Aug 17 2021/

...RED FLAG WARNING HAS EXPIRED FOR WIND AND LOW RELATIVE
HUMIDITY FOR CENTRAL AND NORTH CENTRAL SOUTH DAKOTA...

Relative humidity values have begun to rise, and wind speeds will
diminish overnight, therefore the Red Flag Warning has been
allowed to expire.

$$

Parkin

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.