Alert archive / South Dakota / Special Weather Statements in 2021

Special Weather Statement, NWS Aberdeen, SD

July 26, 2021Corson County, South Dakota

NWS Aberdeen, SD issued this special weather statement at Jul 26, 2021, 3:00 AM MDT for Corson County, South Dakota. It was in force for 30 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Jul 26, 2021, 3:00 AM MDT (09:00 UTC)
Expired: Jul 26, 2021, 3:30 AM MDT
In force: 30 min
Issued by: NWS Aberdeen, SD

County Corson County, SD

The radar

The Bismarck radar (KBIS), 98 km from the middle of the area, began a volume at 09:02 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, 9.0 hours before the alert went out and 98 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 71 J/kg
Mixed-layer CIN: -190 J/kg
Mixed-layer LCL: 3328 m above ground
0-6 km bulk shear: 42 kt
0-1 km storm-relative helicity: -4 m²/s²
0-3 km storm-relative helicity: 101 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.1

Open this sounding in Storm Lab

The text

As transmitted.

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What forecasters said that day

The local office's own words before this special weather statement went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Aberdeen, SD wrote its last area forecast discussion before this special weather statement went out at Jul 26, 2:35 AM MDT, 25 minutes earlier.

Area forecast discussion, Jul 26, 2:35 AM MDT, 25 minutes before

Area Forecast Discussion
National Weather Service Aberdeen SD
335 AM CDT Mon Jul 26 2021

.SHORT TERM...(Today through Tuesday Afternoon)
Issued at 335 AM CDT Mon Jul 26 2021

LLJ/outflow boundary showers/storms in the eastern cwa will be
dissipating/moving east into the early morning hours. Otherwise,
waa/accas storms were developing in south central nd/north central
sd early this morning. Believe these will continue to develop/move
southeast through the morning hours. Therefore, made adjustments to
pops for both of these areas of convection this morning. Otherwise,
after these areas of convection end, expect new development mainly
across northeast sd and west central mn this afternoon and evening
on the edge of the warm mid level capping. The outflow boundary from
this mornings convection and llj will result in good ll moisture
convergence across our northeast cwa. With steep mid level lapse
rates with increasing instability and decent deep layer wind shear,
expect storms to redevelop this afternoon/evening and track
southeast across northeast sd and west central mn. There is a
marginal risk of severe weather across our northeast cwa. Otherwise,
with warmer air building in today and Tuesday as the upper level
high pressure area expands and closes off over the central U.S., the
heat will also expand across our cwa. With abundant sunshine and dry
soils, highs in the 90s and 100s still look on track for both today
and Tuesday. With the combination of heat and humidity, will go with
a heat advisory for the James Valley and west today and most of the
cwa on Tuesday.

.LONG TERM...(Tuesday Evening through Sunday)
Issued at 335 AM CDT Mon Jul 26 2021

The period begins on Wednesday with a surface low pressure system
and associated frontal boundary crossing the region. Per the 0Z
ECMWF, 700 mb temps over much of this CWA at 18Z Wednesday could
reach +15 to +18C. The warm temperatures aloft, along the ongoing
drought should create highs from 90 to 110 degrees. The coolest
temperatures will be felt over northeast SD and western MN, or where
the 700 mb cap is the weakest. A few late afternoon/evening
thunderstorms could be possible over the northeast portion of the
CWA on Wednesday. High pressure, along with cooler temperatures
aloft will progress across the NE portion of the region on Thursday
and Friday, with more seasonal high temperatures. Thursday night
through Friday will also support the potential for pcpn, mainly for
central and south central SD. Seasonal temperatures, along with
mostly dry conditions are anticipated for the weekend.

&&

.AVIATION...(For the 06Z TAFS through 06Z Monday Night)
Issued at 1221 AM CDT Mon Jul 26 2021

Terminals KABR,KATY,KPIR,KMBG

Prevailing VFR conditions can be expected through the valid TAF
period. A few storms could impact the terminals of KATY and KABR
at times, but confidence with timing of thunderstorms is low.
Breezy south to southwesterly winds can be expected today for all
terminals.

&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...Heat Advisory from 1 PM CDT /noon MDT/ this afternoon to 7 PM
     CDT /6 PM MDT/ this evening for SDZ003>006-009-010-015>018-
     033>037-045-048-051.

     Heat Advisory from 1 PM CDT /noon MDT/ to 7 PM CDT /6 PM MDT/
     Tuesday for SDZ003>006-009>011-015>023-033>037-045-048-051.

MN...None.
&&

SHORT TERM...Mohr
LONG TERM...SD
AVIATION...SD

In the hours before

Local storm report, Jul 25, 10:07 PM MDT, 4 hours 53 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE ABERDEEN SD
1107 PM CDT SUN JUL 25 2021

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1105 PM     HAIL             WHEATON                 45.81N 96.50W
07/25/2021  E1.00 INCH       TRAVERSE           MN   CO-OP OBSERVER

&&

SD

Special weather statement, Jul 26, 3:00 AM MDT, 0 minutes before

Special Weather Statement
National Weather Service Aberdeen SD
300 AM MDT Mon Jul 26 2021

SDZ003-260930-
Corson SD-
300 AM MDT Mon Jul 26 2021

...SIGNIFICANT WEATHER ADVISORY FOR NORTHEASTERN CORSON COUNTY UNTIL
330 AM MDT...

At 300 AM MDT, Doppler radar was tracking a strong thunderstorm near
Walker, or 8 miles northwest of Mclaughlin, moving east at 25 mph.

Nickel size hail and winds in excess of 40 mph will be possible with
this storm.

Locations impacted include...
Mclaughlin and Standing Rock Nation.

LAT...LON 4595 10067 4594 10063 4575 10076 4582 10109
      4594 10102
TIME...MOT...LOC 0900Z 291DEG 22KT 4588 10095

SD

The office that day

Everything else NWS Aberdeen, SD issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 25, 6:03 PM MDT	Severe Thunderstorm Warning	ABR	Hand, Hyde	42 min
Jul 25, 6:30 PM MDT	Severe Thunderstorm Warning	ABR	Hand	36 min
Jul 25, 7:11 PM MDT	Severe Thunderstorm Warning	ABR	Clark, Spink	49 min
Jul 25, 7:54 PM MDT	Severe Thunderstorm Warning	ABR	Clark, Codington	51 min
Jul 26, 2:41 AM MDT	Heat Advisory	ABR	Brown, Buffalo, Campbell, Corson, Dewey, Edmunds and 12 more	15 hr
Jul 26, 2:41 AM MDT	Heat Advisory	ABR	Brown, Buffalo, Campbell, Clark, Codington, Corson and 18 more	41 hr
Jul 26, 3:05 AM MDT	Severe Thunderstorm Warning	ABR	Corson	28 min
Jul 26, 6:12 AM MDT	Special Weather Statement	ABR	Day	18 min
Jul 26, 7:35 AM MDT	Special Weather Statement	ABR	Walworth	25 min
Jul 26, 8:03 AM MDT	Special Weather Statement	ABR	Walworth	27 min
Jul 26, 8:43 AM MDT	Severe Thunderstorm Warning	ABR	Walworth	32 min
Jul 25, 9:04 PM MDT	Severe Thunderstorm Warning	ABR	Traverse	26 min

Nearby

Special Weather Statements in South Dakota, 2021 Every special weather statement 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.