Alert archive / South Dakota / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 116, NWS Aberdeen, SD

July 21, 2017Roberts County, South Dakota

NWS Aberdeen, SD issued this severe thunderstorm warning at Jul 21, 2017, 6:16 PM CDT for Roberts County, South Dakota. It was in force for 44 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Jul 21, 2017, 6:16 PM CDT (23:16 UTC)
Expired
Jul 21, 2017, 7:00 PM CDT
In force
44 min
Issued by
NWS Aberdeen, SD
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

County Roberts County, SD

The radar

The Aberdeen radar (KABR), 116 km from the middle of the area, began a volume at 23:16 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Jul 21, 3:07 PM CDTSevere Thunderstorm WatchSPC10 hr

The nearest sounding before it

Aberdeen, SD (KABR), launched 12:00Z, 11.3 hours before the alert went out and 140 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 12:00Z on 2017-07-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 4 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Aberdeen, SD at 12:00Z on 2017-07-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 5 square meters per square second.193958Sfc1 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
4 J/kg
Mixed-layer CIN
-638 J/kg
Mixed-layer LCL
2490 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
5 m²/s²
0-3 km storm-relative helicity
2 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this severe thunderstorm warning 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 severe thunderstorm warning went out at Jul 21, 1:57 PM CDT, 4 hours 19 minutes earlier.

Area forecast discussion, Jul 21, 1:57 PM CDT, 4 hours 19 minutes before
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Hazardous weather outlook, Jul 21, 3:41 PM CDT, 2 hours 35 minutes before
Hazardous Weather Outlook...UPDATED
National Weather Service Aberdeen SD
341 PM CDT Fri Jul 21 2017

MNZ039-046-SDZ003>011-015>023-033>037-045-048-051-221200-
Traverse-Big Stone-Corson-Campbell-McPherson-Brown-Marshall-
Roberts-Walworth-Edmunds-Day-Dewey-Potter-Faulk-Spink-Clark-
Codington-Grant-Hamlin-Deuel-Stanley-Sully-Hughes-Hyde-Hand-Jones-
Lyman-Buffalo-
341 PM CDT Fri Jul 21 2017 /241 PM MDT Fri Jul 21 2017/

This Hazardous Weather Outlook is for portions of west central
Minnesota, central South Dakota, north central South Dakota, and
northeast South Dakota.

.DAY ONE...This Afternoon and Tonight

Heat: Heat indices will range from 100 to 105 degrees across
central South Dakota eastward into the James River valley into
this evening.

Storms: Strong to severe storms are possible into this evening
over north central and northeast South Dakota and west central
Minnesota. Large hail and strong, damaging winds are possible -
with an enhanced threat for northeast South Dakota into west
central Minnesota. An isolated tornado threat also exists over far
northeast South Dakota into west central Minnesota.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday

Elevated fire danger will occur across central South Dakota on
Saturday.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be necessary through this evening along and
east of the Missouri River.

SRF

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 20, 7:21 PM CDTSpecial Weather StatementABRCorson54 min
Jul 20, 7:56 PM CDTSevere Thunderstorm WarningABRCorson49 min
Jul 20, 8:32 PM CDTSevere Thunderstorm WarningABRCorson, Dewey43 min
Jul 20, 9:13 PM CDTSevere Thunderstorm WarningABRCorson, Dewey62 min
Jul 20, 9:45 PM CDTSevere Thunderstorm WarningABRCampbell, Corson, Dewey, Potter, Walworth60 min
Jul 20, 10:41 PM CDTSevere Thunderstorm WarningABRCampbell, Dewey, Edmunds, McPherson, Potter, Sully and 1 more64 min
Jul 20, 11:41 PM CDTSpecial Weather StatementABRWalworth49 min
Jul 21, 12:21 AM CDTSpecial Weather StatementABRCorson, Walworth39 min
Jul 21, 1:05 AM CDTSpecial Weather StatementABRBrown40 min
Jul 21, 6:26 AM CDTSpecial Weather StatementABRHamlin34 min
Jul 21, 11:06 AM CDTFire Weather WatchABR16 hr
Jul 21, 6:56 PM CDTSevere Thunderstorm WarningABRRoberts51 min

Nearby

Severe Thunderstorm Warnings in South Dakota, 2017Every severe thunderstorm warning in 2017

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.