Alert archive / South Dakota / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 124, NWS Aberdeen, SD

July 5, 2020Lyman County, South Dakota

NWS Aberdeen, SD issued this severe thunderstorm warning at Jul 5, 2020, 6:42 PM CDT for Lyman County, South Dakota. It was in force for 78 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 5, 2020, 6:42 PM CDT (23:42 UTC)
Expired
Jul 5, 2020, 8:00 PM CDT
In force
78 min
Issued by
NWS Aberdeen, SD
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

County Lyman County, SD

The radar

The Aberdeen radar (KABR), 207 km from the middle of the area, began a volume at 23:42 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 5, 4:41 PM CDTSevere Thunderstorm WatchSPC6 hr

The nearest sounding before it

Aberdeen, SD (KABR), launched 12:00Z, 11.7 hours before the alert went out and 160 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 2020-07-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2 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 2020-07-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 28 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
2 J/kg
Mixed-layer CIN
-469 J/kg
Mixed-layer LCL
1553 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
28 m²/s²
0-3 km storm-relative helicity
74 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 5, 6:33 PM CDT, 9 minutes earlier.

Area forecast discussion, Jul 5, 6:33 PM CDT, 9 minutes before
Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
633 PM CDT Sun Jul 5 2020

.UPDATE...
Issued at 628 PM CDT Sun Jul 5 2020

See updated aviation discussion below.

&&

.SHORT TERM...(This Evening through Monday Night)
Issued at 227 PM CDT Sun Jul 5 2020

Another round of severe weather is likely late this afternoon and
evening across the CWA. Heavy rain is also a possibility. By late
afternoon/early evening, the front should extend from just west
of ABR southwest to just west of PIR. Showers/storms should erupt
along this boundary. The main focus initially may be over the
Missouri valley where a stronger LLJ should focus into the early
evening. After mid-evening, the LLJ seems to lose focus and this
should lead to a downturn in svr probs. However, up to that point
there will be plenty of moisture/instability across the entire
region for any convection to work off of. Deep layer shear will
remain the strongest over portions of north central SD and
possibly as far east as the northern James Valley. Cell movement
is expected to be somewhat slow, and this could lead to some
hefty rain amounts given pwats approaching 1.8 inches. Will need
to keep this in mind, especially over areas that got a lot of rain
last night.

For Monday, expect lingering morning convection over the CWA, but
as the morning wears on expect the pcpn to end as weak frontal
boundary shifts to the southern part of the state. However, WAA
returns to especially the western CWA Monday night with a renewed
chance for overnight convection. Model blend temperatures looks
fine at this time.

.LONG TERM...(Tuesday through Sunday)
Issued at 227 PM CDT Sun Jul 5 2020

Mid 80s to low 90s will continue for highs through the forecast
period. While lows will mainly be in the 60s, low 70s will be likely
Wednesday morning. Off and on showers and thunderstorms will
continue. Dry weather will be more likely Thursday through Friday
morning, and again Saturday night through Sunday night.

By 12Z Tuesday, a 500mb ridge will be over NM up through
NE, with more zonal flow across the Dakotas and MN. Expect the ridge
to briefly build up through the cwa during the day/early evening
hours Tuesday. The next 500mb low across southern
Alberta/Saskatchewan Wednesday morning will cross into southern
Manitoba on Thursday, and exit into Ontario Friday. The result will
be a ridge building back across the Northern Plains from the
southwestern U.S. Friday through Sunday. The only exception to this
ridge looks to be Friday night, with a trough briefly moving in from
the northwest.

Near the surface the area of high pressure over our far northeastern
counties will be exiting the weather picture. We're still looking at
the potential for strong waa with a 40-50 knot LLJ Tuesday night-
Wednesday that could help spark additional storms. At this point the
best chance is along the ND/SD border and north. The cold front look
to cross the eastern counties during the day Wednesday, with the
chance of showers/storms lingering there through Wednesday evening.

&&

.AVIATION...(For the 00Z TAFS through 00Z Monday Evening)
Issued at 628 PM CDT Sun Jul 5 2020

Terminals KABR,KATY,KPIR,KMBG

Scattered showers and thunderstorms will be possible across the
area through the evening and overnight hours. Some of the storms
could be strong to severe with hail and strong winds. Periods of
MVFR vsbys will be possible with the thunderstorms. Otherwise, VFR
conditions will prevail through the TAF period.

***Construction to improve the taxiway for runway 13 at the KPIR
terminal may cause an occasional temporary visibility reduction due
to blowing dust (bldu), mainly during daytime hours UFN.

&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...Flash Flood Watch until 4 AM CDT Monday for SDZ005-006-010-017-
     018-036-037.

MN...None.
&&

SHORT TERM...TDK
LONG TERM...KF
AVIATION...Parkin
Hazardous weather outlook, Jul 5, 5:03 AM CDT, 13 hours 39 minutes before
Hazardous Weather Outlook
National Weather Service Aberdeen SD
503 AM CDT Sun Jul 5 2020

MNZ039-046-SDZ003>011-015>023-033>037-045-048-051-061015-
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-
503 AM CDT Sun Jul 5 2020 /403 AM MDT Sun Jul 5 2020/

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

.DAY ONE...Today and tonight.

Expect a cold front to be the main focus for thunderstorm
development initially this afternoon, although an expanded area of
thunderstorms is possible later in the evening. Some storms may be
severe with strong winds in excess of 70 mph and hail the size of
golf balls or larger possible. Heavy rain is also a threat.

.DAYS TWO THROUGH SEVEN...Monday through Saturday.

The front will stall on Monday, with additional thunderstorm
development possible in the afternoon and evening, mainly for parts
of southeast South Dakota and west central Minnesota.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will likely be needed. Weather spotters are
encouraged to submit reports to the National Weather Service in
Aberdeen. The public can submit reports on our web page, Facebook
page, or our Twitter feed.

In the hours before

Special weather statement, Jul 5, 4:02 PM CDT, 2 hours 40 minutes before
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Special weather statement, Jul 5, 5:15 PM CDT, 1 hour 27 minutes before
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Local storm report, Jul 5, 5:22 PM CDT, 1 hour 20 minutes before
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<body>
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      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
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Local storm report, Jul 5, 5:37 PM CDT, 1 hour 5 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE ABERDEEN SD
537 PM CDT SUN JUL 5 2020

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

0520 PM     TSTM WND DMG     4 ENE MURDO             43.91N 100.63W
07/05/2020                   JONES              SD   EMERGENCY MNGR

            SEMI TRUCK BLOWN OVER.

&&

KF
Local storm report, Jul 5, 6:13 PM CDT, 29 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE ABERDEEN SD
613 PM CDT SUN JUL 5 2020

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

0538 PM     HAIL             7 SSW HARROLD           44.43N 99.80W
07/05/2020  M1.25 INCH       HUGHES             SD   STORM CHASER

&&

KF
Local storm report, Jul 5, 6:25 PM CDT, 17 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE ABERDEEN SD
625 PM CDT SUN JUL 5 2020

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

0555 PM     TSTM WND GST     8 SW VIVIAN             43.85N 100.41W
07/05/2020  E60 MPH          JONES              SD   TRAINED SPOTTER

&&

KF

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 4, 7:04 PM CDTSevere Thunderstorm WarningABRBrown, Edmunds, McPherson41 min
Jul 4, 7:27 PM CDTSevere Thunderstorm WarningABRStanley19 min
Jul 4, 7:48 PM CDTSevere Thunderstorm WarningABRBrown, Edmunds, McPherson57 min
Jul 4, 7:59 PM CDTSevere Thunderstorm WarningABRCampbell, Edmunds, McPherson, Walworth46 min
Jul 4, 8:29 PM CDTSpecial Weather StatementABRWalworth46 min
Jul 4, 8:39 PM CDTSevere Thunderstorm WarningABRFaulk, Hand, Spink51 min
Jul 4, 8:41 PM CDTSevere Thunderstorm WarningABRWalworth49 min
Jul 4, 8:44 PM CDTSevere Thunderstorm WarningABRBrown, Edmunds46 min
Jul 4, 8:52 PM CDTSevere Thunderstorm WarningABREdmunds, Faulk, Hand68 min
Jul 4, 9:17 PM CDTSevere Thunderstorm WarningABREdmunds, Potter, Walworth43 min
Jul 4, 9:30 PM CDTSevere Thunderstorm WarningABRFaulk, Hand, Spink60 min
Jul 4, 9:41 PM CDTTornado WarningABRFaulk, Spink21 min
Jul 4, 9:50 PM CDTSevere Thunderstorm WarningABREdmunds, Faulk, Potter, Walworth40 min
Jul 4, 10:07 PM CDTSpecial Weather StatementABRCampbell38 min
Jul 4, 11:18 PM CDTAreal Flood WarningABRHand12 hr
Jul 4, 11:22 PM CDTSpecial Weather StatementABRHyde38 min
Jul 5, 12:00 AM CDTSevere Thunderstorm WarningABRHand, Hyde30 min
Jul 5, 12:45 AM CDTAreal Flood WarningABRHand60 hr
Jul 5, 12:54 AM CDTSpecial Weather StatementABRHand36 min
Jul 5, 1:08 AM CDTSpecial Weather StatementABRCorson52 min
Jul 5, 12:34 PM CDTFlash Flood WatchABRBrown, Edmunds, Faulk, Hand, Hyde, McPherson and 1 more15 hr
Jul 5, 1:01 PM CDTSpecial Weather StatementABRSpink29 min
Jul 5, 4:02 PM CDTSpecial Weather StatementABRMarshall28 min
Jul 5, 4:24 PM CDTSevere Thunderstorm WarningABRJones, Stanley51 min
Jul 5, 4:36 PM CDTSevere Thunderstorm WarningABRJones, Stanley39 min
Jul 5, 5:15 PM CDTSpecial Weather StatementABRJones45 min
Jul 5, 5:19 PM CDTSevere Thunderstorm WarningABRJones, Lyman41 min
Jul 5, 5:42 PM CDTSevere Thunderstorm WarningABRHughes, Lyman48 min
Jul 5, 5:53 PM CDTSevere Thunderstorm WarningABRJones, Lyman52 min
Jul 5, 6:07 PM CDTSevere Thunderstorm WarningABRFaulk, Hand, Spink53 min
Jul 5, 6:32 PM CDTSevere Thunderstorm WarningABRFaulk, Hand, Spink48 min

Nearby

Severe Thunderstorm Warnings in South Dakota, 2020Every severe thunderstorm warning in 2020

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.