Alert archive / South Dakota / Mesoscale Discussions in 2011

Mesoscale Discussion 1549

July 8, 20118 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at Jul 8, 2011, 11:20 PM CDT for 8 counties in South Dakota. It was in force for 85 min.

The area

The outline as issued.

The facts

Issued
Jul 8, 2011, 11:20 PM CDT (04:20 UTC)
Expired
Jul 9, 2011, 12:45 AM CDT
In force
85 min
Issued by
the Storm Prediction Center

Counties Beadle County, SD, Brule County, SD, Buffalo County, SD, Hand County, SD, Hughes County, SD, Hyde County, SD, Jerauld County, SD, Lyman County, SD

The radar

The Aberdeen radar (KABR), 175 km from the middle of the area, began a volume at 04:22 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, 4.3 hours before the alert went out and 129 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 2011-07-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 975 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 00:00Z on 2011-07-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 48 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
975 J/kg
Mixed-layer CIN
-10 J/kg
Mixed-layer LCL
1645 m above ground
0-6 km bulk shear
31 kt
0-1 km storm-relative helicity
48 m²/s²
0-3 km storm-relative helicity
117 m²/s²
Significant tornado parameter
0.1
Supercell composite
4.2

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

850 
ACUS11 KWNS 090420
SWOMCD
SPC MCD 090420 
SDZ000-090545-

MESOSCALE DISCUSSION 1549
NWS STORM PREDICTION CENTER NORMAN OK
1120 PM CDT FRI JUL 08 2011

AREAS AFFECTED...CNTRL SD

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 090420Z - 090545Z

A CLUSTER OF STORMS CONTINUES OVER CNTRL SD...WITH POSSIBLE SEVERE
WIND AND HAIL. HOWEVER...THESE STORMS WILL BE EXITING THE
INSTABILITY AXIS FARTHER W AS DEPICTED BY OBJECTIVE ANALYSIS.
THEREFORE...A DECREASE IN INTENSITY OF THESE STORMS IS EXPECTED BY
THE TIME THEY REACH THE HAND TO BRULE COUNTY VICINITY.

..JEWELL.. 07/09/2011

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...FSD...ABR...UNR...

LAT...LON   43990059 44240069 44500044 45019905 44829850 44449823
            43989828 43639871 43509968 43720030 43840046 43990059

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 8, 8:57 PM CDTMesoscale DiscussionSPCBennett, Corson, Dewey, Haakon, Jackson63 min
Jul 8, 10:37 PM CDTMesoscale DiscussionSPCMarshall, Roberts83 min
Jul 9, 6:09 PM CDTMesoscale DiscussionSPCAurora, Beadle, Brown, Brule, Buffalo, Charles Mix and 15 more66 min

Nearby

Mesoscale Discussions in South Dakota, 2011Every mesoscale discussion in 2011

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.