Alert archive / South Dakota / Mesoscale Discussions in 2005

Mesoscale Discussion 2011

August 17, 2005Boyd County, Nebraska; 25 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at Aug 17, 2005, 7:56 PM CDT for Boyd County, Nebraska; 25 counties in South Dakota. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Aug 17, 2005, 7:56 PM CDT (00:56 UTC)
Expired
Aug 17, 2005, 10:00 PM CDT
In force
2 hr
Issued by
the Storm Prediction Center
All 26 counties

Boyd County, NE, Aurora County, SD, Beadle County, SD, Bon Homme County, SD, Brule County, SD, Buffalo County, SD, Charles Mix County, SD, Clark County, SD, Codington County, SD, Davison County, SD, Douglas County, SD, Faulk County, SD, Gregory County, SD, Hamlin County, SD, Hand County, SD, Hanson County, SD, Hutchinson County, SD, Hyde County, SD, Jerauld County, SD, Kingsbury County, SD, Lake County, SD, McCook County, SD, Miner County, SD, Sanborn County, SD, Spink County, SD, Yankton County, SD

The radar

The Aberdeen radar (KABR), 138 km from the middle of the area, began a volume at 00:59 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, 0.9 hours before the alert went out and 83 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 2005-08-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1406 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 2005-08-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 125 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
1406 J/kg
Mixed-layer CIN
-44 J/kg
Mixed-layer LCL
1231 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
125 m²/s²
0-3 km storm-relative helicity
195 m²/s²
Significant tornado parameter
0.7
Supercell composite
2.5

Open this sounding in Storm Lab

The text

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

000 
ACUS11 KWNS 180057
SWOMCD
SPC MCD 180056 
SDZ000-NEZ000-180300-

MESOSCALE DISCUSSION 2011
NWS STORM PREDICTION CENTER NORMAN OK
0756 PM CDT WED AUG 17 2005

AREAS AFFECTED...PARTS OF CENTRAL AND ERN SD

CONCERNING...SEVERE THUNDERSTORM WATCH 728...

VALID 180056Z - 180300Z

STORMS CONTINUE -- MAINLY ACROSS NWRN PORTIONS OF WW.

STRONG/OCCASIONALLY SEVERE STORMS PERSIST AHEAD OF N-S SURFACE
TROUGH...WITHIN AXIS OF MODERATE INSTABILITY.  THOUGH CONVECTIVE
COVERAGE HAS INCREASED OVER THE PAST HOUR...STORMS APPEAR TO HAVE
WEAKENED SLIGHTLY BASED ON LATEST RADAR IMAGERY.  NONETHELESS...WITH
SUFFICIENT SHEAR FOR ORGANIZED CONVECTION ACROSS THIS REGION --
PARTICULARLY ACROSS SRN HALF OF WW...THREAT FOR LOCALLY DAMAGING
WINS/HAIL SHOULD CONTINUE FOR THE NEXT COUPLE OF HOURS WITH STRONGER
STORMS.

..GOSS.. 08/18/2005

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

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

44759984 45229979 45269676 42879729 42899981 44229955

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 17, 9:22 PM CDTMesoscale DiscussionSPCBoyd23 min
Aug 18, 2:05 PM CDTMesoscale DiscussionSPCBox Butte, Dawes, Scotts Bluff, Sioux115 min
Aug 18, 4:49 PM CDTMesoscale DiscussionSPCPawnee, Richardson116 min
Aug 18, 5:35 PM CDTSevere Thunderstorm WatchSPCRichardson6 hr
Aug 18, 3:27 PM CDTMesoscale DiscussionSPCBuffalo, Campbell, Dewey, Edmunds, Faulk, Hand and 8 more2 hr

Nearby

Mesoscale Discussions in South Dakota, 2005Mesoscale Discussions in Nebraska, 2005Every mesoscale discussion in 2005

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.