Alert archive / South Dakota / Mesoscale Discussions in 2007

Mesoscale Discussion 892

May 25, 20074 counties in Nebraska; 17 counties in North Dakota; 37 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at May 25, 2007, 7:22 PM CDT for 4 counties in Nebraska; 17 counties in North Dakota; 37 counties in South Dakota. It was in force for 53 min.

The area

The outline as issued.

The facts

Issued: May 25, 2007, 7:22 PM CDT (00:22 UTC)
Expired: May 25, 2007, 8:15 PM CDT
In force: 53 min
Issued by: the Storm Prediction Center

All 58 counties

Adams County, ND, Barnes County, ND, Burleigh County, ND, Dickey County, ND, Emmons County, ND, Grant County, ND, Hettinger County, ND, Kidder County, ND, LaMoure County, ND, Logan County, ND, McIntosh County, ND, Morton County, ND, Oliver County, ND, Ransom County, ND, Sargent County, ND, Sioux County, ND, Stutsman County, ND, Boyd County, NE, Brown County, NE, Cherry County, NE, Keya Paha County, NE, Aurora County, SD, Beadle County, SD, Brown County, SD, Brule County, SD, Buffalo County, SD, Campbell County, SD, Charles Mix County, SD, Clark County, SD, Corson County, SD, Davison County, SD, Day County, SD, Dewey County, SD, Douglas County, SD, Edmunds County, SD, Faulk County, SD, Gregory County, SD, Haakon County, SD, Hand County, SD, Hanson County, SD, Hughes County, SD, Hyde County, SD, Jerauld County, SD, Jones County, SD, Lyman County, SD, Marshall County, SD, McPherson County, SD, Mellette County, SD, Perkins County, SD, Potter County, SD, Sanborn County, SD, Spink County, SD, Stanley County, SD, Sully County, SD, Todd County, SD, Tripp County, SD, Walworth County, SD, Ziebach County, SD

The radar

The Rapid City radar (KUDX), 190 km from the middle of the area, began a volume at 00:23 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, 0.4 hours before the alert went out and 172 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: 12 J/kg
Mixed-layer CIN: -43 J/kg
Mixed-layer LCL: 1811 m above ground
0-6 km bulk shear: 33 kt
0-1 km storm-relative helicity: 181 m²/s²
0-3 km storm-relative helicity: 349 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

Open this sounding in Storm Lab

The text

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

000 
ACUS11 KWNS 260022
SWOMCD
SPC MCD 260022 
NDZ000-SDZ000-NEZ000-260115-

MESOSCALE DISCUSSION 0892
NWS STORM PREDICTION CENTER NORMAN OK
0722 PM CDT FRI MAY 25 2007

AREAS AFFECTED...SRN ND/CENTRAL SD/PARTS OF NW-NRN NEB

CONCERNING...SEVERE THUNDERSTORM WATCH 298...

VALID 260022Z - 260115Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 298
CONTINUES.

DEEP LAYER FORCING FOR ASCENT ALONG THE COLD FRONT AND AHEAD OF THE
SHORT WAVE TROUGH CONTINUE TO SUPPORT TSTM DEVELOPMENT ALONG THE
PROGRESSIVE COLD FRONT.  MEANWHILE...DEEP LAYER SHEAR VECTORS
BECOMING ORIENTED LESS THAN NORMAL TO THE COLD FRONT AS MID LEVEL
WINDS TEND TO BACK WITH APPROACH OF TROUGH ARE ALSO FAVORING
ACTIVITY TO BECOME MORE LINEAR WITH TIME.  THIS LINE IS CURRENTLY
MOVING EWD THROUGH THE STRONGEST PART OF THE INSTABILITY AXIS...AND
SHOULD TEND TO WEAKEN AFTER 02Z AS THEY MOVE INTO ERN SD WHERE THE
AIR MASS IS MORE STABLE.

FARTHER S...ACROSS SRN SD INTO NRN NEB /CHERRY COUNTY/...THE AIR
MASS EAST OF THE COLD FRONT IS LIKELY MORE STABLE PER INDICATION OF
STABLE BILLOW CLOUDS OVER MUCH OF CENTRAL/ERN NEB INTO FAR SRN SD. 
THUS...TSTM DEVELOPMENT INTO THIS REGION SHOULD BE ASSOCIATED WITH
FORCING FOR ASCENT ALONG THE COLD FRONT.  ALTHOUGH A FEW STRONG TO
SEVERE STORMS MAY OCCUR INTO NRN NEB...THE STRONGEST FORCING ALOFT
SHOULD REMAIN PRIMARILY ACROSS SD/ND AND TEND TO LIMIT SWD EXTENT
FOR SEVERE TSTMS.

FARTHER N...ALTHOUGH PART OF THE WARM SECTOR EXTENDS INTO SOUTH
CENTRAL/SERN SD...AN EXTENSIVE CONVECTIVE CLOUD SHIELD HAS SPREAD
OVER MUCH OF THIS REGION AND HAS AIDED IN STABILIZING THE AIR MASS. 
SEVERE THREAT SHOULD REMAIN MINIMAL WITH ANY STORMS MOVING INTO ND.

..PETERS.. 05/26/2007

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

ATTN...WFO...FGF...FSD...ABR...BIS...LBF...UNR...CYS...

42569881 42040079 41960231 42080274 42870176 44040140
45920303 46700248 47210179 47459988 47219792 46079731
43619773

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 25, 10:58 PM CDT	Mesoscale Discussion	SPC	Blaine, Brown, Buffalo, Custer, Dawson, Frontier and 18 more	92 min

Nearby

Mesoscale Discussions in South Dakota, 2007 Mesoscale Discussions in North Dakota, 2007 Mesoscale Discussions in Nebraska, 2007 Every mesoscale discussion in 2007

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.