Alert archive / South Dakota / Mesoscale Discussions in 2007

Mesoscale Discussion 1021

June 5, 200715 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at Jun 5, 2007, 11:47 PM CDT for 15 counties in South Dakota. It was in force for 88 min.

The area

The outline as issued.

The facts

Issued: Jun 5, 2007, 11:47 PM CDT (04:47 UTC)
Expired: Jun 6, 2007, 1:15 AM CDT
In force: 88 min
Issued by: the Storm Prediction Center

Counties Buffalo County, SD, Corson County, SD, Dewey County, SD, Hughes County, SD, Hyde County, SD, Jones County, SD, Lyman County, SD, Mellette County, SD, Potter 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), 171 km from the middle of the area, began a volume at 04:48 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

Rapid City, SD (KUNR), launched 00:00Z, 4.8 hours before the alert went out and 176 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: 1014 J/kg
Mixed-layer CIN: -43 J/kg
Mixed-layer LCL: 1939 m above ground
0-6 km bulk shear: 43 kt
0-1 km storm-relative helicity: 57 m²/s²
0-3 km storm-relative helicity: 357 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 10.3

Open this sounding in Storm Lab

The text

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

000 
ACUS11 KWNS 060447
SWOMCD
SPC MCD 060447 
SDZ000-NDZ000-060615-

MESOSCALE DISCUSSION 1021
NWS STORM PREDICTION CENTER NORMAN OK
1147 PM CDT TUE JUN 05 2007

AREAS AFFECTED...CNTRL SD...SCNTRL ND

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 060447Z - 060615Z

THERE ARE SOME INDICATIONS THAT SEVERE STORMS WITH HAIL MAY INCREASE
ACROSS PARTS OF THE DAKOTAS LATE TONIGHT. WHILE NOT IMMINENT...A
WATCH IS POSSIBLE IF STORM ACTIVITY BECOMES MORE ORGANIZED AND
INCREASES IN COVERAGE OVER THE NEXT FEW HOURS.

ISOLATED STORMS HAVE RECENTLY DEVELOPED ON THE LEADING EDGE OF GREAT
PLAINS CAPPING INVERSION...ACROSS PARTS OF CNTRL SD. THIS
DEVELOPMENT APPEARS TO BE PARTLY IN RESPONSE TO A WEAK SHORT WAVE
TROUGH TRANSLATING THROUGH THE BROAD RIDGE AXIS SITUATED ACROSS THE
AREA. THIS IMPULSE ALSO APPEARS TO BE PROMOTING AN INCREASE IN MID
LEVEL FRONTOGENESIS WHILE INCREASING NOCTURNAL LOW LEVEL JET
ENHANCES MASS INFLOW AND WARM ADVECTION ACROSS THE REGION. PLUME OF
STEEPER LAPSE RATES SPREADING EAST...COUPLED WITH MOISTENING AND
LIFT ATOP CAPPED BOUNDARY LAYER...COULD RESULT IN SUFFICIENT
ELEVATED INSTABILITY FOR HAIL PRODUCTION. WHILE STRONG DIRECTIONAL
SHEAR APPEARS TO EXIST NEAR THE UPDRAFT SOURCE REGION BASED ON
PROFILER AND VWP WINDS...THIS IS TOPPED BY RELATIVELY WEAK NWLY
MID/UPPER LEVEL FLOW. THIS TENDS TO COMPLICATE A FORECAST OF STORM
TYPE/EVOLUTION BUT EFFECTIVE SHEAR APPEARS TO SUGGEST INITIAL
SUPERCELL CHARACTERISTICS POSSIBLY EVOLVING INTO A SMALL MCS WITH
TIME. WITH UPDRAFTS ROOTED JUST ABOVE THE BOUNDARY LAYER...HAIL
CURRENTLY APPEARS TO BE MAIN HAZARD FROM THIS ACTIVITY.

MIXED SIGNALS ALSO EXIST AMONG LATEST GUIDANCE REGARDING CONVECTIVE
DEVELOPMENT OVER THE DAKOTAS. GFS AND RUC ARE FORECASTING AN
INCREASE IN TSTM COVERAGE...WHILE LATEST NAM/NAMKF AND 4KM WRFS SHOW
VERY LIMITED DEVELOPMENT...AT LEAST THROUGH 06-09Z. THUS...SITUATION
WILL BE MONITORED OVER THE NEXT HOUR OR SO TO DETERMINE IF CURRENT
UPWARD TREND IN DEVELOPMENT IS LIKELY TO CONTINUE.

..CARBIN.. 06/06/2007

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

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

43129996 43220108 43660126 44200128 45510248 46020222
46030049 44869912 43809921

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 5, 7:22 PM CDT	Mesoscale Discussion	SPC	Bennett, Butte, Custer, Fall River, Jackson, Lawrence and 3 more	113 min
Jun 6, 12:36 PM CDT	Mesoscale Discussion	SPC	Butte, Custer, Fall River, Lawrence	114 min
Jun 6, 1:04 PM CDT	Tornado Watch	SPC	Butte, Custer, Fall River, Harding, Lawrence, Meade and 2 more	6 hr
Jun 6, 3:31 PM CDT	Mesoscale Discussion	SPC	Bennett, Buffalo, Haakon, Hand, Hughes, Hyde and 9 more	119 min
Jun 6, 3:45 PM CDT	Tornado Watch	SPC	Bennett, Brule, Buffalo, Campbell, Corson, Dewey and 19 more	7 hr
Jun 6, 6:19 PM CDT	Mesoscale Discussion	SPC	Butte, Custer, Fall River, Harding, Lawrence, Meade and 3 more	26 min
Jun 6, 6:47 PM CDT	Tornado Watch	SPC	Butte, Harding, Meade, Perkins	7 hr
Jun 6, 6:56 PM CDT	Mesoscale Discussion	SPC	Aurora, Beadle, Bennett, Bon Homme, Brule, Buffalo and 28 more	2 hr

Nearby

Mesoscale Discussions in South Dakota, 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.