Alert archive / South Dakota / Mesoscale Discussions in 2003

Mesoscale Discussion 2012

July 29, 20036 counties in Minnesota; 12 counties in North Dakota; 14 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at Jul 29, 2003, 12:42 PM CDT for 6 counties in Minnesota; 12 counties in North Dakota; 14 counties in South Dakota. It was in force for 108 min.

The area

The outline as issued.

The facts

Issued: Jul 29, 2003, 12:42 PM CDT (17:42 UTC)
Expired: Jul 29, 2003, 2:30 PM CDT
In force: 108 min
Issued by: the Storm Prediction Center

All 32 counties

Clay County, MN, Norman County, MN, Polk County, MN, Red Lake County, MN, Traverse County, MN, Wilkin County, MN, Barnes County, ND, Cass County, ND, Dickey County, ND, Grand Forks County, ND, Griggs County, ND, LaMoure County, ND, Nelson County, ND, Ransom County, ND, Richland County, ND, Sargent County, ND, Steele County, ND, Traill County, ND, Brown County, SD, Clark County, SD, Day County, SD, Edmunds County, SD, Faulk County, SD, Hand County, SD, Hughes County, SD, Hyde County, SD, Marshall County, SD, McPherson County, SD, Potter County, SD, Roberts County, SD, Spink County, SD, Sully County, SD

The radar

The Aberdeen radar (KABR), 80 km from the middle of the area, began a volume at 17:42 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Aberdeen, SD (KABR), launched 12:00Z, 5.7 hours before the alert went out and 142 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: 4 J/kg
Mixed-layer CIN: -422 J/kg
Mixed-layer LCL: 1942 m above ground
0-6 km bulk shear: 25 kt
0-1 km storm-relative helicity: 38 m²/s²
0-3 km storm-relative helicity: 143 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

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

700 
ACUS11 KWNS 291742
SWOMCD
SPC MCD 291742 COR
MNZ000-SDZ000-NDZ000-291930-

MESOSCALE DISCUSSION 2012
NWS STORM PREDICTION CENTER NORMAN OK
1242 PM CDT TUE JUL 29 2003

AREAS AFFECTED...PARTS OF ERN ND...CNTRL/ERN SD...WRN MN

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 291742Z - 291930Z

CORRECTED TEXT

TRENDS ARE BEING MONITORED FOR POSSIBILITY OF WW...WHICH MAY BECOME
NECESSARY WITHIN NEXT 1 TO 3 HOURS.

THUNDERSTORMS ARE SLOWLY INCREASING/INTENSIFYING WHERE SURFACE
HEATING HAS BEEN STRONGEST NEAR LOW-LEVEL THERMAL RIDGE AXIS/LEE
SURFACE EXTENDING FROM THE NEBRASKA PANHANDLE INTO CENTRAL/EASTERN
NORTH DAKOTA.  AS SHORT WAVE TROUGH CONTINUES TO DIG INTO THE
NORTHERN PLAINS THIS AFTERNOON...ASSOCIATED MID/UPPER FORCING FOR
UPWARD VERTICAL MOTION IS EXPECTED TO RESULT IN A GRADUAL
CONSOLIDATION OF CONVECTIVE ACTIVITY NORTH/NORTHEAST OF PIERRE SD
INTO THE GRAND FORKS ND AREA.  THIS MAY OCCUR AS EARLY AS THE 20-21Z
TIME FRAME...WHEN MEAN MIXED LAYER CAPE UP TO 2000 J/KG WILL BECOME
INCREASINGLY SUPPORTIVE OF VIGOROUS UPDRAFTS WITH LARGE HAIL...WHILE
DEEP MIXED BOUNDARY LAYER ENHANCES THREAT OF DAMAGING DOWNBURSTS. 
ALTHOUGH MEAN FLOW/VERTICAL SHEAR PROFILES ARE NOW RATHER
WEAK...MODELS SUGGEST A SLOW STRENGTHENING OF SOUTHWESTERLY
LOW-LEVEL FLOW ACROSS THE EASTERN DAKOTAS TOWARD 30/00Z...BENEATH
STRENGTHENING NORTHWESTERLY MID-LEVEL FLOW.  THIS WHICH WILL AID
CONVECTIVE ORGANIZATION AND MAY BECOME SUFFICIENT FOR ISOLATED
SUPERCELLS.

..KERR.. 07/29/2003

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

ATTN...WFO...FGF...FSD...ABR...BIS...

47299843 48039822 48389703 47889601 46449584 45269657
44709798 44289913 44260018 44740063 45319989 45969909
46579866

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 29, 3:05 PM CDT	Severe Thunderstorm Watch	SPC	Becker, Beltrami, Clay, Clearwater, Kittson, Lake of the Woods and 9 more	6 hr
Jul 29, 3:09 PM CDT	Mesoscale Discussion	SPC	Becker, Beltrami, Big Stone, Cass, Chippewa, Clay and 22 more	2 hr
Jul 29, 5:10 PM CDT	Severe Thunderstorm Watch	SPC	Aitkin, Benton, Brown, Carlton, Carver, Cass and 40 more	5 hr
Jul 29, 1:40 PM CDT	Severe Thunderstorm Watch	SPC	Aurora, Beadle, Brule, Buffalo, Charles Mix, Clark and 20 more	5 hr

Nearby

Mesoscale Discussions in South Dakota, 2003 Mesoscale Discussions in North Dakota, 2003 Mesoscale Discussions in Minnesota, 2003 Every mesoscale discussion in 2003

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.