Alert archive / North Dakota / Mesoscale Discussions in 2004

Mesoscale Discussion 1913

August 7, 200421 counties in North Dakota; 10 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at Aug 7, 2004, 12:17 PM MDT for 21 counties in North Dakota; 10 counties in South Dakota. It was in force for 88 min.

The area

The outline as issued.

The facts

Issued: Aug 7, 2004, 12:17 PM MDT (18:17 UTC)
Expired: Aug 7, 2004, 1:45 PM MDT
In force: 88 min
Issued by: the Storm Prediction Center

All 31 counties

Adams County, ND, Billings County, ND, Bowman County, ND, Burke County, ND, Divide County, ND, Dunn County, ND, Golden Valley County, ND, Grant County, ND, Hettinger County, ND, McKenzie County, ND, McLean County, ND, Mercer County, ND, Morton County, ND, Mountrail County, ND, Oliver County, ND, Renville County, ND, Sioux County, ND, Slope County, ND, Stark County, ND, Ward County, ND, Williams County, ND, Butte County, SD, Corson County, SD, Dewey County, SD, Haakon County, SD, Harding County, SD, Meade County, SD, Pennington County, SD, Perkins County, SD, Stanley County, SD, Ziebach County, SD

The radar

The Bismarck radar (KBIS), 175 km from the middle of the area, began a volume at 18:18 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

Bismarck Municip, ND (KBIS), launched 12:00Z, 6.3 hours before the alert went out and 179 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: 13 J/kg
Mixed-layer CIN: -483 J/kg
Mixed-layer LCL: 1580 m above ground
0-6 km bulk shear: 16 kt
0-1 km storm-relative helicity: -51 m²/s²
0-3 km storm-relative helicity: -24 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.

037 
ACUS11 KWNS 071817
SWOMCD
SPC MCD 071817 
SDZ000-NDZ000-MTZ000-071945-

MESOSCALE DISCUSSION 1913
NWS STORM PREDICTION CENTER NORMAN OK
0117 PM CDT SAT AUG 07 2004

AREAS AFFECTED...WRN ND/SD AND EXTREME ERN MT

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 071817Z - 071945Z

THUNDERSTORM WATCH WILL LIKELY BE NEEDED FOR PORTIONS OF WRN ND AND
PERHAPS NWRN SD BY 20Z.

COLD FRONT STRETCHES FROM NORTH OF ISN TO EAST OF MLS TO SHR AT 18Z.
A SURFACE LOW WAS LOCATED NEAR THE MT/SD BORDER WITH A TROUGH
EXTENDING SEWD FROM THE LOW TO NEAR PHP AND THEN NEWD TO WEST OF
ABR. SURFACE WINDS WERE ELY NORTH OF THE TROUGH AND TO THE EAST OF
THE COLD FRONT. 

STEEP MID LEVEL LAPSE RATES AND SURFACE DEWPOINTS IN THE LOWER 60S
WERE RESULTING IN MLCAPES AROUND 2000 J/KG ACROSS MUCH OF WRN
SD...WITH MLCAPES AROUND 1000 J/KG ACROSS WRN ND/EXTREME ERN MT.
CUMULUS CLOUDS HAVE RECENTLY DEVELOP NEAR THE FRONT AND ALL MODELS
INDICATE CONVECTION WILL BREAK OUT ACROSS THE WRN DAKOTAS BY
21Z...AS CONVERGENCE/LIFT ALONG THE FRONT IS ENHANCED BY AN 
APPROACHING UPPER LEVEL TROUGH OVER N CENTRAL MT. STRENGTHING MID
LEVEL WINDS AND DIRECTIONAL SHEAR WILL SUPPORT STORMS WITH SEVERE
WIND AND HAIL LATER THIS AFTERNOON.

..IMY.. 08/07/2004

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

ATTN...WFO...ABR...BIS...UNR...BYZ...GGW...

45600402 47500419 48900393 48910135 45590017 43690085
43810262 44440367

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 7, 1:00 PM MDT	Severe Thunderstorm Watch	SPC	Adams, Billings, Bottineau, Bowman, Burke, Divide and 17 more	7 hr
Aug 7, 2:51 PM MDT	Mesoscale Discussion	SPC	Adams, Burke, Dunn, Hettinger, Mercer, Mountrail and 2 more	54 min
Aug 7, 5:24 PM MDT	Mesoscale Discussion	SPC	Burleigh, Emmons, Grant, Morton, Oliver, Sioux	66 min
Aug 7, 3:45 PM MDT	Severe Thunderstorm Watch	SPC	Bennett, Custer, Haakon, Jackson, Jones, Meade and 5 more	4 hr

Nearby

Mesoscale Discussions in North Dakota, 2004 Mesoscale Discussions in South Dakota, 2004 Every mesoscale discussion in 2004

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.