Alert archive / North Dakota / Mesoscale Discussions in 2007

Mesoscale Discussion 1113

June 12, 200721 counties in North Dakota; 17 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at Jun 12, 2007, 11:40 AM MDT for 21 counties in North Dakota; 17 counties in South Dakota. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Jun 12, 2007, 11:40 AM MDT (17:40 UTC)
Expired: Jun 12, 2007, 1:45 PM MDT
In force: 2 hr
Issued by: the Storm Prediction Center

All 38 counties

Adams County, ND, Benson County, ND, Burleigh County, ND, Dunn County, ND, Emmons County, ND, Grant County, ND, Hettinger County, ND, Kidder County, ND, Logan County, ND, McHenry County, ND, McIntosh County, ND, McLean County, ND, Mercer County, ND, Morton County, ND, Oliver County, ND, Pierce County, ND, Rolette County, ND, Sheridan County, ND, Sioux County, ND, Ward County, ND, Wells County, ND, Campbell County, SD, Corson County, SD, Dewey County, SD, Haakon County, SD, Hughes County, SD, Hyde County, SD, Jackson County, SD, Jones County, SD, Lyman County, SD, Mellette County, SD, Perkins County, SD, Potter County, SD, Stanley County, SD, Sully County, SD, Tripp County, SD, Walworth County, SD, Ziebach County, SD

The radar

The Bismarck radar (KBIS), 22 km from the middle of the area, began a volume at 17:40 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.

Tornado Watch 389Jun 12, 1:00 PM MDT

The nearest sounding before it

Bismarck Municip, ND (KBIS), launched 12:00Z, 5.7 hours before the alert went out and 26 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: 746 J/kg
Mixed-layer CIN: -246 J/kg
Mixed-layer LCL: 871 m above ground
0-6 km bulk shear: 26 kt
0-1 km storm-relative helicity: 24 m²/s²
0-3 km storm-relative helicity: 70 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 121740
SWOMCD
SPC MCD 121740 
NDZ000-SDZ000-121945-

MESOSCALE DISCUSSION 1113
NWS STORM PREDICTION CENTER NORMAN OK
1240 PM CDT TUE JUN 12 2007

AREAS AFFECTED...WRN/CENTRAL ND...WRN/CENTRAL SD

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 121740Z - 121945Z

TSTMS WILL CONTINUE TO DEVELOP AND INTENSIFY OVER WRN ND...AND
NWRN/CENTRAL SD DURING THE NEXT FEW HOURS. A FEW OF THESE TSTMS ARE
EXPECTED TO BEGIN POSING A MARGINAL SVR THREAT BY 20Z...AND A WW MAY
BE NEEDED BEFORE THEN. VERY HVY RAINFALL RATES IN EXCESS OF 2 IN/HR
WILL ALSO BE POSSIBLE SPCLY WHERE CELL TRAINING OCCURS.

DESPITE COPIOUS CLOUD COVER MOVING INTO THE AREA...SUFFICIENTLY
STRONG AND DEEP LAYER CONVERGENCE AHEAD OF AN MCV AND WEAKENING CINH
HAS AIDED IN A NEW ROUND OF TSTMS TO DEVELOP RECENTLY OVER SWRN
ND/NWRN SD WITH ADDITIONAL TSTMS DEVELOPING OVER CENTRAL SD IN THE
WAKE OF THIS MCV. 17Z SURFACE ANALYSIS INDICATED A CORRIDOR OF
HIGHER INSTABILITY /MLCAPES FROM 1500-2500 J/KG EXTENDING FROM
CENTRAL SD NWWD INTO WCENTRAL/SWRN ND. MID LEVEL FLOW WAS ADEQUATE
FOR ROTATING SUPERCELLS /30-40 KTS AT 6 KM PER BISMARCK/RAPID CITY
VWP DATA/ ALONG THE WRN PORTION OF THIS INSTABILITY AXIS /WHERE
CONVECTION WAS BEGINNING TO DEVELOP/. GIVEN INCREASING UPPER FORCING
AHEAD OF APPROACHING VORT MAX OVER CENTRAL MT...AND A VERY MOIST AND
WEAKLY CAPPED ATMOSPHERE /SFC TEMPERATURES NEAR 80 F...EXPECT AT
LEAST ISOLATED SVR TSTMS WITHIN THE NEXT FEW HOURS. ANY SVR TSTMS
THAT DO DEVELOP WILL BE CAPABLE OF PRODUCING LARGE HAIL/DMGG WINDS
ALONG WITH VERY HVY RAIN. AN INCREASING LOW LEVEL JET EARLY THIS
EVENING OVER CENTRAL ND/NCENTRAL SD SUGGESTS THAT AN ISOLATED
TORNADO OR TWO IS ALSO POSSIBLE TOWARD EVENING IF ANY DISCRETE
SUPERCELLS FORM. THE AMOUNT OF MID/HIGH CLOUD COVER MOVING NWD OUT
OF SD AND IT/S EFFECTS ON INSOLATION AND INSTABILITY MAY BE
SUFFICIENT TO PRECLUDE A GREATER COVERAGE OF SVR THREAT OVER ND.

..CROSBIE.. 06/12/2007

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

ATTN...WFO...FGF...ABR...BIS...UNR...

43169996 43350189 46020270 46770265 47350279 47910272
48350210 48590125 48650080 48780041 48830007 48779954
48659976 48109910 44439938

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 11, 8:13 PM MDT	Mesoscale Discussion	SPC	Bottineau, Burleigh, Dunn, McHenry, McLean, Mercer and 7 more	92 min
Jun 11, 10:32 PM MDT	Severe Thunderstorm Watch	SPC	Adams, Billings, Bowman, Burke, Divide, Dunn and 11 more	5 hr
Jun 12, 2:03 AM MDT	Mesoscale Discussion	SPC	Adams, Billings, Bowman, Burke, Divide, Dunn and 11 more	57 min
Jun 12, 1:02 PM MDT	Tornado Watch	SPC	Benson, Bottineau, Burleigh, Cavalier, Dickey, Eddy and 22 more	6 hr
Jun 12, 3:23 PM MDT	Mesoscale Discussion	SPC	Benson, Bottineau, Burleigh, Eddy, Emmons, Foster and 14 more	2 hr

Nearby

Mesoscale Discussions in North Dakota, 2007 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.