Alert archive / North Dakota / Mesoscale Discussions in 2007

Mesoscale Discussion 1721

August 11, 200729 counties in North Dakota

The Storm Prediction Center issued this mesoscale discussion at Aug 11, 2007, 2:37 AM CDT for 29 counties in North Dakota. It was in force for 23 min.

The area

The outline as issued.

The facts

Issued: Aug 11, 2007, 2:37 AM CDT (07:37 UTC)
Expired: Aug 11, 2007, 3:00 AM CDT
In force: 23 min
Issued by: the Storm Prediction Center

All 29 counties

Barnes County, ND, Benson County, ND, Burleigh County, ND, Cass County, ND, Dickey County, ND, Eddy County, ND, Emmons County, ND, Foster County, ND, Grand Forks County, ND, Grant County, ND, Griggs County, ND, Kidder County, ND, LaMoure County, ND, Logan County, ND, McIntosh County, ND, McLean County, ND, Mercer County, ND, Morton County, ND, Nelson County, ND, Oliver County, ND, Ransom County, ND, Richland County, ND, Sargent County, ND, Sheridan County, ND, Sioux County, ND, Steele County, ND, Stutsman County, ND, Traill County, ND, Wells County, ND

The radar

The Bismarck radar (KBIS), 57 km from the middle of the area, began a volume at 07:37 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

Bismarck Municip, ND (KBIS), launched 00:00Z, 7.6 hours before the alert went out and 53 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: 1851 J/kg
Mixed-layer CIN: -226 J/kg
Mixed-layer LCL: 1543 m above ground
0-6 km bulk shear: 48 kt
0-1 km storm-relative helicity: 164 m²/s²
0-3 km storm-relative helicity: 267 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.

000 
ACUS11 KWNS 110738
SWOMCD
SPC MCD 110737 
MNZ000-NDZ000-SDZ000-110800-

MESOSCALE DISCUSSION 1721
NWS STORM PREDICTION CENTER NORMAN OK
0237 AM CDT SAT AUG 11 2007

AREAS AFFECTED...CENTRAL/ERN ND

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 110737Z - 110800Z

WW MAY BE NEEDED ACROSS PARTS OF CENTRAL AND ERN ND...WITH HAIL
BEING THE PRIMARY THREAT.

ELEVATED TSTMS HAVE CONTINUED TO DEVELOP ACROSS SWRN INTO CENTRAL ND
DURING THE LAST 1-2 HOURS WITHIN THE SRN/CENTRAL PARTS OF WW
584...WHICH HAS BEEN LOCALLY EXTENDED IN TIME TO 08Z.  00Z NAM/03Z
RUC BOTH INDICATED THIS CONVECTIVE ACTIVITY SHOULD PERSIST OVERNIGHT
INTO THE EARLY MORNING ACROSS ND AS LARGE SCALE ASCENT ATTENDANT
WITH MID LEVEL IMPULSE OVER ERN MT/WRN ND SPREADS ENEWD.  LOW LEVEL
WAA IN ADVANCE OF THIS IMPULSE AND N/NE OF WRN SD SURFACE LOW WILL
ALSO SUPPORT NEW TSTM DEVELOPMENT.  GIVEN STRONG SURFACE-BASED
INHIBITION...ND TSTM ACTIVITY IS EXPECTED TO REMAIN ELEVATED.  STEEP
MID LEVEL LAPSE RATES...EFFECTIVE BULK SHEAR VALUES OF 40-45 KT AND
VERY STRONG MUCAPE INDICATE HAIL WILL BE THE PRIMARY THREAT. 
COVERAGE THUS FAR HAS BEEN ISOLATED...WITH SOME CONTINUED
UNCERTAINTY IN OVERALL SEVERE WEATHER THREAT DURING THE NEXT SEVERAL
HOURS...GIVEN TIME OF DAY.  IF TRENDS SUGGEST AN INCREASE IN OVERALL
TSTM COVERAGE/INTENSITIES...THEN A WW MAY BE NEEDED.

..PETERS.. 08/11/2007

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

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

47710229 48010164 48149970 48059709 46549670 45949667
45909873 45890103 45910216 46670238

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 10, 8:50 PM CDT	Mesoscale Discussion	SPC	Dickey, McIntosh	55 min
Aug 10, 10:08 PM CDT	Mesoscale Discussion	SPC	Burke, Burleigh, Divide, McLean, Mountrail, Oliver and 4 more	67 min
Aug 11, 12:27 AM CDT	Mesoscale Discussion	SPC	Bottineau, McHenry, Pierce, Renville, Ward	33 min
Aug 11, 12:58 AM CDT	Mesoscale Discussion	SPC	Dickey	62 min

Nearby

Mesoscale Discussions in North 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.