Alert archive / North Dakota / Mesoscale Discussions in 2012

Mesoscale Discussion 1501

July 19, 201211 counties in Minnesota; 15 counties in North Dakota; Grant County, Marshall County, Roberts County, South Dakota

The Storm Prediction Center issued this mesoscale discussion at Jul 19, 2012, 1:56 PM CDT for 11 counties in Minnesota; 15 counties in North Dakota; Grant County, Marshall County, Roberts County, South Dakota. It was in force for 64 min.

The area

The outline as issued.

The facts

Issued: Jul 19, 2012, 1:56 PM CDT (18:56 UTC)
Expired: Jul 19, 2012, 3:00 PM CDT
In force: 64 min
Issued by: the Storm Prediction Center
Chance of a watch: 60%

All 29 counties

Big Stone County, MN, Clay County, MN, Douglas County, MN, Grant County, MN, Lac qui Parle County, MN, Otter Tail County, MN, Pope County, MN, Stevens County, MN, Swift County, MN, Traverse County, MN, Wilkin County, MN, Barnes County, ND, Cass County, ND, Dickey County, ND, Foster County, ND, Griggs County, ND, Kidder County, ND, LaMoure County, ND, Logan County, ND, McIntosh County, ND, Ransom County, ND, Richland County, ND, Sargent County, ND, Steele County, ND, Stutsman County, ND, Wells County, ND, Grant County, SD, Marshall County, SD, Roberts County, SD

The radar

The Fargo/Grand Forks radar (KMVX), 122 km from the middle of the area, began a volume at 18:57 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.

Severe Thunderstorm Watch 497Jul 19, 3:50 PM CDT

The nearest sounding before it

Aberdeen, SD (KABR), launched 12:00Z, 6.9 hours before the alert went out and 182 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: 2076 J/kg
Mixed-layer CIN: -182 J/kg
Mixed-layer LCL: 1372 m above ground
0-6 km bulk shear: 22 kt
0-1 km storm-relative helicity: 94 m²/s²
0-3 km storm-relative helicity: 168 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.4

Open this sounding in Storm Lab

The text

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

655 
ACUS11 KWNS 191857
SWOMCD
SPC MCD 191856
MNZ000-SDZ000-NDZ000-192000-

MESOSCALE DISCUSSION 1501
NWS STORM PREDICTION CENTER NORMAN OK
0156 PM CDT THU JUL 19 2012

AREAS AFFECTED...ERN ND...NERN SD...NWRN MN

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 191856Z - 192000Z

PROBABILITY OF WATCH ISSUANCE...60 PERCENT

SUMMARY...CONVECTIVE COVERAGE WILL INCREASE OVER THE NEXT FEW
HOURS...POTENTIALLY EVOLVING INTO A SEWD PROGRESSING MCS CAPABLE OF
SIGNIFICANT HAIL AND DMGG WINDS.

DISCUSSION...EARLIER ELEVATED CONVECTION ACROSS CNTRL ND APPEARS TO
HAVE LEFT AN OUTFLOW BOUNDARY N OF BIS AND S OF DVL. AREA VAD WIND
PROFILE DATA IN THE VICINITY OF THIS BOUNDARY ARE SHOWING IMPLIED
WARM ADVECTION...WITH NEW ATTEMPTS AT SURFACE BASED CONVECTION
ONGOING. MODIFYING THE 12Z BIS SOUNDING FOR CURRENT SURFACE
CONDITIONS INDICATES THAT ANY REMAINING CONVECTIVE INHIBITION WILL
VERY SHORTLY BE BREACHED. ADDITIONAL CONVECTION MAY INITIATE ALONG A
N-S MOISTURE GRADIENT...CHARACTERIZED BY 100/55 F SURFACE CONDITIONS
AT BIS...AND 92/73 F TO THE EAST AT JMS. ALTHOUGH UPPER LEVEL
FORCING FOR ASCENT REMAINS WEAK...A SUBTLE WAVE NOTED ON 1845Z WV
IMAGERY ACROSS CNTRL/ERN ND AND N CNTRL SD MAY BE SUFFICIENT ENOUGH
TO SUPPORT THE EVENTUAL DEVELOPMENT OF AN MCS...GRADUALLY INCREASING
IN INTENSITY AMIDST A STEEP LOW-MID LEVEL LAPSE RATE ENVIRONMENT AND
STRONG NWLY FLOW ALOFT.

..HURLBUT/MEAD.. 07/19/2012

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

ATTN...WFO...MPX...FGF...ABR...BIS...

LAT...LON   45999947 47280055 47789992 47649783 47149635 46289542
            45369498 44839601 45999947

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 19, 3:48 PM CDT	Severe Thunderstorm Watch	SPC	Clay, Kittson, Mahnomen, Marshall, Norman, Pennington and 4 more	7 hr
Jul 19, 6:11 PM CDT	Mesoscale Discussion	SPC	Becker, Clay, Clearwater, Mahnomen, Norman, Otter Tail and 4 more	94 min
Jul 19, 5:42 PM CDT	Mesoscale Discussion	SPC	Brule, Charles Mix, Gregory, Lyman, Mellette, Todd and 1 more	63 min

Nearby

Mesoscale Discussions in North Dakota, 2012 Mesoscale Discussions in Minnesota, 2012 Mesoscale Discussions in South Dakota, 2012 Every mesoscale discussion in 2012

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.