Alert archive / North Dakota / Mesoscale Discussions in 2021

Mesoscale Discussion 1317

July 19, 20214 counties in Minnesota; 7 counties in North Dakota

The Storm Prediction Center issued this mesoscale discussion at Jul 19, 2021, 12:21 PM CDT for 4 counties in Minnesota; 7 counties in North Dakota. It was in force for 84 min.

The area

The outline as issued.

The facts

Issued
Jul 19, 2021, 12:21 PM CDT (17:21 UTC)
Expired
Jul 19, 2021, 1:45 PM CDT
In force
84 min
Issued by
the Storm Prediction Center
Concerning
Severe potential...watch unlikely
Chance of a watch
5%

Counties Becker County, MN, Clay County, MN, Norman County, MN, Polk County, MN, Cass County, ND, Grand Forks County, ND, Griggs County, ND, Nelson County, ND, Steele County, ND, Traill County, ND, Walsh County, ND

The radar

The Fargo/Grand Forks radar (KMVX), 15 km from the middle of the area, began a volume at 17:24 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 12:00Z, 5.4 hours before the alert went out and 276 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-pSkew-T log-p diagram, Bismarck Municip, ND at 12:00Z on 2021-07-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1332 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Bismarck Municip, ND at 12:00Z on 2021-07-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -9 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
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
1332 J/kg
Mixed-layer CIN
-233 J/kg
Mixed-layer LCL
1421 m above ground
0-6 km bulk shear
16 kt
0-1 km storm-relative helicity
-9 m²/s²
0-3 km storm-relative helicity
49 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.3

Open this sounding in Storm Lab

The text

As transmitted.

787 
ACUS11 KWNS 191721
SWOMCD
SPC MCD 191721 
MNZ000-NDZ000-191845-

Mesoscale Discussion 1317
NWS Storm Prediction Center Norman OK
1221 PM CDT Mon Jul 19 2021

Areas affected...Eastern North Dakota...Northwestern Minnesota

Concerning...Severe potential...Watch unlikely 

Valid 191721Z - 191845Z

Probability of Watch Issuance...5 percent

SUMMARY...Damaging wind gust threat will increase this afternoon in
parts of eastern North Dakota and northwestern Minnesota. The
localized threat is not expected to require a WW.

DISCUSSION...A small cluster of thunderstorms in northeastern North
Dakota has shown a modest increase in intensity over the last hour.
Recent KMVX radar imagery has also shown stronger winds developing
aloft as well. As temperatures continue to warm through the 80s to
near 90 F this afternoon, the moist airmass ahead of the cluster
will continue to destabilize. Forecast soundings indicate 1500-2000
is probable by mid/late afternoon. The initial threat for damaging
winds with this cluster may remain low, but should increase some
this afternoon as low-level lapse rates steepen ahead of it. Drier
air in central Minnesota and influence from convection in northern
Minnesota will likely limit the eastward and southward extent of
severe potential this afternoon. At this time, the threat is
expected to remain localized and a WW is not anticipated.

..Wendt/Hart.. 07/19/2021

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...FGF...

LAT...LON   47829857 48249843 48419760 48089652 47599592 46999570
            46629586 46589667 46629721 46979795 47829857

Nearby

Mesoscale Discussions in North Dakota, 2021Mesoscale Discussions in Minnesota, 2021Every mesoscale discussion in 2021

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.