Mesoscale Discussion 1318

Issued

Jul 19, 2021, 7:04 PM CDT (00:04 UTC)

Expired

Jul 19, 2021, 9:00 PM CDT

In force

116 min

Issued by

the Storm Prediction Center

Concerning

Severe potential...watch unlikely

Chance of a watch

20%

Counties Benson County, ND, Cavalier County, ND, Eddy County, ND, Foster County, ND, Grand Forks County, ND, Griggs County, ND, McHenry County, ND, McLean County, ND, Nelson County, ND, Pierce County, ND, Ramsey County, ND, Rolette County, ND, Sheridan County, ND, Towner County, ND, Walsh County, ND, Wells County, ND

The Minot AFB radar (KMBX), 112 km from the middle of the area, began a volume at 00:06 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.

239 
ACUS11 KWNS 200005
SWOMCD
SPC MCD 200004 
NDZ000-200200-

Mesoscale Discussion 1318
NWS Storm Prediction Center Norman OK
0704 PM CDT Mon Jul 19 2021

Areas affected...central and northern North Dakota

Concerning...Severe potential...Watch unlikely 

Valid 200004Z - 200200Z

Probability of Watch Issuance...20 percent

SUMMARY...A localized severe threat is expected to persist for a
couple of hours with storms near a differential heating zone. Large
hail and damaging gusts are the main threat. A WW issuance is not
expected given the brevity/localized nature of the severe threat.

DISCUSSION...Multiple storms have intensified across portions of
central into northern ND over the past hour or so, with a supercell
in progress across McHenry County. MRMS MESH suggests that
significant (2+ inch) hail is occurring with this supercell storm,
with the public also reporting 2 inch diameter hailstones within the
past hour. This storm is currently traversing a baroclinic zone,
with warmer but drier air (90s F surface temperatures over 60F
dewpoints) to the south, but moister air (upper 60s to 70 F
dewpoints) to the north. 12Z mesoanalysis shows up to 2500 J/kg
MLCAPE and 40 kts of effective bulk shear present along and north of
the boundary, supporting continued severe with the ongoing storms.
2+ inch hailstones and damaging gusts (some potentially reaching 60
kts) will be possible with the ongoing supercell. To the northeast,
severe hail and wind may also occur with an intensifying storm
complex in Towner County, ND, and significant severe hail/wind
cannot be ruled out with these storms as well, so long as MLCINH
remains minimal.

MLCINH is expected to quickly increase with nocturnal cooling in a
few hours, which should contribute to waning severe potential. Given
the localized, short-duration nature of the severe threat, a WW
issuance is not anticipated.

..Squitieri/Edwards.. 07/20/2021

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

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

LAT...LON   47350104 47560149 47850166 48400125 48790057 49049990
            49109933 49089848 48939792 48659758 48299737 47989735
            47689755 47409838 47289938 47350104

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

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.