Alert archive / North Dakota / Mesoscale Discussions in 2021
Mesoscale Discussion 688
The Storm Prediction Center issued this mesoscale discussion at May 19, 2021, 5:03 PM CDT for Kittson County, Marshall County, Minnesota; 12 counties in North Dakota. It was in force for 117 min.
The area
The outline as issued.
The facts
- Issued
- May 19, 2021, 5:03 PM CDT (22:03 UTC)
- Expired
- May 19, 2021, 7:00 PM CDT
- In force
- 117 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe potential...watch unlikely
- Chance of a watch
- 5%
Counties Kittson County, MN, Marshall County, MN, Eddy County, ND, Emmons County, ND, Foster County, ND, Grand Forks County, ND, Griggs County, ND, Kidder County, ND, Logan County, ND, Nelson County, ND, Pembina County, ND, Steele County, ND, Stutsman County, ND, Walsh County, ND
The radar
The Fargo/Grand Forks radar (KMVX), 88 km from the middle of the area, began a volume at 22:06 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.
The nearest sounding before it
Aberdeen, SD (KABR), launched 12:00Z, 10.1 hours before the alert went out and 283 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.
- Mixed-layer CAPE
- 23 J/kg
- Mixed-layer CIN
- -113 J/kg
- Mixed-layer LCL
- 926 m above ground
- 0-6 km bulk shear
- 17 kt
- 0-1 km storm-relative helicity
- 90 m²/s²
- 0-3 km storm-relative helicity
- 103 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
201
ACUS11 KWNS 192204
SWOMCD
SPC MCD 192203
MNZ000-NDZ000-200000-
Mesoscale Discussion 0688
NWS Storm Prediction Center Norman OK
0503 PM CDT Wed May 19 2021
Areas affected...Eastern North Dakota
Concerning...Severe potential...Watch unlikely
Valid 192203Z - 200000Z
Probability of Watch Issuance...5 percent
SUMMARY...Brief landspouts and perhaps isolated instances of severe
hail and/or damaging wind will remain possible through the early
evening hours for parts of eastern North Dakota and extreme
northwest Minnesota.
DISCUSSION...Thunderstorm development has been ongoing over the past
hour along a migratory cold front draped from far northwest MN into
southern ND. Deep-layer flow across the region remains very weak and
effective bulk shear values are expected to generally remain below
30 knots, which will limit the overall severe potential. Despite
this weakness, the environment does exhibit sufficient instability
and steep 0-3 km lapse rates (near 8 C/km per RAP analyses and
forecast soundings). These factors will support an isolated
wind/hail threat with any stronger updrafts. Additionally, ambient
environmental vorticity along the cold front, coupled with the steep
low-level lapse rates, will continue to support the potential for
brief landspout tornadoes (one such tornado has already been
reported). It is unclear how long the landspout tornado threat will
persist given the tendency for most storms to quickly become outflow
dominant. However, new storm development along the front and/or
outflow intersections may maintain the threat through sunset when
boundary-layer decoupling begins. Given the isolated nature of the
threat, a watch is not expected.
..Moore/Dial.. 05/19/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...FGF...BIS...
LAT...LON 46390070 47339977 48169863 48809770 49079695 49049588
48359631 47859703 47469757 46899831 46409900 46069989
46060051 46390070Nearby
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.