SPC MD 1106

MD 1106 CONCERNING SEVERE THUNDERSTORM WATCH 330... FOR WESTERN NORTH DAKOTA

Mesoscale Discussion 1106
NWS Storm Prediction Center Norman OK
0125 AM CDT Sun Jul 05 2020

Areas affected...Western North Dakota

Concerning...Severe Thunderstorm Watch 330...

Valid 050625Z - 050830Z

The severe weather threat for Severe Thunderstorm Watch 330
continues.

SUMMARY...A severe threat is expected to continue for a few more
hours as thunderstorms move eastward across the western half of
North Dakota. Wind damage and hail will be the primary threats.

DISCUSSION...The latest water vapor imagery with RAP 500 mb heights
and vorticity overlaid shows a minor shortwave trough moving through
the northern High Plains. Vorticity maxima are currently analyzed
from northeast Montana into northwestern North Dakota. An MCS with
scattered strong thunderstorms is ongoing just ahead of the
shortwave trough.

Two areas of severe potential exist across WW 330. The first is to
the southeast of Dickinson near the North Dakota and South Dakota
state line. These storms are located just to the north of an
instability maximum with SBCAPE near 2500 J/kg according to the RAP.
These storms will continue to move eastward across southern North
Dakota and northern South Dakota. The second area is located in far
northwestern North Dakota where a secondary max of instability is
located with SBCAPE near 3000 J/kg. The environment in this area
looks a little better than further to the south. This is mainly due
to a bit stronger deep-layer shear, more large-scale ascent and
weaker capping. The strongest storm in this cluster produced a 61 kt
gust at 0534Z at the Williston Airport (XWA). The instability should
help maintain these two clusters of storms across western North
Dakota for a few more hours. Moderate deep-layer shear evident on
the Bismarck WSR-88D VWP and steep mid-level lapse rates will
support a threat for wind damage and hail.

..Broyles.. 07/05/2020

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

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

LAT...LON   48810365 47260344 46060274 45990164 46030088 46850068
            47710076 48490103 48930166 48810365 

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