SPC MD 1022



MD 1022 CONCERNING SEVERE THUNDERSTORM WATCH 340…341… FOR SOUTHEAST MT…WESTERN SD…SOUTHWEST ND

MD 1022 Image

Mesoscale Discussion 1022
NWS Storm Prediction Center Norman OK
0803 PM CDT Fri Jun 07 2019

Areas affected...Southeast MT...Western SD...Southwest ND

Concerning...Severe Thunderstorm Watch 340...341...

Valid 080103Z - 080230Z

The severe weather threat for Severe Thunderstorm Watch 340, 341
continues.

SUMMARY...Severe thunderstorms capable of large hail and severe wind
gusts will continue, with some upscale growth possible later this
evening into northwest SD/southwest ND.

DISCUSSION...Two long-lived elevated clusters are moving across the
northern portion of WW 340 as of 0045Z, with another outflow-driven
cluster moving northeastward out of the Black Hills. The northern
clusters are likely somewhat elevated and are moving along the
northern edge of stronger MUCAPE (1000-2000 J/kg per recent
mesoanalyses). Effective shear of 35-45 kt (for parcels originating
around 800 mb) is more than sufficient to maintain organized
structures through the evening. 

As convection evolves tonight, one or more upscale growing clusters
may develop, either as separate clusters begin to consolidate, or as
bowing segments develop out of the existing clusters. The northern
clusters have shown some tendency toward a more linear mode over the
last half hour, as new updrafts preferentially develop on the south
edge closer to the stronger buoyancy. Should upscale growth occur,
an increasing severe wind threat will spread downstream into the
northeastern portion of WW 340 and the southwest portion of newly
issued WW 341. Otherwise, existing activity will continue to pose a
threat of hail and localized severe wind through the evening.

..Dean.. 06/08/2019

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

ATTN...WFO...ABR...BIS...UNR...BYZ...

LAT...LON   45260466 45980484 46360423 46510318 46560230 46600136
            46470079 46040056 45160084 44490182 44380241 44420386
            45010395 45260466 

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