A Mesodiscussion is issued by the National Weather Service's Storm Prediction Center when there is a chance of a significant weather event impacting an area. These are routinely issued before weather watches or as updated to weather watches.

SPC MD 917

MD 0917 CONCERNING SEVERE THUNDERSTORM WATCH 293... FOR PORTIONS OF MIDDLE/EASTERN TENNESSEE AND KENTUCKY
MD 0917 Image


Mesoscale Discussion 0917
NWS Storm Prediction Center Norman OK
0641 PM CDT Thu May 23 2024

Areas affected...Portions of middle/eastern Tennessee and Kentucky

Concerning...Severe Thunderstorm Watch 293...

Valid 232341Z - 240115Z

The severe weather threat for Severe Thunderstorm Watch 293
continues.

SUMMARY...A locally damaging wind and marginally severe hail threat
will continue for another 1 to 2 hours across portions middle and
eastern TN, and KY.

DISCUSSION...A cluster of thunderstorms associated with an MCV,
along with an embedded bowing segment now moving into Campbell
County, will continue to pose a severe damaging wind threat over the
next couple of hours. After-which, the system will begin to move
into a less favorable thermodynamic environment downstream. In
addition to damaging winds, any of the more discrete updrafts within
30-35 kt of deep effective layer shear could become briefly
organized and produce marginally severe hail up to 1.25" in
diameter. However, poor mid-level lapse rates should keep this
threat fairly isolated. A watch extension east of the cluster may be
necessary.

..Barnes.. 05/23/2024

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

ATTN...WFO...MRX...JKL...OHX...

LAT...LON   35268492 35918454 36408493 37018444 36988405 36978357
            36568329 36098363 35648363 35518392 35148437 35268492 

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SPC MD 915

MD 0915 CONCERNING SEVERE THUNDERSTORM WATCH 295... FOR WESTERN AND NORTHERN NEBRASKA...CENTRAL AND EASTERN SOUTH DAKOTA
MD 0915 Image


Mesoscale Discussion 0915
NWS Storm Prediction Center Norman OK
0554 PM CDT Thu May 23 2024

Areas affected...Western and Northern Nebraska...Central and Eastern
South Dakota

Concerning...Severe Thunderstorm Watch 295...

Valid 232254Z - 240100Z

The severe weather threat for Severe Thunderstorm Watch 295
continues.

SUMMARY...A threat for large hail and severe wind gusts is expected
to continue for several more hours from western and northern
Nebraska into central and eastern South Dakota. An isolated tornado
threat may continue across parts of southwest Nebraska.

DISCUSSION...The latest surface analysis shows a 997 mb low over
central South Dakota with a cold front extending southward from
western South Dakota into western Nebraska. A line of strong to
severe thunderstorms is ongoing ahead of the front. To the east of
this line, surface dewpoints are in the mid to upper 50s F, and the
RAP is analyzing a corridor of moderate instability with MLCAPE in
the 1500 to 2500 J/kg range. Forecast soundings from North Platte
northeastward into southern South Dakota generally have 0-6 km shear
in the 30 to 40 knot range, with 700-500 mb lapse rates of 7.5 to 8
C/km. This environment will support a severe threat, with isolated
large hail and wind damage possible. The wind damage threat will be
the greatest along the most intense parts of the line. A potential
for supercells will exist near the southern end of the line, to the
west of North Platte. In this vicinity, LCL heights are a bit lower
and surface dewpoints are near 60 F. This could be enough for an
isolated tornado threat with supercells that remain semi-discrete
this evening.

..Broyles.. 05/23/2024

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

ATTN...WFO...FSD...ABR...LBF...UNR...BOU...

LAT...LON   42080215 41640252 41260251 41030238 40850200 40820160
            40930102 41140077 41410055 42000009 43679862 44479810
            44929794 45269795 45419823 45379895 44929935 44369979
            43350065 42080215 

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