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 840

MD 0840 Image

Mesoscale Discussion 0840
NWS Storm Prediction Center Norman OK
0555 PM CDT Sun May 19 2024

Areas affected...Eastern KS...far southeast NE...western
MO...southwest IA

Concerning...Severe potential...Severe Thunderstorm Watch likely 

Valid 192255Z - 200030Z

Probability of Watch Issuance...95 percent

SUMMARY...A developing MCS over central Kansas is expected to
accelerate east-northeastward later this evening towards parts of
the Mid to Lower Missouri Valley. Damaging winds from 70-90 mph will
be the primary threat, most likely across eastern Kansas. A
downstream severe thunderstorm watch will be needed.

DISCUSSION...As alluded to in MCD 0839, increasingly widespread
severe wind gusts are expected as multiple intense thunderstorm
clusters over north-central to southwest KS consolidate by
mid-evening. The leading cluster across north-central KS should
spread into northeast KS initially, with additional low-level
warm-advection-driven storms possible farther northeast across the
Mid-MO Valley. Surface dew points are generally in the mid 50s to
low 60s across northeast KS and southeast NE currently and this may
mitigate eastward intensification in the near-term. But a plume of
higher surface dew points exists both to the south, emanating north
from OK, and farther east into central/northern MO. Eventual cluster
consolidation will probably yield eastward acceleration later this
evening with embedded bows spreading across at least eastern KS. A
plume of substantial MLCIN that will increase after dusk across
eastern OK and southeast KS, may result in the more prominent severe
wind threat arcing east-northeastward in time.

..Grams/Smith.. 05/19/2024

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


LAT...LON   39859658 40619637 41179558 41169463 40899345 40459313
            38249378 37019512 37069656 38219623 39299628 39859658 

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SPC MD 839

MD 0839 Image

Mesoscale Discussion 0839
NWS Storm Prediction Center Norman OK
0517 PM CDT Sun May 19 2024

Areas affected...much of Kansas into northwestern Oklahoma

Concerning...Severe Thunderstorm Watch 260...

Valid 192217Z - 200015Z

The severe weather threat for Severe Thunderstorm Watch 260

SUMMARY...A couple of clusters of thunderstorms appear likely to
continue to gradually evolve and organize during the next couple of
hours, with severe wind gusts occasionally exceeding 75 mph becoming
the most prominent severe hazard by 7-8 PM CDT.

DISCUSSION...Embedded within 30-40 kt southwesterly deep-layer mean
flow, an ongoing intense supercell has been rightward (eastward)
propagating toward the Salina KS vicinity.  This motion is roughly
coincident with a west-southwest to east-northeast oriented warm
frontal zone, extending along/north of the Interstate 70 corridor
into northeastern Kansas.  Given enhanced forcing for ascent
associated with low-level convergence and warm advection along this
boundary,  and fairly sizable boundary-layer temperature/dew point
spreads to the south of the front, further upscale growth and
evolution into a more prominent bowing structure with strong
damaging surface gusts becoming the primary severe hazards seems
probable through 23-01Z.

At the same time, as a low-amplitude short wave trough continues to
gradually emerge from the southern Rockies, intensifying storms
along the dryline north of Garden City KS into the Clinton-Sherman
OK vicinity may continue to increase along consolidating eastward
propagating outflows, aided by inflow of seasonably moist air
characterized by large CAPE to around 3000 J/kg.  In the presence of
seasonably moderate to strong shear, this activity seems likely to
gradually organize.  The evolution of one or two increasingly
prominent lower/mid-tropospheric mesoscale vortices appears
possible, with the quasi-stationary front north of Dodge City into
the Russell/Salina vicinities one potential focus for strong,
damaging wind gusts.

..Kerr.. 05/19/2024

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


LAT...LON   39669764 39879551 38509541 37709738 36459817 36049924
            36329991 37309965 38230020 38669959 39149846 39669764 

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SPC MD 838

MD 0838 Image

Mesoscale Discussion 0838
NWS Storm Prediction Center Norman OK
0453 PM CDT Sun May 19 2024

Areas affected...Southeast Florida

Concerning...Severe Thunderstorm Watch 258...

Valid 192153Z - 200000Z

The severe weather threat for Severe Thunderstorm Watch 258

SUMMARY...The threat for large hail and damaging winds continues
across parts of the southeast Florida coast.

DISCUSSION...Regional radar imagery and surface observations
continue to show deep convection developing along and behind a
southward-surging outflow boundary along the southeast FL coast.
While most storms have struggled to intensify due to the
undercutting nature of the boundary, a few deeper cells have managed
to mature within an otherwise favorable supercell environment. A
sea-breeze boundary remains evident along the southeastern FL coast
ahead of the outflow boundary, and while deeper convective
initiation has occurred within the past hour, strengthening
low-level westerly winds has shifted the boundary closer to the
coast, resulting in quick storm propagation offshore. The general
expectation over the next 1-2 hours is for a continuation of
scattered thunderstorms along the southeast FL coast with a few
strong to severe cells capable of large hail and damaging winds.
This threat will gradually abate through the evening hours amid the
onset of nocturnal cooling and a continued southward surge of the
undercutting outflow boundary.

..Moore.. 05/19/2024

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


LAT...LON   26888070 26938060 26938008 26848003 26588002 26418005
            26238008 26098010 25938010 25768011 25688014 25648024
            25628031 25708045 25798057 25938066 26068073 26198078
            26328083 26538085 26668083 26788078 26888070 

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