SPC May 18, 2024 0730 UTC Day 3 Severe Thunderstorm Outlook
SPC 0730Z Day 3 Outlook

Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0227 AM CDT Sat May 18 2024

Valid 201200Z - 211200Z


Severe thunderstorms are possible across parts of Nebraska and
Kansas into western Iowa and northwest Missouri Monday afternoon
into Monday night. More isolated strong to severe storms may extend
into parts of the Middle Mississippi Valley and southern Wisconsin.


An upper shortwave trough is expected to be located over the Lower
MO Valley early Monday. This trough will lift northeast across the
upper Great Lakes through Monday night. Meanwhile, a broad area of
southwesterly flow will continued across the southern/central Plains
east of a deepening upper trough over the western U.S. Deep-layer
flow will become more amplified and stronger across the central
Plains after 00z, as the western trough ejects east toward the High
Plains by early Tuesday.

At the surface, a cold front will be located from the eastern
Dakotas into central NE. This front will continue to shift east
through the evening before stalling from southern MN into eastern NE
and central KS. Southerly low-level flow ahead of the front will
result in a broad area of low to mid 60s F dew points from the
Mid/Upper MS Valley into the central/southern Plains.

...KS/NE into southwest IA/northwest MO...

Large-scale ascent will be nebulous through the afternoon, and
capping will likely suppress convection through at least
mid-afternoon. Thereafter, vertical shear will increase along with
stronger ascent spreading into the Plains during the
evening/overnight as the western trough ejects east. Thunderstorm
clusters may initiate by early evening, with the potential for MCS
development during the nighttime hours. Convective initiation and
evolution is a bit uncertain given several rounds of convection
expected for portions of the region prior to Monday evening.
However, the overall large-scale pattern supports severe convection
capable of all hazards into early Tuesday morning.

...Lower MO Valley to WI...

Convection may be ongoing Monday morning from the MO River into
central IA, northward into northern WI. How this convection evolves
is a bit uncertain. However, some severe potential appears possible
into the afternoon, as at least modest destabilization occurs amid
somewhat favorable vertical shear. Hail and strong gusts will be
possible with this activity through Monday evening.

..Leitman.. 05/18/2024

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