SPC AC 241730

   Day 2 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1230 PM CDT Wed Apr 24 2024

   Valid 251200Z - 261200Z

   ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM WESTERN
   KANSAS SOUTHWARD THROUGH THE EASTERN TEXAS PANHANDLE/WESTERN
   OKLAHOMA INTO NORTHWEST TEXAS...

   ...SUMMARY...
   Scattered severe thunderstorms are expected from late Thursday
   afternoon into Thursday night across parts of the central and
   southern Great Plains. Very large hail, severe wind gusts, and a
   couple strong tornadoes will all be possible.

   ...Synopsis...
   A shortwave trough is forecast to begin the day extended from
   central NV into far northwest Mexico before then quickly moving
   eastward across the Southwest and into the southern/central High
   Plains, becoming increasingly negatively tilted with time. Strong
   mid-level flow will accompany this shortwave, spreading
   eastward/northeastward into the central and southern Plains ahead of
   the parent shortwave.

   At the surface, cyclogenesis is anticipated ahead of the shortwave
   trough across the central High Plains, with the resulting low then
   gradually moving northeastward from eastern CO into western
   KS/southwest NE late Thursday night/early Friday morning. A
   sharpening dryline will extend southward from this low throughout
   most of the period. A warm front will extend east-southeastward 
   from this low as well, extending into northeast OK Thursday morning.
   This warm front is forecast to move northward throughout the day,
   moving through much of KS by early Friday morning. A moist and
   buoyant warm sector will exist south of this front, and strong to
   severe thunderstorms are anticipated the shortwave interacts with
   it.

   ...Southern/Central Plains...
   Numerous showers and thunderstorms will likely be ongoing Thursday
   morning from north-central/eastern KS into western MO and
   northeastern OK, supported by strong warm-air advection across the
   warm front.  Given that at least moderately low-level southerly flow
   is expected to persist throughout the period, expectation is that
   this activity will persist as well, while perhaps gradually shifting
   southeastward with time. Overall buoyancy and vertical shear will be
   modest, but a few stronger cores capable isolated hail are possible.
   Overall evolution of this early morning activity could lead to
   either a sharpening of the warm front from the central KS vicinity
   southeastward through northeast OK into western AR or potentially 
   southward/southwestward slow-moving outflow boundary. This sharp
   boundary is expected to limit to eastern/northeastern extent of the
   greater severe potential.

   Farther west, persistent moisture advection is anticipated amid
   moderate low-level southerly flow ahead of the approaching shortwave
   trough. This is expected to result in mid 60s dewpoints by the
   mid-afternoon across much of the eastern TX/OK Panhandle and OK,
   with low 60s dewpoints reaching into south-central KS. Mid 60s
   dewpoints are expected into western and south-central KS by early
   evening. Steep mid-level lapse rates will exist a top this low-level
   moisture, supporting moderate to strong buoyancy, with the
   strengthening mid-level flow supporting robust deep-layer vertical
   shear as well.

   Some capping is anticipated along the dryline, but the combination
   of strong diurnal heating (in the wake of morning clouds),
   increasing large-scale ascent, and low-level convergence is expected
   to result in convective initiation during the late afternoon. Widely
   scattered to scattered thunderstorm coverage appears probable, with
   storms quickly becoming severe after initiation. Large to very large
   hail will be the primary threat with the initial development. The
   tornado threat will also increase with any supercell that persists
   into the evening, with low-level shear/SRH expected to increase with
   time and eastward extent. As such any longer-lived supercells could
   pose a strong tornado threat, particularly across
   west-central/southwest KS where surface flow will be backed given
   closer proximity of the surface low.

   Additional thunderstorms are anticipated farther south Thursday
   night as the Pacific front surges eastward. Highest storm coverage
   currently appears most likely from southwest OK into northwest TX.
   Initial development could produce large to very large hail before
   then transitioning to a more linear mode. Some downstream severe
   threat into north-central TX and south-central/central OK appears
   likely, although uncertainty remains regarding overall intensity,
   largely as a result of low-level nocturnal stability. However,
   kinematic fields are quite strong and could maintain organized storm
   structures capable of all severe hazards eastward into north-central
   TX and south-central/central OK. This area will be assessed for
   increased severe probabilities in later outlooks.

   ...Central High Plains into Nebraska...
   Numerous thunderstorms are expected to develop from northeast CO/NE
   Panhandle northeastward into NE Thursday night as large-scale ascent
   spreads across the region. Most of this activity will be elevated,
   but the presence of steep mid-level lapse rates and moderate
   vertical shear suggests large hail is possible with these storms,
   with perhaps even some very large hail (i.e. 2 to 2.5" in diameter)
   in the CO/NE/KS border vicinity where surface-based parcels are
   possible.

   ...Eastern WY into Southwest SD...
   Moderate buoyancy will support scattered diurnal thunderstorm
   development into the Black Hills vicinity. Deep-layer shear will be
   weaker in this area than areas farther south, but may still be
   sufficient for modestly organized storms capable of large hail.

   ..Mosier.. 04/24/2024

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