RSS Mesoscale Discussions from Storm Prediction Center
SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0740 AM CDT Sun Apr 28 2024
Valid 281300Z - 291200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THROUGH EARLY
TONIGHT FROM THE ARKLATEX SOUTHWARD INTO EAST TX...
...SUMMARY...
Clusters of severe storms are possible through early tonight, with
the most concentrated threat for wind damage, large hail and a few
tornadoes from the ArkLaTex southward into east Texas.
...MO to east TX/western LA through tonight...
Within a larger-scale trough, a primary shortwave trough will move
northeastward from the central Plains to the upper MS Valley by
tonight. A weak surface cyclone will likewise move northeastward
from KS to IA, and an associated/weak cold front will drift
southeastward across KS/OK/northwest TX.
The warm sector has been altered substantially by an extensive
overnight QLCS that is weakening but continues to move eastward
across southern MO, western AR and northeast into south central TX.
Widespread convective overturning has occurred across areas west of
the line, and many of the overnight forecast models appear too
aggressive with thermodynamic recovery today in its wake. There may
be some recovery later today from eastern OK into MO in advance of
an embedded speed max rotating northeastward from west TX over
OK/MO. However, destabilization is unlikely to be sufficient to
support more than SLGT-risk caliber severe probabilities.
Farther south, the remnant QLCS will encounter the richer
moisture/larger buoyancy in the undisturbed warm sector from the
ArkLaTex southward. Vertical shear will be sufficient for
supercells, but the stronger shear and larger, curved hodographs
appear to be in response to warm advection within the modifying cold
pool that the models appear to remove a little too quickly today
from southeast OK/western AR northward. Thus, the main threat for
any embedded supercells/tornadoes will be along the remnant outflow
from the ArkLaTex southward. It appears possible that additional
storm development by this afternoon could evolve into another linear
cluster that will spread southeastward into southeast TX and western
LA by this evening/overnight with a continued threat for wind damage
and occasional large hail.
..Thompson/Leitman.. 04/28/2024
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Day 4-8 Outlook
Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0359 AM CDT Sun Apr 28 2024
Valid 011200Z - 061200Z
...DISCUSSION...
...D4/Wednesday - Central and southern Plains...
Extended-range guidance generally depicts a broad upper-level trough
gradually moving eastward across the western CONUS on Wednesday,
though differences remain regarding the amplitude of this trough.
Downstream of the trough, a surface low is forecast to deepen across
the south-central High Plains, with rich low-level moisture
streaming northward along/east of a developing dryline and south of
a northward-moving warm front. Moderate to strong buoyancy may
develop across the warm sector Wednesday afternoon, and scattered
thunderstorm development will be possible along/east of the dryline
and also near the warm front.
While mid/upper-level flow is currently forecast to remain rather
modest, deep-layer shear may be sufficient to support some organized
convection. With most extended-range guidance depicting scattered
thunderstorm development during the afternoon and evening within a
relatively favorable environment, a 15% area has been added for
parts of the central/southern Plains, where confidence in an
organized severe threat is currently highest.
Some guidance suggests the threat could extend into parts of
southwest and deep south TX, in advance of a low-amplitude
subtropical shortwave trough, though uncertainty remains rather high
regarding this potential.
...D5/Thursday - Central and southern Plains into the MS Valley...
A continuation of severe potential is expected into Thursday across
parts of the central/southern Plains and potentially into the
mid/upper MS Valley, with moderate to locally strong instability
expected again during the afternoon across the warm sector of a
northeastward-moving cyclone. However, predictability begins to
decrease at this forecast range regarding timing of a cold front
that is forecast to move southeastward and potentially provide a
focus for thunderstorm development during the afternoon and evening.
...D6/Friday - D8/Sunday...
A notable increase in spread amongst extended-range guidance is
noted by D6/Friday into the weekend. In general, a cold front will
likely continue moving southeastward before stalling across parts of
southern Plains into the Southeast. Rich low-level moisture and
stronger instability may be maintained across parts of TX, but
organized severe potential in that area remains very uncertain at
this time.
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