RSS Mesoscale Discussions from Storm Prediction Center
SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1222 AM CDT Thu Apr 25 2024
Valid 251200Z - 261200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS
OF THE CENTRAL AND SOUTHERN GREAT PLAINS...
...SUMMARY...
Scattered severe thunderstorms are expected from late this afternoon
into tonight across parts of the central and southern Great Plains.
Very large hail, severe wind gusts, and a couple strong tornadoes
will all be possible.
...Great Plains...
Water-vapor imagery depicts a well-defined short-wave trough off the
southern CA/Baja Peninsula Coast. 70+kt 500mb speed max is forecast
to translate across the northern Gulf of CA early in the period
before advancing into the southern high Plains at 26/00z, and
central KS by sunrise Friday. In response to this feature, lee
surface low will reposition itself into eastern CO by late
afternoon. While LLJ won't be particularly strong through 26/00z,
boundary layer will moisten significantly across the central High
Plains into northeast CO prior to the approaching jet. Surface
temperatures will warm rapidly across eastern CO such that
convective temperatures will be breached by 21z, favorably timed
with the left exit region of the jet. 60F surface dew points have
spread into the northeast TX Panhandle early this morning, and
should advance into northwest KS prior to expected supercell
initiation. Model forecast soundings exhibit favorable
shear/buoyancy for organized rotating updrafts and the dry line will
be the primary focus for initiation. Very large hail is expected
with this activity along with tornadoes, a few potentially strong.
LLJ will strengthen along the I35 corridor from north TX into NE
during the overnight hours. There will be some propensity for the
western KS convection to spread/develop downstream as low-level warm
advection increases during the latter half of the period.
Farther south along the dry line, it appears a secondary, bimodal
corridor of convection will evolve over west/northwest TX during the
late-evening hours. Deep convection may initially struggle to evolve
along the dry line as some inhibition should linger beyond sunset.
However, large-scale height falls will influence this region by late
evening and profiles will adjust. Thunderstorms are expected to
develop shortly thereafter with initial activity being supercellular
in nature. With time, upscale growth may lead to an MCS-type cluster
that should track northeast across the southern Plains. Very large
hail is possible with the early development, but a transition to
more wind could occur late. Additionally, some tornado risk will
continue overnight despite lifted parcels likely becoming somewhat
elevated.
..Darrow/Weinman.. 04/25/2024
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SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
0100 AM CDT Thu Apr 25 2024
Valid 261200Z - 271200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR PARTS OF
EASTERN NE...NORTHEAST KS...WESTERN IA...NORTHWEST MO...
...SUMMARY...
An active severe weather day appears possible on Friday from parts
of Nebraska and Iowa southward into parts of the southern Great
Plains and Ozarks. A few tornadoes (possibly strong), large to very
large hail, and damaging winds will all be possible.
...Synopsis...
A negatively tilted mid/upper-level shortwave trough and attendant
surface low are forecast to move northeastward toward the upper
Great Lakes from Friday into Friday night. A trailing Pacific
front/dryline will move eastward through the day across the
central/southern Plains, before retreating westward Friday night. A
warm front will move northward in advance of the surface low across
MO into parts of IA. Farther west, another deep mid/upper-level
trough will move eastward across the Southwest into the southern
Rockies.
...Eastern NE/KS into western IA/MO...
Supercells capable of all severe hazards appear possible from
eastern NE/KS into western IA/MO, though coverage of the threat with
southward extent somewhat uncertain at this time.
In the wake of morning convection, at least a narrow zone of
moderate destabilization will be possible from parts of eastern NE
into western IA, between the northward-moving warm front and
approaching Pacific front/dryline. Scattered thunderstorm
development is expected during the afternoon, with favorably veering
low-level wind profiles and moderate deep-layer shear supporting
supercell potential. Steep midlevel lapse rates will support a hail
threat, with some potential for very large hail depending on the
magnitude of destabilization. A few tornadoes will also be possible,
both in the vicinity of the surface low, and with any longer-lived
supercells along the dryline into southeast NE/southwest IA.
Farther south, a broader and potentially more unstable warm sector
is expected to evolve across eastern KS into western MO. While
large-scale ascent will be weaker with southward extent, at least
isolated supercell development will be possible along the dryline by
late afternoon. Any sustained supercells within this regime would
pose a threat for tornadoes and very large hail. A strong tornado or
will be possible if stronger pre-convective destabilization can
materialize.
...Eastern OK/northeast TX into AR/southern MO...
Initially strong storm clusters are expected to move across eastern
OK and potentially northeast TX into AR and MO through the morning,
accompanied by at least an isolated hail and damaging gust threat.
Some of this convection may persist or tend to regenerate along the
eastern periphery of the primary instability axis. The eastern
extent of any severe threat remains uncertain, but favorable
low-level and deep-layer shear could support occasionally organized
convection, with an isolated/marginal threat for all severe hazards.
Farther west, moderate to strong instability and deep-layer shear
will support a conditionally favorable environment along the dryline
from eastern OK into northeast TX. In the wake of the departing
shortwave trough, development along the dryline in this area will
likely be very isolated, though any sustained cells would pose a
threat for very large hail and possibly a tornado.
...Edwards Plateau into the Permian Basin vicinity of TX...
As the dryline retreats late Friday night, convection could develop
prior to the end of the period into parts of southwest TX, in
advance of the approaching southwestern trough. Instability and
shear would be sufficient for organized convection, though timing
and coverage of any threat in this area remain too uncertain at this
time for probabilities.
..Dean.. 04/25/2024
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