RSS Mesoscale Discussions from Storm Prediction Center
SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0254 PM CDT Wed Apr 23 2025
Valid 232000Z - 241200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE SOUTHERN/CENTRAL PLAINS...
...SUMMARY...
Scattered strong to severe thunderstorms are forecast over parts of
the southern/central Plains today and tonight, with large hail and
damaging winds possible.
...20z Update...
The previous forecast generally remains on track with only minor
adjustments needed. A slight westward expansion of 5% hail/wind
probabilities across southeast CO where convective initiation is
underway along the Raton Mesa upstream of a moist/unstable
environment. A significant hail area has also been introduced for
portions of western KS where backed low-level flow within a
moderately unstable environment (MLCAPE around 2000 J/kg) should
promote robust supercells with an attendant large/very large hail
threat. Consideration was given to introducing significant hail/wind
areas across parts of southwest TX; however, recent ACARS and RAP
forecast soundings show somewhat weaker mid-level winds (15-20
knots) compared to yesterday when significant hail/wind occurred in
a similar thermodynamic environment. This, combined with the
potential for more limited convective coverage, limits confidence in
a sufficiently widespread significant hail/wind threat to warrant
additional probabilities. See the previous discussion and recently
issued MCDs #527 and #528 for additional details.
..Moore.. 04/23/2025
.PREV DISCUSSION... /ISSUED 1128 AM CDT Wed Apr 23 2025/
...Central and Southern High Plains...
Modest zonal flow pattern persists across the Plains states today,
with only weak large scale forcing anticipated. However, strong
heating across the High Plains, coupled with circulations along a
diffuse dryline and forcing associated with the nocturnal low-level
jet will aid in the development of scattered thunderstorms from
western KS into the TX Panhandle this afternoon and evening.
The area of greatest concentration of storms will likely be over
western KS, where model guidance shows greatest confidence in a
strengthening low-level jet and some upper support. Storms should
develop by late afternoon, with forecast soundings showing
sufficient deep-layer shear for supercell structures. Large hail
will be the main concern. Low-level moisture will be marginal, but
enlarging hodographs by early evening could also support a risk of a
few tornadoes.
Farther south, thunderstorm coverage will be more widely scattered
across the TX Panhandle into the Big Bend region. Nevertheless,
steep mid-level lapse rates and sufficient westerly flow aloft will
pose a risk of a few supercells capable of large hail and damaging
winds through the evening.
...Northeast KS...
A small cluster of strong storms has developed this morning over
central KS. Several morning CAM solutions suggest an increasing
risk of thunderstorm development/intensification by mid-afternoon
over northeast KS - in vicinity of a weak surface boundary. While
this scenario is unclear, a few of these storms could pose a risk of
large hail and gusty/damaging winds.
...Southeast States...
Strong daytime heating will aid in destabilization across much of
GA/SC this afternoon, with scattered thunderstorm development
expected. Winds aloft are weak and storms should be relatively
disorganized. However, cool temperatures aloft will aid in a few
robust updrafts - posing some risk of hail and gusty winds.
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SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0221 PM CDT Wed Apr 23 2025
Valid 251200Z - 261200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS
OF THE OKLAHOMA AND WESTERN TEXAS AREA...
...SUMMARY...
Isolated severe thunderstorms are possible across parts of Oklahoma
and northwest Texas Friday afternoon and evening.
...Synopsis...
An upper trough sweeping across Hudson Bay/Ontario/the Upper Great
Lakes region Friday will drive deepening of a surface low initially
over the southern Wisconsin vicinity. As it deepens, the low is
forecast to shift east-northeastward across the Upper Great Lakes
through the Day, and then across southern Ontario and into Quebec
overnight. As this occurs, a surface cold front will shift
southeastward across the Ohio Valley region, and more slowly
southward across Oklahoma and the Ozarks region.
Meanwhile in the West, an upper low over the eastern Pacific is
forecast to deepen and shift southeastward toward the vicinity of
the central California Coast overnight. As this occurs, downstream
ridging will evolve/amplify across the central U.S. through the
period.
...Southern Plains...
Convection appears likely to be ongoing at the start of the period
across the Oklahoma vicinity, in the vicinity of the sagging cold
front. Despite increased ridging aloft, rather weak warm-sector
capping will likely support at least isolated storm redevelopment,
both near the front as it shifts southward across Oklahoma and the
Texas Panhandle/South Plains through the day, and near any remnant
outflows from earlier/potentially ongoing convection. The
combination of moderate instability and somewhat modest shear
suggests only isolated severe risk -- mainly in the form of hail and
locally gusty/damaging winds. Low-level jet development expected
during the evening over the High Plains may help sustain convection
through the overnight hours.
...Elsewhere...
Scattered thunderstorms -- and perhaps a couple of stronger storms
capable of producing gusty winds and small hail -- are expected
across parts of the Great Lakes/Midwest/Mid South region, near and
ahead of the aforementioned/advancing cold front. Modest CAPE is
expected across the area, and with rather weak shear as well, any
severe risk would likely remain quite limited/local.
..Goss.. 04/23/2025
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