SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0253 PM CDT Sun May 25 2025
Valid 252000Z - 261200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE SOUTHERN PLAINS AND MID-SOUTH/TENNESSEE VALLEY...
...SUMMARY...
Severe thunderstorms, including the risk for very large hail, swaths
of severe winds with isolated 75+ mph gusts, and a few tornadoes,
are expected across parts of the southern Plains this afternoon and
evening, including northwest Texas and southern/central Oklahoma.
Scattered severe thunderstorms with large hail and damaging winds
will also be a concern across the Mid-South, Tennessee Valley, and
other parts of the Southeast.
...20Z Update...
Minimal changes were made to the ongoing forecast based on recent
high-resolution guidance. The prior forecast reasoning otherwise
remains valid. See the previous discussion for additional details.
..Wendt.. 05/25/2025
.PREV DISCUSSION... /ISSUED 1143 AM CDT Sun May 25 2025/
...Arkansas/Mid-South to Tennessee Valley/Southeast...
A rather complex scenario exists regionally owing to yesterday's MCS
and its impacts in addition to renewed MCS development overnight
across the Ozarks. That said, air mass recovery and boundary layer
destabilization is well underway along the
west/northwest-east/southeast-oriented outflow-reinforced baroclinic
zone across the region. Multi-MCV-related enhancement to the flow
field is also evident across the Ozarks, and this should translate
downstream (east-southeasterly) toward the Mid-South and eventually
Tennessee Valley.
This scenario appears favorable for one or more well-organized
east/southeastward-moving clusters/bowing line segments to evolve
later this afternoon into evening. Damaging winds can be expected,
with occasional large hail as well. Portions of the region have been
upgraded to an Enhanced Risk for this potential.
...Southern High Plains to Oklahoma/North Texas/ArkLaTex...
A low-amplitude mid-level shortwave trough over northern Mexico this
morning will move northeastward across the southern High Plains by
this afternoon/evening. Ahead of this feature, ample daytime heating
will likely aid in the development of moderate to strong instability
by mid afternoon amid a moist low-level airmass. A surface front
will extend from eastern New Mexico across northwest Texas and the
southern Texas Panhandle into parts of western/central Oklahoma,
with a dryline extending southward from the front across west Texas.
Both of these surface boundaries will likely prove instrumental, in
combination with modest large-scale ascent associated with the
shortwave trough, to focus intense thunderstorm development later
today. While mid/upper-level winds are not expected to be overly
strong, veering and gradual strengthening with height should support
around 30-45 kt of deep-layer shear. Stronger shear is forecast near
the front. Convective temperatures will likely be reached by 20-22Z,
and explosive thunderstorm development is expected in this time
frame across west/northwest Texas along the front and dryline.
A mix of supercells and clusters will likely form and spread
east-northeastward through the late afternoon and early evening.
Very large hail (2-3 inches in diameter) will be possible with any
initial supercells given favorably steep mid-level lapse rates and
relatively long/straight hodographs at mid/upper levels. By early
evening, consolidation into a bowing complex appears likely across
northwest Texas and southern Oklahoma. An increasing threat for
scattered to numerous severe winds will exist with this cluster as
it develops generally east-southeastward ward into western north
Texas and southern Oklahoma through the evening.
Given steepened low-level lapse rates and the presence of strong to
locally extreme instability, some wind gusts of 75+ mph appear
possible with the bowing cluster. The potential for supercells to
develop separately farther east along the front in western/central
Oklahoma still remains unclear. If thunderstorms can form here, they
would likely become severe quickly, and pose a threat for very large
hail. Some risk for a few tornadoes may also exist this evening,
either embedded with the bow or with semi-discrete supercells, as a
southerly low-level jet and related 0-1 km SRH gradually
strengthens. A continued threat for severe/damaging winds may
continue into the overnight hours across north Texas.
...Eastern New Mexico...
A somewhat separate area of at least isolated supercell potential is
evident across northeast to east-central New Mexico this afternoon
in a modest low-level upslope flow regime along and north of the
front. Large hail should be the main threat with this activity. The
eastward extent of the severe threat will likely be confined by
weaker instability into the Oklahoma Panhandle and northern Texas
Panhandle.
...Colorado Front Range...
As clouds abate/thin, a relatively isolated/focused severe threat
will again exist near the foothills/urban corridor of east-central
Colorado later this afternoon.
...Florida...
Compared to the prior couple of days, mid/upper-level winds appear
somewhat weaker across the Florida Peninsula today, while mid-level
temperatures are also slightly warmer per regionally observed 12Z
soundings. Even so, another day of scattered thunderstorm
development is anticipated over much of the Florida Peninsula, with
various sea breezes acting as foci for initiation. Moderate
instability coupled with modest deep-layer shear may still support
an isolated threat for marginally severe hail and gusty winds with
the stronger cores that can develop this afternoon.
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