SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1247 AM CDT Sat Jun 07 2025
Valid 071200Z - 081200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS TODAY INTO
TONIGHT ACROSS PARTS OF EASTERN OKLAHOMA...CENTRAL
ARKANSAS...SOUTHERN TENNESSEE...NORTHERN MISSISSIPPI...NORTHERN
ALABAMA...NORTHERN GEORGIA...AND AN ADJACENT PORTION OF WESTERN
NORTH CAROLINA...
...SUMMARY...
One or more organized clusters of thunderstorms may evolve and
overspread a corridor from the southeastern Great Plains through
parts of the Tennessee Valley and northern Gulf Coast states today
into tonight, potentially producing swaths of damaging wind gusts.
...Discussion...
Models indicate that the westerlies emanating from the northern
mid-latitude Pacific will amplify inland of the British Columbia and
Pacific Northwest coast during this period. This is likely to
include building mid-level ridging pivoting from a negative to
positive tilt while shifting inland across the Canadian Rockies,
ahead of inland progressing upstream troughing. Downstream, a
notable mid-level trough is forecast to dig southeast of the
Canadian Prairies toward the northern Great Plains and Upper Midwest
vicinity, accompanied by a developing cyclone and a couple of
reinforcing cool surges, as far southeast as the Upper Midwest
through central Great Plains by 12Z Sunday.
As this occurs, models indicate that more modest mid-level
troughing, now digging to the southeast of the Front Range, will
accelerate eastward through the middle Mississippi and Ohio Valleys
today through tonight. It appears that this will contribute to
amplifying cyclonic flow as far south as the Gulf Coast states,
where subtropical ridging will become suppressed. In lower-levels,
a diffuse frontal zone extending from the southern Mid Atlantic into
south central Great Plains will tend to shift southward as well,
probably becoming reinforced or preceded by increasingly extensive
convective outflow.
...Southeastern Great Plains into Southeast...
Forcing for ascent downstream of the mid-level troughing digging to
the lee of the Front Range is contributing to increasing vigorous
thunderstorm development along the frontal zone across the south
central Great Plains. It appears that low-level updraft inflow of
seasonably moist air characterized by moderate to large CAPE, in the
presence of modestly steep lapse rates, will maintain activity
eastward across northern/central Oklahoma through daybreak. In the
presence of strong deep-layer shear, beneath a prominent westerly
mid/upper jet, further organization and consolidation appears
probable, accompanied by increasing strong to severe surface gusts.
It seems probable that this will continue beyond daybreak across
central Arkansas, where/when daytime heating of a seasonably moist
boundary-layer ahead of the convection may contribute to its
maintenance and perhaps re-intensification. Based on latest model
output, it remains unclear whether the coupling of forcing for
ascent and destabilization will maintain activity as far east as
areas near/south of the southern Appalachians, or whether initial
activity will eventually weaken, with renewed development eventually
occurring upstream along its trailing outflow, aided by low-level
warm advection. Regardless, there appears potential for one or more
organizing clusters to produce swaths of strong to severe surface
gusts.
...Southern Great Plains...
Moderate to strong potential instability is likely to again develop
with daytime heating along a remnant baroclinic zone to the lee of
the southern Rockies into Red River vicinity, and an evolving
dryline to its south, across west Texas. It is possible severe
probabilities may need to be increased, once uncertainties due to
mid-level inhibition and lack of more prominent forcing for ascent
clear.
...Northern Great Plains...
It still appears that destabilization ahead of the southeastward
advancing cold front will remain rather modest, but forcing for
ascent and shear ahead of the vigorous digging mid-level trough may
contribute to a couple of strong storms potentially capable of
producing marginally severe hail and wind.
..Kerr/Squitieri.. 06/07/2025
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