381
ACUS02 KWNS 300503
SWODY2
SPC AC 300501

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1201 AM CDT Thu May 30 2024

Valid 311200Z - 011200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FRIDAY INTO FRIDAY
EVENING ACROSS PARTS OF SOUTHERN OKLAHOMA...MUCH OF CENTRAL/NORTHERN
AND EASTERN TEXAS...ADJACENT PORTIONS OF SOUTHWESTERN ARKANSAS AND
WESTERN LOUISIANA...

...SUMMARY...
One or two organized clusters of storms may evolve by Friday morning
into afternoon and pose a risk for severe wind and hail continuing
across parts of the southern Great Plains into lower Mississippi
Valley, Texas Gulf coast and Deep South Texas by Friday evening.
Additional strong to severe thunderstorm development is possible to
the east of the southern Rockies.

...Synopsis...
Downstream of a lower/mid-tropospheric cyclone forecast to elongate
eastward from the northern Canadian Prairies toward western Hudson
Bay, it appears that initially prominent mid-level ridging will
continue to become suppressed southeastward across Quebec and the
lower Great Lakes region.  Farther east, amplified mid-level
troughing may slowly shift east of the Atlantic Seaboard, but models
indicate that a seasonably dry/stable air mass will be maintained
across most areas east of the Mississippi Valley through this
period.  Another surge of cooler and drier air may continue to
slowly spread through the upper Mississippi Valley, mid Missouri
Valley and central Great Plains.

In the southern mid-latitudes, generally weak zonal flow will
prevail to the north of suppressed mid/upper ridging across the
subtropics.  Inland of the California/Baja coast into the lower
Mississippi Valley, it appears that this regime will include at
least a couple of embedded low-amplitude waves and perhaps one or
two convectively generated perturbations.

Seasonably high boundary-layer moisture content is forecast to
generally remain confined to the southern Great Plains into the
northwestern Gulf coast and lower Rio Grande vicinity, but modest
low-level moistening is possible ahead of the lead wave, across the
central Great Plains into middle Mississippi Valley by 12Z Sunday.
Beneath warm elevated mixed-layer air continuing to advect eastward
into the southern Great Plains, moderate to large CAPE may once
again develop across much of Texas, particularly to the east of the
South Plains.

...South Central U.S...
Latest model output is not much clearer concerning potential
convective evolution for Friday through Friday night.  A large
portion of the southern Great Plains vicinity may be impacted by
convection today through tonight, and it remains uncertain how much
of a stabilizing influence this may for Friday.

In general, models continue to suggest that a prominent
lower/mid-tropospheric mesoscale convective vortex may evolve and be
in the process of migrating eastward near/north of the Red River
Valley by 12Z Friday.  This may be preceded by weak low/mid-level
warm advection driven storms across parts of eastern Oklahoma into
the Ark-La-Tex vicinity, with renewed convective development also
occurring in a trailing warm advection regime across northwest
Texas.  Much more uncertain is the extent of associated convective
outflow and continuing convective development potentially surging
southward across north central/central and/or southeast Texas.

Convection allowing output is rather diverse.  Some model output
continues to suggest potential for the northwest Texas convection to
grow upscale and organize along the modifying trailing flank of the
initial convective outflow during the day.  There would seem to be
potential for this activity to acquire inflow of moist air
characterized by large CAPE as it propagates through south
central/possibly southeast Texas, but it also possible that warming
elevated mixed-layer air may prove inhibitive.

It is also possible that convection on the leading edge of the
initial forward propagating outflow could reintensify in a less
strongly capped, and destabilizing environment with heating, across
the mid/upper Texas and Louisiana coastal plain.  Destabilization
ahead of the initial MCV may also become sufficient to support
strong thunderstorm development as it migrates across eastern
Oklahoma into Arkansas during the day.

Regardless of the particular evolution, stronger storms will pose a
risk for severe wind and hail, given the conditional/potential
convective instability.  Deep-layer flow and shear will remain
modest, but upscale growing clusters may include evolving mesoscale
vortices accompanied strengthening rear inflow with potential to
produce sustained strong to severe surface gusts.

...Lee of Southern Rockies...
Downstream of a low-amplitude wave progressing into the Southwest,
moistening easterly upslope flow may become characterized by modest
CAPE in excess of 1000 J/jg by early Friday evening.  Although shear
may be modest as well, scattered thunderstorm development off the
Front Range and Sangre de Cristo Mountains could intensify while
spreading into the adjacent plains, and pose at least some risk for
severe hail and wind before weakening Friday evening.

..Kerr.. 05/30/2024

$$