ACUS02 KWNS 191719
SWODY2
SPC AC 191718

Day 2 Convective Outlook  
NWS Storm Prediction Center Norman OK
1218 PM CDT Tue May 19 2026

Valid 201200Z - 211200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF
SOUTHWEST TEXAS...

...SUMMARY...
Isolated to widely scattered severe storms are expected Wednesday
afternoon into night across portions of southwest Texas into eastern
New Mexico. Large hail --potentially in excess of two inches-- will
be the predominant severe-weather hazard. Isolated occurrences of
severe wind and/or marginally severe hail are expected Wednesday
afternoon into early evening from the Cumberland Plateau into
Mid-Atlantic and southern New England.

...Synopsis...

A low-amplitude short-wave trough will move through the base of an
eastern Canada trough, with a belt of strong mid/upper-level winds
overspreading New England. Elsewhere, a short-wave trough initially
near the Four Corners will weaken Wednesday while moving into
confluent flow over the central High Plains. There is some model
signal for a lower-latitude impulse to move through northern Mexico
into NM and western TX Wednesday afternoon and evening.

In the low levels, a cold front will move south through New England
and the Mid-Atlantic with the western extension of the boundary
weakening through the forecast period across TX.


...Eastern New Mexico into southwest Texas and the Edwards
Plateau...

Boundary-layer dewpoints in the mid 50s to low 60s will combine with
steep mid-level lapse rates to yield a moderately unstable air mass
by afternoon with MLCAPE increasing to 1500-2000 J/kg across
portions of southwest TX into the Edwards Plateau. Instability is
expected to decrease with northward extent in the immediate lee of
the Guadalupe, Sacramento, and Sangre De Cristo mountains, due to
limited boundary-layer moisture content.  

Isolated to widely scattered thunderstorm development is anticipated
by mid/late afternoon along favored terrain, with initiation
potentially being aided by the mid-level disturbance mentioned in
the synopsis. A slight enhancement of the mid-level flow is forecast
across the area in association with the disturbance, which will
contribute to 35-45 kt of effective bulk shear across the
instability axis. As such, supercell storm modes appear likely,
especially across southwest TX where the strongest instability is
expected to reside. Large hail potentially in excess of 2" will be
the predominant hazard with the afternoon and early evening storms.
A number of the 12z models suggest that the daytime storms will grow
upscale into an MCS across portions of the Permian Basin and Concho
Valley into Edwards Plateau Wednesday evening into night with a risk
for locally damaging wind gusts and large hail. 

Given the above considerations, a level 2/Slight Risk has been added
where confidence is highest in longer-lived supercell potential. 


...Cumberland Plateau into Mid-Atlantic and southern New England...

A hot and a moist air mass is forecast to develop ahead of the front
Wednesday afternoon with MLCAPE increasing to 1000-2000 J/kg with
minimal capping. Convergence along the front along with terrain
influences are expected to foster a gradual increase in thunderstorm
coverage and intensity Wednesday afternoon from northern parts of
the Cumberland Plateau into the Mid-Atlantic and southern New
England. The strongest vertical shear is expected to reside to the
north of the surface warm sector, which coupled with poor mid-level
lapse rates, should limit the potential for organized storm modes.
Nonetheless, model soundings indicate the presence of 1.0-1.5 km
deep, well-mixed boundary-layers, which will be supportive of
locally damaging downburst winds through the afternoon into early
evening. Isolated occurrences of marginally severe hail are also
possible.

..Mead.. 05/19/2026

$$