ACUS01 KWNS 231252
SPC AC 231250
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0750 AM CDT Tue Apr 23 2019
Valid 231300Z - 241200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS FAR
SOUTHEAST NM AND A LARGE PART OF SOUTHWEST INTO CENTRAL TEXAS...
Severe thunderstorms capable of producing isolated large hail and
severe gusts are expected across parts of southeast New Mexico and
Texas this afternoon and evening.
...Southern High Plains and vicinity...
An increasingly low-latitude upper low will continue to dig
southward over northwest Mexico through tonight. Scattered showers
and thunderstorms will continue early today along and north of a
southwest/northeast-oriented front located from southwest Texas into
south-central Oklahoma this morning. Partially aided by the
reinforcement of this convection/outflow, the front will continue a
general southward progression.
Marginally moist southeast low-level flow (surface dewpoints ranging
from the 50s west to 60s east) will contribute to moderate buoyancy
along/south of the front this afternoon, aided by elevated-mixed
layer reinforcement especially over far southeast New
Mexico/southwest Texas as mid-level winds intensify off the higher
terrain later today. After early morning cloud debris lessens,
surface-based storm development is expected by late afternoon
coincident with diurnal heating. Adequate effective shear for
storm-scale organization will support supercells and organized
clusters with the stronger updrafts. Large hail and severe gusts
appear to be the primary severe hazards, including some potential
for larger diameter hailstones especially across southwest Texas. A
gradual weakening in storm intensity is expected by mid-to late
evening as cold pool conglomeration and diminishing surface-based
instability spatially reduce the area for severe storms.
...Mid/upper Ohio Valley including Kentucky to Pennsylvania...
Narrowly spaced dual shortwave troughs over northern Ontario and
Lower Michigan early today will spread generally eastward as they
phase, influencing the region this afternoon and evening. Increasing
forcing for ascent coincident with peak heating will contribute to
increasing thunderstorm development through mid/late afternoon near
an eastward-progressing cold front. A belt of stronger mid- to
high-level flow will overspread mid/upper 50s F dewpoints and
contribute to weak buoyancy (500-100 J/kg MLCAPE) by afternoon near
and just ahead of the front. A few strong storms will be possible
and a few strong/locally damaging wind gusts and small hail could
accompany the stronger cells through early evening.