...DISCUSSION...
...Friday/Day 4 to Sunday/Day 6...
An upper-level trough will move eastward from the eastern Pacific on
Friday into the western U.S. on Saturday, as southwest mid-level
flow gradually strengthens over the south-central states. In
response, low-level moisture advection will continue over the Great
Plains. Ahead of the western U.S. trough, a subtle shortwave trough
is forecast to move into the southern High Plains Saturday
afternoon. A severe threat will be possible ahead of and near the
trough during the afternoon and evening.
On Sunday, the western U.S. upper-level trough is forecast to move
quickly east-northeastward into the southern Rockies. Ahead of the
trough, a moist and moderately unstable airmass is forecast over
much of the southern and central Plains by afternoon. Scattered
thunderstorms appear likely to develop over much of this airmass
during the afternoon and evening. Moderate to strong deep-layer
shear appear likely to be in place, which will be favorable for
severe storms. Supercells with large hail, severe wind gusts and a
tornado threat will be possible. An isolated severe threat may also
develop in parts of the north-central U.S.
...Monday/Day 7 and Tuesday/Day 8...
A secondary upper-level trough is forecast to move into the Desert
Southwest on Monday. Ahead of this system, a moist and unstable
airmass is forecast to remain in place from the southern Plains
north-northeastward into the Upper Midwest. Although a severe threat
will be possible along much of the instability corridor, the
greatest threat is expected to develop in the southern Plains, where
model forecasts show the most favorable environment.
On Tuesday, model forecasts have some agreement concerning the
timing of the trough, which is forecast to eject northeastward
across the southern and central Plains. Ahead of the trough, there
is large variance among the models concerning the distribution of
instability. If a moderately unstable airmass is in place by Tuesday
afternoon ahead of the ejecting system, a severe threat will be
likely from the southern Plains into the mid to upper Mississippi
Valley. However, the system will probably be slower than forecast,
which adds considerable uncertainty this late in the period.
..Broyles.. 04/07/2026
