Severe Storm Outlook Narrative (AC)
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ACUS48 KWNS 220856
SWOD48
SPC AC 220855

Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0355 AM CDT Mon Apr 22 2024

Valid 251200Z - 301200Z

...DISCUSSION...
...Thursday/Day 4 and Friday/Day 5...
An upper-level ridge is forecast to move eastward away from the
Great Plains on Thursday, as an upper-level trough moves through the
Desert Southwest. Mid-level flow is forecast to become southwesterly
over the southern and central Plains on Thursday, as a dryline sets
up during the day. East of the dryline, moderate instability appears
likely by afternoon from parts of west Texas northward into western
Oklahoma and central Kansas. Isolated thunderstorm development will
be possible in some areas to the east of the dryline. Moderate
deep-layer shear is forecast across much of the southern and central
Plains, suggesting a few supercells with large hail and wind damage
may occur. An isolated tornado threat could also develop.

On Friday, the upper-level trough is forecast to move into the Great
Plains, with a mid-level jet moving over a moist and unstable
airmass. Scattered thunderstorms are expected to develop during the
afternoon from north-central/northeast Texas northward into the
lower to mid Missouri Valley. The trough is forecast to be
negatively tilted, and be associated with strong large-scale ascent
and moderate deep-layer shear. This will likely support scattered
strong to severe storms, with the greatest severe threat across
northeast Texas, eastern Oklahoma, eastern Kansas and western
Missouri. Large hail, wind damage and a few tornadoes will be
possible during the afternoon and evening.

...Saturday/Day 6 to Monday/Day 8...
On Saturday, an upper-level trough is forecast to move into the
southern and central Rockies. Ahead of this feature, moisture
advection is expected to replenish a moist airmass in the southern
and central Plains. As surface temperatures warm during the day,
thunderstorms are forecast to develop from parts of north Texas
northward into Oklahoma and southern Kansas. Moderate deep-layer
shear over an unstable airmass should support scattered strong to
severe storms. MCS development could occur across parts of the warm
sector Saturday evening.

From Sunday into Monday, the upper-level trough is forecast to move
from the Great Plains to the Mississippi Valley. A severe threat
could develop Sunday afternoon ahead of the system along and near a
moist axis from the Ark-La-Tex north-northeastward into the Ozarks.
The severe threat, associated with the trough, would be further east
on Monday. At this time, there is considerable spread among model
solutions, concerning the timing of the trough on Sunday and Monday.
A slower solution, which some models suggest could happen, would
result in a large spatial displacement from current model forecasts.
For this reason, predictability remains too low to add a severe
threat area on either day.

..Broyles.. 04/22/2024


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