SPC Aug 21, 2024 Day 4-8 Severe Weather Outlook
SPC Aug 21, 2024 Day 4-8 Severe Weather Outlook
[html]Day 4-8 Outlook
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Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0355 AM CDT Wed Aug 21 2024
Valid 241200Z - 291200Z
...DISCUSSION...
...Saturday/Day 4 to Monday/Day 6...
Heights within an upper-level ridge are forecast to rise across the
central and northern U.S over the weekend, as an upper-level trough
moves across the western U.S. Isolated severe-thunderstorm
development will be possible across the Dakotas in the afternoon and
evening both Saturday and Sunday. The best chance for severe storms
would be on Sunday as large-scale ascent and deep-layer shear both
increase across the northern Plains due to the approach of the
trough.
The severe threat is forecast to shift eastward into the upper
Mississippi Valley on Monday, as the upper-level trough and its
associated cold front advance eastward from the northern Plains into
the upper Mississippi Valley.
...Tuesday/Day 7 and Wednesday/Day 8...
On Tuesday and Wednesday, the upper-level trough is forecast to
deamplify as it moves through the Great Lakes region. Another
upper-level trough is forecast to move through the western U.S on
Tuesday and Wednesday. The best chance for severe storm development
would be on Wednesday afternoon along an instability axis, most
likely in either eastern parts of the northern Plains or in the
upper Mississippi Valley. At this range, large model spread
concerning the timing of the trough and distribution of instability
suggests uncertainty is substantial.
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Source: SPC Aug 21, 2024 Day 4-8 Severe Weather Outlook (http://ht**://www.spc.noaa.gov/products/exper/day4-8/)