Day 4-8 Severe Weather Outlook Issued on Sep 24, 2023
Updated: Sun Sep 24 08:49:02 UTC 2023
Day 4 Risk
Area (sq. mi.)
Area Pop.
Some Larger Population Centers in Risk Area
No Risk Areas Forecast
Day 5 Risk
Area (sq. mi.)
Area Pop.
Some Larger Population Centers in Risk Area
No Risk Areas Forecast
Day 6 Risk
Area (sq. mi.)
Area Pop.
Some Larger Population Centers in Risk Area
No Risk Areas Forecast
Day 7 Risk
Area (sq. mi.)
Area Pop.
Some Larger Population Centers in Risk Area
No Risk Areas Forecast
Day 8 Risk
Area (sq. mi.)
Area Pop.
Some Larger Population Centers in Risk Area
No Risk Areas Forecast
D4
Wed, Sep 27, 2023 - Thu, Sep 28, 2023
D7
Sat, Sep 30, 2023 - Sun, Oct 01, 2023
D5
Thu, Sep 28, 2023 - Fri, Sep 29, 2023
D8
Sun, Oct 01, 2023 - Mon, Oct 02, 2023
D6
Fri, Sep 29, 2023 - Sat, Sep 30, 2023
(All days are valid from 12 UTC - 12 UTC the following day)
Note: A severe weather area depicted in the Day 4-8 period indicates 15%, 30% or higher probability for severe thunderstorms within 25 miles of any point.
PREDICTABILITY TOO LOW is used to indicate severe storms may be possible based on some model scenarios. However, the location or occurrence of severe storms are in doubt due to: 1) large differences in the deterministic model solutions, 2) large spread in the ensemble guidance, and/or 3) minimal run-to-run continuity.
POTENTIAL TOO LOW means the threat for a regional area of organized severe storms appears unlikely (i.e., less than 15%) for the forecast day.
Forecast Discussion
ZCZC SPCSWOD48 ALL
ACUS48 KWNS 240847
SPC AC 240847
Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0347 AM CDT Sun Sep 24 2023
Valid 271200Z - 021200Z
...DISCUSSION...
...Wednesday/Day 4 to Friday/Day 6...
From Wednesday to Friday, an upper-level low is forecast to move
northeastward across the Great Lakes region, as an upper-level ridge
moves through the north-central U.S. At the surface, high pressure
will likely remain in place across the eastern third of the nation.
Weak instability is forecast to develop along and near an
upper-level trough in the Ohio and Tennessee Valleys on Wednesday
and Thursday, where scattered thunderstorm development will be
possible.
Further west, across the northern Plains, southwest mid-level flow
is forecast to develop on Thursday and Friday. In response,
low-level moisture will likely return northward into the northern
Plains, where a pocket of moderate instability could potentially
develop by Friday afternoon. Isolated to scattered thunderstorms,
along with a marginal severe threat, would be possible Friday or
Friday night as destabilization occurs and low-level flow increases.
...Saturday/Day 7 and Sunday/Day 8...
From Saturday into Sunday, an upper-level trough is forecast to move
into the western U.S. as mid-level flow becomes more
south-southwesterly across the north-central U.S. Model forecasts
suggest that a pocket of moderate instability will be in place
across the Dakotas on Saturday, and to a lesser extent on Sunday as
well. Although large-scale ascent will probably be weak across the
region over the weekend, isolated to scattered thunderstorms could
still develop, especially if a boundary moves through the region, as
is suggested by some solutions. A severe threat would be possible,
especially on Saturday afternoon and evening when instability is
forecast to be maximized. At this time, predictability is low
concerning any potential scenario.
..Broyles.. 09/24/2023
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