Day 4-8 Severe Weather Outlook Issued on Aug 23, 2021
Updated: Mon Aug 23 08:13:03 UTC 2021
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
Thu, Aug 26, 2021 - Fri, Aug 27, 2021
D7
Sun, Aug 29, 2021 - Mon, Aug 30, 2021
D5
Fri, Aug 27, 2021 - Sat, Aug 28, 2021
D8
Mon, Aug 30, 2021 - Tue, Aug 31, 2021
D6
Sat, Aug 28, 2021 - Sun, Aug 29, 2021
(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 230811
SPC AC 230811
Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0311 AM CDT Mon Aug 23 2021
Valid 261200Z - 311200Z
...DISCUSSION...
Medium-range models remain in reasonable large-scale agreement
through early stages of the period, in depicting eastward
progression of a western U.S. trough into the north-central U.S.
The advance of the trough will likely be accompanied by at least
some severe potential -- over the northern Plains vicinity Day 4
(Thursday Aug. 26) and then eastward into the Upper Midwest vicinity
Day 5 (Friday Aug. 27). However, differences in the models at
smaller scales, and rounds of intervening convection from prior
days, complicate the scenario, resulting in decreased confidence
with respect to highlighting areas of greatest risk. Beyond Day 5,
increasing differences in the models -- even at larger scales,
suggest a further decrease in predictability with time. Therefore,
will not highlight any risk areas at this time.
..Goss.. 08/23/2021
CLICK TO GET WUUS48 PTSD48 PRODUCT
weather.gov 
@NWSSPC
