Day 4-8 Severe Weather Outlook Issued on Aug 27, 2021
Updated: Fri Aug 27 08:48:04 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
Mon, Aug 30, 2021 - Tue, Aug 31, 2021
D7
Thu, Sep 02, 2021 - Fri, Sep 03, 2021
D5
Tue, Aug 31, 2021 - Wed, Sep 01, 2021
D8
Fri, Sep 03, 2021 - Sat, Sep 04, 2021
D6
Wed, Sep 01, 2021 - Thu, Sep 02, 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 270846
SPC AC 270846
Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0346 AM CDT Fri Aug 27 2021
Valid 301200Z - 041200Z
...DISCUSSION...
Medium-range guidance suggests that upper ridging will persist
across the Southwest and into southern Plains into at least the
middle of next week. Tropical cyclone Ida is expected to make
landfall late Sunday/early Monday, before then recurving towards the
TN Valley Monday and Tuesday. Some tornado threat may accompany this
system, but uncertainty still remains high regarding the overall
evolution of this system and how buoyant the downstream environment
over the Southeast/TN Valley will be.
Farther north, guidance continues to indicate a belt of moderately
enhanced flow across the northern tier of the CONUS. A shortwave
trough may move from the Pacific Northeast across the northern
portions of the Intermountain West on Tuesday and northern Plains
Wednesday. Some severe threat could result as this wave ejects
eastward but uncertainty regarding air mass buoyancy as well as
general uncertainty regarding overall shortwave evolution limit
predictability.
..Mosier.. 08/27/2021
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