(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 190758
SPC AC 190758
Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0258 AM CDT Tue Oct 19 2021
Valid 221200Z - 271200Z
...DISCUSSION...
Model consensus is that a low-amplitude omega blocking pattern with
low severe potential will evolve during the first half of the day
4-8 period. There is agreement among some model solutions including
the ECMWF that a substantial upper trough will move into the Plains
by day 7 or 8, preceded by sufficient moisture return for a severe
weather threat. However, predictability is too low at this time to
introduce a categorical risk area.
..Dial.. 10/19/2021
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