Day 4-8 Severe Weather Outlook Issued on Oct 7, 2020
Updated: Wed Oct 7 08:32:02 UTC 2020
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
Sat, Oct 10, 2020 - Sun, Oct 11, 2020
D7
Tue, Oct 13, 2020 - Wed, Oct 14, 2020
D5
Sun, Oct 11, 2020 - Mon, Oct 12, 2020
D8
Wed, Oct 14, 2020 - Thu, Oct 15, 2020
D6
Mon, Oct 12, 2020 - Tue, Oct 13, 2020
(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 070830
SPC AC 070830
Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0330 AM CDT Wed Oct 07 2020
Valid 101200Z - 151200Z
...DISCUSSION...
Medium-range guidance continues to indicate considerable
amplification within the westerlies across the mid-latitude Pacific
into North America this weekend into early next week. However,
there has been considerable spread within the output concerning the
short wave developments. This persists and appears to increase,
particularly through the early to middle portion of next week in the
latest model runs.
The pattern still appears likely to include the evolution of
large-scale mid-level troughing inland of the Pacific coast, through
the Canadian Prairies and U.S. Great Plains by Sunday. This
probably will be accompanied by deepening surface troughing to the
lee of the Rockies, and embedded surface cyclogenesis Sunday through
Sunday night, which may provide the focus for the most appreciable
severe weather potential during this period. Where forcing for
ascent may be most conducive, across the northern Great Plains, the
extent of this potential remains unclear due to uncertain low-level
moisture return, in the wake of inland migrating Hurricane Delta.
The remnants of Delta might still pose some risk for severe weather
east of the lower Mississippi Valley on Saturday, but
weak/negligible boundary-layer instability will probably remain a
mitigating factor, particularly as low-level wind fields and shear
weaken.
Otherwise, elsewhere through the remainder of the period, low
pattern predictability is a major issue, but guidance, in general,
appears to suggest that any severe weather potential may remain
relatively minor.
..Kerr.. 10/07/2020
CLICK TO GET WUUS48 PTSD48 PRODUCT
weather.gov 
@NWSSPC
