Day 4-8 Severe Weather Outlook Issued on Aug 19, 2020
Updated: Wed Aug 19 08:44:02 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, Aug 22, 2020 - Sun, Aug 23, 2020
D7
Tue, Aug 25, 2020 - Wed, Aug 26, 2020
D5
Sun, Aug 23, 2020 - Mon, Aug 24, 2020
D8
Wed, Aug 26, 2020 - Thu, Aug 27, 2020
D6
Mon, Aug 24, 2020 - Tue, Aug 25, 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 190842
SPC AC 190842
Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0342 AM CDT Wed Aug 19 2020
Valid 221200Z - 271200Z
...DISCUSSION...
Broadly speaking, recent runs of the medium-range models are
exhibiting reasonable large-scale model-to-model similarity. In
general, a gradual trend toward very weak flow over the southern
two-thirds of the country, and zonal/westerly flow over the northern
third, is depicted. Overall, substantial severe weather potential
appears unlikely through the first half of the period.
Severe risk may increase somewhat late in the period, when models
hint that one or two stronger short-wave troughs may progress
eastward across the northern U.S. within the faster belt of
westerlies. The broad area of greater risk would appear to extend
from the northern Plains across parts of the Midwest and Great
Lakes, in the days 7-8 time frame (Tuesday and Wednesday, August 25
and 26). With that said however, differences in timing and
amplitude of this feature preclude sufficient confidence to
highlight any more specific risk areas at this time.
..Goss.. 08/19/2020
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