Day 4-8 Severe Weather Outlook Issued on May 13, 2020
Updated: Wed May 13 08:37:02 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, May 16, 2020 - Sun, May 17, 2020
D7
Tue, May 19, 2020 - Wed, May 20, 2020
D5
Sun, May 17, 2020 - Mon, May 18, 2020
D8
Wed, May 20, 2020 - Thu, May 21, 2020
D6
Mon, May 18, 2020 - Tue, May 19, 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 130835
SPC AC 130835
Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0335 AM CDT Wed May 13 2020
Valid 161200Z - 211200Z
...DISCUSSION...
Medium-range guidance is in good agreement that convective feedback
allows the shortwave trough over TX early D4/Saturday to develop
into a closed upper low. This low is then forecast to become
displaced from the stronger westerlies and drift over the southern
Plains toward the Lower MS Valley through early next week.
The northern stream will be more active, with a shortwave trough
expected to move across the northern Plains on D4/Saturday and the
Upper Midwest and Upper Great Lakes on D5/Sunday before maturing
into a mid-latitude cyclone over the Northeast/Mid-Atlantic on
D6/Monday. Strong upper ridging is anticipated across the central
CONUS in the wake of this system, while upper troughing deepens over
the western CONUS at the same time. The resulting omega block
pattern will gradually drift eastward from D6/Monday though
D8/Wednesday.
Some isolated severe is possible near the southern Plains upper low
this weekend as well as near the lead northern-stream shortwave
trough as it moves through the Upper Great Lakes on D4/Saturday and
Northeast/Mid-Atlantic on D5/Sunday. In all, a low-predictability
severe pattern is anticipated throughout the period.
..Mosier.. 05/13/2020
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