Day 4-8 Severe Weather Outlook Issued on May 27, 2020
Updated: Wed May 27 08:42:03 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 30, 2020 - Sun, May 31, 2020
D7
Tue, Jun 02, 2020 - Wed, Jun 03, 2020
D5
Sun, May 31, 2020 - Mon, Jun 01, 2020
D8
Wed, Jun 03, 2020 - Thu, Jun 04, 2020
D6
Mon, Jun 01, 2020 - Tue, Jun 02, 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 270839
SPC AC 270839
Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0339 AM CDT Wed May 27 2020
Valid 301200Z - 041200Z
...DISCUSSION...
Medium-range guidance is in good agreement that an upper cyclone
will move through northern CA and into the Pacific Northwest on
D4/Saturday. At the same time, upper ridging downstream of the
cyclone will amplify as it shifts eastward into the High Plains.
Some isolated severe is possible in the vicinity of the upper
cyclone across the Pacific Northwest as well as from over the
northern Rockies/northern High Plains. Across the northern
Rockies/northern High Plains, low-level moisture advection will
occur amidst gradually increasing mid-level moisture ahead of the
upper cyclone, resulting in a moist and moderately buoyant air mass.
Background ridging and the lack of appreciable forcing for ascent
results in uncertain storm coverage. Conditionality of the overall
severe potential precludes outlooking any areas with this forecast.
Previously mentioned upper cyclone is forecast to continue
northeastward into the Canadian Prairie Provinces on D5/Sunday and
then eastward through those provinces on D6/Monday. Forecast
guidance begins to diverge on D6/Monday, but most model solutions
still signal favorable low-level moisture across the north-central
CONUS near an active northern-stream. Consequently, some severe
threat may materialize, but variability within the guidance results
in low predictability.
..Mosier.. 05/27/2020
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