(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 250844
SPC AC 250844
Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0344 AM CDT Sat Jun 25 2022
Valid 281200Z - 031200Z
...DISCUSSION...
Perhaps most notable during this period, models indicate that a deep
mid-level low, emerging from the northeastern Canadian Arctic
latitudes, will gradually turn southeastward and eastward across the
Hudson Bay vicinity. As this occurs, it appears that mid-level flow
will trend broadly cyclonic across the Upper Midwest/upper Great
Lakes region through the Northeast late next week through the
weekend, in the wake of low amplitude ridging building across the
region by mid week. Otherwise, a general split flow regime may
linger upstream, around persistent mid-level ridging across the
western Canadian Provinces and mid-level troughing to the south,
generally offshore of the U.S. Pacific coast. At the same time,
mid-level ridging may be maintained across much of the central and
southern tier of the U.S., near and east of the Rockies.
In association with this regime, it appears that a plume of warm and
capping elevated mixed-layer air will advect east of the northern
Rockies toward the Upper Midwest during the early to middle portion
of next week, before becoming cut off and suppressed. This likely
will precede the remnants of an initially vigorous short wave
impulse migrating inland of the Pacific Northwest coast, before
weakening within a confluent regime across the Canadian/northern
U.S. Rockies. Still, models suggest that this impulse might be
accompanied by weak to modest cyclogenesis across the southern
Canadian Prairies and adjacent northern U.S. Great Plains, which
seems to offer the best potential for organized thunderstorm
development (in terms of shear and forcing for ascent) during this
period. At this point, the extent of destabilization and degree of
inhibition remain unclear, as low-level moisture return from the
lower latitudes might remain rather modest.
..Kerr.. 06/25/2022
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