(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 090849
SPC AC 090849
Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0349 AM CDT Fri Jun 09 2023
Valid 121200Z - 171200Z
...DISCUSSION...
Particularly in the northern mid-latitudes, models suggest that
mid/upper flow may remain more progressive across the Pacific into
western North America than east of the Mississippi Valley into the
Atlantic during this period. Within the latter regime, it appears
that a couple of significant quasi-stationary to slow moving
mid-level lows will be maintained, including only a gradual
redevelopment of the trailing low east-northeast of the Great Lakes
through the coming work week.
Farther west, a weakening mid-level low over the southern Great
Basin at the outset of the period is forecast to continuing
weakening farther inland. However, models suggest that a lingering
belt of seasonably strong mid-level flow may propagate around the
crest of mean mid-level ridging across and east of the southern
Rockies, while flow strengthens similarly on the southern periphery
of mean mid-level troughing across the Southeast. Associated
strengthening of deep-layer shear along a quasi-stationary frontal
zone may become conducive to the evolution of organized
thunderstorm clusters on a daily basis. However, the location and
extent of any associated severe weather hazards likely will remain
largely governed by sub-synoptic/mesoscale developments with poor
predictability in the extended time frame.
..Kerr.. 06/09/2023
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