000
ACUS48 KWNS 070900
SWOD48
SPC AC 070858

Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0358 AM CDT Wed Jun 07 2023

Valid 101200Z - 151200Z

...DISCUSSION...
Medium-range guidance is in reasonably good agreement that a
low-amplitude shortwave trough will advance eastward from the
southern High Plains across much of OK/TX on Day 4/Saturday. A
surface dryline should mix eastward across these same areas through
the day. Mid 60s to low 70s surface dewpoints are generally forecast
ahead of the dryline. Daytime heating of this moist low-level
airmass, combined with steep mid-level lapse rates, should foster
the development of at least moderate instability by late Saturday
afternoon. Even though mid-level flow should not be overly strong,
sufficient deep-layer shear to support organized multicells and
perhaps some supercells should be present. Any thunderstorms that
can form along the dryline, or farther east in the warm sector
along/south of a developing warm front, should be capable of
producing large hail and severe wind gusts. Given greater confidence
in convection occurring, have introduced a 15% severe area for
Saturday across parts of OK/TX.

Some severe threat will probably exist on Day 5/Sunday along/south
of a front from portions of the southern Plains into the lower/mid
MS Valley and Southeast as an upper trough/low becomes established
over the Upper Midwest. However, confidence is low in the details of
robust thunderstorm evolution/placement due to the prior day`s
convection, and its potential to overturn much of the warm sector.
Although uncertainty remains, it appears increasingly probable that
some form of an upper trough and related strong mid-level jet will
impact parts of the southern/central Plains into the lower/mid MS
Valley and Southeast from Day 6/Monday through Day 8/Wednesday.
These features will likely overlap an expansive warm sector across
these regions. Depending on the timing, amplitude, and strength of
the upper trough, some severe risk will probably exist each day next
week. Still, too much model spread exists to highlight favored
corridors of severe potential in this extended time frame.

..Gleason.. 06/07/2023