STORM2K

By Day 7/Sunday into Day 8/Monday, most medium-range guidance shows
an upper trough/low moving from the eastern Pacific across the
western states. There appears to be a somewhat bimodal distribution
in various GFS/GEFS and ECMWF/EPS solutions regarding the eventual
ejection of this upper trough across the southern/central Plains.
Some guidance shows a more positively tilted and elongated upper
trough evolution, which could still support severe potential across
the southern/central Plains by early next week. Other solutions show
a more compact, neutral to negatively tilted trough ejection.
Stronger low-level mass response in this scenario would lead to
greater low-level moisture return, related stronger instability east
of a dryline, and a potentially better setup for severe convection
next Monday. Regardless, predictability remains far too low to add a
15% severe delineation at this extended time frame. But, trends will
be monitored.