356
ACUS02 KWNS 111711
SWODY2
SPC AC 111710

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1110 AM CST Tue Nov 11 2025

Valid 121200Z - 131200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
The risk for thunderstorms appears negligible across much of the
U.S. Wednesday through Wednesday night.

...Discussion...
As an increasingly prominent blocking high evolves near the southern
Greenland Atlantic coast, it appears that broad mid/upper troughing
will generally be maintained across the Atlantic Seaboard into
Labrador Sea/Baffin Bay vicinity through this period, though
large-scale ridging inland of the Pacific coast may slowly expand
east of the Great Plains through Mississippi Valley.  Upstream,
particularly across the western into central mid-latitude Pacific,
models indicate that flow will remain more progressive, with
building ridging on the leading edge of this regime shifting across
the central toward eastern Pacific.  As this occurs, it appears that
an initially digging downstream trough across the eastern Pacific
will split while approaching the North American Pacific coast.

There appears increasing consensus within/among the model output
that forcing for ascent, associated with the most vigorous short
wave perturbation within the southern portion of the splitting
trough, will support significant lower/mid-tropospheric cyclogenesis
late Wednesday through Wednesday night.  The deepening,
northeastward migrating surface cyclone center may approach the
southern Oregon/northern California coast by 12Z Thursday, while the
mid-level cold core remains farther offshore--and generally slower
to approach the coast than suggested by prior guidance.

...Northern California...
Latest high resolution, convection allowing ensemble output, and
related guidance, suggests that the deepening surface cyclone might
include an evolving warm sector corridor becoming sufficiently
unstable to support a period of increasing pre-frontal thunderstorm
development Wednesday evening, initially 100-200+ miles offshore of
the northern California coast.  Based on this same guidance, and
forecast soundings from the NAM and Rapid Refresh, it remains
unclear the extent to which thermodynamic profiles will remain
conducive to convection capable of produce lightning, as the
occluding cyclone/front approach coastal areas north of San
Francisco Bay overnight through 12Z Thursday.  Activity will be
embedded within rather strong ambient wind fields, perhaps including
50-70 kt within the lowest kilometer or two above ground level.
However, weak CAPE and stable near-surface lapse rates across and
inland of coastal areas seem likely to limit the potential for
convectively augmented surface gusts.

..Kerr.. 11/11/2025

$$