312
ACUS48 KWNS 290900
SWOD48
SPC AC 290858

Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0358 AM CDT Wed Apr 29 2026

Valid 021200Z - 071200Z

...DISCUSSION...
Latest medium-range guidance, in particular the ECENS and GEFS,
generally maintains forecast trends of prior runs concerning the
evolution of the large-scale features within the prevailing split
flow through this weekend into early next week.  It appears that at
least a transient blocking high may evolve within amplified ridging
offshore of the British Columbia and adjacent Pacific Northwest
coast.  To its south-southeast a notable mid-level low is forecast
to evolve within initial troughing slowly digging toward the U.S.
Pacific coast, with the low bottoming out offshore of the central/
southern California coast by early next week.

Downstream, it appears that a broad area of lower mid-level heights
will be maintained, with lowest heights perhaps reforming
west-northwestward from southwestern Quebec toward southern Hudson
Bay/northwestern Ontario, contributing to the maintenance of a
confluent regime across and east of the Rockies.

Shorter wavelength developments within this pattern remain more
uncertain, particularly by the early to middle portion of next week,
when it appears that the offshore low will begin to progress inland
across California and the southern Sierra Nevada.  Depending on the
timing of the inland progressing mid-level cold core with respect to
diurnal heating, this could be accompanied by relatively minor
severe weather potential across parts of the San Joaquin Valley next
Monday or Tuesday.

Downstream, southerly moist return flow into at least the southern
through central Great Plains, associated with deepening lee surface
troughing, may contribute to destabilization beneath building
mid-level ridging across and east of the southern Rockies.  This
might be accompanied by increasing potential for at least widely
scattered strong to severe thunderstorm development on Tuesday.

Guidance suggests potential for more widespread organized severe
thunderstorm development could increase by Wednesday, but much will
depend on short wave developments which become rather uncertain by
this time.

..Kerr.. 04/29/2026