LIVE MAP (ABOVE) ... SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1116 PM CST Wed Feb 22 2023
Valid 231200Z - 241200Z
...NO SEVERE THUNDERSTORM AREAS FORECAST...
...SUMMARY...
A few lightning flashes will be possible from southwest Oregon
across the California coast and into northwest Arizona throughout
the period. Isolated thunderstorms are also possible across portions
of the Southeast during the latter half of the period.
...Discussion...
Mid-level height rises are forecast across much of the CONUS
Thursday as a belt of broad southwesterly flow will continue from
the southwestern US into New England. The most dominant feature
continues to be the stubborn upper ridge anchored at low latitudes.
This feature will ensure favorable low-level trajectories off the
Gulf Basin into the Gulf States where surface dew points are
expected to hold in the 60s through the period. Even so, instability
should remain modest as poor lapse rates limit buoyancy. In the
absence of meaningful short-wave influences, weak warm advection and
weak frontal forcing will prove instrumental in thunderstorm
potential from northeast LA toward the southern Appalachians. At
this time it appears severe threat is too meager to warrant severe
probabilities due to suppressed forcing for ascent.
Upstream, very cold mid-level temperatures and steep lapse rates
will persist north of the jet from CA into the Great Basin. Model
guidance continues to suggest 500mb temperatures will approach -30C
into portions of the lower CO River Valley as 100kt speed max rounds
the base of the western US trough. Onshore flow along the Pacific
Coast will contribute to weak buoyancy given the very cold profiles.
A few flashes of lightning appear possible with the more robust
updrafts given the low freezing levels. Isolated thunderstorms may
also develop a bit farther inland into portions of northwestern AZ
region.
..Darrow/Wendt.. 02/23/2023
Read more CHECK UPDATE ZOOM GRAPHIC
http://dlvr.it/SjsD6s
