644
ACUS03 KWNS 280718
SWODY3
SPC AC 280717

Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0117 AM CST Fri Feb 28 2025

Valid 021200Z - 031200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Widely scattered, generally weak, thunderstorm activity is possible
across parts of central California into the Great Basin, and across
parts of the central Great Plains, Sunday through Sunday night.

...Discussion...
Split westerlies will remain amplified across the eastern Pacific,
and characterized by generally high mean mid-level heights extending
inland within a broadly confluent belt across the Rockies and east
of the Mississippi Valley by late Sunday night, in the wake of
large-scale troughing slowly progressing east of the Atlantic
Seaboard.  Within this regime, a significant, cold mid/upper trough
is forecast to progress inland of the Pacific coast into the Great
Basin and Southwest, preceded by a less prominent perturbation
crossing the southern Rockies and through the central Great Plains
by 12Z Monday.

In lower levels, modest surface cyclogenesis appears likely to
commence across eastern Wyoming and Colorado into the adjacent high
plains.  Models indicate that this will be accompanied by
strengthening southerly return flow, in the wake of cold/dry surface
ridging shifting east of the Mississippi Valley into Atlantic
Seaboard.  Stronger flow is forecast to develop inland of a
gradually modifying boundary-layer over the western Gulf Basin, but
modest moistening in lower/mid-levels is still probable across the
southern through central Great Plains, beneath (at least initially)
relatively warm/dry layers farther aloft.

...Central Great Plains...
There remains notable spread concerning the motion of the lead short
wave perturbation.  However, guidance suggest that associated
forcing for ascent and mid-level cooling, coupled with the limited
moisture return, probably will contribute to sufficient
destabilization to support scattered thunderstorm development late
Sunday afternoon through Sunday night.  This is likely to be
generally rooted above a stable boundary layer.  While the
environment might become conducive to small hail in stronger cells,
the risk for severe weather appears negligible at this time.

...Central California into Great Basin...
Beneath stronger mid-level cooling and forcing for ascent
overspreading the region, models suggest that destabilization will
become sufficient for widely scattered weak thunderstorms Sunday
into Sunday night.

..Kerr.. 02/28/2025

$$