Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
328 PM EST Fri Feb 24 2023

Valid 00Z Sat Feb 25 2023 - 00Z Mon Feb 27 2023

...There is a Moderate Risk of excessive rainfall over parts of Southern
California on Friday and a Slight Risk of excessive rainfall on Saturday...

...Heavy snow over the Cascades and Sierra Nevada Mountains...

...Snow over parts of the Upper Midwest to the Northeast; Pockets of
rain/freezing rain over parts of the Central Appalachians...

A storm just off the Central/Southern California Coast will move inland to
the Central High Plains by Sunday evening. The system will create
significant mountain snows are likely Friday night into early Saturday,
with major impacts to travel and infrastructure. Downed trees and power
lines are possible. Lower elevations may experience significant snowfall
over areas where snow is unusual. Strong winds will lead to blizzard
conditions in some mountainous terrain and passes and may lead to power
outages and tree damage in lower elevations. Blowing dust is possible in
desert areas. Heavy rain may lead to flooding of some rivers/streams and
flood-prone areas. Strong rip currents and high surf will be hazardous to
swimmers and beachgoers. Temperatures will be well below normal over much
of the region, with below-freezing readings possible in some areas of
Northern California.

Moreover, moisture streaming onshore from the Pacific will produce heavy
rain and a possible thunderstorm over parts of Southern California.
Therefore, the WPC has issued a Moderate Risk of excessive rainfall over
parts of Southern California through Saturday morning. The associated
heavy rain will create numerous areas of flash flooding. Furthermore, many
streams may flood, potentially affecting larger rivers.

The threat of excessive rainfall continues on Saturday but at a slightly
low threat level. Therefore, the WPC has issued a Slight Risk of excessive
rainfall over Southern California from Saturday into Sunday morning. The
associated heavy rain will create mainly localized areas of flash
flooding, with urban areas, roads, small streams, and burn scars the most
vulnerable. Furthermore, the storm will produce heavy snow over the
Cascades and Sierra Nevada Mountains. In addition, the snow will result in
reduced visibility and hazardous driving conditions.

Meanwhile, upper-level energy will aid in producing snow over the Upper
Midwest into the Northeast, northern Mid-Atlantic, and Central
Appalachians through Saturday evening. Additionally, showers and embedded
thunderstorms will develop over parts of the Ohio/Tennessee Valleys, Lower
Mississippi Valley, Southern Plains, Western Gulf Coast, and Central Gulf
Coast Friday night into Saturday. Finally, along the rain/snow line,
pockets of rain/freezing rain will develop over parts of the Central
Appalachians on Saturday morning into the afternoon.

On Sunday, a fast-moving front will keep light snow over the Northeast.
Furthermore, as the California storm moves onto the Plains, moisture from
the Western Gulf of Mexico will stream northward over the Plains and
Mississippi Valley, producing showers and severe thunderstorms over parts
of the Central/Southern Plains. The SPC has issued an Enhanced Risk of
severe thunderstorms over the Southern Plains on Sunday. The hazards
associated with these thunderstorms are frequent lightning, severe
thunderstorm wind gusts, hail, and a few tornadoes. Associated with the
moisture will produce moderate to heavy rain. Therefore, on Sunday, the
WPC has issued a Marginal Risk of excessive rainfall over parts of the
Central Plains and Middle Mississippi Valley. The associated heavy rain
will create localized areas of flash flooding, affecting areas that
experience rapid runoff with heavy rain. 

Ziegenfelder


Graphics available at
https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php