000
FXUS66 KSTO 022218
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
218 PM PST Tue Mar 2 2021

.SYNOPSIS... Dry and mild weather through Friday. Rain and mountain
snow chances will return to Northern California over the weekend
and early next week.

&&

.DISCUSSION...
High clouds are streaming over Central and Northern California
this afternoon, spiraling counterclockwise around a low pressure
system paralleling the coast. Unfortunately, these high clouds
will be about all our area of the state will see with this system;
any precipitation over the next 24 to 36 hours will be largely
limited to southern California. For the short-term this afternoon,
expect highs to max out in the upper 60s to low 70s for Valley
communities, or about 6 to 12 deg F above early March climatology.

Upper level low will push into Southern California on Wednesday
afternoon while Northern California experiences another mostly dry
and mild day. Temperatures are forecast to be within a few
degrees from today. While a slim chance of scattered rain/snow
shower can`t be ruled out tomorrow afternoon in the Sierra/
foothills from US-50 southward, little/no impacts are anticipated.

Southwesterly flow aloft will develop on Thursday over the Golden
State ahead a trough axis centered along the 140th west meridian.
Main day-to-day change with the weather from Wednesday to
Thursday will be a drop in the highs by about 4 to 9 deg F. This
cooling trend will continue into Friday and the weekend as the
next chance of precipitation returns to NorCal. // Rowe

&&

.EXTENDED DISCUSSION (Saturday THROUGH Tuesday)...
Models are coming into better agreement about the expected
forecast for this weekend. A fast moving shortwave trough is
forecast to bring Valley rain and mountain snow showers to the
region late Friday into Saturday. Some slight to minor
inconsistencies among models in terms of timing and location still
exist. However, the forecast is generally calling for this
shortwave to have low to moderate impacts. Snow levels begin
around 4500 to 6000 feet, lowering to 3500 to 4500 feet Saturday
night. Several inches of snow are expected to accumulate at pass
levels. Also, with the cold air aloft associated with this
impulse, we could see some isolated thunderstorms. However,
thunderstorm development will depend on the timing and location of
this wave. We will continue to monitor this possibility.

Some clearing is expected late Saturday in to Sunday before
another system impacts the region early next week. There are some
differences in timing and strength of this next system as well.
Preliminary estimates indicate this to be a possibly more
impactful system than the late Friday - Saturday system.
Thereafter, we could see some more wet weather as we stay in this
generally unsettled pattern though at least mid-week.

&&

.AVIATION...
VFR conditions over interior NorCal the next 24 hour with surface
winds generally below 12 kts.

&&

.STO WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$