FXUS66 KSTO 182235
Area Forecast Discussion
National Weather Service Sacramento CA
235 PM PST Mon Feb 18 2019
Dry Tonight and Tuesday with cold morning lows. Minimum
temperatures near freezing in the Valley. A weak, cold system
moves through Wednesday and Thursday with light mountain and
foothill snow. Dry Friday with more light precipitation possible
over the weekend.
Clear skies, light winds and cold temperatures will allow areas
of frost to develop over the Sacramento Valley this morning.
Sensitive outdoor plants and early budding trees such as almonds,
apricots and peaches are susceptible to the cold, frosty
conditions. Have issued a frost advisory for much of the Valley to
cover this threat with overnight lows forecast from 28 to 33.
Northerly winds are expected to create enough mixing on the west
side of the Sacramento Valley to keep widespread frost from
A cold system will drop south over NorCal Wednesday and Thursday.
This system appears to be quite dry at this time with Valley
rainfall less than 0.10. Due to the cold origin of the system
snow levels could again drop into the foothills. Snow between
1500-3000 feet is forecast to be 1-3 inches with 4-6 inches at
.EXTENDED DISCUSSION (Friday THROUGH Monday)
Upper level ridging builds in on Friday in the wake of a
departing cold upper level low. Northerly upper level flow
develops, with dry weather across the area. Upper ridge breaks
down quickly as yet another cold upper low pressure system drops
out of the Gulf of Alaska and moves into the Pacific Northwest
Friday night and Saturday. Models continue to differ on just how
far south precipitation will reach with the GFS digging
precipitation somewhat farther south than ECMWF. Have continued
the trend of spreading bring precipitation further south, with the
potential for some precipitation across the area starting
Saturday and continuing into Monday. The current track should
limit moisture, so snow and rain amounts are not expected to be
large. Confidence is still low on this system, though. Snow levels
with this system will are currently estimated at around 2500-3500
feet, but this may change as model confidence increases. EK/CJM
VFR conditions expected over the next 24 hours. Northerly winds
10 to 15 kt with gusts 20 to 25 kt through 01z.
Frost Advisory from 1 AM to 9 AM PST Tuesday for Carquinez
Strait and Delta-Central Sacramento Valley-Motherlode-Northeast
Foothills/Sacramento Valley-Northern Sacramento Valley-Northern
San Joaquin Valley-Southern Sacramento Valley.
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