Area Forecast Discussion
Issued by NWS Sacramento, CA
FXUS66 KSTO 230043
Area Forecast Discussion
National Weather Service Sacramento CA
443 PM PST Wed Feb 22 2017
Significant flooding concerns continue as runoff from the recent
rain continues to work its way downstream adding stress to
waterways. Scattered showers with a few thunderstorms into the
evening, then another storm potentially late in the weekend.
Disturbance passing southeast through northern California will
keep showers and a few thunderstorms going into the evening. Some
of the stronger storms will have small hail. A brief period of
heavy snow may pass over the Sierra including interstate 80 and
highway 50 between 5 pm and 9 pm with up to 3 inches of snow
...locally heavier in a few spots.
Northwest flow behind broad upper trough over Rockies will prevail
over NorCal with a couple of weak disturbances dropping southeast.
This will keep a few showers over the mountains...but generally
dry for the valleys Thursday/Friday. Patchy frost with valley
temps low to mid 30`s Friday...especially north Sac valley.
Next system dropping south Saturday continues to trend
weaker...with precip forecast greatly reduced from earlier
forecast. The system is now forecasted to produce less than 0.50
inches mountains and a few inches of Snow. Better potential is
possible later in the weekend.
.EXTENDED DISCUSSION (Sunday THROUGH Wednesday)
Long term models continue to show a cold upper trough dropping
southeastward. This system could bring some light precipitation
Sunday into Monday. Latest model guidance indicates that this
system will split with main moisture plume moving into Socal. QPFs
are trending lower for Norcal from previous model runs. Best
chances of precipitation still will be across higher terrain.
Cold air associated with this system should keep snow levels
relatively low. Dry conditions will prevail generally Tuesday
through at least the rest of next week as upper ridging builds in.
Temperatures will be near or slightly below normal on Wednesday,
with Valley highs in the low 60s.
Scattered showers isolated thunderstorms early this evening in the
Valley as upper low moves across the region. Mainly VFR
with occasional MVFR CIGS/VSBYS in showers. Gusty NW winds G30 kts
in wake of storms. Snow levels around 3000 feet lowering to 2000
to 2500 feet by Thursday morning. VFR conditions on THU as drier
NW flow develops over rtes as upper low moves E of the region.
Flash Flood Watch through Saturday morning for Carquinez Strait