Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Sacramento California
1010 PM PDT Thu Oct 23 2014
a stalled cold front will keep a chance of light rain over the
northern mountains overnight. Dry and warming conditions on Friday
as a ridge of high pressure builds overhead. Stronger weather system
will move into northern California through the weekend bringing
rain...cooler temperatures and gusty winds.
digging ern pac trof along 140w is beginning to amplify the
downstream ridge over the swrn Continental U.S.. the nearly stationary cold
front across the nwrn portion of the County Warning Area is beginning to lift nnwwd
and should be mainly affecting the coastal range and wrn portions of
Tehama/Shasta counties overnite before lifting northwest of our County Warning Area by late
Much warmer temps expected over the nrn third to half of our County Warning Area on
Fri as the rain and thick cloud cover will yield to sunshine. Maxes
should be near or slightly above normal over our County Warning Area...and some 10
to 17 degrees warmer over the nrn half of the County Warning Area and 2 to 5 degrees
over the srn portion of the area which had filtered sunshine on
This weekend, the main weather system will move inland and bring
widespread rain and some breezy to locally windy conditions to
the region. Saturday looks to be the day with the most activity.
Winds, widespread showers and potential for afternoon/evening
isolated thunderstorms. At this time, the winds look like they'll
be a nuisance for outdoor events and may blow Holiday decorations
around. However, the slower progression of this system may result
in slightly higher winds. We will continue to monitor later runs
and see if any wind headlines are necessary. Also, the snow levels
are expected to lower to around 7000 feet Saturday night, so there
could be some light accumulations over the higher passes. Showers
will linger on Sunday, but should see decreasing showers from
south to north through the day. Precipitation amounts this weekend
should be a couple tenths in the San Joaquin Valley to up to half
an inch in the northern Sacramento Valley. The mountains could see
1-1.5 inches of liquid.
Extended discussion (monday through thursday)
Monday will once again see a drying trend as a weak ridge builds
in behind the exiting system with temperatures rebounding to near
Tuesday through the end of the week, a series of weather systems
will flatten the ridge as they move through the Pacific northwest.
These waves will result in an increase of clouds and cooler
temperatures with a chance of precipitation across the northern
mountains on Tuesday and Tuesday night. Beyond Tuesday night, the
models really begin to diverge so confidence in the Wednesday and
Thursday forecast is low. GFS rebuilds a fairly strong ridge over
the West Coast Wednesday and Thursday, while the European model (ecmwf) and Gem
dig the next upper trough into the eastern Pacific. Therefore,
kept a slight chance of showers in the mountains and near seasonal
temperatures. We will continue to monitor the models and adjust
the forecast as needed.
Area of light rain has lifted nwwd mainly along and north of a line from
yolla Bolly-rdd-Lassen park...and is forecast to remain nearly
stationary or possibly lift a little father nwwd overnight. MVFR
conditions with isolated IFR over mtns or valleys possible overnite.
VFR sky clear conditions from myv swd. Friday will see just high thin
clouds with winds from the south between 10-15 mph in the afternoon.