Scientific Forecaster Discussion
fxus66 ksto 210947
Area forecast discussion
National Weather Service Sacramento California
247 am PDT Mon Oct 21 2019
dry weather for at least the next week. Warmer than average for
the remainder of this week. Breezy conditions at times,
especially Wednesday into Thursday when elevated fire weather
concerns are expected.
other than a few high clouds spilling over the eastern Pacific
Ridge, skies are clear across interior norcal early this morning.
Current temperatures range from the 30s in the mountain valleys to
the 50s across the Central Valley and mountain thermal belts.
Warm and dry weather is expected this week as high pressure
centered over the eastern Pacific extends into norcal. A couple of
bouts of breezy northerly winds are also expected. The first will
occur today as surface gradients tighten and subsidence increases
downstream of the upper ridge.
The second round of north winds is forecast for Wednesday into
Thursday as gradients tighten in the wake of a short-wave trough
that passes Tuesday night and early Wednesday. Neither event looks
particularly strong at this point as upper level support is
lacking. However, the combination of the breezy to locally windy
conditions with low relative humidity will elevate fire weather
concerns once again.
High temperatures this week will be around 5-15 degrees above
Extended discussion (friday through monday)...
upper level high pressure ridge is forecast to center over
California on Friday bringing lighter pressure gradients and
decreased winds. With maximum subsidence under the ridge, Friday
is forecast to be generally the warmest day of the week although
downslope effects earlier in the week may produce warmer
temperatures in some locations. A weather disturbance passing
through the Pacific northwest on Saturday will bring a few degrees
of cooling most areas. Models are trending the upper trough as an
inside slider moving from the Pacific northwest into the northern
Great Basin on Sunday then southward into the central Great Basin
by Monday. Northerly flow behind this system will bring cooler
temperatures Sunday and Monday dropping daytime highs down to
several degrees below normal. Surface high pressure building into
the Pacific northwest behind this system will bring another round
of moderate north winds to the County Warning Area Sunday and Monday especially to
the Sacramento Valley and Coast Range. This wind and the drying
expected to accompany it will mean another period of elevated fire
concerns early next week.
VFR conditions the next 24 hours at taf sites. Sustained north to
northeast winds 5 to 15 knots.