Scientific Forecaster Discussion
fxus66 ksto 121105
Area forecast discussion
National Weather Service Sacramento California
305 am PST Tue Nov 12 2019
dry weather pattern continues this week. Cooling trend this week,
but above normal high temperatures continue. Warmer this weekend.
partly cloudy skies (high clouds) cover the region early this
morning. Northerly surface pressure gradients have dropped off
considerably compared to 24 hours ago (kmfr-krdd currently around
1.5 mbs compared to over 6.5 mbs at this time monday) while the
easterly gradient krno-ksac is still around 5 mbs. Local northeast
wind gusts of 15-30 mph linger across the foothills and west
slopes of the northern Sierra. Current temperatures range from the
upper 20s in the mountain valleys to the upper 50s to lower 60s
across the warmer foothill and mountain thermal belts.
Strong ridging will gradually shift east later Wednesday into
Thursday as the closed low, presently near 30n/145w, weakens and
approaches the West Coast. The system will bring some cooling
along with mostly cloudy skies as it moves through Thursday into
Friday. High temperatures will remain above average.
Extended discussion (saturday through tuesday)...
upper level ridging will be in place for the start of the extended
period. This will result in a warming trend along with a decrease
in humidity. High temperatures will be around 5-15 degrees above
average for mid-November.
Upper level ridge flattens early next week as a trough digs into
the pacnw. Deterministic models keep the trough a bit further to
the west and pull in some moisture Tuesday/Wednesday but ensembles
are drier and further to the east with it. We will likely see
models shift to this scenario and have kept the forecast dry. If
ensembles are correct with the placement of the trough we could
see breezy north winds Tuesday continuing into Wednesday with low
relative humidity. -Cjm
VFR conditions the next 24 hours except local MVFR visibilities
from ksck southward 14z-18z Tuesday. Winds generally below 10 kts.