Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

fxus66 ksto 210452 

Area forecast discussion
National Weather Service Sacramento California
955 PM PDT Fri Oct 20 2017

warming temperatures through early next week. Breezy north winds
and possible fire weather concerns return Monday and Tuesday.



Evening update: nwly flow behind the Great Basin trof and in advance
of the ern pac ridge is moist with a plethora of high level
cloudiness spreading from the northwest to the southeast and into norcal...mainly
over the srn portion of our County Warning Area. Clouds should increase over the nrn
portion of the County Warning Area during the day on Sat with some warm frontal
precip spreading over the nrn mtns. The nrn portion of our County Warning Area will
be on the srn edge of the precip spreading into/across the pac northwest as
the ern pac ridge builds inland on Sat and then amplifies over the
area for a big warming trend into next week. Jhm

Upper trough has shifted east into the Great Basin region this
afternoon. Moisture lingering behind the trough in northwest flow is
causing a few light showers over the northern Sacramento Valley.
Inversion around 10,000 feet is suppressing convective growth and
should keep any of the showers from growing into thunderstorms.

Upper ridging will bring warming on Saturday but another
shortwave riding over this ridge will provide another threat of
light showers over the northern mountains again through the day.
Upper ridge continues to build over the West Coast on Sunday for
more warming with any precipitation threat being pushed well north
of the forecast area. Highs on Sunday will push upward to near
normal for this time of year. Daytime highs are forecast to climb
another 5 to 10 degrees on Monday as the upper ridge amplifies
along the West Coast. Breezy north winds down the Sacramento
Valley and increased downslope winds over the Sierra will be
possible Monday. Wind gusts from 25 to 30 mph would likely cause
increased fire weather concerns.

Extended discussion (tuesday through friday)

Upper level ridging is the prominent feature in the extended
period. Hot, dry temperatures will remain for interior norcal most
likely through the weekend. Temperatures cool very slightly
through the week as a slider trough moves just to the east over
The Divide. Daytime highs will still be around 8-15 degrees above
seasonal normals. Generally valley highs will remain in the 80s
and foothills and mountains in the 60s through 80s. The ridge
builds steep as that slider moves by, creating another threat of
strong northerly winds on Thursday. Hec



VFR conditions next 24 hours at taf sites except localized MVFR
at krbl through 20z. Light south to west winds at taf sites today,
less than 10 kts. &&

National Weather Service Glossary of Abbreviations