Welcome to the New NWS' Forecast!
Most changes are behind the scenes, but click here for differences you might notice.

Area Forecast Discussion (AFD)

Issued by Sacramento, CA (STO)

FXUS66 KSTO 142132

Area Forecast Discussion
National Weather Service Sacramento CA
232 PM PDT Tue Aug 14 2018


Near normal temperatures through mid-week. Highs trend upwards 
late this week reaching around 5-10 degrees above average by the 
weekend. Smoke impacts from wildfires may increase again this 



Current temperatures are trending on the cooler side for mid
August across interior NorCal. High temperatures today are
expected to remain right around or slightly below normal, with the
Valley ranging from 82 to 98 and the mountains in the 70s and 80s.
High pressure remains centered over the desert Southwest which is
causing monsoonal moisture to spread north into the forecast area
along with a southwest flow that is bringing cooler, moister 
marine air through the Delta.

Showers and thunderstorms have begun forming over the Sierra 
crest in Tuolumne and Alpine counties early this afternoon. 
Isolated showers and thunderstorms are expected to remain mainly 
south of Highway 50 this afternoon. Recent runs of the NAM nest 
have suggested there may be enough elevated instability this 
evening and overnight for isolated showers and thunderstorms to 
form further north on the crest, so I have increased the coverage 
of thunderstorm chances over the northern mountains into eastern 
Shasta and Plumas counties overnight and early Wednesday morning.

The high pressure will shift slightly east Wednesday, pulling the
monsoonal moisture mostly out of our area. A slight chance of
thunderstorms remains over the Sierra crest in Tuolumne and Alpine
counties in the afternoon & evening hours. Temperatures will warm
a few degrees to near normal Wednesday and Thursday.

High pressure begins to build over the forecast area Friday into
the weekend. Expect temperatures to rise to a few degrees above
normal by the weekend. HEC



Upper ridging moves through interior NorCal over the weekend with
high temperatures warming to about 5 to 10 degrees above normal. 
Upper low then progged to move across Oregon Monday into Tuesday 
with associated upper troughing over the CWA. This will result in 
minor cooling with increased onshore flow. Highs remain several 
degrees above normal with breezy conditions expected in the Delta 
and over higher terrain in the afternoon into evening hours. Dry 
weather persists through the extended forecast period.



Local MVFR/IFR conditions in HZ/FU near wildfires, otherwise VFR 
continues over the area for the next 24 hours. Local SW surface 
wind gusts 25 to 30 kts vicinity of the Delta and over higher 
mountains. Isolated thunderstorms over the Sierra-Cascade crest 
through 12z. EK