Area Forecast Discussion
Issued by NWS Sacramento, CA

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FXUS66 KSTO 261100

400 AM PDT Sat Jul 26 2014

Above normal temperatures this weekend into next week. Daytime
highs topping 100 this weekend most valley locations. The Sierra
crest will see a threat of thunderstorms Sunday through much of
next week and possibly as far north as the Shasta County mountains
on Wednesday.


Little change in the forecast with an upper level ridge remaining
over the western U.S. through the extended period. Airmass warms
just a bit today putting daytime highs in the valley at a touch
over 100 degrees most locations. Higher elevations will see highs
a few to several degrees above normal. Except for some breezy
winds through the delta...light pressure gradients beneath the
ridge will bring generally light winds today. Despite these
relatively light potential across northern California
will remain elevated with afternoon humidity minimums dropping to
the mid teens to single digits most areas. As the upper ridge
continues to amplify and shift westward on Sunday...temperatures
will continue to creep up. Precipitable water values will creep up
as well as monsoon moisture makes a return to northern California.
Most locations will see a slight increase in humidity but the
Sierra crest will see a slight threat of thunderstorms over the
next several days. There will be minor fluctuations in day and
night time temperatures but over all only minor changes are

.Extended Discussion (Wednesday through Saturday)

Little change expected through the extended period as upper ridge
axis remains east of Interior NorCal and upper troughing persists
over the eastern Pacific. Stability proggs show slight instability
over the Sierra cascade range and over the Shasta county northern
mountains on Wednesday as a small scale upper trough clips the
northwest portions of California. This instability combined with
residual monsoon moisture will bring a threat of afternoon
thunderstorms over the Sierra Cascade range and over the northern
Shasta county mountains. Upper flow transitions to more southwest
by Thursday so the afternoon and evening thunderstorm threat will
most likely shift to the north and east of the forecast area. Both
ECMWF and GFS show the weak shortwave over northeast California
sometime on Thursday so have left a slight threat of afternoon
thunderstorms in the forecast for the Burney region for Thursday.
Southwest flow aloft should move any thunderstorm threat to the
north and east of the CWA Friday and Saturday. As the upper level
ridge axis shifts to the east...temperatures will begin to cool
dropping to a little below normal by next Saturday.



VFR conditions with generally light winds the next 24 hours. Near
the Delta, SW winds 10-18 kt continue.



.STO Watches/Warnings/Advisories...

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