Area Forecast Discussion
Issued by NWS Sacramento, CA

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FXUS66 KSTO 261545
AFDSTO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
845 AM PDT Sat Jul 26 2014

.Synopsis...
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.

&&

.Discussion...
High pressure continues over the area with little day to day change
expected for awhile. Monsoon moisture will begin to work its way
back into the northern Sierra Sunday. Look for improving smoke
conditions in the Sac area by the afternoon. No updates.

&&

.Previous Discussion...
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
winds...fire 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 expected.

&&

.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.

&&

.Aviation...
VFR conds exc lcl MVFR vsbys vcnty wildfire E of KMHR. Generally
light winds the next 24 hours exc SW winds 10-20 kts Delta.

&&

.STO Watches/Warnings/Advisories...None.

&&

$$



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