Area Forecast Discussion
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FXUS66 KSTO 121637

Area Forecast Discussion
National Weather Service Sacramento CA
934 AM PDT Thu Jul 12 2018

Well above normal temperatures next several days with hottest
temperatures over the weekend. Monsoonal moisture will bring
chances for showers and thunderstorms to the higher elevations
today into next week.


Monsoon moisture spreading to the NW about as progged and is
forecast to thicken to about 20 kft (15-35kt) over the Nrn SJV this
evening and then NWwd into the coastal range later tonight and Fri.
The increase in moisture combined with seasonably hot temps will
make it feel a little "muggier" than normal by Norcal standards.
(Folks from the Midwest, east, gulf coasts are all too familiar with
that term.)

Although a weak SSEly short wave that will move over the
aforementioned area this evening, elevated instability progs have
low TT`s in our CWA so storm coverage is expected to remain limited
in our CWA. With BUFKIT forecast RH progs showing the thick and
moist mid level cloud deck (bases 15-20kft), can`t rule out a few
sprinkles mainly across the Nrn San Joaquin Vly and into the
coastal range, and possibly the southern Mother Lode. JHM

.Previous Discussion...
Weak upper through that moved through the Pacific Northwest
Wednesday has moved eastward into the northern Great Basin this
morning. This should allow monsoon moisture over the southwest U.S
to move at least a little farther up the Sierra today so Isolated
thunderstorms remain in the forecast south of about Tahoe. Some high
cloud cover will likely occur elsewhere. Daytime highs today will
remain quite warm under upper level ridging. Overall airmass remains
about the same but with high clouds and a slightly deeper marine
layer there may be a drop of a degree or two. As upper ridge pushes
back to the northwest on Friday, monsoon moisture should make it up
the Sierra a bit farther north. The west side of the forecast area
may see a bit of action as well on Friday as a weak offshore low
pivots a shortwave disturbance up the north state coastline which
may generate a few showers or thunderstorms along the coast range.
Otherwise, cloud cover and a slight airmass cooling should bring a
slight cool off for the end of the week but highs will still remain
a few degrees above normal. Overall airmass warms over the weekend
as high pressure strengthens over the west coast. Highs by Sunday
will reach or top 100 across most of the central valley with well
above normal temperatures all areas. Heat risk indicators show heat
advisory should be considered Saturday over the northern Sacramento
valley and foothills with a still bigger consideration area on
Sunday as daytime highs push to about 10 degrees above normal.
Southeast to south flow aloft will continue to bring monsoon
moisture up the coast so Sierra crest thunderstorms will remain in
the forecast.



Strong high pressure will maintain hot weather across the region
next week. The northern Sierra Nevada will continue to see a
slight chance for late-day showers and thunderstorms. Highs across
warmest portions of the forecast area will be around 5-10 degrees
above average.


VFR conditions the next 24 hours. Isolated thunderstorms over the
Sierra Nevada south of Lake Tahoe after 22Z. Local south wind
10-15 kts in the Sacramento Valley, and 20-30 kts in the Delta,
after 00Z.


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