Area Forecast Discussion
Issued by NWS Sacramento, CA

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FXUS66 KSTO 121625
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
925 AM PDT Sat Aug 12 2017

.SYNOPSIS...
Warm and dry thru the weekend, then cooler early next week.

&&

.DISCUSSION...
Temperatures this morning have been running a few degrees warmer
than this time yesterday. A trough along the coast will deepen
slightly and temperatures for most areas will end up being a
couple of degrees cooler than yesterdays highs. Marine layer is
around 1500 ft deep this morning with decent flow expected to
continue through the Delta all day.

.PREVIOUS DISCUSSION...
Clear skies across interior NorCal early this morning. Current
readings are milder across most of the area compared to 24 hours
ago as onshore flow wanes and the marine layer shrinks below 1000
feet in depth. Temperatures range from the 40s in the mountain
valleys to the 60s and 70s across the Central Valley.

Next broad upper trough moves into the region today. Main impact
will likely be an increase in onshore flow and thickening marine
layer by this evening, not early enough to prevent another
warm/hot day inland. Deeper trough follows Sunday with greater
height falls. Guidance showing temperatures cooling several
degrees Sunday. Troughing continues to deepen over the CWA Monday
with additional synoptic cooling. Highs Monday expected to cool
below average.

Available moisture has been scoured eastward by these upper waves,
so only very limited chance of seeing any late-day deep convection
near Mt. Lassen, otherwise a dry forecast through the weekend into
early next week.

&&
.EXTENDED DISCUSSION (Wednesday THROUGH Saturday)


Temperatures will begin to warm up as an upper level ridge
rebuilds across the forecast area. Daytime highs are expected to
be around 5-10 above normal for this time of the year, with highs
in the northern Sacramento Valley reaching the triple digits. In
addition, this high pressure system will keep stable conditions
and will make precipitation unlikely across interior NorCal. By
the end of the forecast period, the ridge becomes flattened as
disturbances move to the north with temperatures remaining above
normal. Latest guidance is suggesting the possibility of afternoon
convection by the end of the forecast period, but confidence is
low.


&&

.AVIATION...


VFR conditions through the TAF period. Generally light winds,
except for gusts to around 30 kts through the Delta.

&&

.STO WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$



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