NWS Scientific Forecaster Discussion


Area Forecast Discussions

Issued by NWS Sacramento, CA



Forecast Discussion for STO NWS Office
000
FXUS66 KSTO 271556
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
855 AM PDT Tue Jun 27 2017

.SYNOPSIS...
Near average temps thru mid-week followed by a warming trend.

&&

.Discussion...
15Z temps running very similar to yesterday as the patchy early
morning stratus erodes/dissipates. Noticeable changes taking place
as the Delta Breeze weakens, e.g. SUU now 15kts compared to 23g29kts
yesterday. Considering the weakening Delta Breeze, today will be a
little warmer, especially in the Delta influenced areas. Hourly
updated LAV guidance running just slightly cooler than our forecast
maxes today, but probably not worth an update as the temps are
expected to be within a couple of degrees or so of the forecast
highs, unlike yesterday which trended several degrees cooler than
forecast.

Yesterday`s short wave trof is nor over ID and moving farther away
allowing flat ridging to build in its wake. However, a weak trof
will move into the Pac NW today with a weak short wave moving across
Norcal early this evening. Hence, the Delta Breeze should increase
again, but likely not as strong as the recent past. Marginal
instability forecast over the Nrn mtns, mostly over the Trinity Alps
and Siskiyous where short-lived convection may materialize, just N
or our CWA.   JHM

Warming returns Wed-Fri as ridging over the eastern Pacific moves
onto the West Coast. This will suppress the marine layer weakening
onshore flow and result in modest synoptic warming. Triple digit
heat will likely return to the northern Sacramento Valley Thu-Fri.

&&

.EXTENDED DISCUSSION (Saturday THROUGH Tuesday)
Dry weather is expected to continue through the extended period.
A weak upper trough is projected to move through Northern
California on Saturday, bringing a brief cooldown. Otherwise,
temperatures through the extended period should remain on the
order of 5-10 degrees warmer than normal. Dang

&&

.AVIATION...
VFR conditions the next 24 hours. South to west winds 5 to 15 kt
will continue today, with afternoon gusts up to 25 kt possible.
Near the Delta...SW wind gusts up to 30 kt expected. Dang

&&

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

&&

$$

NWS STO Office Area Forecast Discussion

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