Area Forecast Discussion
Issued by NWS Sacramento, CA

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FXUS66 KSTO 271028
AFDSTO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
328 AM PDT Wed May 27 2015

.Synopsis...
Gradually warmer temperatures through the end of the week. Daytime
highs 10 to 15 degrees above normal by Friday. A slight threat of
afternoon showers or thunderstorms over the Sierra today. Cooler
early next week with a slight chance of showers over the northern
forecast area as a Pacific trough moves into the Pacific
Northwest.

&&

.Discussion...
High pressure over the eastern Pacific starting to slip inland
as a low over the Pacific Northwest edges eastward. Fair skies
over most of the cwa except through the delta where another strong
onshore breeze is pushing in coastal stratus. Expecting at least
some of this stratus to make it into the Sacramemtn area this
morning. GFS and NAM models both showing a bit of upward motion
over the Lassen area this afternoon and both painting some light
precipitation over this area so left in a slight threat of
afternoon showers there. Otherwise...expecting mainly fair skies
today under strengthening high pressure. Airmass warms a bit today
so expecting a little warming with highs reaching about 5 to 10
degrees above normal. Daytime highs should continue to warm
Thursday and Friday as the high pressure axis centers closer to
the west coast. By Friday afternoon...daytime highs are forecast
to reach from 10 to 15 degrees above normal. A moderate delta
breeze is likely to continue night and morning hours so delta and
near delta stratus may return over the next few nights. High
pressure over the region should preclude any mountain
thunderstorm development so removed all isolated afternoon
mountain showers from the forecast Thursday through Saturday with
mainly fair skies prevailing elsewhere. A slight cool off is
expected on Saturday as a Pacific trough approaches the coast
displacing the west coast ridge to the southeast. Despite this
cooling...daytime highs Saturday should still hit a few to several
degrees above normal.
&&

.Extended Discussion (Sunday through Wednesday)

Medium range models somewhat similar in bringing several short
wave troughs across Interior NorCal late Sunday through Tuesday.
Dynamics and moisture look limited. Main impact appears to be
synoptic cooling with increased onshore flow. Locally gusty
southwest winds expected through the Delta and over higher
mountain terrain. A slight chance of showers and afternoon
thunderstorms are possible mainly over the mountains north of I-80
through this period. High temperatures begin to warm midweek as
upper troughing shifts east and EPAC upper ridging begins to build
inland.

&&

.Aviation...

NWly flow alf as upr trof movs E tda and EPAC upr rdg blds inld
Thu. Mnly VFR conds ovr Intr NorCal nxt 24 hrs exc lcl MVFR/IFR
cigs poss in ST vcnty of Delta into Srn Sac Vly til 19z. Isold
shwr/tstm poss ovr hyr mtn trrn N of I-80 btwn 21z-02z. Lcl SWly
sfc wnd gsts to 30 kts poss at times vcnty Delta thru Thu mrng.


&&

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

$$







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