FXUS66 KSTO 210945

Area Forecast Discussion
National Weather Service Sacramento CA
245 AM PDT Sun Oct 21 2018

Dry with a cooling trend to near normal high temperatures Tuesday
and Wednesday, then slightly above normal through the rest of the

Blocking pattern along 120W with trapped closed low off the CA
coast. Low gradually shifts through CA today into Monday,
weakening to trough. Weak short wave ridging follows Tuesday,
ahead of approaching baroclinic zone. Front weakens under diffluent
flow aloft, and undergoes frontolysis as it moves inland Tuesday
afternoon/evening. No precip expected with front over Interior
NorCal, but some locally gusty wind possible over higher terrain.
Upper ridging then begins to build over NorCal Wednesday. Cooling
trend in progress with high temperatures today upwards of 10
degrees above normal, lowering to near normal by Tuesday and



Upper ridge over the west coast now appears will keep interior of
northern California dry through the extended period. Ridge
amplification over the region on Thursday will bring warm up in
daytime highs with max values forecast to come in a few degrees
above normal. Just a bit more warming is expected on Friday. Upper
ridge axis shifts eastward into the Great Basin by next Saturday
as a Pacific frontal system approaches the coast. Saturday could
be the warmest day of the extended period before a significant
cool off back down to near normal next Sunday as the weak frontal
band pushes through the Pacific Northwest. This system will bring
the cooling and some cloud cover but at this time...models
indicate any precipitation should remain north of the forecast


VFR conditions will continue for interior northern California
over the next 24 hours. Winds generally below 10 knots except
southwest gusts 15 to 20 knots through the delta.



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