Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

fxus66 keka 182200 

Area forecast discussion
National Weather Service Eureka California
300 PM PDT sun Aug 18 2019

Synopsis...near normal temperatures will persist across the
interior through Tuesday, with another warming trend forecast
during the latter part of the upcoming week. Otherwise, dry
weather is expected to prevail.


Discussion...marine stratus returned along the coast overnight
and continues to impact a good portion of the north coast early
this afternoon. Acv profiler shows a fairly deep marine layer,
which has impacted coastal and slightly inland temperatures a
little today. Lowered temperatures in these areas this afternoon
and tomorrow as the marine layer is expected to persist near its
current depth for the next day or two. Stratus and patchy fog will
likely follow a routine pattern over the next couple of days,
with nightly intrusions, followed by localized clearing in the
afternoon and evening hours. Areas of patchy drizzle will also be
possible during the early morning hours of Monday and Tuesday as
a couple of impulses pass over the area.

Water vapor loop shows a weak upper-level disturbance exiting the
region and an upper-level trough entering the northeast Pacific.
Near normal temperatures across the interior will persist through
Tuesday, with troughiness lingering across the northeast Pacific
through Wednesday. High pressure will then nose into the area
during the latter part of the upcoming week. Afternoon highs
across the interior are forecast to warm up into the mid to upper
90s in some of the warmer interior valleys as a result.
Additionally, some stratus may push up Russian River valley again
tonight and impact Ukiah, but confidence is low.


Aviation...a deepening marine layer has allowed stratus to linger
well into the afternoon along portions of the north coast, bringing
persistent IFR ceilings to cec and intermittent low cigs to acv as
well. Recent observational trends suggest that southerly winds may
hinder any improvement for the remainder of the day at cec, while
acv will likely see some continued fluctuation between VFR and IFR
through late afternoon. More extensive stratus development this
evening will keep coastal terminals at IFR/LIFR overnight, with the
potential for some patchy drizzle to hamper visibilities towards
morning. Troughing offshore will continue to promote a deeper marine
layer for the next few days, likely resulting in stratus taking
longer to dissipate during the afternoon. Meanwhile, interior
locations will remain predominantly VFR, although there is some
potential for low clouds to encroach up the Russian River valley
towards uki in the morning. /Cb


Marine...winds and seas will continue to trend downward through
this evening as increasing troughiness over the eastern Pacific
helps to weaken the coastal pressure gradient through the middle of
the coming week. Cancelled the small craft advisories for the
nearshore waters a few hours early as observations and hi-res
guidance indicate conditions have fallen below advisory level,
although some localized gustiness and higher waves may persist into
this evening in the vicinity of Point Saint George and Cape
Mendocino. Advisories look on track to expire later this evening for
the outer waters as well, although elevated seas could linger a bit
longer over the southern waters. Thereafter, a lighter wind regime
and calmer seas will persist through Wednesday before northerlies
start to pick back up towards the end of the week. A couple of small
mid-period swells will also move through the waters from the
northwest over the next few days. /Cb


Eka watches/warnings/advisories...
Northwest California coastal waters...Small Craft Advisory until
11 PM PDT this evening for pzz470-475.



Visit US at https://www.Weather.Gov/Eureka

Follow US on facebook and twitter at:

National Weather Service Glossary of Abbreviations