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Area forecast discussion 
National Weather Service Eureka California
302 PM PDT sun may 24 2015

Synopsis...dry weather will prevail tonight due to high pressure
over the region. An upper trough will bring a chance of showers
and thunderstorms to Trinity County on Monday. The coast can
expect overnight and morning clouds with partial clearing each


Discussion...dry weather will prevail tonight due to high pressure
over the region. Clouds will build along the coast. An upper
trough will move across the Pacific northwest on Monday with the trailing
edge clipping far northern California. All the
models...GFS...ECMWF and nam12 indicate precipitation developing with
daytime heating over Trinity County. Profiles look better for
storms with much less capping and higher cape across the eastern
portion of Trinity County. Moisture is not very deep so there may
not be much in the way of cloud cover initially. Precipitable waters approach 1
inch but northwest flow aloft will carry the storms quickly to the
southeast. Isolated heavy rain will be possible.

Ridging over the area on Wednesday and Thursday should bring drying...warming
and increasing stability in the interior. Based on the surface
pressure pattern and the dgex boundary layer humidity...coastal
areas will most likely see low clouds and perhaps some fog each
day and night. The models have been consistently showing fairly
dry southwest flow aloft around middle week. The GFS does show
convective parameters favorable for isolated convection over the
higher terrain on Friday and Sat as a couple of short waves move
toward the area and into the ridge. Confidence is not high enough
at this point to add storms that far will leave the
forecast dry.


Aviation...after a brief clearing along the coast this
afternoon, look for low clouds to return this evening. An upper
trough moving in from the north is expected to deepen the marine
layer, so ceilings along the coast should be in the 007 to 012 range.
If the surface ridge hangs on a bit stronger ceilings will drop below
005. Ceilings are expected to lift nicely on Monday with the
possibility of afternoon VFR. The interior tonight will be
interesting with the deepening marine layer. Clouds are expected
to penetrate deeper into the coastal river valleys, bringing down
ceilings at fot and other similar locations. The main issue will be
whether the low clouds will make it into uki. So long as the
marine layer deepens as expected, we should see the low clouds
make it in. Went ahead and put this in the tafs but at this point
only moderately confident in ceilings coming in. Bfg


Marine...pressure gradient driven northerly winds will continue
this afternoon and evening, contributing to locally generated
short period steep waves, generally at 7 to 10 feet. The northerly
winds and steep seas will persist at least another 24 hours due to
an offshore high pressure system over the eastern Pacific. The
pattern begins to change during the first half of the week as an
upper level low pressure system moves over the
region...diminishing the coastal pressure gradient which will
cause lowing winds and steep seas. Bfg/djb


Eka watches/warnings/advisories...


Northwest California coastal waters...

Small Craft Advisory for pzz450-455-470-475.



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