Calpella, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

036
FXUS66 KEKA 122223
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
323 PM PDT Wed Mar 12 2025

.SYNOPSIS...Risk for very slippery road conditions will increase
tonight through Thursday morning as the potential for small hail
and low elevation heavy snow showers increase. A brief break is
anticipated Thursday evening before the next round of low
elevation snow arrives by Friday morning. Snow levels should rise
over the weekend as a moderate atmospheric river storm brings an
increase risk for heavy rain and strong winds.

&&

.DISCUSSION...Frontal boundary moving across the area today has
been producing widespread moderate to locally rainfall. As of 2
PM, 24 hour totals generally ranged from 0.50 to 1.0in with
higher amounts in the King Range (2.00-2.50) and 1.0 to 1.5
inches in Del Norte. Prime concern going into tonight and Thu
is lowering snow levels and potential for accumulations above
1500-2500 feet. Precip rates and coverage will fall off tonight
in the showery air mass regime after frontal passage, however
impacts will be much greater as snow levels plummet to 1500-2000
feet by early Thu. Thus we hoisted a winter weather advisory for
most all interior zones tonight/early Thu AM where just 1-2
inches could create slippery driving condition and impact travel
on major highways. Snow levels should rise up during the day on
Thursday and potential for localized intense precip rates should
diminish in the afternoon. HRRR is by far the most aggressive
with heavier precip rates compared to other CAMS in the HREF.

A winter storm warning remains in effect for Trinity County with
hefty accumulations of a foot or more likely above 3500 feet.
Snow accumulations for lower elevations are less certain for
Trinity tonight behind the frontal boundary in the showery air
mass. Westerly upslope flow into the coastal ranges of Del Norte
and Humboldt should support snow amounts sufficient for a winter
weather advisory with totals of 3-5 inches above 2000-2500 feet
by 11 AM Thu. This will have significant impact on travel over
Berry Summit on 299 as well as route 36 around Dinsmore. Confidence
is less for Del Norte on route 199 where an inch or two could
accumulate by 11 AM Thu.

Another hazard tonight into Thu is small hail with convective
storms. Impacts may be much greater considering how rapidly hail
accumulates in what may seem like safe driving conditions. We may
end up needing a winter weather advisory for coastal areas if the
hail accumulates, causing multiple pile ups. We will continue to
message this insidious hazard via social media outlets and a
weather story graphic on our webpage. Convective allowing models
continue to show simulate composite reflectivities over 40dBz and
we will need to monitor the activity for the possibility of
strong storms and perhaps waterspouts in the lee of Cape
Mendocino/around Shelter Cove.

After a brief break Thu evening, another storm with low snow levels
(1500-2500 feet) is forecast to arrive quickly late Thu night
into Friday morning. Snow levels will start out lower with this
next round of precip and impacts on major travel corridors and
populations will likely be greater even though overall snow
amounts will be lower compared to today`s storm.

We may see a break in the active and wet weather on Saturday as a
ridge pumps up over the area. An atmospheric river storm (AR1/AR2)
will likely bring another bout of moderate to heavy rain and
possibly hefty high mountain snow as well as strong winds toward
the latter portion of the weekend and early next week. Snow levels
should rise up over the weekend, however travel impacts above
4000-4500 feet are possible. There is still a great deal of variability
and spread with the timing and magnitude of winds with this next
storm and fine details are difficult to resolve multiple days out.
Stay tuned for updates. Another break in the wet and active
weather is forecast for Tuesday as a transient ridge builds. The
active flow pattern with periods of precip will probably continue
mid to late week next before more stout ridging aloft returns. DB

&&

.AVIATION...A cold front, developed into a frontal wave and
ushered in much rain today. Shortly after noonday, the frontal
wave began to move onto the North Coast. Therefore, airport
impacts became more substantial due to Cig/Vis lowering and rain
intensities becoming greater. A threatening flight hazard today
was LLWS, associated with a low level jet, ahead of the front. The
LLWS hazard diminished as the wave moved onshore. Surface winds
were less along the coast as the pressure gradient was more
relaxed around a low center off the Del Norte Coast...and
associated with the frontal wave. However, the gradient was
greater over the Mendocino Interior resulting in continue gusty
winds at UKI. As rain persisted today, embedded showers were
frequent along the North Coast. These showers, some heavy, will
bring a few periods of IFR conditions to the coastal terminals.
Convection possibilities will be greater in the evening as
instability increases. VCTS is appropriate to be added to the
coastal TAFs tonight. /TA

&&

.MARINE...A strong frontal system passed through this waters this
morning and gale to strong gale criteria were met in all waters.
Winds have eased behind an area of low pressure which followed the
front, and the heightened steep, wind driven seas will continue to
slowly subside. The southerly winds became quite strong in the
southern zones today as the low moved ashore, and steep, hazardous
seas are expected in those zones into the late afternoon. Seas are
not likely to drop below 10 ft as a 14 second WNW swell builds to 10-
12 ft through Thursday. Winds turn northwest up to 20 kts tonight
behind the front. Winds will only briefly ease Thursday before
southerly winds increase again Thursday night into Friday with the
next strong frontal system. Gale strength winds are forecast, and
Gale Watches are up for all zones. As the steep wind driven
southerly waves subside, a steep westerly swell will then build in
Friday evening at around 12-14 ft at 12 seconds and may contribute
to a chaotic sea state. Southerly winds are then forecast to once
again increase Saturday through Sunday, and gale conditions with
potential steep and hazardous seas look likely again with that
frontal system. JJW

&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
     Winter Weather Advisory from 5 PM this afternoon to 5 PM
     PDT Thursday for CAZ102-105.

     Winter Storm Watch from Thursday evening through Friday
     evening for CAZ102-105-111-114.

     Wind Advisory until 2 PM PDT this afternoon for CAZ104>106.

     Winter Weather Advisory from 11 PM this evening to 11 AM
     PDT Thursday for CAZ104-106-110-111-113>115.

     Winter Storm Warning until 8 PM PDT this evening for CAZ107-
     108.

     Winter Storm Watch from late Thursday night through Friday
     evening for CAZ107-108.

     Wind Advisory until 5 PM PDT this afternoon for CAZ109-110-
     112-113-115.

     Winter Storm Watch from late Thursday night through Friday
     afternoon for CAZ110-115.

NORTHWEST CALIFORNIA COASTAL WATERS...
     Small Craft Advisory until 6 PM PDT this evening for PZZ450-
     470.

     Gale Warning until 2 PM PDT this afternoon for PZZ455-475.

&&

$$

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For forecast zone information
see the forecast zone map online:
https://www.weather.gov/images/eka/zonemap.png