Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Eureka California
528 PM PDT sun Mar 16 2014
a cold front will be accompanied by a period of rain tonight
mainly north of Cape Mendocino. This front will also bring
much cooler temperatures to inland areas on Monday. Otherwise
high pressure will build across the eastern Pacific and Pacific
northwest with dry weather and moderating temperatures for the
tweaked sky cover this evening to convey clear skies along the
Mendocino coast and thicker cloud cover further north along the
Redwood coast. Still some brief clearing will occur around Fortuna
and Crescent City, but otherwise most spots north of cape mendo
will stay cloudy this evening. Had to slow the forecast timing of
the rain this evening a few hours as well. Models are insisting
that rain will arrive between 10-11 PM at Crescent City but
satellite looks at least a couple hours slower. Still expecting
just some isolated showers to linger after sunrise on Monday.
Rest of the forecast looks good. Aad
Previous discussion......issued at 348 PM PDT...
a cold front will push east toward northwest California this
evening with rain arriving from northwest to southeast tonight.
There is a window of clear skies just ahead of the front resulting
from some subsidence which may bring a brief period of clearing at
the Humboldt and del norte coast this evening. Rain tonight will
range from nothing in southern Mendocino County to around a half
inch in del Norte County tonight through Monday morning. Snow
levels will decrease with the front and will fall to near 3500
feet in the northern half of the warning area Monday morning. The
majority of the precipitation will fall before snow levels fall
significantly...so at this time snow accumulation is expected to
be minimal with 1 to 4 inches possible at elevations over 4000
A drying trend will begin on Monday as skies clear and drier air
filters into the region. There will be the potential for frost in
some interior valleys Monday night and again Tuesday night. At this
time frost is anticipated to remain very isolated in northern
Mendocino County so no advisories are currently expected. Afternoon
high temperatures will be 10-15 degrees cooler on Monday than on
Sunday across interior northwest California.
Models are now indicating a more persistent upper ridge will likely
develop over the West Coast beginning on Tuesday through the end of
the week resulting in warmer than average temperatures and mostly
dry conditions. A weak front will bring a chance of rain on
Wednesday but even that front is now dry in both the GFS and European model (ecmwf)
models over northwest California. Have restricted slight chance probability of precipitation
to the northern edge of the County Warning Area on Wednesday and Wednesday night
followed by dry conditions into next weekend. Rpa
Aviation...overnight and through the morning the coast remained
entrenched with low clouds and limited visibilities. Even though
clouds hovered over the coast north of Cape Mendocino...ceilings were
on the rise from average 015-035 and visible VFR by early afternoon. As a
cold front moves toward the north coast...expect ceilings to range from
MVFR-VFR with light rain starting in the far north by early evening.
2130z Sat picture had placed the front around the 200 mile range
give or take. Southerly winds along the coast will become a little
breezier as the gradient strengthens with the approaching front.
Aviation conditions over the interior: late evening and overnight
(mostly lgt) rain with some snow and its associated hazards over
higher elevations. Ta
Marine...west swell built several feet higher than model guidance
suggested this morning. As a result...a high surf advisory was
issued for the Redwood coast and this remains in effect through the
evening hours. 20 to 24 feet surf is likely along west and northwest facing
beaches in the advisory area with 16 to 20 feet along the Mendocino
coast. This swell will begin to gradually subside after midnight
tonight and through the day Monday. As this happens...surface winds will shift
to northwest to north and increase with gusts over gale force possible over the
offshore waters. Hoisted a gale watch for Monday afternoon through Tuesday
evening. This will likely be upgraded to a warning tonight. The
watch is mainly for frequent gusts to 35 to 40 knots...but sustained
gales are possible...especially over the S offshore leg. Continued
small craft advisories for the near shore waters through the end of the
offshore gale watch. Second
California...high surf advisory until 11 PM PDT this evening caz001.
Northwest California coastal waters...
Small Craft Advisory until 9 PM PDT Tuesday pzz450-455.
Gale watch from Monday afternoon through Tuesday evening
Small Craft Advisory until 3 PM PDT Monday pzz470.
Small Craft Advisory until 3 PM PDT Monday pzz475.
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