Scientific Forecaster Discussion
fxus66 ksgx 191820 aaa
Area forecast discussion...updated
National Weather Service San Diego California
1020 am PST sun Feb 19 2017
high surf warning downgraded to a high surf advisory. West/W/a and
beaches sections updated.
scattered, light showers will linger along and west of the mountains
today, shifting toward the mountain slopes by afternoon as the clouds
gradually break. Light showers may linger over Orange, San
Bernardino, and northwest sections of Riverside County at times into
Tuesday as weather systems move through northern portions of the
state, but San Diego and most of Riverside counties should be dry
and a little warmer. Breezy and cooler midweek as a trough passes
with a period of showers possible. Even cooler by next weekend with
another chance of rain and mountain snow.
Discussion...for extreme southwestern California including Orange...
San Diego...western Riverside and southwestern San Bernardino
National Weather Service radar showed scattered, light showers continuing to move east,
off the coastal waters, and inland. The bulk of the echoes were
across San Diego County, but rain gages indicate light rain is
widespread across the San Bernardino Mountain coastal slopes as
well. Based on remote rain gage data through 8:30 am pst; the rain is
very light, with two hour totals remaining below 0.05 inch.
At 8 am PST...satellite imagery showed a thick cloud deck from the
mountain crests, west across the coastal waters. Skies were mostly
cloudy in the Coachella Valley where some fog was reported this
morning, but mostly clear over the San Diego and SW San Bernardino
County deserts. Surface pressure gradients were running around 4-6
mbs onshore ksan-Nevada and 2-3 mbs onshore to the lower deserts. Peak
wind gusts were mostly under 20 mph, except in wind-prone Mountain
Pass and canyon areas where westerly gusts were 25-35 miles per hour.
No changes to current forecast.
From previous discussion...
Short term (today through tuesday)...
a few light showers will continue this morning...mainly along and
west of the mountains in San Diego County and in the inland
Empire...decreasing this afternoon. In the deserts...there are
areas of low clouds and some patchy fog as well. There was a
recent spotter report of dense fog in the Borrego Springs area.
For tonight through Tuesday...precipitation from storms moving
into northern and central California will extend into portions of
Southern California at times. Light precipitation may extend into
portions of southwest California at times...mainly for areas
bordering Los Angeles County. Snow levels will be fairly
high...mostly 7000 feet for above.
Long term (wednesday through saturday)...
a colder low pressure system moving inland through California
Wednesday night will bring strong gusty west winds in the
mountains and deserts with chances for light precipitation along
and west of the mountains. Dry and little warmer for Friday...then
a little cooler for next weekend with chances for precipitation.
The current forecast leans a little slower than the European model (ecmwf) and not
as amplified as the GFS with a low pressure system that could
bring precipitation late Saturday into Sunday.
191619z...bkn-ovc cloud decks within the 1500-7000 ft msl layer with
isolate-to-scattered light showers, areas of 3-5 sm vis, local vis 1-
2 sm, and mountain obscuration of coastal slopes will continue
through 2100 UTC, with areas of 2-4 sm vis, local vis 1/4 sm and
cigs of 500-1500 ft agl in the lower deserts likely lifting and
clearing through 1800 UTC. 2100-20/0900 UTC, showers dissipating,
with clouds becoming scattered-broken in the 3000-6000 ft msl layer, mountain
obscuration continuing, and otherwise vis p6sm prevailing. 20/0900-
1500 UTC, scattered-broken cloud decks within the 5000-15000 ft msl layer
developing, with mountain obscuration of higher slopes, possible
isol showers in Orange and San Bernardino counties, and otherwise
p6sm vis prevailing.
at 7 am, buoy observations indicated 13 foot seas in the outer
waters and 9-12 foot seas in the inner waters. A Small Craft
Advisory continues through this evening for the large combined seas.
Seas should lower below 10 feet by late this evening, if not
Another storm system may create more hazardous marine weather
conditions late Wednesday into Thursday, with northwest winds of 25-
30 kt possible and seas near or above 10 feet.
1020 am update...latest buoy and surf observations indicate that
seas and surf continue to trend down, with surf heights well below
warning levels, and swell will continue to gradually lower through
the day. Thus, the high surf warning has been downgraded to a high
surf advisory. Nevertheless, high surf of 5-10 feet will continue
today, with strong rip currents as well, resulting in dangerous
Skywarn activation is not requested. However weather spotters are
encouraged to report significant weather conditions.
California...high surf advisory until 10 PM PST this evening for Orange County
coastal areas-San Diego County coastal areas.
Pz...Small Craft Advisory until 10 PM PST this evening for coastal
waters from San Mateo Point to the Mexican border and out
to 30 nm-waters from San Mateo Point to the Mexican border
extending 30 to 60 nm out including San Clemente Island.