Scientific Forecaster Discussion
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Area forecast discussion
National Weather Service San Diego California
945 PM PDT Thu Apr 26 2018
gradually cooler through the weekend, with increasing low clouds
spreading inland to the coastal mountain slopes. Expect stronger
onshore flow with strong and gusty southwest to west winds in the
mountains and deserts during the afternoons and evenings. For
Monday and Tuesday...cooler with stronger onshore flow and gusty
northwest to west winds in the mountains and deserts, further
deepening of the marine layer with small chances for light
precipitation along and west of the mountains.
Discussion...for extreme southwestern California including Orange...
San Diego...western Riverside and southwestern San Bernardino
No major changes were made this evening. Still looks like possibly
reaching Wind Advisory criteria by Saturday afternoon into Saturday
A low pressure system currently off the coast of northern California
will move slowly inland during the weekend. This will bring stronger
onshore flow to Southern California with slow cooling spreading
inland. The low pressure system will draw subtropical moisture with
some mid and high clouds into Southern California today...decreasing
tonight and Friday. As the marine layer slowly deepens...night and
morning low clouds and fog will spread inland to the coastal slopes
Friday through the weekend. Stronger onshore flow will also bring
periods of gusty southwest to west winds in the mountains and
deserts during the afternoons and evenings.
For early next week...the global models are in better agreement
with a low pressure system from the northwest that will move into
Southern California Tuesday. This will bring additional cooling
for Monday and Tuesday. There will be stronger and gusty
northwest to west winds in the mountains and deserts. The marine
layer will deepen onto the coastal mountain slopes. There are
small chances for light precipitation west of the mountains early
Monday and slightly greater chances for light precipitation along
and west of the mountains for Tuesday into early Wednesday.
For next Thursday and Friday...an upper level ridge building in
from the west will bring fair and warmer weather with lighter
winds and a shallower marine layer.
270330z...coast/valleys...stratus,with bases around 1500-1800 ft mean sea level
and tops to 2500 ft mean sea level will spread into the inland valleys
overnight. Areas of 3-5 sm vis possible in the inland valleys 09-
16z. Stratus and vis restrictions clearing 15-18z. Scattered-broken clouds
with bases near 2000 ft mean sea level spreading back inland after 28/02z.
Mountains/deserts...local west-northwest wind gusts of 30-40 kt will
occur through tonight and again Friday afternoon and evening over
portions of the Desert Mountain slopes and through San Gorgonio
Pass. Otherwise a few high clouds and unrestricted vis through
no hazardous marine conditions are expected through Friday morning.
West to northwest winds will strengthen Friday afternoon, with gusts
of 25 to 30 kt possible through Saturday evening over the outer
waters. Combined seas will also increase to 6-9 ft. A Small Craft
Advisory has been issued for the period. Winds will temporarily
diminish late Saturday into Sunday morning, but increase again
Sunday afternoon through Monday night.
Skywarn activation is not requested. However weather spotters are
encouraged to report significant weather conditions.
Pz...Small Craft Advisory from 2 PM Friday to 10 PM PDT Saturday for
waters from San Mateo Point to the Mexican border extending
30 to 60 nm out including San Clemente Island.