Scientific Forecaster Discussion
Area forecast discussion
National Weather Service San Diego California
342 am PDT Sat may 30 2015
Synopsis...high pressure moving through the region will once
again bring warm weather to Southern California today for inland
locations...and keep night and morning low clouds and fog closer
to the coast. Areas of fog should also be expected early this
morning in the coastal valleys. A trough of low pressure will
move over the western United States early next week...increasing
onshore flow...deepening the marine layer...and bringing gusty
west winds across the mountains and deserts. Temperatures will be
near to a bit below normal for most of new week.
Discussion...for extreme southwestern California including Orange...
San Diego...western Riverside and southwestern San Bernardino
The marine layer has become quite shallow and onshore flow is
pretty weak for example the San Diego to Daggett gradient is
onshore about 4 mb. Marine stratus decks are persistent but
relegated to the coastal waters and only about 5 to 10 miles
Today and Sunday will be the warmest days with temperatures
topping out inland in the middle to upper 90s in the High Desert and
103-105 in the lower deserts...as the upper ridge maximizes and
eventually moves into The Four Corners region on Sunday. A fast
moving upper level shortwave...the first in a likely progression
of additional waves later in the week...will move across socal on
Monday. This feature will bring a much more pronounced marine
layer and inland intrusion of marine air and low clouds.
On Tuesday...behind the shortwave a healthy onshore flow will
continue as upper level flow becomes zonal. Another shortwave but
weaker will pass through Wednesday...keeping our region in an
onshore dominant pattern with temperatures near to slightly below
Pressure gradients will be pretty healthy Monday and Tuesday and
westerly winds will become gusty with the strongest winds likely
Tuesday through the mountain passes and into the deserts. Gusts of
50 to 60 miles per hour will be possible and may reach Wind Advisory criteria
in the more wind prone locations of the mountains and deserts.
Some better run to run continuity with a possible stronger low
moving through California Thursday through Friday. The ecm is the
strongest solution with this feature and could bring some coastal
drizzle along with cooler temperatures and gusty winds.
301000z...high clouds over the region through this evening. Low
clouds...with bases from 1200 to 1500 feet mean sea level and tops near 1700 feet
mean sea level...will continue to develop along the coast this evening...and
push around 25 sm inland overnight. Bases will lower a few hundred
feet overnight...with visible dropping to 1-3sm br where stratus nears
higher terrain. Low clouds will clear towards the coast by late
Sat morning...and likely hug the beaches throughout the day.
Otherwise...few/sct high clouds with unrestricted visible through Sat
300 am...no hazardous marine weather is expected through
300 am...some south swell of 5 feet/14 seconds is likely to occur
from Hurricane Andres from around 170 to 180 degrees. This could
bring some elevated surf and long-shore currents to northern
Orange County late Monday and Tuesday...but the steep angle will
keep the surf from getting above 5 or 6 feet at most beaches.
Skywarn activation is not requested. However weather spotters are
encouraged to report significant weather conditions.