Scientific Forecaster Discussion
Area forecast discussion
National Weather Service San Diego California
130 PM PDT Thursday Mar 26 2015
High pressure aloft over California will bring another unseasonably
warm day Friday. Weak onshore flow will bring minor cooling near the
coast but it will remain hot inland. On Saturday and Sunday the
cooling will spread inland and marine layer clouds will return to
the coastal areas. High pressure will rebuild over the region Monday
with temperatures remaining above average early next week.
Discussion...for extreme southwestern California including Orange...
San Diego...western Riverside and southwestern San Bernardino
Today was another exceptionally warm day thanks to high pressure
aloft over California and the Santa Ana winds. The downslope flow
made it all the way to the coast this morning and the temperatures
rose quickly after sunrise in the dry airmass. 1 PM temperatures had
reached 90 or higher at Rancho Bernardo...Escondido...Poway...Lake
Forest and Fullerton. Santa Ana winds gusted to 30-40 miles per hour this
morning in the San Diego mountains but had since weakened. The sea
breeze kicked in around 11 am which slowed the warming at the coast.
The high amplitude ridge over California today will dominant our
weather through Friday which will be another warm/hot day with
record highs likely. The ridge axis shifts east over the lower
Colorado River valley but 500 mb heights and thickness show only minor
decreases. The biggest difference between today and tomorrow will be
the lighter offshore winds in the mountains and foothills due to
weaker offshore pressure gradients. A shallow marine layer and an
earlier onset of the sea breeze should bring a few degrees of
cooling to the coastal areas and western valleys...but farther
inland it will be nearly as warm as today. Mountains and deserts will
actually be warmer by a few degrees.
The ridge will break down Saturday ahead of a weak trough that will
deepen along the California coast this weekend. Patchy low clouds
and fog may return to the coast Saturday morning with the
development of a shallow marine layer. Saturday will be cooler west
of the mountains...but mountain and desert temperatures will remain
relatively unchanged. Palm Springs is likely to reach 100 degrees
for the first time this year which would break the record high of 97
set in 1969.
Sunday through Thursday...the weak trough trekking across so-cal
Sunday and Sunday night will be too moisture-starved to bring
precipitation...but it will bring middle and high clouds. The trough moves
east Monday and will be followed by weak high pressure and warm
weather Monday. Prevailing zonal flow/weak troughing Tuesday through
Thursday will keep temperatures at or above average as we head into
the first week of April.
Climate note: the record highest average temperature for the month
of March at Lindbergh Field is 64.3 set in 1978. This year the
average temperature through March 25th is 66.1. This will be yet
another temperature record that will be broken.
Aviation... 262000z...scattered clouds at or above 15000 feet with unrestricted
visible through tonight. Local model guidance is indicating a return of
marine layer stratus to the coast tonight...however the current
visible satellite is not trending in this direction. Therefore
forecaster confidence is low for low ceiling/visible formation along the
coast tonight and have left it out of the tafs for now.
100 PM...no hazardous marine weather is expected through Monday.
100 PM...a south swell with a long period of 17-20 seconds will
arrive at area beaches Friday...creating strong rip and longshore
currents this weekend...as well as somewhat elevated surf along
south-facing beaches. For details...see the beach hazards statement
Skywarn... Skywarn activation will not be needed Friday.
California...beach hazards statement from late tonight through Sunday
afternoon for Orange County coastal areas-San Diego County