Scientific Forecaster Discussion
Area forecast discussion
National Weather Service San Diego California
930 PM PST Sat Feb 28 2015
Synopsis...a deep slow-moving trough over the West Coast will bring
scattered Showers...Mountain snow...and cool weather through
Tuesday. Dry and warmer for the latter half of the week with locally
gusty northeast winds at times.
Discussion...for extreme southwestern California including Orange...
San Diego...western Riverside and southwestern San Bernardino
Scattered showers were filling the radar beam this evening but
rain amounts have been mostly light so far. Totals range from a
a low of a few hundredths of an inch in the inland Empire to a
high of a half-inch in the San Diego County mountains. A precipitation
summary is headlined on our webpage.
Snow was falling in the mountains above 5500 feet. 1-2" of new
snow was reported in the San Bernardino Mountains above 7000 feet
Showers extended westward over the coastal waters all the way
past pt Conception this evening. These showers will move eastward
across so-cal tonight in the southwest flow ahead of a 500 mb closed
low over San Luis Obispo County. This upper low will stall over pt
Conception Sunday...so scattered showers in the moist southwest
flow will continue over socal. A shortwave west of pt Conception
will round the base of the trough Sunday afternoon and may enhance
precipiation Sunday evening. Thunderstorms are possible Monday when
the trailing 500 mb cold pool and steeper lapse rates moves over the
A second upper level disturbance will bring another chance for more
showers Monday night into Tuesday. However...recent model runs have
taken this shortwave and its vorticity maximum farther west over the ocean
Monday night...and take it across northern Baja California Tuesday. This
westerly track would keep most of the precipitation over-water and
only graze southwest California with light precipitation as the bulk of
the energy passes by to the southwest.
Warmer Wednesday through Friday as the eastern Pacific Ridge
offshore builds back over California and into the Great Basin.
Northeast winds between this building ridge and the stalled
closed low over Sonora Mexico will bring a period of moderate
offshore flow for the latter half of the week.
clouds layers between 2000 and 7000 feet mean sea level continuing through Sunday
evening over and west of the mountains isolated light showers becoming
more widespread and heavier late tonight into Sunday morning. Local
ceilings 1000-1500 feet mean sea level and visible 3sm or less are possible in heavier
showers...and coastal slopes of the mountains will remain obscured in
clouds and precipitation. There is a slight chance of thunderstorms Sun
afternoon and evening. These storms may produce small hail...heavy
rain...and brief gusty winds.
Deserts...gusty west winds will continue to diminish this evening.
Isolated-scattered light showers will develop late Sun morning and continue
through sun evening with local visible 3-5sm in heavier showers. There
is a small chance of thunderstorms during this time...mainly over
the High Desert. Otherwise variable cloud layers above 7000 feet mean sea level
and unrestricted visible through Sunday evening.
830 PM...periods of showers will occur through Monday
night...with isolated thunderstorms possible late Sunday morning
through Monday night. These storms have the potential to produce
small hail...brief heavy rain...gusty winds...and cloud-to-water
lightning. There is a chance of showers Monday night into Tuesday.
No hazardous marine weather is expected Wednesday and Thursday.
Skywarn activation is not requested...but reports of rain and snow
totals are appreciated.
California...Winter Storm Warning until 4 PM PST Monday
for Riverside County mountains-San Bernardino County
mountains-San Diego County mountains above 5000 feet.