Area forecast discussion
National Weather Service San Diego California
200 PM PDT Friday may 24 2013
Synopsis...
daytime temperatures will remain slightly below seasonal averages
through Memorial Day...with only minor day-to-day variations.
Onshore flow with gusty winds in the mountains and deserts will also
continue...along with areas of low clouds extending into the inland
valleys during the nights and mornings. For Tuesday through early
Wednesday...increasing clouds with even lower temperatures and a
chance for precipitation. Dry and warmer for Wednesday and Thursday
with stronger northwest winds in the mountains and deserts.
&&
Discussion...for extreme southwestern California including Orange...
San Diego...western Riverside and southwestern San Bernardino
counties...
Skies are mostly clear this afternoon...except for a few patches of
low clouds over Orange County as a coastal eddy persists. Surface
pressure gradients remain onshore with +5.1 mb san-tph.
Through Memorial Day...the large-scale low/trough over the West
Coast will maintain the onshore flow for gusty west winds in the
mountains and deserts. Daytime temperatures will continue to be a little
below seasonal averages...and the marine layer will remain
relatively deep with night and morning low clouds extending into the
inland valleys. The coastal eddy will likely persist but could
weaken at times. Small day-to-day variations in the marine layer
depth are expected as minor shortwaves move through the mean
cyclonic flow aloft.
For late Monday night through Tuesday night...a stronger shortwave
moving through the northwest flow aloft...is expected to deepen the
trough...forming a closed upper low over central California by Tuesday morning.
The deterministic models still show differences in the timing and
track of the low as it moves eastward through Tuesday night...and
the individual models continue to make minor adjustments to their
various solutions. However...confidence is growing that this system
could produce rain and showers late Monday night through Tuesday night.
Preliminary rainfall estimates are for one tenth to one quarter inch
near the coast and one half to one inch in the mountains. Snow
levels are likely to remain above 7500 feet...so only the highest
elevations of the San Bernardino and Riverside Mountains could see modest
amounts of snow. Onshore flow will likely strengthen and strong west
winds could develop in the mountains and deserts...with gusts of 45 miles per hour
or more possible.
Dry and gradually warmer for Wednesday through Friday in northwest flow aloft as the
trough moves east and heights rise over socal. This will bring gusty
northwest winds in the mountains and deserts and a shallower marine layer.
&&
Aviation...
242000z...coast/valleys...areas of few-scattered stratus will continue
west of the mountains with bases 2500-3500 feet mean sea level and tops to 4000
feet mean sea level through late afternoon. Visible will remain p6sm. Stratus
returning tonight between 25/0100-0400z. A higher pressure aloft and
a weaker coastal eddie will lead to a slightly lower cloud tonight.
Bases between 2500-3000 feet mean sea level and tops near 3500 feet mean sea level. Visible is
expected to remain above 5sm. Stratus will erode back to the coast
between 25/1500-1700z.
Mtns/deserts...westerly winds gusting to 35 knots will occur over the
Desert Mountain slopes and through/east of San Gorgonio Pass late this
afternoon/evening. Winds gusts to 25 knots elsewhere across the lower
deserts. Otherwise...mostly clear with unrestricted visible through
Saturday afternoon.
&&
Marine...
astronomical high tides to 7.2 feet and below normal low
tides...with swings of 8.9 feet...will combine with slightly above
normal surf to bring a small chance of minor coastal flooding today
through Memorial Day. Strong rip currents will continue through
Memorial Day...partly due to the swings in The Tides.
&&
Sgx watches/warnings/advisories...
California...none.
Pz...none.
&&
$$
Public...pg
aviation/marine...jt
