Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

fxus66 ksgx 300410 

Area forecast discussion
National Weather Service San Diego California
910 PM PDT Sat Apr 29 2017

Synopsis... onshore flow will strengthen over the next few days,
bringing cooler marine air with areas of low clouds and fog back to
coastal areas Monday through Thursday. Farther inland it will remain
fair and warm with high pressure building over the west. Cooler next
weekend with a deep trough of low pressure develops near the West


Discussion...for extreme southwestern California including Orange...
San Diego...western Riverside and southwestern San Bernardino

Gusty Santa Ana winds worked their temperature magic Saturday with
80 degree highs in coastal Orange County. Newport Beach set a record
high of 87, besting the high of 86 set in 1921. Oceanside Harbor
also set a record high of 80, breaking the old record of 79 in 1981.

It was a warm start in the oc and ie this morning with overnight
lows as gusty northeast winds kept the atmosphere well mixed, and
overnight lows were only in the mid to upper 60s. Highs today were
in mid to upper 80s, with the highest being 89 at Yorba Linda,
Anaheim and Santa Ana. That equaled the desert highs of 89 at Palm
Springs and thermal.

The strongest wind gust today was 70 mph at Fremont Canyon at 651
am. Coto de Caza had a gust of 52 mph at 351 am. Wind gusts in the
ie and the mountain passes/foothills ranged from 35 to 50 mph range,

*from previous discussion*

The pattern...a deep low pressure trough over the central U.S., And
strong high pressure over the eastpac will maintain a northwest flow aloft
over socal through the first half of next week. For mid next week,
the ridge off the coast drifts inland across CA, then farther east
as a sharp long-wave trough deepens along the West Coast over the

The weather...after a very warm day today, cooling will begin over
coastal areas Sunday as onshore flow increases. Inland areas will
remain quite warm under fair skies. Daytime temperatures will be
near to slightly above average along the coast, and 5 to 10 degrees
f above average inland through Thu. Low clouds/fog will likely
become more prevalent under a strong marine inversion for the coming
week, perhaps not totally clearing the beaches some days. Once the
ridge drifts off to the east, onshore flow will increase further
Fri, into the weekend, deepening the marine layer for further

For the extended period...after next Saturday, the global models are
coalescing around a large Omega blocking pattern across the western
hemisphere. For now, the western cut-off portion of this block is
favored to develop just off the socal coast. If this position of the
cut-off were to verify, it would be much cooler, with even some
showers possible. But given the fickleness of cut-offs, and how far
this is into the future, it would be prudent to lean toward
climatology at this point.


300345z...clear with unrestricted vis through Sunday evening. Patchy
stratus with bases at or below 1000 ft mean sea level and areas of vis below 5 sm may
develop along the coast after 01/09z.


Skywarn activation is not requested. However weather spotters are
encouraged to report significant weather conditions.


Sgx watches/warnings/advisories...


National Weather Service Glossary of Abbreviations