Scientific Forecaster Discussion
Area forecast discussion
National Weather Service San Diego California
200 PM PDT Sat Mar 15 2014
sunny and warm with gusty northeast winds continuing this afternoon
near the coastal foothills of the Santa Ana Mountains and the San
Bernardino County mountains. Winds will weaken late this afternoon.
Sunny and warm again on Sunday with locally gusty offshore winds.
Onshore flow will return for late Monday with cooling...a return of
coastal low clouds and fog...and gusty west winds for the mountains
and deserts. For the rest of next week...periods of weaker onshore
and offshore flow will alternate with temperatures slightly above
Discussion...for extreme southwestern California including Orange...
San Diego...western Riverside and southwestern San Bernardino
Not a cloud in the sky this afternoon...as recent acars soundings
show the marine layer now less than 500 feet deep in response to the
upper level ridge building over the West Coast. Surface high
pressure over the Great Basin and NE winds aloft continue to produce
offshore flow with locally gusty NE winds...and a few locations have
reported wind gusts greater than 45 miles per hour. Surface pressure gradients
remain offshore to the north with -5.4 mb san-tph...but surface
gradients and winds are expected to weaken by late afternoon. Temperatures
will continue to increase through sun and the marine layer become
shallower as the upper ridge builds. Little or no marine layer low
clouds and fog is expected tonight...and temperatures are expected to reach
the upper 80s to around 90 degrees across portions of the inland
valleys on sun.
For late Monday and early Tuesday...a low pressure trough moving
through the Pacific northwest into the Great Basin and central
rockies will weaken the upper level ridge and push the surface high to
the southeast...out of the Great Basin. This will bring increasing onshore
flow with cooler conditions...a return of coastal low clouds and
fog...and gusty west winds in the mountains and deserts. West to northwest
winds of 20-30 miles per hour will be possible with isolated gusts near 45 miles per hour
in wind-prone locations. Low clouds and fog could spread inland to
the coastal slopes late Monday night.
For the rest of next week...shortwaves moving inland to the north in
west northwest flow aloft will alternate weaker onshore and offshore
flow with daytime temperatures slightly above seasonal averages...locally
gusty northeast winds on the coastal foothills at times...and patchy
coastal low clouds and fog during the nights and mornings.
152000z...mostly clear skies with unrestricted visible through Sunday.
Mtns/deserts...areas of north-NE winds gusting 25-35 knots along the mts
and coastal foothills through 16/00z. Low level wind shear and moderate uddfs possible
over and S/SW of the mts due to these winds...including vicinity kont
and ksna. Offshore winds will weaken this afternoon.
another long period northwest swell will arrive in the coastal waters Sun
night and peak on Monday at 7-8 feet with a period of 17 seconds. This
will result in elevated surf at beaches south of del Mar in San
Diego County...and north of Huntington Beach in Orange County. Local
sets of 7 feet or more are possible in these areas Monday...becoming
more intermittent on Tuesday. Large tidal swings and elevated surf will
create strong rip currents as well. Surf and swell will subside
Wed/Thu. See cfwsgx for details on the beach hazards statement in
effect through Monday evening.
A reinforcing...steep westerly swell up to 8 feet will arrive in the
coastal waters Monday night continuing into Tuesday morning. Combined seas
of around ten feet are possible...resulting in very rough seas and
potentially hazardous small craft conditions.
Skywarn activation is not requested. However weather spotters are
encouraged to report significant weather conditions.
California...beach hazards statement from 10 am PDT this morning through
Monday evening for the beaches in the Orange County coastal
areas...San Diego County coastal areas.
Wind Advisory from until 5 PM PDT this afternoon for the Orange
County coastal areas...San Bernardino County mountains...San
Bernardino and Riverside County valleys-the inland
Empire...Santa Ana Mountains and foothills.