Area forecast discussion
National Weather Service San Diego California
140 PM PDT Wednesday Jun 19 2013
Synopsis...
upper level trough will remain in place through this weekend...with
only minor changes in the temperatures and marine layer. For this
reason...expect the night and morning low clouds along the coast and
in the western valleys...and some beach locations possibly not
clearing during the day. Gusty west winds will also develop each
afternoon and evening in the mountains and deserts. High pressure
may finally rebuild by early next week...bringing warmer conditions
to the inland areas.
&&
Discussion...for extreme southwestern California including Orange...
San Diego...western Riverside and southwestern San Bernardino
counties...
Water vapor imagery continues to show a negatively tilted trough
moving inland across the intermountain west this afternoon...with
Southern California remaining under the dry westerly flow aloft. As
a result...skies are clear and sunny this afternoon...with just a
few marine clouds over the bight. The eddy pulled the low clouds
out earlier today...and drifted far enough south that even the beach
areas completely cleared. There is also a slight offshore gradient
to our north...so think this also played a part in the marine layer
clearing today. Because of this clearing and more sun...coastal
areas are running slightly warmer at this time today than
yesterday. However...inland areas are a little cooler...thanks to
the influence of the upper level trough. Meanwhile...the onshore
gradients to the east are within half a mb of this time
yesterday...and will likely continue to increase through the evening
hours...as a disturbance moves through the flow aloft.
Therefore...the Wind Advisory for the Banning pass and areas north
of Interstate 10 in the Coachella Valley look on track for late this
afternoon through late tonight. Otherwise...expect a pleasant
evening across the Southland tonight...with the marine layer
returning to the beaches later this evening.
This upper level trough will remain over the west through this
weekend...and potentially into Monday...as several disturbances move
through it. As a result...only expect minor fluctuations in
temperatures and the marine layer over the next several days. An
eddy will likely redevelop each night...with low clouds and fog
pushing back into the coastal areas and into the San Diego County
valleys. The inland Empire will remain mostly clear...but some low
clouds may sneak into the outer fringes of the inland Empire by this
weekend. Otherwise...expect locally gusty conditions to develop in
the mountains and deserts each afternoon and evening.
Models are now in pretty good agreement for early next
week...showing The Four Corners ridge expanding westward into the
Desert Southwest by Tuesday. However...the 12z European model (ecmwf) and now the
12z GFS are showing hints of a weak disturbance along the Southern
California by middle week. For this reason...think the inland areas
will likely see a decent warming trend for Monday through
Wednesday...but coastal areas will continue remain on the cool
side...with low clouds.
&&
Aviation...
192000z...coast/valleys...VFR conds through this evening.
Stratus...with bases around 1200 feet mean sea level and tops near 2000 feet
mean sea level...will develop along the coast late this evening and push around
25 sm inland by middle Thursday morning. Visible 2-4 sm br is expected where
stratus nears higher terrain tonight. Visible and ceilings will improve to
VFR around 17 UTC Thursday morning.
Mtns/deserts...westerly wind gusts to 35 knots will develop over mountain
ridges and Desert Mountain slopes this evening through tonight. Locally
strong up/down drafts and low level wind shear are possible north of kpsp.
Otherwise...clear and VFR conditions will continue through Thursday afternoon.
&&
Marine...previous discussion...
northwest wind gusts around 20 knots will develop over the outer coastal
waters this afternoon through this evening. Conditions are expected
to remain below Small Craft Advisory criteria.
Some of the highest tides of the year are forecast this
weekend...with tidal swings around 9 feet possible. Although surf is
expected to be low to moderate...minor coastal flooding could be
possible. Strong rip currents are forecast throughout the weekend.
&&
Sgx watches/warnings/advisories...
California...Wind Advisory until 3 am PDT Thursday for the Coachella Valley.
Pz...none.
&&
$$
Public...Palmer
aviation/marine...jjt
