Area Forecast Discussion
Issued by NWS San Diego, CA
FXUS66 KSGX 270958
Area Forecast Discussion
National Weather Service San Diego CA
258 AM PDT Thu Apr 27 2017
Fair and breezy weather will continue today. Onshore winds today
will turn offshore tonight and continue into Saturday morning.
High pressure will bring fair and warmer weather next week with
gradually increasing coastal clouds.
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
High clouds were decreasing while coastal low clouds increased
this morning. An eddy circulation is helping the marine layer get
organized. Brisk northwest flow aloft will continue today with
breezy areas in the mountains and deserts, but winds won`t be as
strong as they were last night. The winds will be quite squirrely
and hard to nail down the next few days with eddies and
onshore/offshore transitions interacting with each other. The low
clouds will clear out this morning to offer a mostly sunny day
through thin high clouds. Late tonight the flow turns abruptly
offshore of the northerly kind. Winds will pick up from Cajon Pass
into northeast Orange County, but not a lot in Riverside or San
Diego Counties. A low pressure trough diving south into Arizona
will boost the offshore flow Friday night into Saturday. Offshore
winds will be quite strong from the northern Inland Empire through
most of Orange County, but not very strong elsewhere.
Temperatures will rise near the coast from the offshore flow this
weekend. As the flow turns onshore Sunday and beyond, the warmer
weather will head inland as it cools a little near the coast. Lots
of sunshine and warm weather will prevail next week as high
pressure aloft sets in over the West. At some point the marine
layer will redevelop and create some coastal clouds for the
standard springtime appearance nights and mornings.
270900Z...Coast/Valleys...BKN-OVC stratus with bases 1000-1500 ft
MSL along the coast and up to 20 miles inland through 17Z this
morning. BKN-OVC stratus after 06Z this evening through Friday
morning, with SCT-BKN cloud layers AOA 20000 ft MSL through
Mountains/Deserts...W-NW winds this morning with surface gusts 35-45
kt along mountain ridges, desert slopes and through the
passes...resulting in strong uddfs/llws over and east of the
mountains. Vis briefly reduced in BLDU and sand in the deserts.
Otherwise SCT-BKN cloud layers AOA 20000 ft MSL and unrestricted vis
through Friday morning.
Northwest winds gusting 20-30 kt through Friday night with combined
seas 8-12 ft. A Small Craft Advisory for the outer waters remains in
effect through Friday night. A Small Craft Advisory for the inner
waters is in effect from 3 pm this afternoon through Friday night.
Skywarn activation is not requested. However weather spotters are
encouraged to report significant weather conditions.
PZ...Small Craft Advisory until 5 AM PDT Saturday for Waters from San
Mateo point to the Mexican Border Extending 30 to 60 nm out
including San Clemente Island.
Small Craft Advisory from 3 PM this afternoon to 5 AM PDT
Saturday for Coastal Waters from San Mateo Point to the
Mexican Border and out to 30 nm.