Ation/marine Discussion,
Visible satellite imagery reveals a battle early this afternoon between the typical retreat of low clouds toward the coastline and a robust coastal eddy pushing the other way. As a result, low clouds may linger through the afternoon at the immediate SD County coastline. Regardless of how that plays out, cool and breezy conditions will dominate the region this weekend along with increased cloud cover for the coastal basin as an unseasonably deep upper trough over the PNW makes its presence known. Temperatures will be around 5 degrees below average at the coast and 5 to 15 degrees below average for inland areas today. For Sunday, those values drop to 5 to 10 and 10 to 20 degrees below average, respectively. In fact, temperatures may still be slightly overdone as models are struggling to deal with this anomalously cool pattern for late June. Additionally, a deepening marine layer may allow for drizzle at the coast and locally into valleys Sunday morning.
The main story for the deserts this weekend will be the wind. West-southwest winds are expected to peak in strength this evening with widespread gusts 35-55 mph and local gusts exceeding 65 mph along desert slopes and through the San Gorgonio Pass. See the Wind Advisory for more details. Winds will be slightly weaker on Sunday as the core of the upper trough begins to progress eastward toward the High Plains.
Models are in strong agreement that reinforcing shortwaves will keep the longwave troughing pattern in place over the western CONUS through next week. This will keep temps cool through the forecast period with strong marine layer influence for the coastal basin and breezy conditions for the deserts. A shortwave is expected to round the base of the trough sometime late Monday into Tuesday. There is some discrepancy in the exact track and strength of this shortwave, but it may briefly reinforce already elevated winds for the deserts. The longwave trough is expected to slowly diminish in strength by late next week, allowing for a slow warming trend. Even so, the mean of the ensembles indicates temperatures and upper heights will remain at least slightly below average through next weekend.
A broad low pressure system will continue to deepen the marine layer and keep temperatures below average for the next several days. Morning low clouds through the coastal basin each day with a chance for a few fully overcast days at the coastline. Strong winds will continue through the weekend for deserts and desert slopes, peaking today and slowly weakening over the next several days.
For extreme southwestern California including Orange, San Diego, western Riverside and southwestern San Bernardino counties,
, Updated Aviation/Marine Discussion,
Visible satellite imagery reveals a battle early this afternoon between the typical retreat of low clouds toward the coastline and a robust coastal eddy pushing the other way. As a result, low clouds may linger through the afternoon at the immediate SD County coastline. Regardless of how that plays out, cool and breezy conditions will dominate the region this weekend along with increased cloud cover for the coastal basin as an unseasonably deep upper trough over the PNW makes its presence known. Temperatures will be around 5 degrees below average at the coast and 5 to 15 degrees below average for inland areas today. For Sunday, those values drop to 5 to 10 and 10 to 20 degrees below average, respectively. In fact, temperatures may still be slightly overdone as models are struggling to deal with this anomalously cool pattern for late June. Additionally, a deepening marine layer may allow for drizzle at the coast and locally into valleys Sunday morning.
The main story for the deserts this weekend will be the wind. West-southwest winds are expected to peak in strength this evening with widespread gusts 35-55 mph and local gusts exceeding 65 mph along desert slopes and through the San Gorgonio Pass. See the Wind Advisory for more details. Winds will be slightly weaker on Sunday as the core of the upper trough begins to progress eastward toward the High Plains.
Models are in strong agreement that reinforcing shortwaves will keep the longwave troughing pattern in place over the western CONUS through next week. This will keep temps cool through the forecast period with strong marine layer influence for the coastal basin and breezy conditions for the deserts. A shortwave is expected to round the base of the trough sometime late Monday into Tuesday. There is some discrepancy in the exact track and strength of this shortwave, but it may briefly reinforce already elevated winds for the deserts. The longwave trough is expected to slowly diminish in strength by late next week, allowing for a slow warming trend. Even so, the mean of the ensembles indicates temperatures and upper heights will remain at least slightly below average through next weekend.
280330z, Coast/Valleys, Low clouds based 1500-2000 ft MSL are covering more than 10 miles inland of southern OC and San Diego County. Most of the coastal basin, including KONt/KSBD to have cigs by 07z. VIS reductions along mountain foothills where clouds meet terrain. Bases lift early Sun, around 13z, above 2000 ft MSL and clear the valleys 17-19Z Sun, with a 60% chance of only partial and intermittent clearing along the immediate coast Sun afternoon. Clouds fill inland after 01z Mon with similar bases.
Mountains/Deserts, West winds currently gusting 25-50 kt on the desert slopes into the deserts with local gusts to 55 kt through the San Gorgonio pass. MOD up/downdrafts in lee of mountains. Winds decrease and become more localized 06-10Z Sun. Winds re-strengthen Sunday afternoon after 22z - though not as strong - gusting 25-45 kts along the desert slopes.
Breezy NW winds occasionally gusting around 20 kt this evening near San Clemente Island may create hazardous conditions to small craft. Otherwise, no additional hazardous marine conditions are expected through Friday.
Ca, Wind Advisory until 5 AM PDT Sunday for Apple and Lucerne Valleys.
Wind Advisory until 11 PM PDT Sunday for San Diego County Deserts.
Wind Advisory until 2 AM PDT Monday for San Gorgonio Pass near Banning.
PZ, None.
