Warm and dry conditions will continue into Sunday. Temperatures will fluctuate a few degrees each day through mid-week, but mostly stay above average for this time of year. Low clouds and fog expected Sunday morning and again Monday morning along the coast. Pattern change expected for the end of next week, with cooler, windier, and wetter conditions.
For extreme southwestern California including Orange, San Diego, western Riverside and southwestern San Bernardino counties,
.Evening Update,
Mostly clear skies are seen over the region. The low cloud forecast continues to look tricky this evening. Skies over the water are clear for now, but low clouds should start to develop later in the night closer to the coast. If any clouds do form, expect reduced visibility. Areas of high clouds will move into the area on Sunday with minimal changes in temperatures expected throught the middle of the week. We'll continue to keep an eye on the potential for a wetter weather pattern later next week as a low pressure system nears the area.
.Previous Discussion (1247 PM Saturday),
Warm and dry conditions will continue for Sunday although the coast is expected to see a few degrees of cooling, with the mountains and deserts warming a few degrees. Areas of fog are expected to become more widespread overnight into Sunday morning. Fog may be locally dense, most likely near higher coastal terrain. Low clouds and fog are expected Sunday night into Monday morning with local high resolution guidance indicating a slight deepening of the marine layer with the passage of a weak shortwave trough. That deepening will keep the fog with the lowest visibility confined to the coastal mesas/higher terrain.
Highs on Monday will be a few degrees cooler across the area due to that shortwave trough. Breezy westerly winds may develop over the mountains and locally into the deserts, but no impacts expected. Weak ridging will build over California on Tuesday, which will bring a degree or two of warming to some inland locations. The ridge will quickly be pushed aside on Wednesday as stronger troughing sets up over the Eastern Pacific.
There remains quite a bit of uncertainty in the ensemble guidance in regards to the timing of the low's passage and expected precipitation amounts. Members of the GEFS are showing a quicker passages of the low with the bulk of the precipitation centered on Thursday/Friday, while the majority of the ensemble members of the ECMWF are showing a slower progression and the bulk of the precipitation centered over next weekend. Both of the global models have quite a bit of spread in precipitation amounts as well. In addition to timing of rainfall, the forward progression of the low will influence when the strongest winds and coldest conditions will occur. It's possible the mountains will see some late season snow out of this system. There still remains considerable uncertainty in snow levels with NBM guidance indicating snow levels may range from 6500-8000 feet Thursday through Saturday.
050415z, Mostly clear skies through this evening. Chances for low clouds 400-800 ft MSL to impact coastal areas after 10Z Sun, best chances (50-60% chance) for southern SD Co VCTY KSAN/KCRQ. Lower chances (20% chance) for cigs to impact KSNA. Vis restrictions of 2- 5SM in BR possible, with restrictions 1 SM or less near higher coastal terrain. Any low clouds and vis restrictions should scatter 16-18Z Sun with BKN-SCT clouds over 20K ft MSL for much of Sunday elsewhere.
No hazardous marine conditions expected through Wednesday. Winds and seas may increase late next week due to an incoming weather system. Low confidence in details.
Ca, None. PZ, None.
