Cooler, Foggy Conditions to Give Way to Slight Weekend Warming Trend

A persistent marine layer bringing fog and potentially very light drizzle to the Pasadena area is expected to continue through Saturday before giving way to a significant warming trend beginning Sunday, according to the National Weather Service.

Current temperatures are hovering below seasonal averages in the mid-60s, with Wednesday’s high struggling to reach 68 degrees under cloudy conditions and light south-southwest winds of 5 to 10 mph.

Forecasters predict the pattern of night through morning low clouds, fog and occasional drizzle will continue through Friday. Thursday will see similar conditions with a high near 69 degrees and light to moderate southwest winds that could gust up to 15 mph by afternoon.

A cooling trend will take hold Friday when highs will drop to around 64 degrees. Saturday is expected to be the coolest day of the forecast period with temperatures potentially approaching record low maximums for the date in the region.

While no significant rainfall is expected, the deep marine layer will produce patchy drizzle through Saturday morning. Friday night into Saturday looks most favorable for measurable precipitation as a cutoff trough approaches the California coastline, with amounts generally less than a quarter inch.

“A significant pattern shift begins Sunday as an upper-level ridge of high pressure builds into the West Coast,” the weather service said.

This shift will bring a sustained warming trend with diminished marine layer influence. Monday is expected to reach 72 degrees, followed by continued warming Tuesday with highs potentially reaching 78 degrees.

Here is the latest forecast for Pasadena from the National Weather Service as of 4:41 a.m. on Wednesday, April 23:

Wednesday: Possible patchy light drizzle and fog before 11:00 a.m. Cloudy, then gradually becoming mostly sunny, with a high near 68. South southwest wind 5 to 10 mph.

Wednesday Night: Patchy drizzle and fog after 11:00 p.m. Mostly cloudy, with a low around 48. South southwest wind around 5 mph.

Thursday: Patchy drizzle and fog before 11:00 a.m. Cloudy through mid-morning, then gradual clearing, with a high near 69. Light southeast wind becoming south southwest 5 to 10 mph in the afternoon. Winds could gust as high as 15 mph.

Thursday Night: Mostly cloudy, with a low around 49. South southwest wind 5 to 10 mph becoming light southeast in the evening. Winds could gust as high as 15 mph.

Friday: Partly sunny, with a high near 64.

Friday Night: Mostly cloudy, with a low around 47.

Saturday: Partly sunny, with a high near 63.

Saturday Night: Mostly clear, with a low around 46.

Sunday: Sunny, with a high near 68.

Sunday Night: Mostly clear, with a low around 48.

Monday: Sunny, with a high near 72.

Monday Night: Mostly clear, with a low around 52.

Tuesday: Sunny, with a high near 78.