Cool Today But Weekend Will Warm

Cooler-than-normal temperatures are expected to persist in Pasadena through Friday due to a deep marine layer and strong onshore winds, according to the National Weather Service.

Temperatures on Thursday are forecast to be 6 to 12 degrees below average, with cloudy skies gradually becoming mostly sunny in Pasadena. The city can expect a high near 63 degrees and south-southwest winds of 5 to 10 mph.

“The marine layer is 3,300 ft deep,” the National Weather Service said in a synopsis issued at 3:17 a.m. Thursday. “There is strong onshore flow to the east and weak but increasing onshore flow to the north.”

Friday will bring breezy conditions as northwestern winds peak, helping to clear out low clouds. However, temperatures will remain below seasonal norms despite a slight warming trend.

The weekend promises sunnier skies and a moderate increase in temperatures, with the warming trend continuing into Sunday and Monday. Valleys could see temperatures reaching the low 80s by Monday, potentially the warmest day of the upcoming week.

Tuesday’s weather will depend on the movement of an overhead ridge and the strength of onshore flows, which could lead to slight cooling. By Wednesday, a return of coastal low clouds and increased onshore flow is likely to drop temperatures by about 4 degrees compared to Tuesday’s highs.

Here is the latest National Weather Service forecast for Pasadena issued at 3:29 a.m. Thursday morning:

Thursday: Cloudy, then gradually becoming mostly sunny, with a high near 63. South southwest wind 5 to 10 mph.

Thursday Night: Increasing clouds, with a low around 50. Southwest wind around 5 mph becoming east southeast in the evening.

Friday: Cloudy through mid morning, then gradual clearing, with a high near 69. South southeast wind 5 to 15 mph becoming west in the morning. Winds could gust as high as 20 mph.

Friday Night: Mostly clear, with a low around 50. West wind 5 to 15 mph becoming north northwest in the evening. Winds could gust as high as 25 mph.

Saturday: Sunny, with a high near 72.

Saturday Night: Mostly clear, with a low around 51.

Sunday: Sunny, with a high near 76.

Sunday Night: Mostly clear, with a low around 53.

Monday: Sunny, with a high near 79.

Monday Night: Clear, with a low around 54.

Tuesday: Sunny, with a high near 80.

Tuesday Night: Mostly clear, with a low around 55.

Wednesday: Sunny, with a high near 77.