Weather Synopsis – June 11, 2024

James Murakami

Tue11th70/57Low clouds clearing to a sunny afternoon. Return of evening low clouds likely.
Wed12th71/56Low clouds clearing to a sunny afternoon. Chance of late evening low clouds.
Thu13th72/56Chance of early morning low clouds; Otherwise, mostly sunny day. Mostly clear evening.
Fri14th71/58Chance of early morning low clouds; Otherwise, sunny day. Clear evening.
Sat15th75/60Chance of some early morning low clouds; Otherwise, sunny day. Clear evening.


A belt of high pressure aloft covers an area from northern California southeastward through the Southwest. It’s responsible for the hotter than normal weather over much of the interior sections of the aforementioned, high pressure zone. There is a weak, upper level low pressure west of northern Baja California, but it has so far been devoid of relevant weather (somewhat disrupted low cloud field in the area of low pressure). In coastal, southern California low level on-shore flow dictates the weather as is typical for this time of year.

The numerical models are predicting relatively minor day to day changes with the surface, on-shore flow strength. On-shore flow is expected to reach a low point Saturday morning. It may return to a similar weakness sometime early next week, depending on which model solution verifies. These predicted changes should have a more noticeable affect on temperatures and cloud cover for well inland locations than for areas close to the coast. The marine layer should get shallower during on-shore flow weakness, but most model forecasts don’t show the marine layer going away (remains defined enough to promote low clouds at times for the near coastal zone). In short, moderate swings in temperatures (during shallow marine layer episodes) should be confined to the coastal valleys, the interior, and possibly parts of the well inland, coastal plain (probable warmer than normal weather during these periods). For areas near the coast (campus included), the warming cycles should be more muted (UCLA maximum temperature so far this month has been only 71 degrees…normal for early June). “June Gloom” weather may prevail in the coastal zone for at least the next several days.

As I’ve mentioned in past synopses, subtle day to day changes in the wind flow pattern (affecting the Southland) can have noticeable affects on the “behavior” of the marine layer clouds. The aforementioned, Baja low pressure is forecast to make a nearby pass (to our south) on Friday. Since the marine layer is expected to get shallower later this week, there is potential for a disruption of the low cloud field at that time. This could result in sunnier and warmer weather near the coast than I currently expect (not drastically warmer, however…will require a lack of on-shore flow for more warming). I’ve leaned today’s forecast with some modest warming on Saturday, but confidence is low at this time.

A separate, predicted trough early next week also has some potential to disrupt the low cloud field (valid Tuesday). For the time being, I’m not expecting any major weather changes for the campus area, but the marine layer could surprise at some point. Oh, should the marine layer deepen significantly during strengthening on-shore flow episodes (such as late in the weekend), spotty early morning drizzle/light rain is possible (as has happened earlier this week).

Next issued forecast/synopsis may be on Thursday, 13 June.