| Day | Date | High/Low | Forecast |
| Mon | 12th | 80/63 | Sunny day. Mostly clear evening. |
| Tue | 13th | 79/63 | Mostly sunny day except chance of some early morning low clouds/fog. Mostly clear evening. |
| Wed | 14th | 79/63 | Mostly sunny day except chance of some early morning low clouds/fog. Mostly clear evening. |
| Thu | 15th | 79/63 | Sunny day. Mostly clear evening. |
| Fri | 16th | 79/63 | Mostly sunny day with some high clouds. Some high clouds in the evening. |
Synopsis
High pressure aloft, as is commonly the case, dominates most of the Southwest. However, recently, a trough along the Pacific Northwest coast has extended down through northern California. That has depressed the center of high pressure southward and eastward of southern California (one center well southwest of Los Angeles; main one over New Mexico). The resultant weather has been some modest cooling for well inland areas (compared with several days ago). The temperature trends in the coastal plain have been mixed (some spots a little cooler; some spots actually a little warmer than several days ago…complexities related to effectiveness of a shallow marine layer).
The computer models are pointing toward minor day to day changes in the wind flow pattern affecting southern California this week. A couple of weak troughs this week should prevent any strong redevelopment of high pressure over the Southland (any warming cycles should be fairly minor in most locales). However, subtle shifts in the low level, wind flow pattern may influence how widespread, marine layer clouds and fog will be on any given day (applicable to the coastal plain). It can be a futile task sometimes regarding when and where low clouds/fog may occur near the coast (largely bypassed L.A. County last couple of days). Today’s campus forecast relies on the model consensus (Pacific Northwest trough becoming less of a weather influence down here). It shows a mostly persistence forecast (seasonable temperatures), but day to day changes could go up or down a couple of degrees.
If the model consensus holds up, renewed troughing is forecast for next week. This should favor mostly seasonable to slightly cooler than normal weather (includes interior sections). If some model solutions are right (?), the trough could strengthen further even down to our latitude. A further cooling trend could occur by the end of next week (lasting a couple of days). High pressure would start to impinge on the Southland again thereafter, but at this point, no strong high pressure is foreseen (i.e. no major warming trend).
Throughout the aforementioned period of time, no relevant, “monsoon” moisture incursion is expected in southern California (staying to the south and east of the state). Some model solutions show some potential for a “monsoon” incursion toward the end of the month, but this is far from certain.
Next issued forecast/synopsis should be on Monday, 19 August.