| Day | Date | High/Low | Forecast |
| Mon | 22nd | 79/65 | Mostly sunny with some mid/high clouds possible. Some evening mid/high clouds possible. |
| Tue | 23rd | 79/64 | Chance of some early morning low clouds; Otherwise, generally sunny with variable mid/high clouds. Partly cloudy evening. |
| Wed | 24th | 80/64 | Chance of some early morning low clouds; Otherwise, mostly sunny day with some high clouds. Mostly clear evening. |
| Thu | 25th | 80/64 | Mostly sunny day except chance of early morning low clouds. Mostly clear evening. |
| Fri | 26th | 78/62 | Mostly sunny day except chance of early morning low clouds. Chance of late evening low clouds. |
Synopsis
High pressure aloft was centered over southern Nevada early this afternoon. The center is forecast to meander, but there should be a general motion toward Arizona by midweek. By the weekend, the center should be moving back toward the Four Corners area. Another move back toward southern California is expected next week, but that shouldn’t be before Monday at the earliest.
The proximity of the high pressure center promoted the recent warming trend. Since all the computer models predict it will strengthen slightly more for a day or two, a little more warming is likely through Wednesday (should level off on Thursday). Minor to modest cooling should follow as the high pressure should weaken and move away from southern California. A new warming cycle is expected early next week, but at this time, no significant warming trend is predicted for later next week.
As has been the case this summer (so far), the departure from normal has been the least near the coast (thanks to a shallow marine layer). The latest warming trend shouldn’t result in temperatures as high nor as persistent as what took place earlier in the month (string of 110+ degree days in the interior 4th through the 9th). Some of the model forecasts show a brief return to seasonal normals over the weekend, but recent model forecasts have over predicted recent cooling cycles. So, don’t be surprised the same occurs this weekend.
Although the “monsoon” boundary has included southern California of late, it has stayed mostly around the Colorado River. Today, “monsoon” moisture increased sufficiently to promote isolated thunderstorms from the San Bernardino mountains northeast through parts of the desert (mostly east of I-15 highway). Tomorrow could be a little more widespread in shower clouds if some model forecasts are right. Some model solutions show variable mid/high clouds developing all the way to the coastal waters tonight into tomorrow morning. While I don’t include it in today’s forecast, unofficially, there is some threat of sprinkles/light showers west of the mountains early tomorrow (mostly before sunrise in L.A. County). I didn’t write it into the campus forecast because a number of things have to occur at the right place at the right time. In any case, I nor the numerical models are expecting measurable rainfall in the coastal plain.
A predicted shift in winds aloft should diminish “monsoon” moisture in southern California after Wednesday morning. The second half of this week should be back to mostly clear weather in the interior. While the low cloud field should remain mostly on the patchy side for the next couple of days, it may make a return to more widespread conditions by the weekend (continuing next week). Areal coverage shouldn’t extend much into the coastal plain (as has been the case lately).
Next issued forecast/synopsis should be on Monday, 29 July.