| Day | Date | High/Low | Forecast |
| Mon | 2nd | 74/57 | Sunny day. Clear evening. |
| Tue | 3rd | 79/66 | Sunny day. Clear evening. |
| Wed | 4th | 86/66 | Sunny day. Some evening high clouds developing. |
| Thu | 5th | 80/60 | Partly cloudy day with mid/high clouds . Partly to mostly cloudy evening. |
| Fri | 6th | 72/57 | Partly to mostly cloudy through the evening. |
Synopsis
Although it’s cooled off (daytime temperatures) thanks to marginal on-shore flow, the start of February is still a warm one (relative to what it should be…afternoons typically in mid-60s at UCLA). A weak, upper level trough that fostered the recent cooling cycle will be displaced southward for a few days. High pressure aloft is forecast to once again intensify over the state. A full fledged, off-shore flow should return tomorrow. Depending on when that takes place (question of morning versus afternoon), temperatures tomorrow near the coast (campus included) may not jump as much as I show in this forecast. Widespread 80 degree weather west of the. mountains (excepting the beaches) is likely for Wednesday/Thursday (80 degree weather possible tomorrow but not widespread in areal extent). Some record high temperatures (for the date) may occur. Cooler weather should occur Friday/Saturday with a second, nearby pass of the aforementioned, upper level trough. However, at this point, cooler than normal weather isn’t expected (at best, seasonable on Saturday).
As with the last off-shore flow event, much of the significant wind should be restricted to higher elevations. Also, areal coverage should be more around east-west oriented canyons/passes (more easterly wind predicted this time around). Peak wind speeds should be comparable to the previous event (mid-60s for highest wind gusts), but locations may differ from the previous event.
That trough that gets displaced to the south is forecast to pick up sub-tropical moisture while west of lower, Baja California. Considerable mid/high clouds should get directed into southern California by Thursday. Noticeable cooling should occur with the cloud cover, but it should remain warmer than normal. There are some computer model forecasts showing scattered, light showers developing over parts of the Southland Thursday night into Friday. The chief threat of showers should be over the southern mountains/southeastern desert. SInce the vast majority of model solutions don’t favor wet weather in L.A. County, I omitted any shower chances in today’s forecast issuance. In any event, rainfall should be minor (under a quarter inch due to relatively high cloud bases and fairly dry air beneath those clouds).
A second, upper level trough is forecast to reach the state by Saturday. It should be too weak to pose a shower threat, but it may promote a return of widespread, marine layer clouds (FYI–some were noted over the coastal water early today but just a few low clouds reaching the coast in San Diego County). With or without coastal low clouds, temperatures should fall back to seasonable levels for a day.
A weak, marginal off-shore flow is predicted for Sunday. Modest warming is expected that day (slightly warmer than normal weather most areas). However, a large Pacific trough is expected to approach the state next Monday (9th). Sometime between the 10th and 11th, there is a chance for widespread showers (distinctly cooler than normal weather too). The model consensus doesn’t favor anything greater than an “ordinary” storm (quarter to half inch rains in the lowlands away from the mountains). Since there are some model solutions depicting a weaker storm (possibly no widespread wet event), it’s too early to have great confidence in the model consensus (for now). However, there may finally be a shift in the Pacific jet stream that doesn’t favor persistent high pressure over the state (shorter duration alternation between high pressure and low pressure).
Next issued forecast/synopsis may occur on Friday, 6 February, time permitting.