| Day | Date | High/Low | Forecast |
| Fri | 28th | 64/53 | Some lingering clouds but mostly sunny remainder of day. Variable clouds in the evening. |
| Sat | 29th | 65/54 | Chance of morning low clouds; Otherwise, mostly sunny day with variable high clouds. Becoming most cloudy in the evening. |
| Sun | 30th | 60/55 | Mostly cloudy through the evening. Slight chance of occasional drizzle/light rain. |
| Mon | 31st | 62/53 | Amended…Mostly cloudy morning with a chance of drizzle/light rain; Partial afternoon clearing. Partly cloudy evening. |
| Tue | 1st April | 65/52 | Partly cloudy through the evening. |
Synopsis
My last forecast (Monday) had less than stellar results. For the most part, campus temperatures stayed lower this week than I expected. The marine layer rushed into coastal plain more quickly than even the numerical models had predicted. The most unexpected outcome (for me) was the morning drizzle/light rain on Wednesday. It wasn’t widespread in areal coverage (mostly on the Westside), but it was an extreme case of marine layer induced rain. To those caught off guard by the wet weather, my apologies. In hind sight though, I don’t know if I would have written in a chance for drizzle for that morning (24 hours in advance). There was no obvious trigger mechanism shown by the models (just a deep marine layer situation supportive of “May Gray”/”June Gloom” weather.
The various models continue to forecast minor day to day changes in the wind flow pattern. The main “storm action” should remain well to the north of southern California (occasional minor to modest, at best, wet weather for northern California. A deep marine layer should persist in the Southland for several more days, at the least (possibly through the next work week). Spotty, early morning mist/drizzle will be possible each day. However, depending on the small scale, low level, wind flow, marine layer clouds may be only scattered in coverage in places. Today was a case where most of the coastal plain cleared out nicely, but many locales up against coastal facing mountains remained mostly overcast into the afternoon.
I decided to include a “slight chance” of drizzle in the campus forecast valid for Sunday. Water vapor content is forecast to rise that day (lasting through Monday morning). It’s possible that a storm that passes to our north may get just close enough to trigger marine layer drizzle or light rain (better chances west of L.A. County, however). My confidence level is low (complexities of marine layer physics). If the storm remains farther to the north than predicted, Sunday may not be as cloudy and cool as I show in this forecast.
I amended the forecast valid for Monday to increase rain chances (from “slight” in the preliminary, morning edition). Some of the models, including the usually reliable ECMWF model, show widespread, measurable rain in L.A. County (falling mostly early morning hours). It wouldn’t be anything significant (storm totals well under a quarter inch away from the mountains), but it possibly might be a wetter situation than what occurred a couple days ago (should be more widespread in areal coverage). My main concern is that the predicted, small, low level disturbance won’t verify in the right location (could make landfall to the north or south of L.A. County).
For the remainder of next week, recent model forecasts have trended toward “inside slider” type troughs affecting the state. If this holds true, there would be no widespread, wet weather events next week (many were showing a decent, for April, soaking storm sometime late Wednesday-Thursday). Each trough would be more wind storm than wet storm (not much wetter nor widespread than recent marine layer drizzles). Generally cooler than normal weather should continue for the work week, but some days (in between “inside sliders”) may have seasonable temperatures (better chances inland locales). Potentially, dry and warmer weather may occur over the subsequent weekend.
Next issued forecast should be on Tuesday, 3 April.