UCLA Weather

from the Department of Atmospheric and Oceanic Sciences.

Thursday - 2:27pm

Fog

73°

High - 75°

Low - 65°

Today: Low clouds clearing late morning to hazy sunshine remainder of the day.. Chance of some low clouds in the evening.

Five Day Forecast

Latest Average Hourly Temperatures

Note: No forecast will be issued on Friday (20 September).

New synopsis to follow around 3 PM.

Previous Synopsis: On-shore flow picked up this morning, but the low cloud field remained tattered in appearance (from satellite imagery). Low clouds prevailed in the coastal plain from L.A. County southward. Some areas had a brief duration overcast, but many areas had nothing more a few low clouds briefly (campus included). A new, upper level trough will pass through the Southland tomorrow, and it should help promote more widespread, low clouds (west of the mountains). However, recent satellite imagery showed no appreciable increase in low clouds off the coast. What may happen instead is that partly cloudy skies will occur as a weakening cold front passes by tomorrow morning.

The aforementioned trough hasn't produced much cooling over most of southern California (a different story in northern California where scattered showers/isolated thunderstorms prevail). Tomorrow is expected to be the coolest of the next several days in the Southland, but it probably won't be more than few degrees lower than it gets today west of the mountains (a little better cooling in the interior). A marginal, off-shore flow is predicted for Friday into Saturday morning. That will herald a new warming trend that should peak over the weekend. High pressure aloft isn't forecast to get particularly strong over the Southland. So, temperatures shouldn't get out of hand. Temperatures in 90s should be common in the valleys but triple digit heat may not occur this time. The inland, coastal plain shouldn't reach the 90 degree mark. Depending on how diluted the marine layer gets, the campus area may not reach the mid-80s as it did the previous weekend.

A passing, "inside slider" type trough should bring brief cooling on Monday (breezy in the interior). There could be extensive, morning low clouds that day, but the low cloud field may not have much time to recover from the weekend dilution of the marine layer. Another, marginal, off-shore flow could develop on Tuesday and last for a few days. Some model solutions show strong high pressure aloft, which would promote much warmer than normal weather. For now, I'm staying more conservative with the forecast (not expecting anything warmer than it gets this weekend). Whatever the outcome, cooler weather should develop over the subsequent weekend (how much cooling, remains to be seen...varied model scenarios).

UCLA Forecasts and analyses are written by James Murakami

– posted: 2019-09-19

Data and technology is provided by UCLA's Department of Atmospheric and Oceanic Sciences

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