textproduct: San Diego

SYNOPSIS

One more day of widespread record breaking temperatures today with highs 15 to 20 degrees above average for inland locations. Cooler, windier, and cloudier conditions expected for the middle of week. Slight chance (15-20 percent) of light precipitation on Wednesday for areas along and west of the mountains. Drier and warmer conditions for the end of the week with potential for Santa Ana winds.

..UPDATED 00Z AVIATION/MARINE DISCUSSION BELOW

Visible satellite at 10 AM was showing a fog bank along the southern Orange County beaches, extending south towards Mission Beach in San Diego County. Lifeguards have reported visibility of 1/8 to 2 miles where the clouds are reaching land. Visibility should improve by later this afternoon but areas of low clouds and fog are expected redevelop overnight into Monday morning. One last day of record breaking temperatures for inland locations can be expected today. By Monday the high pressure aloft will weaken enough to kick off a cooling trend through mid-week. Highs Monday will be 5 to 10 degrees cooler than Sunday for inland locations.

Weak troughing over the US West Coast will continue to cool conditions back to near seasonal average by Wednesday. A few additional degrees of cooling on Thursday will make it the coolest day of the week for most locations. Widespread cloud coverage can be expected for the middle of the week. Westerly winds will increase over the mountains and into the deserts in the afternoons and evenings Tuesday through Thursday. Strongest winds are expected Wednesday and Thursday with peak gusts of 40 to 55 mph.

Precipitation chances on Wednesday are holding steady at around 15 to 25 percent chance of measurable rain, with the highest chances on the coastal slopes of the mountains. The track of the trough will keep the bulk of the moisture to our north. Rainfall totals for the coast and valleys will be 0.10" or less, with the coastal slopes of the mountains having a 20 to 25 percent chance of rainfall totals exceeding 0.10".

Once the aforementioned low is to our east, the majority of global model ensemble solutions show it digging south into the Great Basin Friday and Saturday. This would turn the pressure gradient offshore, bringing chances of Santa Ana winds, dry air, and another uptick in temperatures west of the mountains. While most guidance is in agreement on this general pattern, there remain differences in how far south the low will dig and how fast it will continue to move east. Both of those factors will have an impact on the strength and duration of Santa Ana winds that develop. Latest guidance from the CW3E WRF ensemble has a 60 to 80 percent chance of a weak Santa Ana wind event Friday and Saturday, with a 40 to 60 percent chance of a weak to moderate Santa Ana wind event.

AVIATION

292330Z...A few low clouds around 200ft MSL have been making their way in and out over south coast of SD. Low clouds are expected to fill in after 04Z-06Z and push inland 5-10 miles from the coast. Bases near 600-1200ft MSL with lower visibilities in fog on higher coastal terrain. Low clouds will begin to clear after 17Z-19Z.

Otherwise, increasing cloud coverage through the TAF period with clouds AOA 20,000ft MSL.

MARINE

No hazardous marine conditions expected through Wednesday. Northwest winds increase Thursday to near 20 kts across all marine areas.

SKYWARN

Skywarn activation is not requested. However weather spotters are encouraged to report significant weather conditions.

SGX WATCHES/WARNINGS/ADVISORIES

CA...None. PZ...None.