textproduct: San Diego

SYNOPSIS

High clouds will move to the north today, with a few very light showers possible over the San Bernardino mountains this morning. Expect a slow warming trend through Monday with lingering moisture before drier conditions and more substantial warming towards mid- week. Minor to moderate HeatRisk returns for the inland areas and deserts next week. The marine layer will become shallower with less low cloud coverage during the nights and mornings.

..UPDATED AVIATION DISCUSSION

This morning...Temperatures are generally higher than at this time yesterday, with inland areas as much as 5-10 degrees warmer. The marine layer is about 1500 ft deep and low clouds are increasing in coverage over the coastal areas and western parts of the San Diego County valleys. Low clouds are unlikely to spread farther inland than about 10-15 miles. SoCal is in a "dry slot" with clouds and showers over central CA and southern AZ but very light showers can't be ruled out over the San Bernardino mountains this morning.

Through Tuesday, SoCal will be caught between low pressure to the northwest and high pressure to the southeast with gradually drier southwest flow aloft. The high pressure will gradually expand westward exerting its influence over the region. This will bring dry and warmer weather through Friday. Wednesday and Thursday will likely be the warmest days, with high temperatures in the 70s-80s for the coastal areas, the 80s to 90s in the San Diego County valleys and inland OC, the 90s to low triple digits in the Inland Empire, the 80s to low 90s in the mountains, about 100-107 in the high desert, and 110-115 in the low deserts. The inland valleys could experience minor HeatRisk Tue-Thu. The high desert could experience minor to moderate HeatRisk Wed-Fri and the low deserts could experience moderate to locally high HeatRisk Tue-Fri.

The building high pressure will also make the marine layer shallower restricting low clouds and fog to the coastal areas and western portions of the inland valleys during the nights and mornings.

As we move into next weekend, the high could change position becoming centered near the Four Corners. This could allow for a return of moisture from the sub-tropics as southerly flow develops over SoCal. However, this scenario is still fairly uncertain at this time due to differences in model solutions.

AVIATION

051730Z....Coast/Valleys...Low clouds have quickly cleared to the coast with just a few lingering along the OC coast. Low clouds are expected to redevelop after 02-04Z Monday, increasing in coverage and pushing 15 miles inland after 05-07Z in SD County and after 10Z for OC. Bases are expected to be around 800-1200ft MSL. Low clouds will begin retreating to the coast after 15Z Monday, clearing the area by 17-18Z.

Otherwise...Localized 3-5 SM in HZ/FU from fireworks smoke expected through 20Z, then unrestricted vis and decreasing cloud cover at/above 20,000 ft MSL through the end of the TAF period.

MARINE

Gusts near 20 kts will be possible at times in the afternoons near San Clemente Island today through Wednesday. Otherwise, no hazardous marine conditions are expected through Thursday.

SGX WATCHES/WARNINGS/ADVISORIES

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