textproduct: San Diego

SYNOPSIS

Temperatures remain below normal into Wednesday with a present marine layer. Warmer weather returns for the end of next week as high pressure builds.

DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE

SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES...

Mid-level water vapor satellite imagery shows a trough over the PacNW with a squished ridge just off the OR coast on the heels of the trough. Temperatures warm Saturday as the trough is pushed eastward and the ridge sets up over the West Coast, increasing heights. Even with this pattern change, temperatures will still remain below normal by about 1-4 degrees, with highs in the mid 70s for the coast & mountains, 80s for inland spots and High Desert, and near 100 for the lower deserts. The marine layer both Saturday and Sunday morning will be slightly shallower than its been the past few days, burning off quicker and not making it as far inland.

The ridge won't remain in place for very long as a secondary trough immediately behind it punts it eastward. This next trough is poised to become a closed low, settling over Central CA by Monday. Onshore flow will increase late Sunday and Monday while the marine layer will deepen once again. Temperatures in turn will be cooler Sun-Tue, coldest Monday, with highs 5-12 degrees below normal.

The pattern changes once again Wednesday as the trough becomes absorbed into the upper level pattern with a massive low sitting off the Canadian coastline. High pressure slides over the SoCal waters and builds quickly late next week. This should return us to a warming trend, rebounding temperatures back above normal. At this point, models disagree on the overall placement of the high, as well as how the aforementioned Canadian low might move. As such, models show a significant temperature spread for the end of next week and into the weekend, with some resolving highs closer to near normal with others around 5-8 degrees above. Some guidance also indicates that the southwesterly flow could push monsoonal moisture back up into the SoCal mountains, but a clearer picture of where the high pressure may be is needed before there is significant confidence in this.

AVIATION

181800Z...Coast/Valleys...Low clouds based 3000-4000 ft MSL are swiftly retreating west, with clearing expected by 19-20z. SKC through the afternoon, then clouds develop throughout lower SD County 04-08z Sat at 2000-3000 ft MSL, before spreading into OC and the south IE early Sat morning. Clouds are unlikely to make their way into vcnty KONT/KSBD (only about a 15% chance for cigs). Clouds clear offshore again 16-18z Sat.

Mountains/Deserts...Mostly clear and VFR conditions through Sat.

MARINE

No hazardous marine conditions are expected through Tuesday.

SGX WATCHES/WARNINGS/ADVISORIES

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