textproduct: San Diego

SYNOPSIS

Widespread light rain will continue this morning, becoming more scattered during the day before tapering off this afternoon and evening. Dry and warmer for the remainder of the week with highs near to a few degrees below normal each day.

DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE

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

Morning water vapor imagery shows the upper level trough beginning to move across the California Bight with a weak Atmospheric River feeding into far southern CA. Widespread light rainfall continues this morning with rainfall rates generally 0.10 inch/hour or less. Isolated heavier showers with rates near 0.30-0.50 inch/hour are possible later this morning as colder air aloft moves overhead. Rain will transition to more scattered showers around sunrise, then taper off from north to south this afternoon, ending by late evening.

Additional rainfall totals will range anywhere from 0.25-0.75" for the coasts to the mountains, locally 1" or more in the San Diego County Mountains, and 0.05-0.30" in the deserts, highest in San Diego County. Snow levels near 9500-11000 ft this morning will gradually fall to 7000-7500 ft this evening as precipitation ends, with only a light dusting on the highest peaks of the San Bernardino and San Jacinto Mountains. Otherwise cool today with high temperatures 10-15 degrees below normal.

An upper level ridge of high pressure moves in from the west on Monday and Tuesday. This ridge, aided by weak offshore flow, will provide warmer and drier weather Monday and Tuesday, though highs will still be a few degrees below normal - generally low to mid 70s across the coastal basin, mid 60s to mid 60s in the mountains, upper 60s to low 70s in the high desert, and upper 70s to low 80s in the low desert.

Another upper trough moves through California late Tuesday into Wednesday morning, but at this time chances of measurable precipitation are less than 10%. Another round of weak offshore flow follows for the remainder of the day Wednesday into Thursday under weakly cyclonic flow, bringing minor warming. Ensembles begin to diverge a bit more Friday and Saturday with the potential development of another low digging into the Desert Southwest. Around 23% of the ensemble members have a deeper low for cooler weather but slightly stronger offshore flow, while the remaining members have a much weaker trough Friday and ridging by Saturday for weaker offshore flow and warmer weather.

AVIATION

010600...OVC mid-high level clouds region-wide through Sunday morning. Generally widespread -RA will continue to move northeast across the region through Sunday morning, bringing intermittent MVFR cigs/vis 1500-3000 ft MSL and 3-5 SM respectively through the coastal basin. Localized SHRA embedded within the overall storm along the coast and over the mtns may produce brief IFR conditions. Little to know cig/vis reductions expected in the deserts with - SHRA overnight.

-RA will become more SCT from west to east 15-18z Sun with mid-high level clouds also clearing, bringing generally widespread VFR conditions. ISO/SCT -SHRA will linger through Sunday evening in San Diego County and in the mtns.

MARINE

There is a 5% chance of isolated thunderstorms over the waters Sunday morning. Westerly winds increase Sunday afternoon and evening with gusts 20-25 kt. A Small Craft Advisory is in effect for the outer coastal waters from 11AM - 9PM Sunday. Weaker winds expected Monday, followed by more elevated onshore winds Tuesday afternoon and evening, with gusts in the outer coastal waters potentially exceeding 20 knots.

BEACHES

Southwesterly swell (3 ft at 15 seconds from 200 degrees) will bring elevated surf this weekend into Monday, with breaking wave heights 3 to 6 feet through Monday. While high tides will continue to wane through the weekend, tides will remain just above 6 feet which could still lead to local minor tidal overflow during high tides in areas where breaking waves approach 5-6 feet, mostly on southwest facing beaches Sun.

SKYWARN

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

SGX WATCHES/WARNINGS/ADVISORIES

CA...None. PZ...Small Craft Advisory from 11 AM this morning to 9 PM PDT this evening for Waters from San Mateo Point to the Mexican Border Extending 10 to 60 nm out including San Clemente Island.