textproduct: San Diego

SYNOPSIS

Well above average temperatures will continue through the weekend. Patchy low clouds continue to develop early this morning, clearing by mid-morning and less likely to return through early next week due to widespread high cloud coverage. Cooler and breezier conditions are likely by the middle of next week, although precipiation chances continue to decrease.

..UPDATED 18Z AVIATION/MARINE DISCUSSION BELOW

Daily high and low temperature records continue to break (listed on our weather.gov/sandiego homepage) and are expected to continue to break through Sunday, especially in the mountains and deserts. The ridge is expected to have a peak 500 mb height around 590 dam this afternoon, centered over west Texas, yielding another day of temperature anomalies of 15-25 degrees above average. Onshore flow will limit those anomalies along the coast with highs remaining in the 70s where the sea breeze kicks up in the late morning. The marine layer will be very shallow Saturday night and clouds/fog will be almost non-existant (even over the waters), yielding to another mild night across the region. Lows will struggle to drop up below the mid-60s in the mountain foothills and north of the SR-210 corridor. While high temperatures Sunday will be very similar to today's highs, the broad ridge over Texas is expected to weaken and slide eastward, allowing for the marine layer to deepen and bring noticeably cooler nighttime temperatures in the 50s across the coastal basin. By Monday, highs drop noticeably inland - about 6 to 10 degrees - as upper level flow over the Western US turns more zonal. A relatively shallow trough is then expected to dig into the Pacific Northwest mid-week, weakening significantly as it makes it southward trek, though setting the stage for cooler, cloudier and breezier conditions for mid-week.

Precipitation chances continue to dwindle, however, for Southern California as the majority of model ensemble runs remain completely dry, and the remaining others showing no more than a trace for the entire coastal basin. The window for any light showers appears to be focused on early Wednesday, with the highest chances (15-25%) in the mountains, where guidance shows increasing confidence for no more than 0.10" total. Confidence is much higher that temperatures return close to average Wednesday and Thursday.

AVIATION

281710Z...Increasing confidence for low clouds 400-800 ft MSL to come back along San Diego County coastal areas tonight, lesser confidence in Orange County. Confidence in timing is low to moderate with best chances for low clouds between 08-18Z Sun, though clouds may be delayed until 10-12Z. Vis reductions 2-5 sm, with higher terrain obscured in fog. Low clouds scattering 16-18Z Sun.

Otherwise, inland areas partly to mostly clear with clouds AOA 20K ft MSL through the TAF period.

MARINE

Breezy northwest winds this afternoon with gusts near 20 kts near San Clemente Island. Otherwise, no hazardous marine conditions expected through Wednesday.

SGX WATCHES/WARNINGS/ADVISORIES

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