textproduct: San Diego

SYNOPSIS

Cooler conditions through the middle of the week with periods of elevated winds over the mountains and into the deserts. Light precipitation is possible west of the mountains Tuesday evening into Wednesday, which coincides with the timing of the strongest westerly winds. Thursday will warm a few degrees. Cooler conditions likely this weekend, with periods of increased winds and potentially another round of light precipitation west of the mountains.

DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE

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

High temperatures today west of the mountains are expected to be a few degrees cooler than yesterday with no change or a few degrees of warming in the mountains and deserts. Additional cooling is expected through the middle of the week as a trough of low pressure influences the US West Coast. The trough of low pressure is expected to approach the West Coast Tuesday and be to our east by Wednesday evening. This low will bring widespread cloud coverage, increase winds over the mountains and deserts, and areas of light precipitation.

Southwest to west winds will begin to strengthen Tuesday afternoon, peak in strength overnight, and weaken Wednesday morning. Strongest winds will be over the mountains and into the deserts. Peak gusts of 40 to 60 mph expected, with a few isolated gusts to 65 mph on the northern slopes of the San Bernardino mountains. Winds will decrease through the day Wednesday with gusts mainly 35 to 45 mph, locally up to 55 mph through wind prone passes like the San Gorgonio Pass. Periods of light precipitation are expected Tuesday evening into early Wednesday morning. The forecast has trended drier, with the most likely place for measurable precipitation in the San Bernardino County mountains. Hourly rainfall rates are expected to be 0.10 inch or less.

Dry and warmer conditions expected on Thursday. Highs along the coast will be a few degrees warmer, with inland locations up to 7 degrees warmer than Wednesday. The temperature increase will bring conditions near to slightly above normal for this time of year. Another area of low pressure looks likely to move across the US West Coast for the upcoming weekend. While there remains some timing differences between the global models, the trough will bring another round of cooler conditions, increase in westerly winds, and potential for light precipitation.

AVIATION

201800Z...Coast/Valleys...Patchy low clouds 1800-2500 ft MSL will gradually develop and expand after 05Z tonight into Tuesday, with similar areal to this morning and non-uniform coverage. Conditions will bounce between VFR and MVFR most of the night. Low clouds clear 14-17Z Tue morning.

Mountains/Deserts...West to west-southwest winds will increase after 22Z today, and continue to be gusty tonight into early Tuesday. Strongest winds will gust 25-35 knots through mountain gaps, along the desert slopes and locally into deserts, producing moderate up/downdrafts in lee of mountains.

Otherwise, mostly clear and VFR conditions are expected today and tonight.

MARINE

Westerly winds will increase Wednesday, generating conditions that could be hazardous for small craft Wednesday into Thursday, with gusts 20-25 knots likely. Otherwise, no hazardous marine conditions are expected through Friday.

SKYWARN

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

SGX WATCHES/WARNINGS/ADVISORIES

CA...Wind Advisory from 2 PM Tuesday to 7 AM PDT Wednesday for Apple and Lucerne Valleys-Riverside County Mountains-San Bernardino County Mountains-San Diego County Deserts-San Diego County Mountains-San Gorgonio Pass near Banning.

PZ...None.