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Forecast Discussion for San Diego, CA
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000 FXUS66 KSGX 220431 AFDSGX Area Forecast Discussion National Weather Service San Diego CA 930 PM PDT Tue Mar 21 2023 .SYNOPSIS... Occasional rain, snow and gusty winds will continue over Southern California through Wednesday night as a powerful spring storm moves slowly inland. Precipitation will wind down on Thursday, setting up A period of dry, and continued cool weather through the weekend. Another low pressure system dropping south across the West, could bring more precipitation by the middle of next week. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... -The Zone Forecasts, Warnings and Advisories have been updated. The Flood Watch remains in effect. An organized line of moderate rainfall swept inland earlier this evening, adding another one-quarter to one-half inch of rain to many sites west of the mountains. Scattered showers remain, and will likely continue through the night. Locally heavy rain is still possible near any of the heavier showers or thunderstorms that may develop. Please see our webpage for all the latest storm reports, Rainfall totals, and the Advisories and Warnings still in effect at weather.gov/SGX. A deep low pressure center near San Francisco will slowly weaken overnight, but continue to spread showers and gusty winds over large portions of the State through Wednesday. Precipitation should wind down on Thursday, as the last disturbance associated with this storm drops SE, allowing the parent trough to drift farther inland. A broad trough will remain over the West for the remainder of the week, holding temperatures in check, but keeping any further significant precipitation well to the north. This weekend, northerly flow down the west coast of Canada, will steer another wave to just off the PacNW Coast by Monday. The track of this system remains to be confirmed, but it looks like at the very least, it will keep our temperatures below average into next week, and could even bring more precipitation. This is evident in the spread of ensemble solutions of all of our major global models. We will have to wait to see how they coalesce in the coming days to see just how this system might impact us. && .AVIATION... 220330Z...Coast/Valleys/Mountains...SCT -SHRA is expected through the evening into much of Wednesday. SCT-BKN clouds low clouds with bases mostly 3500-6000 ft MSL, closer to 2500 ft MSL in heavy rain with vis reduced 1-3 sm at times. Widespread terrain obscurations will prevail through tonight. Southwest winds will weaken for coastal and valley areas sticking near 20 kts, though still be quite strong across the mountains through Wednesday with gusts 30-45 kts. Snow levels lowering tonight, with -SHSN continuing through the night into much of Wednesday across the mountains. Deserts...ISO -SHRA before midnight, with drying through early morning. Some areas may see ISO -SHRA Wednesday afternoon. Southwest winds on desert mountain slopes and locally into the deserts will lower, with gusts 25-35 kt with MOD UDDFS and LLWS over/northeast of the mountains. BKN-OVC bases 3000-5000 ft MSL, locally 1500-2000 ft MSL with clouds lifting to above 5000 ft MSL after midnight. && .MARINE... A pacific storm will bring southerly gales and hazardous seas into Wednesday. There is a chance of thunderstorms and waterspouts tonight and Wednesday morning. Check the Gale Warning for details and stay tuned for any special marine weather bulletins that may be issued. Winds and seas will gradually subside late Wednesday. Northwest winds will increase again for Thursday through Saturday in the outer waters, which would bring more hazardous winds and choppy conditions. && .BEACHES... A Pacific storm will bring large short-period swells and surf tonight through Thursday. Breakers will range from 4 to 8 feet, with sets up to 10 feet in southern San Diego County. This will produce hazardous swimming conditions and local beach erosion. Swell and surf should subside Thursday. Check the High surf advisory for details. && .HYDROLOGY... After this evening, showers will become more scattered and intermittent through Wednesday night. This will help to diminish the flood threat at lower elevations. In the meantime, a Flood Watch remains in effect. The snow level will fall from between 4500 and 5000 feet this evening, to 4000/4500 feet by Wednesday morning. Additional rainfall and liquid equivalent above the snow level through Thursday morning is expected to range from around 0.5 to one inch coast/valleys, to 1 to locally 3 inches in the mountains. One-tenth to one-half inch additional is possible for the deserts. The Santa Margarita and San Diego Rivers are forecast to crest at minor flood stage at 3 AM PDT overnight, then trend lower through Thursday. Low-lying roads near the rivers will be impacted. Other areas of concern are the Mojave River, which is flowing within it`s banks; the Whitewater River, and Coachella Canal in the Coachella Valley, which is expecting to see some flow; and possibly low-lying areas in the Tijuana River watershed. && .SKYWARN... Skywarn activation is not requested. However weather spotters are encouraged to report significant weather conditions. && .SGX WATCHES/WARNINGS/ADVISORIES... CA...Flood Watch through Wednesday evening for San Diego County Coastal Areas-San Diego County Mountains-San Diego County Valleys. High Surf Advisory from 2 AM Wednesday to 9 PM PDT Thursday for San Diego County Coastal Areas. Flood Watch through Wednesday afternoon for Orange County Coastal Areas-Orange County Inland Areas-Riverside County Mountains-San Bernardino County Mountains-San Bernardino and Riverside County Valleys-The Inland Empire-San Gorgonio Pass Near Banning-Santa Ana Mountains and Foothills. Winter Storm Warning until 5 AM PDT Thursday for Riverside County Mountains-San Bernardino County Mountains. Winter Weather Advisory until 5 AM PDT Thursday for San Diego County Mountains. High Wind Warning until noon PDT Wednesday for Apple and Lucerne Valleys-San Diego County Deserts-San Gorgonio Pass Near Banning. Wind Advisory until 10 PM PDT this evening for Coachella Valley. High Surf Advisory from 2 AM Wednesday to 9 AM PDT Thursday for Orange County Coastal Areas. PZ...Gale Warning until 9 AM PDT Wednesday for Coastal Waters from San Mateo Point to the Mexican Border and out to 30 nm- Waters from San Mateo Point to the Mexican Border Extending 30 to 60 nm out including San Clemente Island. && $$ PUBLIC/HYDROLOGY...10 AVIATION/MARINE/BEACHES...APR |
Previous Forecast Discussions may be found at
NWS San Diego, CA (SGX) Office Forecast Discussions.
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