County Meteorologist's Forecast

Public Works meteorologist Rand Allan has his forecast for the rest of Friday and the weekend.

Moderate rain is currently affecting most of the county. Radar shows a short break around 9:30-10:30 am, then the rain begins to move in again, becoming heavy at times in the afternoon and evening. Small stream and urban flooding is likely this afternoon and evening with a chance of minor debris flows in the most recent burn areas. Snow levels will be above 5000’ with significant accumulations. High winds will be a problem this afternoon and evening, and the saturated soils may make it easier to blow over trees, conditions similar to the high wind storms experienced in January 2016. Expected rain amounts through early tomorrow morning are 1”-1.25” coast, 2.4”-3.5” mountains, and around 0.75” deserts. The NWS has also issued a flash flood watch below 5500’ and a winter storm warning above 5000’.

Rains decrease Saturday morning to scattered showers by afternoon with no heavy rain expected. Snow level should be around 4500’ rising to 5000’ afternoon with 1”-2” of snow possible. Moderate to high winds will still be a problem all areas on Saturday.

The next storm approaches Sunday morning with rain becoming heavy at times during the afternoon and evening hours. This storm is expected to be the heaviest of the storm series, and with fully saturated soils, most of the rain will translate into runoff into the rivers, streams, and urban roads, with debris flows possible in the recent burn areas. Several of the major rivers such as Santa Margarita, San Diego, and Tijuana are expected to flood. Most reservoirs are at low capacity right now, so they should be able to contain most mountain runoff. Additionally, the snow level rises above 6000’ with this storm, so snow melt should add to the problems of significant runoff from the mountains. The cold core of this storm settles over the area on Monday with snow levels plunging to 3500’. Showers should pretty much end Monday night, but there is hints that another pulse of energy could keep the shower activity going into Tuesday.

Storm totals from today into Tuesday are estimated to be:

  Coast and Valleys: 2-5 inches

  Mountains: 4-10 inches, with isolated 12+ inches

  Deserts: 0.50-2 inches

Weather clears out for fair and cool days Wednesday and Thursday.