Significant storm system arrives, bringing heavy rain down the coast
A strong storm system will slowly move over the region through Tuesday. Rain, heavy at times, and high elevation snow will develop through Monday night as the storm moves down the state. Gusty and potentially damaging winds are expected over the area through Tuesday. Amounts are expected to be between 1-3" for coast and valleys with more in the mountains bringing impacts to the area including the chance of debris flows for the most recent burn scars and localized street flooding. A flash flood watch has been issued for the Alisal fire burn scar until late tonight.
Another weak storm system will affect the region Thursday followed by dry weather next weekend.
Main features will be a strong upper low moving across the area Monday night through midday Tuesday. Moderate/heavy rain, associated with a cold front will impact San Luis Obispo County and Santa Barbara County Monday afternoon and night with the rain pushing south and east tonight and Tuesday with moderate/heavy rain across LA County on Tuesday. Behind the front, there will be some lingering showers Tuesday afternoon, mainly across the northern slopes. Rainfall totals with this storm still look to range from 1-3 inches for coasts/valleys and 3-6 inches across the foothills and mountains. Locally higher amounts will be possible in the more favored upslope areas through Tuesday afternoon. Hourly rainfall rates generally 0.33" to 0.66" per hour are expected with local rates up to 1.00" per hour possible. With a strong jet moving across the area on Tuesday, there will be a slight chance of thunderstorms all areas during the day on Tuesday which could enhance rainfall rates. Due to the potential for significant rainfall and rainfall rates, a FLASH FLOOD WATCH has been issued for the Alisal Fire burn scar through noon on Tuesday.
With this system, snow levels will remain quite high through Tuesday (above 6000 feet) as the heaviest rain moves through. So, resort levels can expect anywhere from 1 to 3 feet of snowfall. For lower elevations, snow levels will not drop until late Tuesday afternoon/night when the rain will be tapering. So, snowfall totals at lower elevations will be much less. However, there is a possibility of 1-3 inches of snowfall Tuesday night. A Winter Storm Warning is in place for the Ventura County Mountains until 8PM Tuesday.
Finally, the third main hazard with this storm will be strong and gusty winds. Gusty southerly wind will continue to increase tonight and Tuesday across the area. Across the local mountains as well as the interior valleys of SLO/SBA counties, warning level wind gusts are likely and a HIGH WIND WARNING remains in effect for these areas. Elsewhere, advisory level wind gusts are likely and WIND ADVISORIES remain in effect for all other areas.
After a cool and dry Wednesday, another system is expected to impact the area on Thursday. However, this system on Thursday is much weaker than the current system. Initial rainfall estimates are small with this system with the heaviest rainfall possible along the Central Coast.
A ridge will build for the weekend allowing more sunshine and dry conditions.
Temperatures for this week will stay below normal in the mid 50s to low 60s.