9:03pm update from meteorologist Dave Hovde:
The plume begins to migrate to the east. This will end the non-stop rainfall for our area but propel us into the scattered showers with isolated thunderstorms portion of the forecast. A number of advisories are set to drop tonight. Here is a new video explaining the situation as of 9:00pm. This video includes some updated rainfall totals.
The two-day storm is producing some epic rainfall totals as had been in the forecast since last week. 3-10" of rain generally across the area with the highest totals in northern SLO county.
The high rainfall was produced by an atmospheric river even where ample moisture supply is paralleled with winds driving the moisture at the coast. This interacted with an area of low pressure and cold front which amplified rainfall. Additionally the atmospheric river stayed focused along the SLO county area for nearly a full day.
Now that plume has migrated into Santa Barbara county where will it hit the area into the afternoon. It will continue to move south and east which will end the semi-persistent rainfall so activity will become scattered however the atmosphere will become quite unstable.
A trough of low pressure containing cold air aloft will roll over us into early Friday. The scattered thunderstorms introduce brief local heavy rainfall potential along with brief, localized and potentially damaging winds with hail and lighting all possible. That said, no severe thunderstorm watch has been issued as of this time.
The activity will continue overnight into early Friday before we get a break in the weather over the weekend and Monday with the next chance of rain being Tuesday. After that it looks quiet again.
There are a number of advisories in place, please check the KSBY.com website or KSBY microclimate weather app as these advisories are sure to change with time today.
The rain has helped lake levels, keep in mind water is still flowing in but numbers are up.