Central Coast Forecast
A cooling trend will begin Friday and turn significantly cooler over the weekend as a cold storm system moves over the region. Rain showers and mountain snow are expected between Saturday afternoon and Monday. Brief heavy downpours with small hail are possible with any thunderstorms, mainly on Sunday. Dry but cool weather is expected the rest of next week. But before any of that happens, there is still a little offshore wind left and with clear skies and dry air, frost and freeze conditions are likely again tonight and have prompted these advisories:
Offshore Winds Continue Today
Offshore gradients have peaked and are trending weaker. Expecting this trend to continue through tonight and turn onshore later on Friday.
While gradients will be weakening, lingering offshore winds are still expected through Friday morning, especially over the higher terrain. Most coastal areas will transition to an onshore sea breeze Friday afternoon, resulting in a significant cooling trend from around 80 today to high 60s and low 70s Friday.
Valleys and other inland areas should have another warm day.
Cold Upper Low Brings Rain and Mountain Snow
Attention then turns quickly to the upper low that will be moving into the area this weekend. The most notable change in the models today was a slightly slower arrival into central and southern California. Models now are keeping the low north over the Bay Area through midday Sunday, then near Pt. Conception Sunday night. If this timing holds it would likely delay the onset of showers later into Saturday. Other than that, there's still a lot uncertainty with how this storm will play out in our area.
Models continue to cluster tightly around the quarter to half-inch range for a storm total across Santa Barbara County and slightly less to the north in SLO County. But there are still is some uncertainty, a few models like a wetter system.
For the SoCal burn scars, especially the most recent ones this month, chances are still very low, around 5-10%, that rates will exceed the half-inch per-hour rate. Peak rain rates are generally expected to be a quarter inch per hour, and for much of the time a tenth of an inch per hour or less.
Snow Levels
Snow levels with the morning runs weren't quite as low as before, now keeping the snow level slightly above 4000 feet through Sunday evening. In this scenario, it's unlikely the Grapevine will see anything more than a dusting of snow at pass level. If the low drops farther south Sunday night into Monday there could be up to an inch on the Grapevine during that time.
Elsewhere in the mountains from 4500 and up, accumulations will range from an inch to as much as 10 inches above 6500 feet.
Temperatures
Much cooler this weekend with highs 55-60 for most coast and valleys areas. Next week looks generally cool as well.
