Latest Bay Area storm expected to include lightning, snow

An onslaught of Bay Area rain that has no real end in sight over the next week was braced to increase in its fury on Tuesday while also being accompanied by two other elements not all that normal for this region.

According to the National Weather Service, expect loud claps of thunder and many flashes of lightning throughout the region and pockets of snow in places not normally seen.

RELATED: Chart: Bay Area rain totals from this week’s first wave

All of it is courtesy the second in what is expected to be back-to-back-to-back storm systems that have kept precipitation in the forecast for all but a day or two well into next week. The first of those systems battered the region on Sunday night and much of Monday.

“The ridge that was blocking everything and keeping us dry has shifted,” NWS meteorologist Dalton Behringer said Tuesday. “Once it eroded out, you get the pattern chance, and you get a chance downstream of that (in the atmosphere). Once that happened, the door opened. And once you have a blocking ridge elsewhere, that can get you a really active pattern, because the systems head down the same path.”

That seems to be what is happening with this series of storms, according to the weather service. The pattern change actually started last week with more low pressure and the first of the storm systems came down from the Gulf of Alaska on Sunday.

By Tuesday morning, the weather service said the second of the systems already had brought trace amounts of snow in the Santa Lucia Range along the Central Coast and on Mount Hamilton in Santa Clara County. A winter weather advisory remained in place there Tuesday morning and remained in effect until 4 p.m. Wednesday.

That same advisory went into effect in Santa Clara County at 6 a.m. and lasts until 4 p.m. Wednesday. Temperatures are expected to dip into the low 30s.

The snowfall also is expected to increase Tuesday night into Wednesday, when temperatures plummet several degrees, Behringer said. Mount Diablo is likely to see snow as well, and the weather service said the snow-level could fall as low as 1,800 feet.

“We’ve already got some of that cold air in place, and it’s going to get colder,” Behringer said.

As for the rain, it continued to come down in sheets in many areas of the region early Tuesday, affecting the morning commute and causing several minor crashes on Bay Area freeways, according to the California Highway Patrol.

The weather service also recorded dozens of lightning flashes in the North Bay, and Behringer said the weather service was “expecting lightning strikes at least through (Tuesday) afternoon, pretty much everywhere.”

More than an inch of rain fell in the Santa Cruz Mountains over a 24-hour period ending at 7 a.m. on Tuesday. A half-inch fell in Oakland and in south San Francisco, while about four-tenths fell in downtown San Francisco. At least three-quarters of an inch fell in Hayward and Castro Valley; two-thirds of an inch fell in San Jose and Orinda, and five-hundredths of an inch in Concord.

The weather service did not have cumulative rain totals since Sunday night immediately.

The rain on Tuesday was expected to fall throughout the day and may be accompanied at times by small hail, according to the weather service.

A tiny period of some dry time mixed with on and off light showers is likely to follow this system, and a third system is then likely to level the region by Thursday.

“We expect that to be a lot like what we have (Tuesday),” Behringer said. “Then it will be scattered on and off on Friday and Saturday. So yeah, pretty wet and cold all week.”