No, that wasn't the garbage truck rumbling outside your window this morning: Thunder and lightning, those rare San Francisco beasts, were rumbling and striking this morning, as the winter storm season officially kicks into gear.

The storm hit San Francisco in earnest by around 7 a.m. Monday, with a decent amount of rain, flashes of lightning, and rumblings of thunder.

And with the rain comes slick roads, with "dozens of minor crashes" on Bay Area highways by 8:30 a.m., according to a California Highway Patrol dispatcher. As Captain Christopher Sherry, Commander of California Highway Patrol, San Francisco, says, everyone just needs to slow down.

The National Weather Service says that hazardous weather is expected throughout the day, with isolated showers with brief heavy downpours" expected "from the North Bay to the Santa Cruz Mountains," the Chron reports.

According to KRON4, we should expect the heaviest rain from now until 2 p.m., but even after that we're in for "a scattered shower forecast for the rest of the day with a chance of pop-up thunderstorms."

Though the rain should taper off by tonight, expect cold temperatures tomorrow and the rest of the week, with rain likely to return by next weekend.