We told you they were both valid.

Let’s start with the science. Start with cold air — Professor Norman Miller, a staff scientist specializing in climate science at Lawrence Berkeley National Laboratory, and Dave Reynolds, the Bay Area National Weather Service forecast office, differed some on where the cold air originated. Miller mentioned the Gulf of Alaska and Aleutian Islands while Reynolds pinpointed Northwest Canada. Either way, it’s a place where cold air is as ubiquitous as ice fishing, hockey, and synonyms for snow.

In any event, the cool air up north developed into a low-pressure system to the point where, Miller notes, it “dropped down along the planetary wave weather travels on. What we’re seeing here is called the ‘polar jet stream.’” This is where advection comes in. The cold air reached the Bay Area not long ago — but didn’t deluge us immediately. A more temperate high-pressure system kept the icy barbarians at the gate for several days. But when the high-pressure system moved on, the cold weather descended upon us rapidly. It’s a bit like teenagers crashing a bar the moment the bouncer goes out for his smoke break.

So there you go. But both Miller and Reynolds noted that it’s not that cold.

“It’s nothing out of the ordinary. I live in the Berkeley Hills, and in the last 15 years I’ve seen this amount of snow in the morning at least six times,” says Miller. “We’re spoiled here. Every time the weather gets outside a narrow little temperature range, all of the sudden we find ourselves shaking in our boots.”

Reynolds, based in Monterey, notes that he’s sure some record lows have been set for this date — “But this is not an extreme cold outbreak. It’s not an unusual situation to occur at this time here in the Bay Area.”

But, yes, it’s nippy. Reynolds is a born-and-raised Bay Area native and he’s not used to this (and, he notes, he’s very pleased it will likely warm up come Thursday). Miller is an East Coast guy. But he’s been in the Bay Area for quite some time. “Yesterday I was hesitant to do certain outdoor sports. It was too cold for me,” he admitted. “I opted to sit in the hot tub instead.”

Ice Fishing Lake Manitoba Narrows

Manitoba Auto Dealers

• Giro Candela Women's Cold-Weather Cycling Gloves A women's glove that's tailor-made for rides where warm, dry hands are essential (40ºF/5ºC). The Candela combines a water and...
• Fishing Report: April 2, 2010 Sturgeon,  Salmon and Halibut At both Berkeley/Emeryville and Pillar Point, you can catch a salmon fishing trip on either Saturday...
• Fishing Report: January 08, 2010 Striped Bass, Crab and Halibut At Berkeley/Emeryville, sturgeon trips are ready to go now as long as enough people are...
• Fishing Report: February 5, 2010 Striped Bass, Crab and Halibut A whopping 80-pound sturgeon came out of Berkeley/Emeryville on the last sturgeon run. More trips...
• How to Care For Acoustic Instruments Caring for your acoustic instruments is not difficult, but it does take a little bit of know how if you...
• Women Now Suiting Up for Snowboarding Snowboarding gear, womens snowboards, and snowboarding clothing can be expensive, but if you want to be comfortable, you can't skimp...
• Save Money by Ensuring Your Vehicle is Winter Proof This article was written by Andreas Nicolaides, a personal finance author for Money Supermarket. At this time of year, the...