Tonight's Storm May Qualify as Bomb Cyclone, With Winds Topping 60mph

"Meteorologists and their weather models have not come to any agreement about whether Tuesday's incoming storm will meet the criteria of a "bomb cyclone," but suffice it to say it will be really windy and wet. There is a huge area of low pressure out over the Pacific Ocean, carrying with it wind, rain, and potential thunderstorms, and it is scheduled to hit the Northern California coast with a vengence by 7 pm."

"Per the Chronicle's meteorology team, models are showing that we could still get more moderate storm impacts, with winds up to 50 mph in San Francisco still a very significant storm. Or, things could get more intense, with winds 60 mph and up, and northern counties like Mendocino and Del Norte potentially seeing destructive gusts of 80 mph, equivalent to a Category 1 hurricane."

"SFO was already seeing 30-minute average delays on outgoing flights Tuesday afternoon, and 80-minute delays for incoming flights with a ground-delay program in place, due to high winds. Those delays could escalate into cancellations as the day wears on, and Christmas Eve travel could be a real challenge. As with many winter storm systems like this, the heaviest rain totals are forecast for the coastal mountains of the North Bay, Santa Cruz, and Big Sur."

Meteorologists lack consensus on whether the incoming Pacific low will qualify as a bomb cyclone, but the system will bring strong wind and heavy rain. The low-pressure center about 700 miles southwest of San Francisco is expected to reach the Northern California coast by 7 p.m., carrying wind, rain, thunderstorms and potential tornado activity. Models show a range of outcomes: moderate impacts with winds up to 50 mph in San Francisco, or more intense conditions with sustained winds of 60+ mph and gusts up to 80 mph in northern counties. SFO already faces significant flight delays and possible cancellations. Coastal mountains face the heaviest rain totals.

Read at sfist.com