Bomb cyclone hit San Francisco

[wholybee]

A bomb cyclone hit San Francisco yesterday. Close to 100 kts was reported in Sausalito. The famous "Taj Mahal" houseboat sank. Across the bay in the estuary a marina lost an entire dock. I check on my boat tomorrow morning, in Sausalito near the Taj Mahal, but behind a breakwater. I can still reach it via Starlink, so she is at least above water. Unrelated to sailing, windows were falling out of skyscrapers landing on the streets. Sorry for all the facebook links, that is how many people post photos.

https://www.facebook.com/captbenr/vi...0332311426471/

https://www.facebook.com/alain.poule...jv1bWy8gzLg17l

https://www.facebook.com/photo.php?f...9983309&type=3

https://www.facebook.com/photo/?fbid...16321138485829

https://www.facebook.com/photo/?fbid...16321138485829

[Jamme]

Wow. Sound really awful.

https://www.cbsnews.com/amp/sanfranc...dly-windstorm/

Best of luck with your boat.

[Jim Cate]

More info:

https://us.yahoo.com/news/two-girls-...112755341.html

Glad I was down here in peaceful Tasmania!

Jim

[Don C L]

Glad I was here in SoCal! We only had a gale warning.

[donradcliffe]

We we did decide to scrub the Tuesday nite racing. I think "bomb" translates to the forecasters ignored the obvious weather pattern I saw developing out the windows. It was a tight little local low that the models did not do well on.

The good news is that there was no major damage in Santa Cruz, outside of a few boats who need to secure their roller furling jibs better. I think the waves moved some more sand in the entrance of the harbor, and it would be nice if the dredge worked a bit on the trouble spots before this weekend. The other good news is that the drought blamed on climate change is over.

[Franziska]

Originally Posted by Jim Cate

More info:

https://us.yahoo.com/news/two-girls-...112755341.html

Glad I was down here in peaceful Tasmania!

Jim

JIM, that was the wrong link I guess [emoji848]

[GordMay]

According to the National Ocean Service (NOAA):
Bombogenesis occurs when a midlatitude (the latitudes between the tropics and polar regions) cyclone rapidly intensifies, or strengthens, over a 24 hour period. This intensification is represented by a drop in millibars.

The American Meteorological Society defines a “bomb” as:
An extratropical surface cyclone with a central pressure that falls on the average at least 1 mb h-1 for 24 hours.

Simply put, this means a storm is intensifying very quickly, which can result in more severe impacts, than what a weaker storm would produce. Most [but not all] Bomb Cyclones develope over water, more often on the US East coast, than the West.

The intensification required to classify as "bombogenesis" varies by latitude. At 60 degrees latitude*, it is a drop of at least 24 millibars (24 hectopascals) over 24 hours. At the latitude of New York City, the required pressure drop is about 17.8 millibars (17.8 hectopascals) over 24 hours.

Bombogenesis can happen when a cold air mass collides with a warm air mass, such as air over warm ocean waters. It is popularly referred to as a bomb cyclone.

To calculate the pressure drop needed for a bomb cyclone, you take the sine of the latitude where the low pressure is located, and divide it by the sine of 60 degrees*. Multiply that result by 24, and that is the number of millibars the storm's pressure must drop, to officially qualify it as a bomb cyclone, at the given latitude.

* Why 60 degrees? Swedish meteorology researcher, Tor Bergeron, initially defined "rapidly deepening" storms as those that met the 24 millibars-in-24 hours criterion, and that's the latitude where Bergeron was, when he developed the initial scale.

[Jim Cate]

Originally Posted by Franziska

JIM, that was the wrong link I guess [emoji848]

well Damn! Sorry about that, dunno how it snuck in!

Real link (I hope);

https://www.latitude38.com/lectronic...n-gate-bridge/

Jim

[wholybee]

My boat is fine, thankfully. I had a dockline break, but a kind person took care of it for me. Another boat in the marina lost their jib, but overall we seem to have faired well

The next dock over, the Taj Mahal is listing, and i hear large pumps running.

[NorthCoastJoe]

Facebook will not let me look. Im not a member .