San Francisco Weather

spwill · Unread post by **spwill** » Sat 07/09/2013 09:53

Looks like warm weather with moderate winds for the sailing this weekend.

Coastal San Francisco has a surprisingly cool warm season ( in the averages) compared with Auckland which is on a similar latitude given San Francisco has a much sunnier/ drier climate and does get some hot spells which are more likely in the Autumn.

Simon Culling · Unread post by **Simon Culling** » Sat 07/09/2013 11:41

Due to a persistence of north westerly winds through the summer months, areas close to the coast remain cool, but not far inland (e.g. Oakland) it can be 10-20*F warmer. As the Pacific high migrates more to the NW in autumn the winds become more offshore (rather than onshore as in the summer) and the city often records it highest temperatures of the year in September and October.

There should be plenty of wind at this location for the yachts in this years America's Cup.

spwill · Unread post by **spwill** » Sun 08/09/2013 08:06

Simon Culling wrote: often records it highest temperatures of the year in September and October.
.

I see Auckland is still warmer than San Francisco for the equivalent time of the year( Autumn), coastal zones.

Those onshore winds for San Francisco are cool due to cool sea temperatures along the Californian coast.

Simon Culling · Unread post by **Simon Culling** » Mon 09/09/2013 01:00

Yesterday (Sat 7th) the weather for the first race (which I believe NZ won) was sunny and hot with winds from between WSW and NNW (10-15kts) depending on location, but generally onshore. Maximum temperatures recorded on the NOAA site were:

San Francisco International Airport (west side of the Bay) 88*F
Moffett Field Airport, Mountain View (south side of the bay) 94*F
Half Moon Bay (on Pacific coast and to west of SF) 72*F
Point Reyes Lighthouse (on Pacific coast, but to NE of SF) 71*F
Fort Funston (west shore of the city + on the Pacific coast) 65*F
Napa Valley Airport (inland a bit and to the N of the Bay) 96*F
Sacramento (well inland) 98*F

As can be seen, quite a range in temperature. The cool Pacific sea certainly moderates the climate on the coast.

Nev · Unread post by **Nev** » Mon 09/09/2013 15:20

Simon Culling wrote:Yesterday (Sat 7th) the weather for the first race (which I believe NZ won) was sunny and hot with winds from between WSW and NNW (10-15kts) depending on location, but generally onshore.

According to the stats, WSW windspeeds during Race One averaged 16 kts, peaking at 21 kts, and during Race Two averaged 16.6 kts, peaking at 19.5 kts.

Temps at the start of Race One (1:15pm PDT) were 62°F (17°C).

Update: WSW windspeeds during Race Three today averaged 16.8 kts, peaking at 19.3 kts, and during Race Four averaged 19.5 kts, peaking at 23.3 kts (Oracle's top speed was 46.0 kts & Team NZ's 45.0 kts).

spwill · Unread post by **spwill** » Mon 09/09/2013 21:54

It will be interesting to see how the boats go in light winds if such weather eventuates.

NZstorm · Unread post by **NZstorm** » Tue 10/09/2013 06:54

Possibly won't get light winds due to the big thermal difference at this time year.

spwill · Unread post by **spwill** » Fri 13/09/2013 14:03

NZstorm wrote:Possibly won't get light winds due to the big thermal difference at this time year.

While Auckland is on a small land mass surrounded by relatively warm sea so we don't get the same afternoon breeze here at that time of year, we get a lot of light wind days here Feb/Mar.

Michael · Unread post by **Michael** » Fri 13/09/2013 20:14

Much of SFO climate is dry like auckland in the summer but with a persistant westerly (like our SWer) clears the cloud (fog) early revealing a sunny day often but a cold wind.

RWood · Unread post by **RWood** » Tue 17/09/2013 07:46

Michael wrote:Much of SFO climate is dry like auckland in the summer but with a persistant westerly (like our SWer) clears the cloud (fog) early revealing a sunny day often but a cold wind.

There are major differences. SF's annual rainfall is less than that of Ch'ch, and it is virtually rainless in July in particular and close to that for summer overall. It is much sunnier than NZ cities, particularly inland.

spwill · Unread post by **spwill** » Tue 17/09/2013 14:20

San Francisco averages about 7mm for the 3 summer months, that would be from drizzle I would say.

looks windy for sailing tomorrow 15-25 kt

tunster · Unread post by **tunster** » Thu 19/09/2013 02:26

spwill wrote:San Francisco averages about 7mm for the 3 summer months, that would be from drizzle I would say.

looks windy for sailing tomorrow 15-25 kt

In August 2009 a rare upper low passed slowly over them, and though they didn't get any rain maybe in other years they could have.

Otherwise, their summer climate is so reliably dry it would be quite foreign to anyone from NZ. I don't think there's anywhere in Western Australia or South Australia which has such a reliably dry summer climate either.

I agree that the coastal winds there can feel outrageously cold and the sea is ridiculous:
http://www.ospo.noaa.gov/data/sst/conto ... orn.fc.gif

I would like to know what their farmers do. We saw this year the impact of drought across the North Island. A Californian summer is sunnier and drier (and much hotter inland) than the NZ 12/13 summer every single year. There is also huge pressure on river systems. Farmers there will know that once they're into May they won't see any precipitation for ~ 5 months. How do they cope with this?

Manukau heads obs · Thu 19/09/2013 13:13

Irrigation...
(which has resulted in increased salinity)

Simon Culling · Unread post by **Simon Culling** » Wed 25/09/2013 17:42

8-1 down to 8-8.......one hell of a comeback by our cousins across the pond!!!!

it must be getting a tad warm in the kiwi camp.

Orion · Unread post by **Orion** » Wed 25/09/2013 17:55

Today's was the first race I'd watched...

NZstorm · Unread post by **NZstorm** » Fri 27/09/2013 07:07

That would have to be NZ's biggest sporting defeat ever.

I hope the team can rebuild for a future NZ AC challenge, time will tell.

spwill · Unread post by **spwill** » Fri 27/09/2013 11:31

Simon Culling wrote:8-1 down to 8-8.......one hell of a comeback by our cousins across the pond!!!!

it must be getting a tad warm in the kiwi camp.

I didn't see Team Great Britain there, some might say there were two Kiwi camps with the strong NZ influence on Oracle

Certainly was sport at its very best, hopefully a future challenge by a NewZealand based team

jamie · Unread post by **jamie** » Sat 28/09/2013 10:08

Future challenge by team mega. Dotcom has said he's willing to throw money at it which I can't see as a bad thing. Doesn't help bring costs down tho I suppose. It keeps it a rich mans thing.

NZstorm · Unread post by **NZstorm** » Sat 28/09/2013 14:07

jamie wrote: Dotcom has said he's willing to throw money at it

Americans could reopen Alcatraz just for Dotcom!

Simon Culling · Unread post by **Simon Culling** » Mon 30/09/2013 00:12

You make a valid point, spwill. It was rather ironic that a notable element of the American team was Kiwi based and that they had to call upon a Brit to tell them how to sail the boat!

It looks like Sir Ben is looking to motivate the British into making a challenge next time:

http://www.bbc.co.uk/sport/0/sailing/24322443

NZstorm · Unread post by **NZstorm** » Mon 30/09/2013 07:52

Simon Culling wrote:You make a valid point, spwill. It was rather ironic that a notable element of the American team was Kiwi based and that they had to call upon a Brit to tell them how to sail the boat!

It looks like Sir Ben is looking to motivate the British into making a challenge next time:

http://www.bbc.co.uk/sport/0/sailing/24322443

Yes, he perhaps saved Oracle. Ainslie has been a member of TNZ in the past.

spwill · Unread post by **spwill** » Mon 30/09/2013 09:37

Simon Culling wrote: they had to call upon a Brit to tell them how to sail the boat!

It was Team NZ that showed Oracle the best way to sail the boat in that first week/10days, no doubt Ainslie helped.

Simon Culling · Unread post by **Simon Culling** » Tue 01/10/2013 06:47

Nice narrative on the climate of the city......the main climate drivers being the Pacific and the local topography:

http://www.wrh.noaa.gov/mtr/sfd_sjc_cli ... IMATE3.php

Orion · Unread post by **Orion** » Tue 01/10/2013 09:44

Really interesting, especially the history - thankyou Simon.

Willoughby · Unread post by **Willoughby** » Wed 02/10/2013 00:05

Walking over the Golden Gate Bridge in June 2008 sure was interesting - warm winds coming down from the sheltered valley and quite cool westerly winds coming in through the channel battling against each other. Felt very strange switching and switching like that!!

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