myiW Current Conditions and Forecasts Community Forums Buy and Sell Services
 
Hi guest · myAccount · Log in
 SearchSearch   ProfileProfile   Log in to check your private messagesLog in to check your private messages   RegisterRegister 
Mac asks: So why is this the gustiest season of memory?
Goto page 1, 2  Next
 
Post new topic   Reply to topic    iWindsurf Community Forum Index -> Southwest USA, Hawaii, Mexico
View previous topic :: View next topic  
Author Message
windfind



Joined: 18 Mar 1997
Posts: 1561

PostPosted: Tue Jul 02, 2019 9:39 am    Post subject: Mac asks: So why is this the gustiest season of memory? Reply with quote

mac wrote:
So why is this the gustiest season of memory? NW winds have always been gusty, but now the SW winds are as well.


Hi Mac,

Simple answer... This season we have often had:

1. El Nino conditions that make it more likely that part of the North Pacific High will be pushed into far Northern California creating NNW ocean winds so eddies become more likely. (see kink in the isobars into far Northern California below) Eddy induced southerly winds "push" through the gaps in the coast range rather than being "pulled" smoothly by the pressure gradient to the Central Valley. These pushed winds are less stable and interact more with topography and become turbulent hence gusts. Have you noticed that during eddy winds you often do not see the smooth "fogfalls" of fog flowing like water over the Marin Headlands like we see most summers?

2. The North Pacific High has been severely disrupted by the El Nino so it has elongated south and especially way north even into the Gulf of Alaska (see image below). Normally the NPH is centered west of the Gorge by June but this season part of it is still very near the Bay Area. So in recent days, we have seen our typical WSW surface winds but ALSO strong NW wind just aloft. This also creates turbulence and wind shifts. Hence gusts and sudden fades.

3. El Nino also means a more southerly storm track. (see low pressure in image below )So many areas in California had more rain and snow this winter. But this also means that we are seeing a more southerly track of low-pressure system this summer. This brings unstable air over the west coast. Unstable air does not hug the terrain and lifts from the surface easily. So gusty winds.

All this means some sites often have been very gusty.

For details see an upcoming blog.

The image below shows how the NPH is unusually far North and the weird location of a small low pressure. Plus, see that huge storm west of the Aleutian islands? You will probably be hearing more about this storm as it swings far more south this El Nino year.

Mike Godsey
iwindsurf.com/ikitesurf.com
Weatheflow.com



ZZ6A1CAEA6.jpg
 Description:
 Filesize:  187.52 KB
 Viewed:  13056 Time(s)

ZZ6A1CAEA6.jpg




Last edited by windfind on Tue Jul 02, 2019 2:25 pm; edited 1 time in total
Back to top
View user's profile Send private message
WNDZRFR



Joined: 28 Mar 2000
Posts: 86
Location: Greater East Bay Area

PostPosted: Tue Jul 02, 2019 11:59 am    Post subject: Reply with quote

Just as Trump is great for late night talk show hosts and comedians, climate change gives a new and exciting challenge to weather men!
_________________
Sponsored by Starboard and The Loft
Back to top
View user's profile Send private message
ctuna



Joined: 27 Jun 1995
Posts: 889
Location: Santa Cruz Ca

PostPosted: Tue Jul 02, 2019 3:01 pm    Post subject: It's the trend Reply with quote

If you are lucky enough to get Gusts
Actually last year was pretty gusty to.
I can't remember many even days.
Never use to hear about Eddy coming to town.
Back to top
View user's profile Send private message
dllee



Joined: 03 Jul 2009
Posts: 4604
Location: East Bay

PostPosted: Tue Jul 02, 2019 3:19 pm    Post subject: Reply with quote

Some years are good, some years are bad.
We change just as much.
Back to top
View user's profile Send private message
windsrf



Joined: 01 May 1998
Posts: 376

PostPosted: Tue Jul 02, 2019 4:35 pm    Post subject: Reply with quote

Mike,

Your #1 point helps explain why even the hot Central Valley days we've had don't result in the smooth "pull" of winds from GG across the Eastbay.

Thanks, David
Back to top
View user's profile Send private message
mac



Joined: 07 Mar 1999
Posts: 13136
Location: Berkeley, California

PostPosted: Wed Jul 03, 2019 1:01 pm    Post subject: Reply with quote

Mike--your graphic which shows the two lobes of the north Pacific High helps explain things as they are now. NOAA has indeed called the current situation an El Nino, but last fall (as of October) predicted a weak El Nino. Did the temperature anomaly strengthen over the winter? Or did it strengthen in the Spring, leading to NOAA's update in April?

We know that there is a lot of heat stored in the deep ocean, but El Nino is a surface phenomenon, and I believe that there is still an active debate over how much the deep ocean temperatures and surface temperatures are linked. Have you seen any research that provides a more definitive picture, or any statistical analysis that shows a statistically significant increase in either the frequency or the strengthen of El Nino events?
Back to top
View user's profile Send private message
dllee



Joined: 03 Jul 2009
Posts: 4604
Location: East Bay

PostPosted: Wed Jul 03, 2019 1:24 pm    Post subject: Reply with quote

Could ANOTHER 5-17 mph day be brewing for Berkeley?
All indicators do show it coming.
Maybe I should rig bigger than 5.3?1
Back to top
View user's profile Send private message
windfind



Joined: 18 Mar 1997
Posts: 1561

PostPosted: Wed Jul 03, 2019 2:40 pm    Post subject: Reply with quote

Hi Mac:

Current El Nino status
https://www.cpc.ncep.noaa.gov/products/predictions/90day/fxus05.html

Since El Nino involves the full width of the Pacific and the current ocean buoy array to record that huge span of water is quite new it is hard to directly know if El Ninos are have become more common.

So scientists study other variables that are highly correlated with ocean and air temps. Among these variables studying isotope patterns in coral reef core samples and tree rings. Basically, these studies strongly suggest that El Nino patterns have become more common over the last 400 years.

Whether El Nino are becoming stronger is a much tougher question since El Ninos vary from very weak to very strong and we only have a small time section of solid data.

Regarding deep ocean temperatures: this study in the premiere Journal Nature covers the deep water data from the epic 19th century Challenger expedition to the array of Argo floats that profile temps down to 2000 meter depths.

https://www.nature.com/articles/nclimate2915.epdf?referrer_access_token=8SznqZ834K3wu2IcVDhhlNRgN0jAjWel9jnR3ZoTv0O52T_z3xdIZTeJhjUyMTWREQtgEo_1gP3K5ezHJr6e6d9v4hD0rDYlp7TW72Lwdes-EA_3ms6iOmza4WNC0VAODs6vPgdNiYCxi5iint2Xf_Cs2GNJUkw9Cf8XAYzUBMzMYiCgE8SZuuS-0vjJaiu7EjYhQVHxMhdwvEnXVkHGEJZYJ0gu127BIusUW95mmhnxw3-1RyayiTSL1jb01UEa&tracking_referrer=www.theguardian.com

Mike Godsey
Back to top
View user's profile Send private message
us44eric



Joined: 25 Jun 2003
Posts: 16

PostPosted: Wed Jul 03, 2019 2:47 pm    Post subject: Reply with quote

Tying in to Mac's, Mike's, and dllee's comments --- Look at the crazy anomalous conditions at Berkeley yesterday, including SE 10-17mph in July, not on a rainy day.

Often iW forecasts talk about potential East Bay shut downs or shifty conditions, particularly when there's NW wind influence. But yesterday the WSW wind at Berkeley was dismal and brief. It then began to slightly build and sustain for a few hours to ~10-17mph, BUT this occurred as it clocked back to S, SSE, SE!!!



BerkWindGraph7-1-19_Screen Shot 2019-07-03 at 12.26.08.png
 Description:
 Filesize:  60.36 KB
 Viewed:  12778 Time(s)

BerkWindGraph7-1-19_Screen Shot 2019-07-03 at 12.26.08.png


Back to top
View user's profile Send private message
MalibuGuru



Joined: 11 Nov 1993
Posts: 8611

PostPosted: Wed Jul 03, 2019 7:15 pm    Post subject: Reply with quote

Meanwhile down here, point conception is blowing 42 to almost 50. Spring pattern in summer
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic    iWindsurf Community Forum Index -> Southwest USA, Hawaii, Mexico All times are GMT - 5 Hours
Goto page 1, 2  Next
Page 1 of 2

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You can attach files in this forum
You can download files in this forum

myiW | Weather | Community | Membership | Support | Log in
like us on facebook
© Copyright 1999-2007 WeatherFlow, Inc Contact Us Ad Marketplace

Powered by phpBB © 2001, 2005 phpBB Group