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windfind
Joined: 18 Mar 1997 Posts: 1901
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Posted: Tue Jul 02, 2019 9:39 am Post subject: Mac asks: So why is this the gustiest season of memory? |
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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
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Last edited by windfind on Tue Jul 02, 2019 2:25 pm; edited 1 time in total |
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WNDZRFR
Joined: 28 Mar 2000 Posts: 124 Location: Greater East Bay Area
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Posted: Tue Jul 02, 2019 11:59 am Post subject: |
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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 |
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ctuna
Joined: 27 Jun 1995 Posts: 1126 Location: Santa Cruz Ca
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Posted: Tue Jul 02, 2019 3:01 pm Post subject: It's the trend |
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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.
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dllee
Joined: 03 Jul 2009 Posts: 5329 Location: East Bay
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Posted: Tue Jul 02, 2019 3:19 pm Post subject: |
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Some years are good, some years are bad.
We change just as much.
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windsrf
Joined: 01 May 1998 Posts: 464
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Posted: Tue Jul 02, 2019 4:35 pm Post subject: |
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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
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mac
Joined: 07 Mar 1999 Posts: 17748 Location: Berkeley, California
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Posted: Wed Jul 03, 2019 1:01 pm Post subject: |
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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?
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dllee
Joined: 03 Jul 2009 Posts: 5329 Location: East Bay
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Posted: Wed Jul 03, 2019 1:24 pm Post subject: |
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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
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windfind
Joined: 18 Mar 1997 Posts: 1901
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us44eric
Joined: 25 Jun 2003 Posts: 24
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Posted: Wed Jul 03, 2019 2:47 pm Post subject: |
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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!!!
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MalibuGuru
Joined: 11 Nov 1993 Posts: 9300
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Posted: Wed Jul 03, 2019 7:15 pm Post subject: |
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Meanwhile down here, point conception is blowing 42 to almost 50. Spring pattern in summer
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