West Coast Wind Blog: Forecasting UP AND DOWN Gorge winds.

 

Here is a animation I am working on to help explain the UP AND DOWN winds today.  Even over the ocean at dawn you can see the instablity.

look at all of those vertical strat-cus west of the Cascades

there must be a lot of mid-level cool air

Notice reform clouds on eastern mountains

Luv how the marine layer clouds and wave clouds get wiped out.

they erode and are replaced by that garbage strat-cu

I really like how these animations allow you to review things over and over in motion.

very clearly replacing the cool stable layer with a cool unstable mid-level layer

yeah…these rocking animations are highly useful

Shud try to grab and compare Troutdale 7AM and 7 PM profiler and skew t

that could actually be pretty amusing

now you see the thin inversion…now you don’t!
alas, the models were way overestimating the thickness of the marine inversion on Monday/Tuesday for today so I expected today to be better for longer

very…very-weak top-of-boundary-layer inversion in the morning, then immediately wiped out by steep lapse rates in the midday period

Actually looking at the satellite more closely there was not much of marine layer over Troutdale

it looks very muted even on that profiler chart

what about Portland?
or Astoria

So even at dawn unstable air had moved to Troutdale.

so it would appear. :confused:

You can see it arriving at Astoria

no inversion at all

quite cold at the top of the boundary layer

This would make a good tutorial for Gorge mets. I will grab this conversation and imagery and put into a blog. Then you can add texts. Not all blogs have to be aimed at customers.  We can publish it just for internal use.

modeling as of late Monday had a little bit of an upper ridge over the NW US…instead it’s a little bit of an upper-trough

that makes a large difference

We have to get better at forecasting winds beyond the typical up and down.

new messages

the users are getting a bit savvier and have higher expectations these days

West Coast Wind Blog: Inside Golden Gate wind rages while calm just outside.


by Mike Godsey, iwindsurf.com/ikitesurf.com, mikeATwindsurf.com

I took the helicopter photo in my banner above on a day when it was nearly calm at Pt. Diablo just outside the Golden Gate’s north tower. But the strong NW aloft were buffeting the copter and there were strong surface winds inside the Golden Gate off Crissy. This morning a customer mailed me about yesterday’s winds which sound like a similar day.

“Everyone was asking me today why outside the GG bridge was nearly zero, just inside the bridge was solid 25 gusting higher, Anita was gusting to 30. When I went down to Blunt it was much lighter than I was expecting and much lighter than it has been for the past week. I can’t explain it … Would make for some interesting forecast comments and maybe even a blog post. MS”

Here is my response (slightly elaborated for clarity):

Hi MS,

I have not forecast since last Friday so I am a bit out of the loop. However, I have seen the pattern you are describing so I can take a somewhat educated guess.

The Marin ridges NW of the Central Bay are one of my favorite for meteorology hikes since I can both see the Central Bay water, feel the nature of the wind above the Bay and, politically incorrectly,  sometimes release Helium filled toy balloons. From the high ridges above the Marin Headland, I could watch the balloons erratic vertical flight pattern as it headed above the Golden Gate.  (in recent years I have done the same in the Hwy. 92 gap trying to understand the SW eddy flow that impacts 3rd…. not much luck there…yet)

The hikes and balloon play suggested the following hypothesis.

This first image shows the 449 Mhz. Bodega profiler from yesterday. Note how Bodega, which is upwind of the Golden Gate,  had very strong WNW to NW wind just aloft from 200 meters to over 1000 meters.

At this elevation these winds would crash into the Marin coast range and which creates a lot of NW to WNW moving turbulent wind that would end up several hundred feet above the Marin Headland and Sausalito hills inbound to the north tower Golden Gate to Point Blunt area.  

Now, look at the insert above which shows the Mt. Tam winds yesterday at about 2572 feet.  Since Mt. Tam is way taller than nearby hills you would expect steady winds unless there was turbulence. But the data clearly shows there you can see the Mt. Tam wind is extremely gusty.

Meanwhile, at sea level, you have NW surface wind that is curving in through the Golden Gate as WSW wind at Crissy and to Treasure Island. This is a cool dense wind and as such, it tends to hug the surface of the water. And just above that WSW wind you have turbulent warm air moving from the WNW-NW. What I have observed that when this happens the WSW wind mass is pushed slightly southward leaving a much lighter wind area outside the Golden Gate, near the north tower and near Point Blunt.

A similar pattern happens frequently to Pt. Isabel with strong NW winds aloft and at the surface as you can see in this blog and the following animation.

https://blog.weatherflow.com/why-did-i-forecast-strong-winds-everywhere-except-pt-isabel-and-berkeley/

Looking at the animation notice how the WSW wind inbound from the Golden Gate is diverted away from Pt. Isabel and since Brook’s Island blocks any NW wind people are slogging outside.

So, looking at the animation, mentally just shift that diverting flow over the Central Bay to over the Marin Headland and you can see how that might weaken the Point Blunt,  north tower and winds outside the Golden Gate.

Incidentally, my experience is that the WRF greatly overestimates the impact of this pattern on Treasure Island and somewhat overestimates it for Point Blunt. Tell me what happens today.

This pattern is rarely as pronounced as you describe. But when I think I see this pattern I mention in my forecast something like: “Strong winds inside at Crissy and Treasure Island but fading towards the north tower and Point Blunt”

Let me know if the above makes sense. I will probably do a blog suggesting this as a possible explanation for what people observed. (And here is the promised blog)
Mike

 

West Coast Wind Blog: Blame it on the Kid. Part 2, the aftermath.

by Mike Godsey, mikeATiwindsurf.com

In Part 1 of this blog, Blame in on the kid I wrote about how unusual this season has been due in part to an El Nino pattern.

 

And for the west coast, El Nino means an unusually southerly storm track.

 

That blog left off talking about an 1000 mile wide winter type storm and cold front that was poised to stall off the coast of the Pacific Northwest.

Part 2 covers what this low pressure has done to our winds the last few days focusing on today July 11, 2019.

This first image shows that the low pressure is now centered NW of the Gorge and due west of the Canadian border.

 

You can also see the isobars of a ridge from the North Pacific High over the Gorge. As you know this means westerly winds for the corridor.

 

 

However, there are a  few more players poised to spoil those west winds.

 

This next image shows the modeled rainfall for today as depicted by the ECMWF.

 

And radar imagery confirms that we had spotty rain in the Pacific Northwest much of the day.

Combine all of this together and you have a pattern of

  1. unstable air
  2. a disrupted marine layer
  3. winds that easily lift from the surface

 

This is a recipe for UP AND DOWN winds.

The animation below is a composite of satellite imagery, sky photos, profiler imagery and winds graphs focusing on 3 PM today at the Hatchery.

 

 

 

West Coast Wind Blog: Blame in on the kid: Gorge winds weaken: Part One

 

by Mike Godsey, mikeATiwindsurf.com

Here is part 2 of this blog.

Did you notice how much weaker the Gorge winds were yesterday July 8, 2019?

And you have also probably noticed that this season has mostly had cooler air and water temperatures for this time of year.

And there have been more winds out east than typical for late June and early July.

And it is hard not to notice the atypical clouds most days. And now… look at the forecast for mild wind and showers from Portland to the coast.

Then there is the little matter of a 1000 mile wide winter type storm and cold front that will hit the coast today.

In the simplest terms, we are still in an El Nino pattern. And for the west coast, that means an unusually southerly storm track. Hence all the atypical variables above.

More specifically it means that the upper troughs at 500 MB. that steer storms, deepen the marine layer and increase onshore flow are still coming over the Pacific Northwest in July just like it was May or early June

This is obviously this is a topic for a major blog, which we are working on, but today I only have time to highlight the current storm.

So look at this animation that shows the storm and the associated upper trough (the southward extending loop of upper-level winds) as they appeared yesterday.

Note that lobe of the North Pacific High off our coast. This helped create our mild pressure gradient yesterday and today that lobe has retreated into California waters

So our pressure gradient is weaker today and if you check the radar later today you will see showers east of Portland.

Now note the upper ridge which is the northward extending loop in the upper-level winds over the Pacific
Northwest. That upper ridge is probably going to block the eastward movement of the storm. So it will linger along the coast and slowly drift northward into Canadian waters where it dies. Except for that upper ridge, we would be seeing
more lot more rain.

 

West Coast Wind Blog: Using sensors in the Wall to Rufus corridor

by Mike Godsey, mikeATiwindsurf.com

We have added a Public Domain sensor located on the John Day River Bridge east of Rufus. It will read LOW compared to the actual wind at Rufus but by looking at the wind at The Wall sensor and this sensor you will have a good idea of how windy it is at Rufus.

It also gives you another way to interpreting the often incorrect readings at the Maryhill and The Wall sensors. If there is a hint of WNW on the new John Day sensor the Maryhill and The Wall sensors will show strong winds that are mostly on the OR side of the river.

This blog link has lots of imagery and details about the wind and sensor issues at The Wall

If the John Day sensor shows hints of WSW winds the Wall will rock and the sensors will be accurate.

Below is a graphic that shows what is happening.

And here is a link to the John Day River Bridge sensor:

https://wx.iwindsurf.com/map#45.695,-120.78,12,1

West Coast Wind Blog: Bay Area and Gorge wind and weather go bonkers!

by Matt Sounders & Mike Godsey

You may have noticed that the weather has gone a bit bonkers this year for much of the west coast. And, no, you’re not alone in having this impression since the data backs up your impression. And, no, it is not Global Weirding, at least not directly.

This year the Gorge had snow on the ground for almost a month in late winter. Then it had a crazy long May heat wave. Then unending mid 30’s wind in June. And currently a long period of weird clouds and wind.

In the San Francisco Bay Area we have seen long periods of eddies and southerly winds along the Bay Area coast with the beloved NW winds AWOL. The frequent southerly flow has been a delight for kiters and windsurfers at Bay sites north of the Bay Bridge. But for Crissy, the coast and much of the Peninsula it has been a wind drought.

So what is behind all this Gorge and San Francisco weirdness? Blame El-Nino!

 

You may have noticed that it is a weird summer with the wind cycling between WSW eddy wind and, more rarely, out of season very strong NW ocean wind. Why? El Nino has enhanced Pacific ocean warming towards the Artic. Such warmth encourages a larger elongated North Pacific High to span the waters from west of Hawaii into Alaska to the tip of Baja. <b>In normal years the North Pacific High develops an inland kink over the Pacific Northwest as systems pass to the north which makes the Gorge blow. But in an El Nino year, the average storm track is further south. This makes the high pressure kink over far Northern California. And as you can read below…. this leads to an eddy.</b>

Every few years, the El Nino-Southern Oscillation – a warming of tropical Pacific sea-surface temperatures linked to a slowing or even reversal of the normally easterly trade winds – begins. El Nino is tied to a host of changes to the normal climate of the west coast. If you live in California you know that a strong El Nino brought more rain than normal to California this winter.

However, El Nino’s effects in the summer are not as well understood, but, this year, we are seeing a doosy. El Nino increases westerly winds south of the North Pacific High. Those west winds have often been stretching the North Pacific High north and sout . That is why the forecast has sometimes noted that the NPH stretched up to the Gulf of Alaska. Those El Nino westerly winds  have sometimes crippled the North Pacific High southern flank disrupting Hawaii’s trade winds. [this would be a good place to show a figure from the last couple of days with the hilariously northward displaced NPH with its sad southern flank under attack by a subtropical lows.

To read about how this has impacted the Gorge click here.

In the San Francisco Bay Area the  distorted NPH is doing several things.

First, it’s weakening northerly winds at the coast as pieces of the NPH are pushed east onto shore.

Second, it’s creating an opening for unusually sharp upper-level troughs to pass through the region which keeps temperatures far cooler than normal and changes the nature of marine layer clouds in the Corridor, giving them more height and picking them up off the floor of the Gorge.

Third, those same upper troughs have limited the heating of the waters flowing into the Columbia hence the cool waters for the July 4 holiday.

Fourth, it’s keeping surface pressure gradients unusually strong in the Near and Far East, making for many windy days at a time of year when that should become rarer.

Fifth, finally, it’s displacing the Columbia Basin low east of its normal hangout, causing winds just above the eastern Gorge to, more often, come from the WNW, rather than the WSW – this is making Maryhill and The Wall often weak at the launch sites while enhancing Rufus winds.

West Coast Wind Blog: Customer asks a leading question about the San Francisco gusty 2019 season.

by Mike Godsey, mikeATiwindsurf.com

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. 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. 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. 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.

West Coast Wind Blog: Unexpected very fast clearing brings winds stronger than forecast for Southern California coast.

by Mike Godsey, mikeATiwindsurf.com

The Southern California coast winds were a bit stronger than forecast yesterday June 28. With an upper trough overhead, the marine layer clouds far inland at dawn and typically the onshore flow and an AM eddy would keep the clouds lingering near the coast. This in turn typically limits heating and the local pressure gradient.

But as you can see in these images the Palos Verdes Peninsula/Long Beach and Catalina Island experienced very fast heating that became a focal point for the entire Southern California bight clearing. This, in turn, allowed inland valley heating and slightly more robust local sea breezes than forecast for most of Southern California. This was especially true for Ventura

West Coast Wind Blog: Weird things happen to marine layer clouds when there is no inversion… but no chicken little forecast here!

by Mike Godsey, mike@iwindsurf.com

So it was mid-day and hour after my 11:30 AM forecast update for the San Francisco Bay Area when the messages from customers started arriving: The first was from boggsman1

From: boggsman1
To: windfind
Posted: 26 Jun 2019 19:16
Subject: Re: FOG! Quote message
Mike, Its practically raining in the city today,

thickest fog this year…Doubt you get clearing

at crissy today.

This was interesting since I had specifically mentioned in the forecast that an inbound upper trough had mixed out the marine layer clouds which would mean early but somewhat unstable winds and here was Boggsman saying we had the thickest fog of year!

This is when you are tempted to turn Chicken Little and issue a special update saying in effect that “The fog is coming, the fog is coming” and drop the wind forecast for the coast and Crissy and many other sites near the coast. And watch in this first animation how incredible fast the fog came in! I could almost feel feathers growing as I watched the cams.

Fortunately, I had been following the cams, the Bodega Profiler and the RAWS hill top sensors. So I was pretty sure that without an inversion of warm air above the fog it would lift and mostly evaporate FAST. So I stuck to my guns. And almost every site reached its forecast wind value although Crissy was weaker than forecast.

These animations tell the story. Notice how incredibly fast the fog developed in the first animation and how fast it disappeared the second animation.

West Coast Wind Blog: Battle Royale… North Pacific High’s surface NW winds vs. Southerly eddy winds!

by Mike Godsey, mikeATiwindsurf.com

The battle is on! There is a tiny eddy near Stinson and a larger ribbon like eddy running from the Golden Gate to Santa Cruz creating southerly ocean winds near shore.

Meanwhile, very strong NW winds from the North Pacific High are roaring just west of our ocean buoys.

At dawn NNE winds at 1000 – 2000 feet aloft are holding the NW surface winds away from the Bay Area.

You can see these wind aloft in the 2nd image.

If you have ever sailed Sherman Island on northerly winds you know that these winds always fade as the morning progresses.

So as the NNE winds fade midday the NW wind moves over the coast.

Then as the pressure gradient towards Bakersfield goes up these winds roar through W and NW facing gaps in the coast range.

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