Major Wind Event For Western Oregon and Washington

A major wind event is now probable for western Oregon and Washington, potentially the strongest windstorm so far this winter.

Very strong winds, with gusts to 50-80 mph, will move up the Oregon coast this evening and then pummel western WA in the morning hours, ending with a powerful surge of westerly winds in the Strait.

This is serious, so I would be prepared (batteries, don't drive around during strong winds, etc.).  There will be power outages.

The 8 AM GOES-17 weather satellite imagery shows the storm west of northern CA and southern Oregon (you can see the swirl of the clouds).

And the sea level pressure forecast for 10AM this morning suggests an elongated area of low pressure associated with the storm, with an area of very large pressure change (gradient) to its south. THAT is where the strong winds will be.

By 10 PM tonight, the area of large pressure change moves along the northern Oregon Coast, bringing very strong winds from Seaside down to North Bend.

Three hours later (1 AM Sunday) the hyper pressure gradient reaches southwest Washington.

And by 4 AM has pushed over Northwest Washington, including Puget Sound.

I will now show you the output of the UW high-resolution ensemble system, probably the best regional ensemble system in the U.S. (this is the kind of system I have been trying to convince the National Weather Service to do nationally).   The graphic is from the Seattle WindWatch website, by the way (and was create by UW Research Meteorologist Jeff Baars).

This graphic shows the maximum wind gust forecast over Seattle from a large number of high-resolution forecast runs.    Wow.  I am charging my smartphone immediately!  Nearly all of the forecasts are going for a significant event (gusts over 40 mph) and several have gusts over 50 mph! The timing of the peak winds vary a bit (between roughly 1 and 7 AM).

Now let me give you a more spatial view, showing the 4-km resolution WRF run made at the UW this morning. 

At 10 PM tonight (Saturday), really strong winds (blue and brown colors) are hitting the northern Oregon coast (up to 65 knots, about 75 mph!)

By 1 AM, the WA coast is being savaged by 50+ knot gusts, and strong winds are just reaching Olympia.

One hour later, Puget Sound is in the crosshairs of mother nature, with up to 60 kt gusts reaching south Seattle.   Big winds continue on the coast.

At 4AM, winds have decreased slightly over Puget Sound, but an extraordinarily strong westerly wind surge has pushed into the eastern Strait of Juan de Fuca, northern Whidbey Island, and the southern San Juans.   We are talking about 60 knot gusts.

In short, it is highly probable that this will be a major wind event.  Perhaps not the equal of the truly historic storms (eg., Chanukah Eve and Inauguration Day Storms), but quite possibly the big wind event of the winter.   The only thing that will help mitigate the power outages is the pruning by previous wind events.  But I expect that tens of thousands will lose power over the region.

Now back to charging all my electronic gear.

from Cliff Mass Weather and Climate Blog http://bit.ly/2RzoClY

Major Wind Event For Western Oregon and Washington

A major wind event is now probable for western Oregon and Washington, potentially the strongest windstorm so far this winter.

Very strong winds, with gusts to 50-80 mph, will move up the Oregon coast this evening and then pummel western WA in the morning hours, ending with a powerful surge of westerly winds in the Strait.

This is serious, so I would be prepared (batteries, don't drive around during strong winds, etc.).  There will be power outages.

The 8 AM GOES-17 weather satellite imagery shows the storm west of northern CA and southern Oregon (you can see the swirl of the clouds).

And the sea level pressure forecast for 10AM this morning suggests an elongated area of low pressure associated with the storm, with an area of very large pressure change (gradient) to its south. THAT is where the strong winds will be.

By 10 PM tonight, the area of large pressure change moves along the northern Oregon Coast, bringing very strong winds from Seaside down to North Bend.

Three hours later (1 AM Sunday) the hyper pressure gradient reaches southwest Washington.

And by 4 AM has pushed over Northwest Washington, including Puget Sound.

I will now show you the output of the UW high-resolution ensemble system, probably the best regional ensemble system in the U.S. (this is the kind of system I have been trying to convince the National Weather Service to do nationally).   The graphic is from the Seattle WindWatch website, by the way (and was create by UW Research Meteorologist Jeff Baars).

This graphic shows the maximum wind gust forecast over Seattle from a large number of high-resolution forecast runs.    Wow.  I am charging my smartphone immediately!  Nearly all of the forecasts are going for a significant event (gusts over 40 mph) and several have gusts over 50 mph! The timing of the peak winds vary a bit (between roughly 1 and 7 AM).

Now let me give you a more spatial view, showing the 4-km resolution WRF run made at the UW this morning. 

At 10 PM tonight (Saturday), really strong winds (blue and brown colors) are hitting the northern Oregon coast (up to 65 knots, about 75 mph!)

By 1 AM, the WA coast is being savaged by 50+ knot gusts, and strong winds are just reaching Olympia.

One hour later, Puget Sound is in the crosshairs of mother nature, with up to 60 kt gusts reaching south Seattle.   Big winds continue on the coast.

At 4AM, winds have decreased slightly over Puget Sound, but an extraordinarily strong westerly wind surge has pushed into the eastern Strait of Juan de Fuca, northern Whidbey Island, and the southern San Juans.   We are talking about 60 knot gusts.

In short, it is highly probable that this will be a major wind event.  Perhaps not the equal of the truly historic storms (eg., Chanukah Eve and Inauguration Day Storms), but quite possibly the big wind event of the winter.   The only thing that will help mitigate the power outages is the pruning by previous wind events.  But I expect that tens of thousands will lose power over the region.

Now back to charging all my electronic gear.

from Cliff Mass Weather and Climate Blog http://bit.ly/2RzoClY

Forget El Nino, StormFest is about to Hit the West Coast

Things often calm down after January 1 during El Nino years....but not this year...with the U.S. West Coast from central California to Washington State about to be pummeled by a series of storms.   Rain, snow, wind?  Plenty for everyone.

A view of the latest infrared satellite imagery shows an amazing line-up of one storm after another stretching way into the Pacific.  A traffic jam of storms.

Let's examine our stormy future, using a series of sea level pressure forecasts from the UW WRF weather forecast models (solid lines are sea level pressure, shading in lower atmosphere temperature).

At 10 PM today, a  strong low is just off the northern tip of Vancouver Island.

10AM Saturday brings an energetic low center into northern CA.

10 PM Sunday?   Another storm hits central Oregon!  And another system is in the wings.

That storm is right off our coast late Wednesday.

 

El Nino late winters generally have less action---not so this year!   

What about precipitation you ask?   Do you really want to know?  The accumulated total through 4 AM next Thursday is impressive, with 5-10 inches over many mountain areas and even 10-20 inches over parts of northern CA, the Olympics and southern BC.

Snow?   There will be abundant amounts.   For example, here is the accumulated snowfall for the 72 hours ending 4 PM Wednesday.  2-3 feet for the high terrain from the central Sierra Nevada to southern BC.  Our winter ski season is secure.

Wind?  You bet.  Each of these storms will bring strong, damaging winds to a favored area of the coastal zone and mountain peaks.  

There is a silver lining of all this action of course:  it will provide an immense amount of water to fill our reservoirs and enhance our snowpack, a snowpack that is now in pretty decent shape (see latest summary below).  Water resources should be fine next summer.

But all these facts on the ground and favorable forecasts don't stop some of Seattle's wacky local media from talking about drought for our region, with the Seattle Stranger being one of the worst (see below).  Facts should matter---apparently not at the Stranger.

from Cliff Mass Weather and Climate Blog http://bit.ly/2s4S8li

Forget El Nino, StormFest is about to Hit the West Coast

Things often calm down after January 1 during El Nino years....but not this year...with the U.S. West Coast from central California to Washington State about to be pummeled by a series of storms.   Rain, snow, wind?  Plenty for everyone.

A view of the latest infrared satellite imagery shows an amazing line-up of one storm after another stretching way into the Pacific.  A traffic jam of storms.

Let's examine our stormy future, using a series of sea level pressure forecasts from the UW WRF weather forecast models (solid lines are sea level pressure, shading in lower atmosphere temperature).

At 10 PM today, a  strong low is just off the northern tip of Vancouver Island.

10AM Saturday brings an energetic low center into northern CA.

10 PM Sunday?   Another storm hits central Oregon!  And another system is in the wings.

That storm is right off our coast late Wednesday.

 

El Nino late winters generally have less action---not so this year!   

What about precipitation you ask?   Do you really want to know?  The accumulated total through 4 AM next Thursday is impressive, with 5-10 inches over many mountain areas and even 10-20 inches over parts of northern CA, the Olympics and southern BC.

Snow?   There will be abundant amounts.   For example, here is the accumulated snowfall for the 72 hours ending 4 PM Wednesday.  2-3 feet for the high terrain from the central Sierra Nevada to southern BC.  Our winter ski season is secure.

Wind?  You bet.  Each of these storms will bring strong, damaging winds to a favored area of the coastal zone and mountain peaks.  

There is a silver lining of all this action of course:  it will provide an immense amount of water to fill our reservoirs and enhance our snowpack, a snowpack that is now in pretty decent shape (see latest summary below).  Water resources should be fine next summer.

But all these facts on the ground and favorable forecasts don't stop some of Seattle's wacky local media from talking about drought for our region, with the Seattle Stranger being one of the worst (see below).  Facts should matter---apparently not at the Stranger.

from Cliff Mass Weather and Climate Blog http://bit.ly/2s4S8li

Fogs Engulfs Seattle

There was a stunning series of images this morning from the Space Needle panocam as inland fog pushed over Seattle.

It was clear this morning around sunrise over downtown Seattle, but a shallow fog bank loomed to the southeast (picture below for 7:30 AM).

By 8:30 AM the fog had begun to move across downtown.

And  by 10 AM the city was well covered, with only the top of the Columbia Center extending above the cloud deck.

At 11:30 AM,  the fog had begun to thin (see below)

But looking towards Queen Anne hill, one could see a wonderful example of a dramatic optical effect--a glory- centered at the top of the shadow of the Space Needle.  Note the circular array of colors caused by dispersion effects of diffraction.  Magnificent.

The fog bank also moved in at the NOAA facility near Magnuson Park in NE Seattle and the vertical sounder there showed how the temperature structure was altered by the fog bank (see plot below of temperature with height a various times).  At 1200 and 1300 UTC (4 and 5 AM PST), temperatures warmed with height in the lowest 100 meters (cyan and yellow lines).  But after the fog moved in (black, red and green lines), there was a large cool down in the lowest 300 meters (about 600 ft).   Not much change above that. 

Finally, the fog was evident in the 10:45 AM image from the new GOES-17 weather satellite (see below).  Fog extended east, north and south along the river valleys, but ended at the Sound.  A wonderful morning to hike up to the top of Cougar or Tiger Mountains and look down on the clouds below.  Great visibility aloft.  And the fog won't last...much will burn off during the next few hours.

from Cliff Mass Weather and Climate Blog http://bit.ly/2RsVTPC

Fogs Engulfs Seattle

There was a stunning series of images this morning from the Space Needle panocam as inland fog pushed over Seattle.

It was clear this morning around sunrise over downtown Seattle, but a shallow fog bank loomed to the southeast (picture below for 7:30 AM).

By 8:30 AM the fog had begun to move across downtown.

And  by 10 AM the city was well covered, with only the top of the Columbia Center extending above the cloud deck.

At 11:30 AM,  the fog had begun to thin (see below)

But looking towards Queen Anne hill, one could see a wonderful example of a dramatic optical effect--a glory- centered at the top of the shadow of the Space Needle.  Note the circular array of colors caused by dispersion effects of diffraction.  Magnificent.

The fog bank also moved in at the NOAA facility near Magnuson Park in NE Seattle and the vertical sounder there showed how the temperature structure was altered by the fog bank (see plot below of temperature with height a various times).  At 1200 and 1300 UTC (4 and 5 AM PST), temperatures warmed with height in the lowest 100 meters (cyan and yellow lines).  But after the fog moved in (black, red and green lines), there was a large cool down in the lowest 300 meters (about 600 ft).   Not much change above that. 

Finally, the fog was evident in the 10:45 AM image from the new GOES-17 weather satellite (see below).  Fog extended east, north and south along the river valleys, but ended at the Sound.  A wonderful morning to hike up to the top of Cougar or Tiger Mountains and look down on the clouds below.  Great visibility aloft.  And the fog won't last...much will burn off during the next few hours.

from Cliff Mass Weather and Climate Blog http://bit.ly/2RsVTPC

Year in Review

With new year's coming up tomorrow night, it is appropriate to look back on the weather of the past year.

The essential take away:  2018, and particularly the late spring and summer, were much warmer than normal.

We can illustrate this with a nice graph (see below) produced by the National Weather Service for Seattle-Tacoma Airport, showing the observed temperatures (blue line), the normal range (green shading) and the records for each date (high records-red color, low records, blue color).

One is struck immediate by the many dates that were above normal, particularly from May 1 to Sept. 1).    A number of these days hit highs 10-15F above normal.    On the other hand, the annual extremes were not impressive...on day got to 94F and the lowest temperature all year was 24F, with only one cold spell in late February.

Precipitation was a very different story--the annual precipitation will end up slightly below normal (see middle graph, top of light green shows accumulated precipitation), resulting from a wetter than normal first half of the year, a dry summer, and moist late fall.

Snow in Seattle was almost absent:  about 1 inches compared to a normal total of around 6 inches.

A regional view of the differences from normal of temperature and precipitation for 2018 is shown below.   For temperature, the entire region west of the Rocky Mountains has been warmer than normal, particularly the U.S. Southwest.   Here in WA state, roughly 1-2F above normal.   But note the cooler than normal weather over the northern Plains.  That will be important.

Precipitation is more complex.  Most of the west was near normal in 2018, except from southwest WA to northern CA, where is has been quite dry.  The contrast across western WA is really substantial.

So what it the cause of the warm anomaly in the West?

Anthropogenic global warming might be making some contribution, but there is much more going on.    A hint at this comes from taking a broader perspective, looking at all of North America (see below).   This figure shows the temperature anomaly (difference from normal) for 2019.  Blue indicates colder than normal and  red/orange above normal.   The western U.S. is warm, but the middle of the country is cold, while the East Coast is warm.

This pattern was associated with an amplified upper-level wave pattern, with ridging (high pressure) over the West Coast, with troughing (lower pressure) over the central U.S..   This pattern was evident for much of the year, including our warm/dry period in November and during the late spring. 

To illustrate, here is a map produced by the National Weather Service showing the average upper level (500 hpa) height anomaly in November (sorry it is blurry, the government shut-down makes it impossible for me to get better graphics).  Red indicates higher than normal heights (ridging), blue indicates troughing).  Ridging produces localized warm surface temperatures, the opposite for troughing.  Ridging also suppresses precipitation, explaining our drier than normal conditions.

There is no reason to expect that this pattern has anything to do with global warming (note:  the "lazy jet stream" hypothesis has been firmly disproved in the peer review literature). 

How much of our warm year might be due to anthropogenic global warming?   We can get some insights into this by using the wonderful Washington State Climatologist climate plotting site (with kudos to Karen Bumbaco and Nick Bond).    The annual temperature in Seattle is shown below.  A small upward trend of perhaps .5F, with human caused global warming undoubtedly contributing during the past 30 years.  Other local stations are similar.

The take away is that most of the warming this year (1-2F)  is due to the anomalous upper level pattern, which is probably the result of natural variability.  Why am I stressing this point?  Because too many people, and unfortunately some in the media, make the assumption that every warm anomaly is mainly the result of increasing CO2 in the atmosphere.   This is simply not true.



from Cliff Mass Weather and Climate Blog http://bit.ly/2Sr4Oi0