Does Your App Show Snow For Next Week? Here’s Why

January 18, 2018

7:30pm Thursday

Did you notice a snowflake or flakes on your app for about a week from now?  This is what our FOX12 OREGON app shows this evening:

Capture

All extended forecasts on apps are automated, so keep in mind it’s just computer modeling without human input.  Here at FOX12 we also put our regular 7 Day Forecast on the right side, you should always look there first.  But wait!  OUR forecast also has snowflakes in next Thursday.

What’s going on?

Thursday & Friday of next week we get a cool and showery weather pattern, just like today but maybe 5-8 degrees colder.   Today we were in the mid-upper 40s during the afternoon hours.

Jet Stream Forecast 2017

This isn’t an “arctic blast” sort of pattern; there will be no east wind pouring cold air out of the Gorge like we see in our real snow/ice events.  No this is the “wet snow” setup that frustrates so many of us.

AT THIS POINT it appears these showers will be accompanied by “onshore flow” or air flowing from the ocean inland.  That modifies the lowest part of the atmosphere enough that it’s really tough to get sticking snow (more than a dusting) down to sea level where most of us live.  But it is very easy to get sticking snow up around 1,000′ and above in this pattern.   In this upcoming pattern that app forecast is just right.  We’d typically see highs 40-46 in the lowlands and lows in the 30s in this setup and that’s our forecast too.

It’s hard to believe, but THIS IS THE FIRST TIME WE’VE HAD THIS PATTERN THE ENTIRE WINTER!  The only other time we’ve been close to snow in the lowlands was for about 4 hours on Christmas Eve…that’s it!  It’s been a mild winter so far.

So we’ll keep an eye on it, but it’s probably safe to say a lot of us will at least SEE snow in the air later next week, it’s just a matter of whether it sticks at your location.  If you live at/above 1,000′ it looks like possibly next Thursday or Friday you might see some snow on the ground.  But a lot can change in 7 days…

Chief Meteorologist Mark Nelsen


Big Waves On the Beaches Today

January 18, 2018

6pm Thursday

30-35 foot waves arrived on the Oregon Coast late last night as expected.  They continued to pound the coastline through the day.  There doesn’t appear to be much widespread damage, but the pictures and video have been amazing!  At midday a large wave smashed into the Sea Gypsy motel/condos.   The wave in action (courtesy of Joel Hernandez)

Bigwaves_JoelHernandez

 

A few pics of the damage from David Willis:

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Take a look at a buoy about 30 miles west of Astoria

Wave Height One Buoy 24 Hrs

An important point is that this is SIGNIFICANT WAVE HEIGHT, not the highest waves.  These numbers show the average height of the highest 1/3 of waves.  So assuming we’re talking a 32-33′ sig. wave height, that means maybe 1 in 1000 waves passing a location could be as high as double that height!  In fact the NWS noted this buoy measured a 60′ tall wave around 1am this morning!

Where did the action come from?  FAR offshore.  A deep area of low pressure maybe 1,000 miles to our southwest generated a large field of southwest wind.  This is 48 hours ago:

OceanWaveHeight Observed

Then 24 hours ago the field of large swell was about to arrive on the coastline:

OceanWaveHeight Observed2

This isn’t quite as rare as you think.  It seems that at least once a winter we talk about 30′ waves, and the folks over at Portland NWS think we last saw conditions like this a little over two years ago, during that stormy December 2015.  That was about the same time as the Battle Ground tornado.

The wave/swell height is dropping now and should be down to around 20 feet by tomorrow midday & afternoon.

It’s amazing nowadays with social media how quickly great pics and video spread from the coastline to…the rest of the world.   20 years ago we would have just received an email with maybe a still pic…maybe.  Quite a change!

Chief Meteorologist Mark Nelsen

 

 

 


How About Those Crazy “Asperitas” Clouds This Afternoon?

January 17, 2018

10pm Wednesday

Thanks to all of you that sent it pictures of the neat clouds just ahead of the rain today.   This one is from Larry Cloud…

photo_larrycloud_gresham

They are named ASPERITAS clouds (formerly Undulatus Asperatus).  The name comes from the Latin word for “roughness” or “harshness”.  In fact the name just changed last year as the World Meteorological Organization decided it was time to give them an upgrade with this very detailed explanation:

“Well-defined, wave-like structures in the underside of the cloud; more chaotic and with less horizontal organization than the variety undulatus. Asperitas is characterized by localized waves in the cloud base, either smooth or dappled with smaller features, sometimes descending into sharp points, as if viewing a roughened sea surface from below. Varying levels of illumination and thickness of the cloud can lead to dramatic visual effects”

There you have it.  I’ve seen these maybe once/twice a year in our area, which is pretty rare considering how many clouds we get in 365 days!

Here are some more pics from viewers…enjoy a little slideshow!

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Chief Meteorologist Mark Nelsen

 


Worst “La Niña” Snowpack on Mt. Hood So Far, But Big Snow Ahead!

January 16, 2018

6pm Tuesday

Remember the excitement in mid-November when heavy snow was dumping in the Cascades and ski areas opened up quickly?  Things have sure changed in two months.

Today we passed an important threshold on Mt. Hood that tells us this La Nina winter is not behaving as it “should”…at least so far.

  • The amount of “snow water” in the snow pack is 15.4″ at the Mt. Hood Test Site 
  • IT’S THE LOWEST ON RECORD FOR JAN. 16TH…DURING A LA NINA WINTER 

Basically this means in the past 35 years we haven’t made it this deep into the winter season with such a low snow pack while a La Nina winter was in progress.  The sensors were installed around 1980; so we have 13 other La Nina winters to compare this one to.  Notice all of Oregon is in pretty bad shape right now:

You can read more about what we typically see in La Nina winters by clicking up top on the banner that says WINTER 2017-18 THOUGHTS.  These are winters that are typically known for abundant mountain snowfall and plenty of lowland rain.   But this year we’ve had a mix of a) mild/rainy systems, b) very dry period in December, c) warmer & drier than normal the 1st half of January.

Now it HAS been close to this bad.  January 1996 & 2012 were close, but then things improved the 2nd half of winter.  In fact 1996 was a poster child for how quickly things can turn around in the mountains the 2nd half of winter.  There was only 1″ snow on the ground at Government Camp on January 15th.  A snowy & cool pattern arrived two days later.  In just two weeks, 94″ was on the ground at Goverment Camp!  I remember those amazing two weeks;  cross-country skiing at only the 2,000′ elevation east of Corbett on about 2 feet of snow!

So what’s ahead?  Some good news!  My gut feeling is we don’t have a crazy 1996-style 2 weeks ahead, but I do see quite a turnaround coming the next 10+ days.  A series of colder systems that should bring many feet of snow.  Take a look at the ECMWF ensembles showing a steady accumulation of rain in the lowlands the next two weeks:

First, we are still in the warm air for tomorrow, so I see one last very warm day.  It’ll be our 9th day at/above 50 this month.

We’ll be within a degree or two of our 59 degree record.  Thursday a cold front moves through the region, dropping snow levels down to around 3,000′ by afternoon.  After that point just about every system during the following week will bring snow to pass elevations and above.   Note the GFS would imply snow could briefly dip into the Coast Range Saturday and/or early next week:

I see maybe a foot of fresh snow on the ground for Saturday skiers, then a bunch more for both Sunday and Monday.  Here’s the ECMWF estimate of snowfall up around 5,000′ through late next week.  3-5 feet, that’s a nice turnaround isn’t it?  I have plans to ski NEXT weekend, the 25th-27th…timing seems to be working out right!

The GFS shows similar totals…maybe 3′ in the next 7 days up there:

Down in the lowlands I think you know what this means…lots of wet weather and temperatures should cool back to normal.  Maybe even a few degrees below normal next week.  At this point I don’t see a setup for lowland snow/ice, or even a real strong storm.  That’s one other thing that’s been missing this winter (a series of strong storms) but that doesn’t appear to change in the next week or two.

To summarize, the 2nd half of January should be wetter and cooler than the first half, with some nice snowfall in the Cascades.  Things are going back to normal the next two weeks!

Chief Meteorologist Mark Nelsen

 


Record Warm Sunday, But A Rainy Week Ahead

January 14, 2018

8pm Sunday

Today was a “January Scorcher” with temperatures in the metro area running 10-15 degrees above normal.  We were just two degrees short of our 60 degree record

Todays Observed Highs OrWa 2017

Salem, Hillsboro, & Astoria all broke records for the date

Record Highs Cities

What a change from last year eh?  The first two weeks of January are the warmest in 12 years in Portland, meanwhile the first two weeks of LAST January were the coldest in 38 years.

Winter Snow_Ice Compare

The next 3 days remain mild, although temps will be much closer to normal.  Clouds thicken tomorrow and a cold front moves inland in the evening.  This will stop the snowmelt in the Cascades; it’s been in the 40s up there since yesterday morning at the ski areas.  Note the snow depth at the lower part of Timberline Ski Area (the SNOTEL site) is the 2nd lowest of the last 10+ years:

Mark Mt Hood Snowpack January 1

The good news is that we finally see a change coming for building the mountain snow pack.  Several much cooler systems arrive Thursday through at least early next week.  That turns things wetter in the lowlands, plus a bit cooler.  See the big drop in snow levels on Thursday?

ECMWF Snow Level From 850mb Temps

In the mountains we should finally, for the first time in over a month, see a rapidly building snow base.  Check out the morning Euro model run estimate of snowfall from now through Saturday evening; 2-3 FEET in the Cascades during that time.  Almost all of this falls after Wednesday:

ECMWF Snow Accumulation

These will be colder systems moving onshore, but they will be accompanied by “onshore” flow, which means a breezy west or southwest wind with each.  That’s why I don’t expect snow in the valleys for now.

As of now I’m not sure if this is “the big change” to La Nina conditions or just a week of cooler/wetter systems.  We’ll see about that.   To sum things up, I think there are several key points for the next 7 days:

  1. IT’S GOING TO TURN WETTER THIS WEEK
  2. SKIING/SNOWBOARDING WILL BE MUCH BETTER NEXT WEEKEND
  3. SNOW IN THE LOWLANDS APPEARS UNLIKELY IN THE NEXT 7-10 DAYS
  4. SNOW IS LIKELY AT SOME POINT ABOVE 1,000′ IN THE FOOTHILLS AND COAST RANGE IN THE NEXT 7-10 DAYS

Here’s my Government Camp forecast, along with snow forecast for the ski areas at Mt. Hood (lower snow #s are for Govy, higher #s up around 6,000′)

7 Day Forecast GOVT CAMP

Chief Meteorologist Mark Nelsen


Blustery January Day, But Beautiful Weekend Ahead

January 11, 2018

8pm Thursday

Today we had a nice little Pacific Northwest wet & windy day.  Neither the rain or the wind was too much.  Note the rain totals generally under one inch:

Rain Metro Today Databound

Peak wind gusts didn’t cause much damage either at the Coast (generally under 60 mph) or in the Valley (gusts 30-40 mph) as expected:

Wind Metro Peak Gusts Today

One thing that really stuck out though…the warm temps!

Today was the warmest since Thanksgiving Day in Portland.  We tied a record high of 58 degrees.  That meant mainly rain in the Cascades, except at the highest parts of the ski areas.  A cold front is moving through Oregon right now, but the air behind it isn’t very cold.  Snow levels will only come down to around 4,000′ tonight and Friday.  That’s the lowest we’ll see snow, since a much warmer airmass surges into the Pacific Northwest beginning Friday night.

A strong upper-level ridge of high pressure develops Saturday through Monday along the West Coast.  Note the ECMWF model showing heights WAY above normal

m500za_f072_bg_NA

That gives temperatures between 50-55 degrees up around 5,000′.  Now if it was late March or April, we’d be forecasting high temperatures in the 70s for the weekend.  But of course it’s not, and the warm air doesn’t mix all the way down to the surface due to winter inversions+weak sunshine.

So how warm could it get?  Models keep pushing temperatures into the upper 50s or even 60.  That won’t happen in January.  But if we get the perfect setup of cloud cover all  Friday night (keeping temperatures warm overnight), then they lift north quickly and we turn sunny?  I could see highs in the mid 50s as a light easterly wind develops out of the Gorge.  I’ve gone for a high of 54.  Clear skies Saturday night mean a tougher break through the inversion Sunday, plus east wind looks stronger.  The result should be high temps close to 50, but it’ll feel like 40 on the east side of town in the wind zone.

Regardless of the exact temperature details for this weekend, keep in mind we have a MOSTLY SUNNY WEEKEND WITH COMFORTABLE TEMPERATURES IN JANUARY!  That’s almost unheard of, usually it’s sunny and cold (last year at this time) or sunny & windy/cool.

We have a period of wet weather coming up again next week, with rain arriving on Monday (MLK DAY) afternoon.   You can see that on the ECMWF meteogram (blue bars from left to right) for the next 10 days

By the way, there is no sign of stormy weather (a windstorm), flooding, or lowland snow/ice in the next 7-10 days.  We MIGHT get by with a snow-less January.  That is not unusual, check out the last 11 January’s.  Only 4 of 11 had measurable snow.  Apparently we may have had a little “overdraft” with those 8″ last year.

January Snow PDX

Enjoy!  Chief Meteorologist Mark Nelsen


January 2018: Much Different Than 2017!

January 8, 2018

9pm Monday

As I mentioned almost a week ago, the weather the past couple of weeks has been very S-L-O-W.  Check out how different the first week of the month has been compared to last year!

Winter Snow_Ice Compare

So far this winter (beginning December 1st), we’ve seen temperatures near normal, but it’s sure been a bit drier than normal.  Most obvious has been the lack of mountain snowfall.  You see all of Oregon is at/below 50% of average “snow water” for this date:

Snowpack Oregon Plus Facts

At this point last winter we were finishing up our 2nd ice storm of the season with two more to go.   That was the weekend snow then ice event (very similar to what just happened Christmas Eve).  The big snowstorm followed just two days later (a Tuesday evening).  So far this month is running warmer than the past 4 Januarys…yes, quite a change.

Looking ahead, we are still in a split-flow pattern early this week, with big rains falling way down in southern Oregon.  That continues the next two days, then a more organized Pacific frontal system moves inland Wednesday night and Thursday.  This gives us a nice rainy/windy 12 hours…ah, back to normal!

Then an upper-level ridge of high pressure pops up over the West Coast through the MLK weekend.  East wind SHOULD clear out the metro area for some sunshine Saturday and Sunday, although we’re still deep in inversion season so it won’t get much above 50.

There are signs of a pattern change which now appears to only be 8-10 days away.  Models and their ensembles want to develop upper-level troughing over the western USA or at the least a wet/stormier westerly flow.  I’m talking sometime after next Tuesday, depending on the model.   Note the ECMWF ensemble 500mb height anomaly for NEXT week and the FOLLOWING WEEK (the 2nd half of January) shows the lower heights along the entire West Coast and a much warmer eastern USA:

And the same two-week precipitation anomaly maps show a wetter than normal West Coast:

This WOULD be the change to typical La Nina conditions many of us have been looking for if it comes to fruition.  We’ll see.  The ECMWF is pretty clear, check out the 850mb ensemble chart; excellent agreement on those temps going down beginning on the 16th. NEXT week is consistently cooler than normal at 4,000′ in the Cascades.

ecmwf_850mbtimeseries

This could mean we’ll finally start building a good base of snow in the Cascades.  What we DON’T see in the next 8-10 days is a pattern that would get snow/ice in the lowlands.  So it’s probably safe to say the first three weeks of January will not be featuring any snow/ice events.

Chief Meteorologist Mark Nelsen