Raging in The Gorge: Another 100+ Day!

January 24, 2014

 

The east wind has ramped up in the Gorge this morning; peak gusts are around 75 mph at Corbett and 87 (as of 8am) at Vista House.  That’s STRONGER than what we saw Monday when Matt Sloan recorded a 115 mph gust on the steps.   Since that time it appears a power outage may have put Vista House out of service.  Today is definitely a 100+ day out there.  Actually last night was too.

East wind has backed off in most of the metro area this morning but as expected the wind is much stronger in the west end of the Gorge as the flow is channeled through a smaller area.  A strengthening inversion is the reason for this.  I see observations near Estacada and Sandy around 1,500′ and above are about 10 degrees warmer at 10am compared to yesterday at the same time.  Pressure gradient is higher than what we saw Monday too, around 11 millibars from PDX to The Dalles.

Hang on!

Everyone else can enjoy the sunshine and mainly calm wind…oh, and don’t start any fires, there’s a Red Flag Warning for the Cascade foothills.  It’s getting real weird out there…

MarkFireRedFlagWarning

Chief Meteorologist Mark Nelsen


Is It Too Late For the Ski Areas?

January 23, 2014

The short answer is a NO.  There is still some good time available to get some great snowstorms although on average more than half the normal winter snowpack has accumulated by this point in the winter season.

The longer answer? It’s becoming increasingly unlikely that we’ll see a “great” volume of snow in the Cascades in the next month or two.  At least recent history generally tells us that.

The ski season so far has been the worst since 2004-2005.   It’s January 23rd.  There is no significant snow (more than 6″ or so) in sight through the end of the month; in fact a little rain is likely at the lower parts of the resorts next Tuesday.

So as of February 1st, we’ll likely still have a bunch of ski resorts unable to open more than a lift or two in Oregon…very rare.  That includes Cooper Spur, Summit, Ski Bowl, Hoodoo, Willamette Pass, and Mt. Ashland.  Only Mt. Hood Meadows, Timberline, Bachelor, and Anthony Lakes are near normal operations.

You may remember that I posted about a month ago on the poor snow situation.  The only thing that changed in the entire month was one minor snowstorm and one big snowstorm in the middle of the month.  Other than that pretty much nothing!  We are finishing up a 2nd week of totally dry weather and most of next week looks drier than normal too.  During that posting in late December I mentioned that in some years we’ve seen the weather pattern suddenly change at some point in January and we saw a ton of snow in the mountains as a result.

That didn’t happen; so I figured this evening I’d look back at previous snow years and see what happened from THIS POINT forward.  Take a look at the snow chart from Northwest Avalanche Center data for Mt. Hood Meadows base area.  The data go back to the early 1970s:

MarkMeadowsSnowChartNWAC

The red line is this year, the gray is average.  I plotted all years (8 of them) that had about 65″ or less snow on the ground on February 1st.  Right now Meadows has about 50, it hasn’t changed much in two weeks.  I see several points:

1. Almost every year that is this low at this point in the season stays below average, many years significantly below average.

2. 1/4 of those years (1978-79 & 1993-94) had a snowy pattern arrive for about a month from early February to early March, pushing snowpack up close to normal.  Interesting that in both those years March warm spells cut the snowpack back down again.

3. In another 1/4 of those years (1976-77 & 2002-03) a snowy pattern arrived in the 2nd half of February, but snowpack remained below normal. That means in one half of previous bad years there was some sort of change in the month of February, but the other half of the years we just limped along into spring without any big change.  There you go; a 50/50 chance of a big weather pattern change for the mountains.

4.  Crunch time for snow in the Cascades is the next 5 weeks.

For the weather geeks I think it’s interesting that we’re tracking close to 2002-2003 and 1978-1979 which were both mentioned by many earlier in the winter as possible analogs to this year.

In the near-term (next week or so), all models advertise a weather pattern change around next Wednesday-Thursday, but to what?  It appears the strong ridge over us will shift to the northwest (up closer to Alaska), and allow some flow from the west to arrive on the West Coast.  At the same time northerly flow coming around the big ridge tries to move south into the Pacific Northwest around February 1st.  This says we get out of the totally dry weather and go to just a more typical “drier than normal” pattern.  Meanwhile temps cool off quite a bit, especially at the higher elevations.  Take a look at the 00z GFS ensemble chart:

tseries_850t_000-384_Portland

and the 12z ECMWF ensemble chart:

tseries_850t_000-360_Portland

They both show temps around 5,000′ cooling off quite a bit the next 10-14 days.   With a ridge off to the northwest there’s always the chance arctic air could attempt to sneak into the Pacific Northwest, but there’s no obvious sign that is in the cards…for now.

Chief Meteorologist Mark Nelsen


Windiest Day in a Year in Portland

January 23, 2014

Today’s peak gust of 47 mph at PDX was the strongest since a 48 mph southerly gust a little over a year ago.

PLOT_Wind_Metro_PeakGusts_Easterly

Two thoughts on that:

1) We don’t get strong wind much anymore.  The last real windstorm here in the metro area was over 7 years ago; December 2006.

2) East wind gusts in the 35-45 mph range don’t produce nearly as many power outages as the same speeds from the south.  That’s because over a good chunk of the Portland metro area trees are used to a regular beating from east wind during the winter.  It looks like there were only around 5,000 PGE customers out of power at the peak of the wind early this afternoon.  Compare that to 10-20,000 with similar speeds from the south.

It was enough to tip a traveling manufactured home off a semi trailer and almost into the Columbia River.

i205 backup 2

Can you guess where?  Of course, the “scary when it’s windy” Glen Jackson bridge on I-205.  There used to be a functioning ODOT wind sensor there, but apparently it doesn’t work anymore.  Observations from the site only show temp now.  On the flip side, I see a new ODOT sensor is working at the Sunset Transit Center at Hwy26 & 217 is working now.  That’s the windiest spot along that highway with an east wind.

 

MarkWind_PeakGustPDX

The wind spread out across the whole metro area today, as we (and models) forecast.  A 39 mph from the east is a respectable speed in Hillsboro!   The pressure gradient through the Columbia River Gorge has been up around 9 millibars today and should stay about the same or just weaken a bit tomorrow.

Temperatures in the atmosphere overhead will warm quite a bit tomorrow (stronger inversion).  That means the wind should back off quite a bit in the metro area; probably peak gusts in the 25-35 mph range instead of what we saw today.  But at the same time the wind will INCREASE quite a bit through the Gorge since the inversion will squeeze the windflow into a smaller area.  Should be a raging day with 70+ mph gusts at Corbett and 75-80 mph gusts on that poor sideways sensor at Vista House.  That means up around 100 mph gusts on “the steps”.

Other than that…sunshine through the weekend and maybe into part of Monday too.  Then a change, more on that later.

Chief Meteorologist Mark Nelsen


Fire Weather In January? A Weird Winter

January 21, 2014

The dry winter continues; the next chance for rain is Tuesday…maybe.  Other than that it appears we’ll be mainly dry through the end of the month.

The weak weather system moving through the region tonight and Wednesday morning gives us cloud cover and just a few sprinkles.  Then it’s back to strong offshore (easterly) wind through the weekend.  Due to the very dry forest in SW Oregon, the Medford NWS has issued a fire weather watch (in anticipation of a red flag warning) for Thursday evening.

MarkFireRedFlagWarning

I don’t think I’ve seen that in my 20 years forecasting here…we need rain!

Chief Meteorologist Mark Nelsen


115 mph in Gorge Today; Windiest in Oregon So Far This Winter

January 20, 2014

A wild day at the western end of the Columbia River Gorge today.  Here are the peak gusts so far:

MarkEastWind_GorgeandMetro

This is a pure “gap wind” event with the strongest wind confined to a very narrow area centered within a mile of the Columbia River and the Gorge from Troutdale to Multnomah Falls.  The 115 mph gust was recorded on a Maximum anemometer (quality equipment) by Matt Sloan sitting in a car at the base of the steps on Vista House.  The 83 mph gust at Vista House is not reliable (too weak) because the anemometer is swinging around on its mast.  It is bent at quite an angle and not working properly for that reason.  The 80 mph gust at Corbett Elementary School is the strongest gust there since I’ve been involved with it.  At least since 2009.  We’ve seen stronger wind gusts at the other locations on the map; mainly during the east wind storm of January 2009 (click on link to see speeds).  At that time the Corbett sensor gusted to 79 mph and we saw 50-60 mph gusts spread well into Troutdale, Gresham, and even East Portland.

The cold pool east of the Cascades really thickened the last 24 hours…did anyone notice Redmond went from a high of 58 yesterday to 27 today?  That’s quite a change!

MarkEastWind_ExplainWinterPattern_wRedmond

Looking ahead, the wind will die down quite a bit the next 48 hours as a weak system moves through our upper-level ridge.  But the ridge won’t go anywhere and will just bounce back Thursday-Sunday.  With little or no erosion of the cold pool eastside, the strong east wind will return through the 2nd half of the week.  This should keep persistent fog and low clouds away from most of the metro area for lots of sunshine through the weekend.

Models all show the ridge at least somewhat disappearing next week.  ECMWF is a little wetter than the ridgier looking GFS.  In a nod to the ECMWF I finally put rain in the 7 Day forecast for next Monday.  We’ll see if that really shows up.

Chief Meteorologist Mark Nelsen


ECMWF Weekly Maps

January 20, 2014

Last night’s ECMWF run out to one month.  Looks like the ridge is pretty much gone after this week, replaced by weak troughing the following 3 weeks.  Hmmm, GFS isn’t so sure.  Some sort of pattern change ahead but not sure what:

500za_week1_bg_NA

500za_week2_bg_NA

500za_week3_bg_NA

500za_week4_bg_NA


Get To Vista House! 100+ gusts likely today

January 20, 2014

Big surprise this morning, extremely strong east wind event in progress at the west end of the Columbia River Gorge.  I just checked the Corbett wind sensor:

screenID005

Wow!  I haven’t seen an 80 on there in the last 10 years!  For comparison, during the 2010 “Keely Chalmers Wind”, the peak speed was around 72 mph at this location.  There was a 78 at that location during the 2008 windstorm, and I think it was 78 during the damaging east wind event in January 2009.  Why so strong suddenly?  Not sure exactly why, but the gradient is up to 9 millibars and we have a strong inversion.  The wind must be getting squeezed through a very narrow channel in the atmosphere quite close to the river.  The high wind area must be even more localized than normal.  Vista House sensor was getting tilted (bent) in the past month, and I’m guessing it is  just be flipping around half-broken.  That might account for the unusually low readings compared to Corbett.

Anyway, get up there and enjoy the strongest east wind of the season!  Just dress warm, wind chill is around 20 degrees.

Chief Meteorologist Mark Nelsen