Strong Wind This Evening & Heavy Rain Update

March 15, 2015

8:30am Sunday…

What a soaker!  And possibly our strongest south wind since December on the way late this afternoon.  Suddenly we have some exciting weather after 2 months of nothing.


Over 2″ has fallen all across the metro area so far and some spots will easily get 3″ right here in the lowlands.  Models did pretty well showing a lot of rain.  I just did some good old-fashioned number crunching adding total rainfall since the rain began up to 8am today.

AURORA:  2.48″
SALEM:  2.20″

Looks like only minor “urban” flooding.  That means mainly small creeks, intersections etc…  In this case the soaking is excellent since we’ve been so dry since late January.  The ground probably soaked up the first inch.  As the narrow band of heavy rain lifts north, rain will taper off a bit in the metro area and points south the next few hours.  Then more rain, although not as heavy, returns this afternoon as the cold front moves through west to east.


  1. Gusty wind arrives late this afternoon from the south.  Gusts 35-45 mph are likely in the metro area, similar to what we saw on February 9th.  That was the rainy Monday.
  2. There is a chance the storm is stronger and produces widespread gusts to 50 mph, if so that’ll give us lots of outages and more trees down since the ground is suddenly very wet.
  3. Timing is 3-8pm regardless of the intensity.

Since yesterday’s runs, models have been showing a surface low tracking northeast along the coastline late this afternoon, making landfall just north of Astoria.  It’s not very deep, but there’s quite a southerly pressure gradient on the south side of the low.  The NAM-MM5 has been most aggressive showing a deepening low almost up to landfall.  Here’s 5pm today:


That is “minor windstorm” category, probably gusts 45-50 mph in the northern Willamette Valley; strongest we’ve seen since the December storm.  Other models are not as strong.  Take a look at a product from the trusty ECMWF model, showing all 51 low pressure locations at 5pm from its different ensembles.


All generally have the same track but you can see wide differences on the depth of the low.  A lot of these would only produce gusts maybe 30-35 mph.  But some would be strong like the NAM-MM5 shown above.

The atmosphere is very warm and it’ll be easy for the strong wind a few thousand feet up to surface, that happens in March, just like in October.  No inversion this time of year.


Pretty bad as expected.  Here are two pics from Mt. Hood Meadows and Timberline (it looks the same elsewhere at the same elevation) where the snowpack is falling apart at the lower elevations.  Several inches of rain aren’t good on a thin snowpack.  A few fresh inches VERY high on the mountain today (6,500’+) but otherwise nothing new until next weekend.



One last bit of good news.  The rain is helping to fill reservoirs.  Check out the 10 foot rise forecast in Detroit Lake over the next day or so.  At least heavy spring rain can be captured:


Chief Meteorologist Mark Nelsen

Is This Weekend The End of The Ski Season?

March 13, 2015

The short answer is…possibly.  At the least I am confident skiing terrain on Mt. Hood will become much more limited after this weekend’s rain.

This has been a brutal ski season, Mt. Hood Skibowl says it is the worst they have seen since the 1950s!  And as I detailed in a blog posting 8 days ago, we are now entering uncharted territory.  We’ve never seen snow conditions this bad on March 15th and beyond.  And there is no sign of a cool and wet pattern.


  • 3 of the 6 main ski areas in the central/northern Oregon Cascades have been closed since early January.  That’s Hoodoo, Willamette Pass, & Mt. Hood Ski Bowl.
  • I don’t see those ski areas reopening this year, they are likely done.  There is no weather pattern in the next two weeks that would produce the 3 feet of snow needed.  Plus on average in late March there is more melting than accumulation at 4,000-5,000′.
  • Timberline has 3 of their main lifts shutdown: Pucci, Jeff Flood Express, & Molly’s.
  • Meadows isn’t operating Heather Canyon & Hood River Express.
  • The lower parts of both of these ski areas have large bare sections.  Grooming crews have done a spectacular job moving snow around this season, but there isn’t any more to move in to cover those lower areas.  We’ve seen more and more grass/soil appear on the webcams.
  • There is plenty of snow up around 6,000′ and above, but how to you get skiers back down from those spots if you can’t ski back down?



  • Heavy rain…1-3″ will fall on Mt. Hood with temperatures above freezing almost the entire time.  A warm and thin snowpack, that’s been exposed to two weeks of warm sunshine and temps in the 40s/50s won’t handle that very well.
  • Possibly some fresh snow (a few inches) Sunday above 6,000’…MAYBE


  • More warmer than normal weather…melting will continue up on the mountain, especially the later half of the week
  • No new snow, although NEXT weekend there are hints of some cooler weather and snow showers up there.

As a result…

THERE WILL BE SIGNIFICANTLY LESS SNOW ON THE GROUND A WEEK FROM NOW WHEN OREGON’S SPRING BREAK BEGINS.  Combine that with the already bare areas mentioned above and that’s a big problem.  There is a very real possibility that for the first time on record (that I know of) there will be very limited skiing on Mt. Hood for the start of spring break.

Chief Meteorologist Mark Nelsen

ECMWF Weekly Maps: Warmer Than Normal Continues

March 12, 2015

It’s Thursday afternoon and another run of the ECMWF model and its ensembles to 32 days in the future.  That takes us to mid-April.

Surprise!  No big changes, the pattern we’ve seen off/on for the past 18 months, and this past winter will continue.  Upper-level ridging along/near the western coast of North America and cool troughing over the eastern half of the continent.

Take a look at the first two weeks, which goes through next week and then Oregon’s Spring Break.  Strong ridging is centered to our north, which will allow some weak systems to move by to the south.  We already see this in next week’s model forecasts.



Weeks 3 & 4 which is basically the first half of April, show higher than normal upper-level heights remaining over or just west of us.  Systems that come through will be weaker than normal and temperatures should average above normal.  Early April may end up more like a typical early May.



WHAT DOES THIS MEAN?  A lot for gardeners!

1. You are probably okay to plant cool-weather veggies in the next couple of weeks (carrots/beets/salad greens etc…).  Some years the constant cold and rain could rot these in mid/late March but not this year!

2. Unless there is some dramatic turnaround, early season veggies and berries could end up arriving much earlier than normal.  Like strawberries in early-mid May instead of late May.

3. You have a chance to get lots of work done outside in the next month, more so than in a typical rainy/cold spring.

Chief Meteorologist Mark Nelsen

Italy Snow Drama & Another Northwest Ski Resort Closes

March 11, 2015

There has been talk, and lots of video, of a “record-setting” snowfall in the mountains of central Italy.  Media reports say 100.8″ fell in 24 hours and there are all sorts of proclamations that A NEW WORLD RECORD HAS BEEN SET!!!!

Is it a new world record?  Could be, but the WMO doesn’t keep extreme snowfall records so there is no “official” value.  The two most commonly accepted 24 hour records are in Japan and Colorado here in the USA:


A new wrinkle showed up online this evening.  USA Today is reporting that the official total was only around 3 ft. and residents measured the 100.8″ in drifts!  If so, this will be another stunning example of how bad information can suddenly become “reality” in our digital age.  I did notice in the video that the roofs don’t have much snow.  Shouldn’t there be feet of snow up there? Hmmm…

We’ll see as the drama unfolds…


Meanwhile, another Cascade ski resort has closed.  The snowiest one in the Pacific Northwest, Mt. Baker, is closing until they get more snow.

We have a lot of rain headed for Mt. Hood Saturday and Sunday and this may put Timberline and Meadows in a real pinch. The last 7 days that have been warm and sunny, it rained up there this evening, warm and sunny returns through Friday, then warm rain for two days this weekend.  We might get into a situation where those resorts have to shuttle skiers higher on the mountain for skiing and use the lowest lifts for transport only.

Chief Meteorologist Mark Nelsen

East Wind Season Has Ended

March 10, 2015

November through February is our “East Wind Season” in the Portland metro area and in the west end of the Columbia River Gorge.  Did it seem like a windy winter?  It was.  I’m working on a winter weather presentation and finished this graphic which makes the point:


The east wind disappears (mostly) in March because the land starts warming and we lose the inversions so prevalent in winter.  West wind starts to show up in the Gorge later in March and April as higher pressure tends to build offshore more often and fronts bring surges of the wind through the eastern end.

By April we only get gusty easterly wind with thermal troughs and much warmer than normal weather.  From June through August it only blows during heat waves and rarely gets very strong.

Don’t worry if you missed it this year…it’ll be back again in November!  Like an old friend…

Chief Meteorologist Mark Nelsen

What a Weekend! Mild Weather Will Continue

March 9, 2015

I can’t believe we’ve seen four consecutive sunny weekends.  This weekend topped them all; more like a nice May weekend than early March!  We hit 68 Saturday and 69 Sunday in Portland.  In fact today (at 69) was the 6th day at/above 60 degrees.

Looking ahead, temperatures look very mild for the next 7-10 days, and likely beyond.  This isn’t going to be like any March we’ve seen in many years.  We get one wet system Wednesday, and then some more this coming weekend.  We actually need the rain, since we’ve only seen .43″ in Portland in the last month…crazy stuff for this time of year!

The reason we’ll stay mild (although with rain at times) is the same we’ve seen all winter long.  Actually much of the last two winters and parts of the warm season too.  Upper-level ridging wants to continue along the western coast of North America or in the Gulf of Alaska.  That keeps storms away and weakens those that do move through the ridge.  Take a look at the 15 day 500mb height anomaly map from the 12z GFS, GEM, and ECMWF.  This is the ensemble average of all the runs from each model for Tuesday the 24th.  That’s in the middle of Oregon’s Spring Break:




Surprising how similar they are isn’t it?  All show the ridging centered to our north/northwest.  This may allow some precipitation into California at times, but in general it’s a warmer and drier than normal pattern like we’ve seen.


The 00z ECMWF monthly run is almost the same.  The maps above end at the end of week #2, so I’ll just show you week #3 and week #4:



Same story continues through the first week of April.  Cold trough in the east and mild ridging along the West Coast.  The heights weaken a bit over Alaska.

By the way, I think it’s unlikely any of the closed ski resorts will reopen and it’s even possible skiing goes down to just higher slopes of the other ski areas with the warmer than normal weather continuing.  Much of the precipitation the next 7 days will fall as rain at the base of Meadows and Timberline:


Chief Meteorologist Mark Nelsen

Could Be The Worst Ski Season in 40+ Years, But Alpine Slide Will Open in March!

March 5, 2015

Mt. Hood Skibowl says they are now planning to open up much of their summer adventure park by Oregon’s Spring Break, just two weeks away.  Probably a good choice since we don’t see any sort of snowy weather pattern ahead (note previous post) and their slopes look like this:


This ski season is about to enter into uncharted territory; conditions are developing that we have not seen at least since I was born (1969).  Am I being a bit dramatic?  I don’t think so…let me explain.

First, the current situation:


80-90% of the typical snowpack we see on the ground this time of the year doesn’t exist in the Cascades!


There is no snow on the ground below the 5,000′ elevation and Willamette Pass has announced they are finished for the season on their website.

In NUMEROUS past seasons we have seen a terrible start to the ski season turn into either average or great conditions.  Remember last year was terrible until the first week of February and then great powder conditions for several weeks.  In ALMOST ALL OTHER SEASONS we have seen the turnaround to cool/wet by the 1st of March.

In our area, the (publicly available) snow depth observations for Mt. Hood only go back to the early 1970s at Timberline Lodge so I can only see back to that point.  Right now there is 49″ of snow on the ground at that 6,000′ location.

There are only three REALLY BAD years, where snow depth was still under 50″ on March 1st.  Older ski bums remember these years.  2004-2005, 1980-1981, 1976-77.  Thanks the Ski Mountaineering site for the chart.


In 1976-77 the pattern changed in early March and the snow accumulated quickly.  So we know this year will be worse than ’76-77 with no recovery in at least the first half of March.  We also know that the entire 2nd half of March 2004-05 saw a ton of snow with the best skiing of winter over Spring Break.  So most likely we’ll be worse off than that year.  In 1980-81 the 2nd half of the month saw the depth go from around 35″ to 60″.  That still looks unlikely, but possible.

To wrap it up, in less than two weeks we’ll likely be experiencing the worst or 2nd worst snow season in the Cascades in the past 45+ years!

By the way, this evening’s fresh new GFS model has either warm and dry, or warm and wet in the mountains for the next 16 days.

Chief Meteorologist Mark Nelsen