March Ends Cool & Wet; Plus Forecasting Weather During a Pandemic

March 29, 2020

8:00pm Sunday…

I haven’t posted much the past two weeks for two reasons.  One is that the weather has been relatively slow so it’s tough to get inspired.  Second, because our society has been consumed by the COVID-19 pandemic; weather seems like a minor concern during this unprecedented time in American history.  Of course weather can be a big deal, but during these past two weeks it has been relatively quiet in the Pacific Northwest anyway.


You might be wondering what has changed in the FOX12 weather center these past two weeks?

Well, we have a supply of Purell, Lysol, & other disinfectants just like all the rest of you.  Many of you are now working from home to avoid interacting with others.  “Social-distancing” is THE big thing right now, although “physical-distancing” is probably a better description.   Should we really be “socially-distant” from each other?  I don’t think so.

So why aren’t WE working from home?

It’s because we’ve been able distance ourselves at work quite well due to nature of our work space.   IF there are two of us in the weather center (much of the time we are alone), we already sit six feet or so apart.  And we are far removed from other coworkers.  I know at least one other TV station in Portland has the weather anchors working right in the middle of the newsroom (during normal times).  I’m now glad that is not the case here.  We are fortunate that all our work is done on computers in the main broadcast studio.  That’s “Studio A”…what you see on television IS our office.  We sit back there below those three big monitors.


So unless a newscast is on, we sit alone in a massive warehouse-like room.  I didn’t see another person for about two hours today.  During our shows, we stand maybe 10-12 feet away from the anchor(s) at that large monitor, and while sitting about 21 feet away.  Yes, I actually measured today.

FOX12 management has also done a great job turning a regular “office cubicle newsroom” into a more appropriate work space during this pandemic.  Most reporters/photographers remain out and away from the station while gathering/producing news content.  Producers that put together the shows are either widely spaced in the newsroom OR working from home.   News anchors are sitting widely spaced in our other studio, “Studio B”.  This is the studio you see in November/December; a Christmas tree with toys piled many feet deep around it.  A pic this evening shows only Bonnie Silkman in that enormous room.


Editors and a few other folks are scattered about our two-level office building.  But just about all other workers (sales/promotions, engineers, etc…) are working from home like many of you.  It’s a very quiet place right now…

What else has changed?

  • I now bring my own food, some of us used to cook.  No more going out to grab a sandwich from a restaurant at lunch either.  I used to do that all the time.  But I figure each time I leave the station and come back I could be introducing a virus to the office.
  • I avoid door handles at work
  • Less wandering around the station catching up on the latest from coworkers during breaks.
  • I’ve stopped doing “errands” on the way to work each afternoon.  I used to stop at a coffee shop, home improvement store, auto store, grocery store, etc…  Now I pretty much just go from home to work.  Again, safer to just go back and forth.

I’m totally comfortable with this work setup, we’ll see how it goes over the next few weeks.

Alright, so what about weather?

Quite a change this past week.  Sure, March has been cooler than average, but we were seeing so much sun this month, until the past six days.  What would have been Oregon’s spring break was cool and showery…surprise!  Friday and Saturday were especially gray/drippy.

We have a second cool/wet work week on the way.    A cool upper-level trough will settle in over western Canada and the Pacific Northwest through at least the next week.  You can see the cool trough over the Gulf of Alaska today


Almost right over us by Wednesday


Then the ECMWF ensemble forecast for next Saturday.  This is a cool western North America setup with very warm weather east of the Mississippi River.


Tonight the leading edge of the colder airmass moves inland after midnight.  That’s a cold front and you can expect to hear rain coming down in the wee hours of the morning.  A gusty southerly wind accompanies that cold front too.  A few gusts 30-40 mph are likely between midnight and 6am.  Behind the front we’ll see cold showers and sunbreaks mix; a classic spring hail/thunder setup for both Monday and Tuesday.  The atmosphere appears more unstable Tuesday; that’s our better chance for thunderstorms.

To summarize

  1. Cool and wet weather continues for at least the next 7 days.  Not a soaker every day, but it’s tough to find a totally dry day.
  2. There will be some “decent outdoor weather” for a few hours at a time later this week.  Keep a close eye on the radar if you want to take a run or bike ride.  I’d skip tomorrow and Tuesday.
  3. There’s no sign of a significant warm/dry spell as we head into the first week of April.
  4. Lots of snow is on the way in the Cascades.  Typically early April is the beginning of melt season in the Cascades, but we’ll be adding to the snow pack instead this year.  That will be excellent for our summer water supply.

Chief Meteorologist Mark Nelsen

Warmest Day of 2020 Today; Plus A Look Back At Our BORING Winter

March 19, 2020

6pm Thursday…

What a fantastic stretch of March weather we’ve been seeing this week!  It’s a total counter-programming to all the depressing virus/financial news.  Quite the contrast isn’t it?

We’ve hit at least 64 in Portland today, quite possibly a degree warmer.  Official highs are reported at 5pm & 11pm (every six hours) in the warmer part of the year.  The entire Willamette Valley was warm today

Todays Observed Highs OrWa 2017

Very weak offshore flow tomorrow morning, plus a slightly warmer atmosphere overhead should push our afternoon temperatures up 1-2 degrees.  This means 65-68 in the Willamette Valley and Columbia River Gorge.  I wouldn’t be surprised to see a 70 degree high at The Dalles tomorrow.

Weak onshore flow Saturday knocks temps down a few degrees, then they pop back up a few degrees Sunday.  Regardless, we have three more sunny/warm afternoons on tap.

This evening is the “Vernal Equinox”, specifically 8:49pm PDT.   That’s the point in our orbit around the sun where the sun is right over the equator.

The Seasons Spring Explained

Officially spring begins on March 1st in the northern hemisphere, that’s as it relates to weather

Mark Spring Definition_MeteorologicalvsAstronomicalSeasons

So how did winter turn out?  That’s December through February.  It was warmer and drier than average; very much acted like a weak El Nino winter.  I presented a Winter 2020 recap at the Oregon AMS meeting last week.  Since I know lots of you have PLENTY OF TIME, here’s a link to the 42 minute video of my presentation.

Just a few highlights follow…What a boring winter!




It was the lowest snowpack for Christmas Vacation we’ve seen on Mt. Hood in decades.  Remember Skibowl wasn’t able to operate the lifts until early January!


But the big snow in mid-January kicked the ski season into gear big-time.  Over the last month, snowfall has tapered off along with lots of sunshine.  So right now we’re running a bit below normal but there is still plenty on the ground in the Cascades; no sign of a drought.  Lots of snow to come next week too.  Unfortunately ski season appears to have ended early in the Cascades due to COVID-19.  We’ll see if some resorts try to re-open in April.


Of course last Saturday we finally had our “big snow” for the winter.  0.5″ in the city.


This winter completes another decade weatherwise.  Take a look at Portland snowfall each decade since the airport weather station was established in 1940.  Divide any of those numbers by 10 and year get the average yearly snowfall.  When I started my career in 1991, that downward trend was a big deal.  But now the average yearly snowfall in Portland hasn’t changed significantly in 30 years.  Interesting isn’t it?  Especially considering winter temps have continue to gradually warm.  More occasional large storms but fewer small snow events?  Maybe, but I haven’t looked into it.


Snowfall records go further back in time in Downtown Portland.  Since 1973 those records have been taken at KGW-TV.  There you see the big snow years of the late 1800s and then a gradual decline since that time.  Again, you see it hasn’t changed much downtown the past 30-40 years.


There you go, we just “endured” a very boring winter that was milder and drier than aveage.  On to spring!

Chief Meteorologist Mark Nelsen

Unusually Dry March Continues; Lots of Sunshine This Week

March 16, 2020

6pm Monday…

Time for a break from the news.  Forget viruses and crashing financial markets, let’s talk about weather!

Spring is back today after three very cold days (for mid-March).  Portland’s high temperature jumped 14 degrees today!


The 42 degree high Saturday broke a record for coldest *high* temperature on March 14th.  Friday and Sunday were close.

Meanwhile, EVERYONE saw a much warmer day today.  Check out the lower 60s along the coast.

Todays Observed Highs OrWa 2017

It only took one day for the unseasonably cold airmass east of the Cascades to modify substantially under the strong mid-March sunshine.  Hood River jumped from 34 to 50 from Sunday to this afternoon.  Government Camp 29 to 45.  That doesn’t happen in winter (December-February).  So our cold east wind Sunday became a mild/warming easterly wind today.

Tomorrow the east wind dies down, that plus 850mb temps around +4 should push us to 60 degrees once again.

Later this week an upper-level disturbance drops down along the West Coast, although it appears just about all the cloud cover and rain stays offshore.  It’s headed for California, not us.  The result is very nice late March weather.  This ECMWF model cloud cover loop covers this evening through Friday morning.  You can see that system swirling offshore Thursday night and early Friday.


This month has been dry.  Sure, somehow PDX picked up almost 3/4″ precipitation Friday/Saturday, but the month is running well below average across most of the West


Every month of this cold season, except January, has been drier than average.

Rain So Far This Month Or and Wa Earth Scene

As that trough passes by, weak upper-level ridging builds overhead Friday/Saturday.  This MAY lead to the warmest temperatures so far this season.  850mb temps come up to around +3 or +4.  That should give us highs 60-65 those two days.

Beyond Saturday?  Models are in pretty good agreement we turn a bit wetter for what WAS Oregon’s Spring Break.  Now it has turned into a very long break that has already begun.

Check out the ensemble precipitation forecast from the ECMWF for the next two weeks.  Most members dry through Sunday, but then a clear signal for wet weather by next Monday.  The lower (green) section shows the ensemble average precipitation accumulation.  Looks wet next week…


That’s it for now, enjoy the sunshine.

Chief Meteorologist Mark Nelsen

It Finally Snowed In Portland; In March

March 14, 2020

2pm Saturday…

It’s very nice to see the snow forecast turn out as close to perfect as it can get.  That’s rare.  Last night (see previous post) we forecast Zero to 2″ in the western valleys.  We expected little impact on lowest elevation roadways plus snow showers continuing through the day as temps rise to around 40 degrees or so. That’s pretty much what happened.  It appears most areas saw at least a dusting, and a few spots even in the lower elevations up in Clark County picked up 3″.  Areas around 1,000′ or so have see up to 4-5″.  Temps at 2pm…higher as sunbreaks pass over, lower under snow showers.

web_metrotemps (2)

Sure enough, a steady band of snowfall developed after midnight and temperatures dropped close to freezing, bringing sticking snow down to the valley floor in many spots.


0.5″  < The Big Total

Yes, the NWS (in Parkrose) picked up 0.3″ leading up to 5am, a trace from 5am-11am, then 0.2″ just after that time.  That adds up to 0.5″, our only measurable snow of the “winter”.

Are you thinking March snow (even a little) doesn’t seem too unusual lately?  It isn’t.  Actually through the first 10-15 years of my career it was pretty much a no-show.  We’ve only seen measurable snow in March 6 times in the past 50 years!  Only once in the 30 years from mid-70s to mid-2000s.  Now we’ve seen it three times in 10 years.

Portland Snow Last Few Times In March

Today’s snowfall also ties for the 4th latest on record in Portland.  Official records go back to 1940 at PDX/NWS forecast office locations.

Portland Snow Latest 2

The latest is the 0.3″ on March 25, 1965.

Portland Snow Latest

There had been some “later snow events” (one in 1968), but the NWS cleaned those up and decided they were hail and not snow.  And the old downtown records show an April 1st snow back in the 1930s.

We have LOTS of sunshine ahead, after a couple of cold nights.  I’ll be back at work tomorrow afternoon

Chief Meteorologist Mark Nelsen

Better Chance for Sticking Snow Saturday Morning in Metro Area

March 13, 2020

7pm Friday…

It was nice to see snowflakes this morning.  I was driving through Gresham taking care of errands and it was dumping snow…at 37 degrees around 11am.  By the time I got home at 1,000′ there was maybe 1/4 to 1/2″ on the ground.  Then showers tapered off; exciting while it lasted.  By the way, in my “Winter is Over” blog post three weeks ago I mentioned this setup.  It can still happen this late in the season

Mark Winter is Over3

Tomorrow more of us will see sticking snow during the morning hours.  Even some low elevation spots could see enough for some quick sledding (1″ or so…low standards in Portland).   Others?  Wake up to nothing.  No matter what happens the first half of the day, the 2nd half will be like today.  Partly to mostly cloudy with temperatures reaching the low-mid 40s.

We don’t expect any sort of widespread “life-altering” snowfall west of the Cascades in the I-5 corridor tomorrow.  This is the forecast graphic I’m using this evening:

Snow Cold Look Ahead End of Event

Why such a wide range?  Zero to 2″????  There’s good reason for that.  We’re talking scattered showers late tonight through about noon tomorrow.  If you are under a heavy shower, an inch could suddenly accumulate.  If those heavy showers miss you?  Little or nothing accumulates.   For Example: In this pattern, someone that gets dumped on near the Columbia River (~ sea level) could get an inch or two.  But another location up around 1,000′ that misses out on the showers gets only a trace!  It’s not just about elevation.  That said, colder temps up in the hills do give a better chance for “sleddable” snow there.

Snow Cold Look Ahead End of Event2

Technical Talk

Colder and very dry air is surging south through eastern Washington this evening; by sunrise it should be pouring out of the Gorge and into the metro area.  That airmass has Even though temps with this will probably be up around 36-40 degrees, any precipitation falling into the very dry airmass will bring temps down to near freezing.  That’s the 2nd reason we have a better chance for sticking snow tomorrow morning along with precipitation intensity.

Models are looking a bit more consistent this evening.  Most giving us very light snowfall, only a trace to 1″ generally.

Snow Model Accumulation Several

So in the end I think this will be another “non-event” like what we saw Thanksgiving Weekend, mid-January, and early February.  Just a little here and there.

We do have some fantastic early spring weather coming back for early next week.  Check out the high temperature forecast for Portland.  Some nice stuff ahead…get outside and enjoy the sunshine.

Data Driven Forecast Highs Next 7 Day Meteogram

Chief Meteorologist Mark Nelsen

Three Chilly Days Ahead; Plus Sticking Snow For Some of Us

March 12, 2020

8pm Thursday…

Today has been another fantastic early spring day; sunshine with temperatures reaching into the 50s.  That will change tomorrow as a cold upper-level trough drops down along the West Coast.  The result is a wet & cool Friday.  In fact you may even see some snowflakes mixed in.  The sticking snow level will be around 2,000′ tomorrow.

Models have come into better agreement on what happens beyond.  A surface low lingers off the Oregon coastline through Saturday, pulling cool/cold Canadian air south into the Pacific Northwest.   At the same time lots of moisture in the form or snow/rain showers will be rotating around the upper-level trough overhead.   This is what I’m thinking for Saturday in the Portland metro area; some “conversational snow”.  I doubt any snow Saturday will affect your life.  Certainly far less than the current COVID-19 cancellations.

Snow Spring Headlines


Saturday night and Sunday almost all the moisture pulls south and skies start to clear out.  By Monday/Tuesday we’re back into a nice spring weather pattern; sunshine with afternoon highs into the 50s or even 60.

Sure, models agree on the basic progression of weather the next 4-5 days.  But how much precipitation shows up?  And how much cold air comes in from the east?  Those are the big questions.    Trends the past 24-48 hours suggest less precipitation than earlier expected.  More obvious is models getting warmer and warmer as we approach this event.  2-3 days ago the GFS/ECMWF were at least down around -8 degC at 850mb (or much colder in the case of the GFS).  Now they both bottom out around -5 to -6!  Without cold air coming in from the east, that doesn’t produce lowland snow.

Some models have backed off on precipitation totals for Saturday.  The ECMWF was very wet last night but ensemble average shows less than 0.50″ now.  Of course if temperatures were below freezing from tomorrow night through Saturday afternoon that could produce 5″ of snow.  But that’s not happening.


All of our modeling shows very reasonable (for mid-March) temperatures between 36-42 degrees during the daytime Saturday.  That’s cold enough to see snow in the air, but definitely not any significant sticking.  Basically a non-event in the lowest elevations.  If you live up around 1,000′ and above, I think a Trace to 2″ is very likely at some point between Friday night and Sunday morning.  Still, even up there it’ll be tough to get any snow on roads during the day, it would only stick at night.

Put this all together and I feel the latest NAM-3KM is a pretty good representation of what to expect Saturday.  Some white on the hills, and maybe even briefly in the lowest elevations, but this likely ends up similar to our other 3 “close calls” this season


I know it’s a brief post, but as you can imagine it’s been a crazy day in the news business.  I’m off work Friday and Saturday, that’s my “weekend”.  But if something more significant (widespread snow) shows up I’ll be on Facebook and Twitter and possibly shoot out another blog post.

Chief Meteorologist Mark Nelsen


Cold Showers This Weekend; Maybe Some Snowflakes Too

March 10, 2020

9:30pm Tuesday…

Today was a spectacular early spring day with temperatures reaching the lower 60s just about everywhere east of the Coast Range

Todays Observed Highs OrWa 2017

This is due a weak and “splitting” jet stream.  Most of the action is sliding by to our north

Mark Jet Stream

Now that inversion season is over, we don’t get significant fog stuck in the valleys either.  This same setup with weak onshore flow might have left us with all-day long fog or low clouds in December/January.

Models are in very good agreement that the mild ridging over us will move farther offshore as a new ridge develops over the Gulf of Alaska this weekend.  By Saturday it looks like this…

Mark Jet Stream2

This is a classic setup for a snow “close-call” in the lowlands.  A cold upper-level trough digs south out of western Canada, and then cold north or northeast wind at the surface follows as the upper-low moves south of us.   If it was winter (Thanksgiving to late February) I’d be thinking we have a decent chance of getting sticking snow out of this, but in mid-March everything has to be EXACTLY RIGHT (or wrong) to get sticking snow near/at sea-level.

Right now it appears a surface low will “spin up” along the Washington coastline Friday, sending rain inland along with an increasing southerly breeze.  That means cold rain Friday with high temps 45-50 degrees.

Then on Saturday models generally agree that surface low is either right over us or shifting slow south offshore.  That potentially allows colder arctic air to slip south into the Pacific Northwest.  That would be on a north or easterly wind (through the Gorge).  The regularly awful (with cold weather) GFS model thinks the airmass will be so cold it stays in the 20s in the central/eastern Gorge all day Saturday.  That’s not going to happen.  More likely 10-15 degrees warmer than that as ECMWF and GEM models show. Our 7 day forecast numbers here:

Data Driven Forecast Highs Next 7 Day Meteogram

Precipitation intensity Saturday plus how much cold air (if any) arrives will determine our snow chances.  If we get cold easterly flow before precipitation runs out, then we could easily see snow in the air just about anywhere later Saturday or Saturday night.  During the daytime Saturday we’ll be up around 42-48 degrees.  That’s a good 10 degrees below average for mid-March.  It seems prudent to put those “mixed showers” in the forecast for Saturday so we did.  I should have a much better idea by Thursday, two days ahead of time.

By the way, we’ve only seen measurable snow in March (in Portland) 5 times in the past 50 years!  We saw 0.5″ last year and in 2012.  That March 22, 2012 event is the latest on record at the airport/NWS office.  Those records go back 80 years.

Portland Snow Latest 22

There was one snowfall in the old downtown record books on April 1, 1935.

Portland Snow Latest 2


All models forecast that cold upper-level trough to move south quickly Sunday.  That puts us back into lots of sunshine, a cold east wind, and likely dry later Sunday and Monday.  Then as high pressure gets closer temperatures jump back into the 50s, if not Monday then Tuesday.

That’s the real story; our unusually dry February/March will continue.  The ECMWF and GEM models both show only about 1/2″ rain in the next 10 days!  Just the ECMWF is shown here


Chief Meteorologist Mark Nelsen