9:30pm: Light Snow Falling, Forecast On Track

February 4, 2019

We got lucky this evening and avoided widespread snow during the commute.  Instead it started around 8pm in the central/east side of the metro area.  At this hour everyone is below freezing in Portland

2017 Current Temps PDX Metro Area Earth Scene

Of course that means snow is sticking everywhere except for treated roads.  I’ve also seen pics of pavement that is wet; likely slow to cool after a warm winter so far.  Eventually an entire night of temps in the 20s will freeze these roads as well.

FORECAST

WEST HILLS AND CENTRAL/EAST METRO

  • Trace to 2″ this evening & tonight.
  • The 2″ total is more likely out east of I-205 (Gresham, Happy Valley, Camas, Battle Ground)
  • 2-4″ east of Washougal, Corbett, Sandy, Estacada
  • Snowy roads likely for morning commute in hills and east of I-205, plus Clark County

WEST METRO & SOUTH METRO TO SALEM

  • Less than 1/2″, None for many of you
  • Just a few icy road spots

Snow showers should finally end by 4am or so.  Tomorrow we’ll be partly cloudy with slowly melting roads during the morning

Chief Meteorologist Mark Nelsen


3pm: Temps & Snow Level Dropping

February 4, 2019

I was concerned in my 11am post that the ECMWF was showing cold air coming up the Columbia River and into the metro area this afternoon.  Excellent forecast and it  is happening now.  Temps are approaching freezing in the central/east metro area where snow has been falling steadily.  It’s mainly dry in central/north Clark county and Washington county.  Notice it’s warmer where no precipitation is falling in much of Washington County.

2017 Current Temps PDX Metro Area Earth Scene

Now that lower dewpoints/colder air has moved in, who gets snow and who doesn’t will be totally based on snowfall intensity.  I think that’s still most likely (widespread white on the ground) in the central/east metro the next few hours with little or no snow west metro.

If you live near work and have nothing critical to do central/east metro…head home now just to be safe.  Even if we don’t get widespread snow, that will lighten load on roads for later. Some freeways are already jamming up as they would any day at 2:30pm but current weather sure doesn’t help.

FORECAST

WEST HILLS AND CENTRAL/EAST METRO

  • A Trace to 2″ this evening & tonight.
  • The 2″ total is more likely out east of I-205 (Gresham, Happy Valley, Camas, Battle Ground)
  • 3-5″ east of Washougal, Corbett, Sandy, Estacada
  • Snowy roads likely for morning commute, especially hills and east of I-205

WEST METRO & SOUTH METRO TO SALEM

Less than 1/2″, None for many of you

Looks like almost all the snow action will be central/east metro as I mentioned this morning.  I think it’s unlikely Salem gets anything significant as well

Chief Meteorologist Mark Nelsen


Snowy Evening Commute Possible Northern Clark County and Far East Metro

February 4, 2019

10:30am Monday…

Forecast worked out pretty well, except more snow than expected on the beaches! This pic from Joanne Jene in Oceanside.

photo_joanne_jene

Reports of 1-3″ from Astoria down to Tillamook and even farther south.  I had 1.5″ at 1,000′ and I see Sandy at 1,000′ had about the same. Last night was all about precipitation intensity.  Basically very little precip (too dry) in the western Valleys.  Portland Airport only had .02″ all night!   More precip and a few hundred feet of elevation = some snow on the ground this morning.

We knew that was the case, the reason I mentioned, in each newscast, “LOTS OF YOU WILL WAKE UP TO NOTHING”.  Forecast was for Zero to 1″ maximum.

What’s happening today and tonight?  The action is shifting east. First, a cold arctic airmass has frozen Seattle, the Washington coast, and all of Eastern Washington

web_temperature_ORWA

In northwest Oregon temperatures remain where they are right now for the rest of the day; staying under 40.  No sticking snow in most of metro area through at least early evening.  That cold arctic air won’t be surging much farther south.  The result?

Little or nothing interesting happens now through Thursday from I-5 west to the coastline.  Too warm (daytime) to bring snow to the lowlands west metro today, and it’ll be too dry when it’s cold enough.  But east metro and north/central Clark county will be different.

Today a storm (low pressure center) is moving on an unusual path south to north across Eastern Oregon and into Idaho.  You see it at 7am, 1pm, and 10pm

This slideshow requires JavaScript.

Snow wraps around north and west of that system.  I expect solid snowfall; a snow storm.  That includes the Columbia River Gorge, North Cascades of Oregon, and north-central Oregon.  Take a look at a snowfall forecast now through late tonight.  Look at those areas getting 8″ or more from the Hood River Valley east to Condon! IGNORE ANYTHING OTHER THAN THE COLORS BLUE THROUGH PINK.  Note snowfall west of the Cascades is in the foothills or extreme east Portland metro area.

hrrr_snowthrough2am

FORECAST FOR REST OF TODAY

Portland Metro roads remain snow-free today, although light snow will fall at times anywhere, mainly eastside.  It won’t stick much since temperatures remain in mid-upper 30s.

YOUR EVENING COMMUTE SHOULD BE FINE THROUGH AT LEAST 6PM…EXCEPT POSSIBLY TURNING SNOWY EAST OF I-205, AND IN CENTRAL/NORTH CLARK COUNTY.

THIS EVENING & OVERNIGHT

  1. Light snow continues falling east metro area and western Gorge + temperatures fall.  After sunset it cools enough that areas around Gresham/Troutdale/Camas/Estacada will definitely see sticking snow.  Maybe 1-2″ in those towns, possibly 3-4″ by the time you get up to Sandy, Corbett, and Mt. Pleasant area east of Washougal.  Cool air coming in from the north will likely freeze roads north of Vancouver in Clark County too.
  2. West metro area shouldn’t see sticking snow tonight, of course a dusting is possible but that would be it.  Temperatures hang near freezing.
  3. IF we get clearing tonight (a very big question), and temperatures fall to freezing, there could be icy spots in the morning on some roads.  Of course that happens many times in the winter so we’re used to that.

TUESDAY-THURSDAY

Mainly sunny & chilly days and cold nights.  Dry

TECHNICAL TALK FOR THE WX GEEKS

That arctic front is uncomfortably close and I’m concerned that precip continuing this evening could turn much of the metro snowy after sunset.  The arctic front is the boundary of the cold/dry air where things are pretty much frozen.  It has progressed to Kelso west of the Cascades and Hood River in the eastern Gorge.  I’m worried about that brand new ECMWF showing cold/dry air surging up the Columbia River and into the metro area by 4pm.

ecmwf_uv100m_portland_3

If precipitation continues this evening, those lower dewpoints + evaporative cooling coming in from the north could easily push sticking snow right down into the city.  In fact ECMWF has temps dropping down to freezing after sunset.  Oh please no evening commute fiasco… The precip forecast:

ecmwf_tprecip_portland_8

and snow forecast

ecmwf_tsnow_portland_8

Could be a coating of white all the way west to downtown if that’s the case.  Obviously the Gorge and north-central Oregon gets a nice snowstorm next 24 hours!

Chief Meteorologist Mark Nelsen