Snow Ends, Cold Night Ahead

February 18, 2018

11:45pm…

Did we say ZERO to 1/2″ in the lowest elevations?  Well it ended up as ZERO to 3″ in the lowest elevations of the metro area and Willamette Valley.  Quite a wide variety of snow totals…here’s the final snow map, I’ll add in a few numbers tomorrow.

Snow Totals Metro Area

That disturbance really dumped the heavier stuff on the eastside and then up into Clark County.  West and south metro were left out again.  Salem had nothing, except in the hills.  So in reality most of the western valleys of Oregon had very little.

So officially at the NWS office we now have two measurable snowfalls this season (Christmas Eve and Presidents Day “Eve”), plus one Trace (Valentine’s Day).  Nice holiday lineup.  What’s coming on St. Patrick’s Day?

Enjoy the bright sunshine tomorrow and drive carefully the next 10 hours as roads freeze up.

Chief Meteorologist Mark Nelsen


9pm Update: Widespread Snow East Metro

February 18, 2018

Well, it never works out EXACTLY as planned with snow around here.  Everything was looking good until about 6pm.

A few models had shown a last surge of snow showers this evening and they were right!  A little disturbance is rotating directly over the metro area, seen nicely in radar the past 3 hours.  It started out over Battle Ground, swung south over East Portland, and now appears to be shearing off to the west as easterly flow has begun blowing over the Cascades and through the Gorge.  This easterly flow SHOULD dry out the showers the next few hours, I sure don’t expect a repeat of 1-4″ snow turning to 2-18″ like January 2017.

But it is pretty clear that NOTHING TO 1/2″ will turn into NOTHING TO 3″.

I’m on the air on FOX12 PLUS right now (Channel 49, 13 on cable), and I’ll be on FOX12 from 10 to 11:30pm.

Here are the snow totals so far, feel free to add yours in the comments below

Snow Totals Metro Area


Nice Snow Globe Effect Today

February 18, 2018

 

 

10am Sunday

Some heavy snow showers are rolling through NW Oregon and SW Washington this morning.  When they hit it looks like your neighborhood briefly inside a snow globe doesn’t it?

Our forecast has been working out perfectly so far (surprise!) with most lowland locations getting either nothing, or just a light dusting.  Coolest temps have been west and north metro and that’s still the case at 10am:

web_metrotemps

That southerly breeze is still going which is almost always a snow-killer at the very lowest elevations:

web_wind_ORWA

Quick look at ODOT and WADOT cameras shows most areas bare at 9am, and all roads clear in the lowlands too

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The forecast remains the same today…we can just chop off the morning part:

NOW THROUGH 6PM

– Snow showers continue, lots of sunbreaks too.  In fact it may be just partly cloudy the entire 2nd half of the day for many of us.

NEAR/ABOVE 1,000′  Some light accumulation at times since temps remain closer to freezing up there.  Slushy or wet roads up there

LOWER ELEVATIONS  Wet or dry roads, snow in the air at times…we top out in the lower 40s

THIS EVENING AFTER 6 PM

– Light snow showers could stick anywhere and then eventually end.  If you get lucky, a heavy shower could pass right over your neighborhood and you get a quick inch!  This happened during a very similar weather pattern January 1st, LAST YEAR.  A line of heavy showers dropped up to 2″ snow from Canby over to Molalla while most of us got nothing or just a dusting.

TOTAL SNOW BY THE TIME IT DRIES OUT TONIGHT?

  • NOTHING TO 1/2″ Most likely for lowest elevations of Western OR & Clark County
  • TRACE-1″ more likely Kalama to Longview (slightly “wetter” up there)
  • 1-3″ near/above 1,000′

***  I’ll be on the air 5-6 PM on FOX12, then 8-10PM on FOX12 PLUS (the old PDX-TV 49 or 13 on cable), then 10-11:30PM on FOX12.  Lots of newscasts on weekends now too! ***

MONDAY AM

– Dry skies, frozen ground/streets.  If no snow falls in your neighborhood this evening, then it’ll just be scattered icy spots for AM commute.

REST OF MONDAY  Roads dry out, chilly and mainly sunny

 

TECHNICAL INFO:

Nice surface low is spinning down through Western Washington right now and will pass right over or just north of the metro area by early afternoon.  I have a feeling someone will get lucky in the metro area and see a quick dump of 1-2″ snow under a heavy shower band…sometime between now and when it dries out this evening.  But of course I don’t know where.

Late tonight through Tuesday midday is an easy forecast…cold & dry.  850mb temperature forecasts have been consistent showing at least a -11 deg. at 850mb during the daytime tomorrow.  As usual, the NAM is on the cold side, but GFS and ECMWF have been more reasonable.  Getting to -10 or below is somewhat rare, even in winter here.  In fact if the Salem sounding site gets down to -11, that might be the coldest in a few years.  I don’t recall that happening last winter, most of that cold air was low-level for each of those events.

12z models (haven’t seen ECMWF yet) have backed off a little on possible widespread snow Tuesday night in NW Oregon and SW Washington.  The ECMWF and GEM went full-on snow event for Tuesday night & Wednesday AM.  No warming southerly low-level wind and a dry airmass (for evaporational cooling)

web_ECMWF_Text96Hrs_00z

Note the 2-4″ snow in metro area followed by clearing and frozen conditions Wednesday AM!  Remember this is last night’s run.  That “BC Slider” forecast to come down the coastline is a bit farther offshore on the NAM/GFS this morning, while the morning GEM & ECMWF still sends snow over us.  I’ll be watching it closely!

See you on-the-air this evening!  Well, actually it’s a one-way thing.  You can see me but not the other direction.

Chief Meteorologist Mark Nelsen