Freezing Rain Threat Ends; Temperatures Warming

9:30am Monday…

It seems like all 4 of the weather systems that have moved through our area the past week have been ahead of schedule.  That happened this morning too.  Rain arrived around 7-8am.  Luckily, clouds had moved in and temperatures warmed a bit during the night.  Portland was up to 32-33 once the rain arrived, keeping new ice accumulation to a minimum.

Now the best news:

Road temperatures have warmed enough that any ice accumulation is done…it’s back to normal rain

Air temperatures are mainly 32-33 degrees and heading uphill slowly

The last of the Gorge wind (our open freezer door) is dying down

Southerly pressure gradient in the valley is increasing, about 5 millibars from Eugene to Olympia.  That means fresh (milder) air is moving in and out of the western valleys.  I notice Kelso has seen a gusty SE wind all morning keeping those temps above freezing.  Eventually south wind will develop between Salem and Portland too.

The freezing rain threat is pretty much finished now in the metro area, it’ll be confined to the Columbia River Gorge the rest of the day.  And after a few more hours it’ll only be east of Multnomah Falls

Check out the latest road surface temps:

• I205/Division:  34
• Canemah/Oregon City:  37
• Hwy 26/Sunset Transit Center:  37
• RockyPt. US 30:  37

All of those were at or below freezing a few hours ago…the melt is finally on!  And today it’ll be much faster than yesterday.

Chief Meteorologist Mark Nelsen

 

 

 

Patchy Freezing Rain Monday AM, Then the Big Thaw

Today’s slow thaw was VERY slow.  PDX hit 33, other parts of the metro area were up in the 33-37 degree range.  But now we are seeing plenty of refreezing because skies have cleared out.  Snow cover on the ground and a clearing sky means temps can easily drop back to freezing.  Around 9:30pm this semi truck went flying off the I-205/I-5 interchange near Tualatin:

There will be no warming south wind overnight, and the only thing that would keep temps near/above freezing would be thick cloud cover moving in.  Don’t count on that.

Here is the plan for tomorrow morning:

• Most side roads will be icy, or at least have lots of leftover slush/snow on them
• Freeways should be mainly okay though
• I don’t expect a widespread freezing rain event
• But some showers will arrive after 8am, and in some spots those will fall as freezing rain.
• Will you be able to tell the difference between a few spots of freezing rain and icy streets left from overnight freezing…I doubt it.  Not much different from what we have right now.
• By 10am temps will be rising above the point which liquid rain would freeze to roads anyway (30-31) ) so then we are out of it, including the far eastside of town (Troutdale/Gresham)

In the Gorge, it’ll stay frozen all day, except the far west end near Corbett and above Washougal which will get warming southerly wind in the afternoon/evening.  So maybe 1/2″ ice accumulation from Multnomah Falls to Hood River.  Lighter amounts at The Dalles.

So drive carefully tonight and tomorrow morning.  If you DO plan to go to work, rest assured that roads will be MUCH better in the afternoon and evening.  Really!

Chief Meteorologist Mark Nelsen

Much Better Driving Sunday Afternoon…On the Main Roads

I just got in to work at 5pm Sunday; it only took me about 5 minutes longer than normal!  But that’s because my commute is mainly on I-84 and U.S. 26 (Corbett to Beaverton, 37 miles).  The good news is that freeways are in excellent shape, mainly wet with just some leftover junk in spots, generally the far left lane.  I was able to go normal (or a little above) speed with the light traffic.

The other main roads I drove on were just okay, but still lots of slop left.  Once you get on a side road though…what a sloppy slushy mess!  We are located on  Greenbrier Parkway just off Hwy 26 and it was the worst part of my entire commute; even worse than the solid snow/ice at home.  Thick slush/ice pack breaking up; I was all over the place even in my 4Runner.  This is what it looks like, probably quite similar to the street outside your home if you don’t live on a main road and don’t have a plow running by.

Luckily the forecast of no precipitation (or very little) worked out great.  Other than spots of drizzle we’ve been dry for about 18 hours in the metro area.

By the way, my commute home at midnight last night was really weird, even fewer cars than I have seen while commuting at the same time during previous snow/ice storms.  That surprised me since it was a Saturday night; apparently people who party don’t like to drive on ice and snow.  In fact from around Gateway to my exit east of  Troutdale, I never had a vehicle in sight either ahead of me or behind.  It really is nice to just move back and forth across a 3 lane freeway with no one else around.  And ODOT crews had it down to just a thin ice/snow layer, so no big bumps or snow chunks…very smooth driving about 40-45 mph the whole way.

Temps just barely climbed above freezing and combined with a sunbreak or two, cleared those main highways/roads a bit.  PDX hit 33 today, so far.

Looks like dry weather will continue through at least sunrise Monday.  But I haven’t looked at the rest of the forecast so I don’t have any other comments on that.  More later when I pull myself together and stare at maps/models.

Chief Meteorologist Mark Nelsen

Storm #3 Wraps Up; Now On To A Thaw

11pm…

Here are some of your snow totals; I got in a hurry so I missed quite a few of them…sorry!  It’s obvious that we forecast too high on snow accumulation this time.  Most of the metro area had 1-3″  Far west side (Forest Grove) and north (Felida) had 5-7″!

Now radar is looking pretty dry and I don’t see any organized weather system for tomorrow.  As a result, we begin a slow thaw.  This is what I’m thinking as of 11pm:

There will not be any warming southerly wind tomorrow, but just a few more degrees of gradual warming of our cool low-level airmass.  As a result at best I see 33 at Troutdale, 35 at PDX, and 36-39 in most of the rest of the metro area.  With no east wind returning tomorrow night and some light showers moving in, temperatures should remain above freezing.

That means lots of snow still left around Monday morning, but temps above freezing; a sloppy mess.  The Columbia River Gorge will remain frozen through Monday morning.  Time for the drive home!

Chief Meteorologist Mark Nelsen

4:30pm Saturday: Freezing Rain & Sleet Moving In

As expected, warmer air is pushing in a couple thousand feet above our heads in the metro area this evening, so many of us are seeing the snow change to ice pellets and/or freezing rain.  Remember freezing rain is liquid, ice pellets are snowflakes that melted into raindrops and then refroze into little chunks of ice.  It almost sounds like small hail when it hits your window or your head.  We’ve had some very heavy bands of precipitation move through in the past hour or so too:

THE HIGHLIGHTS FOR TONIGHT:

• Expect road conditions to go downhill between now and midnight as many metro area roads start to get a glazing of ice…on top of the packed snow.  Tonight’s road conditions will probably be the worst we have seen.
• Temperatures hold steady or drop a degree or two; any roads (mainly south metro) that thawed a little today will refreeze after sunset.
• Another 2-4″ snow is possible across the north and west metro where the cold air is thicker.
• East wind is just about the strongest we’ve seen out of all 3 storms out in the Gorge, it’ll back off quite a bit after midnight like it did yesterday evening.

Thanks for all your snow totals.  It looks like the storm has underperformed except out near Banks and Forest Grove.  Around 6″ new out there.  Most of us have only seen 1.5″ to 3″.   The switch to ice pellets and freezing rain hasn’t helped much.

Look at the current temps, how about that 56 in Roseburg!  Big ice storm in progress in the southern valley; thanks Paul for the 3/4″ ice report.  That’s got to be a real big issue with trees and power lines falling.

Chief Meteorologist Mark Nelsen

Snow Totals: Storm #3 Saturday

Time to tell us how much snow you have.  We are looking for 3 bits of info…

1. Location (City or area)

2. NEW SNOW TODAY ONLY

3. How much you have on the ground now

4. If you have only had freezing rain or rain today, I would love to know that too.

Leave all other discussion on previous posts.

 

Chief Meteorologist Mark Nelsen

Storm #3: 6 Hours Early!

10am Saturday…

Just woke up and checked out radar; here we go!  Storm #3 is moving in WAY ahead of schedule today with heavy snow across the metro area already before 10am.  It appears the atmosphere is still cold enough to support snow (for now) north of Salem.  A new winter storm warning is up now through tomorrow morning for most of the Willamette Valley and now an Ice Storm Warning for the central/south Willamette Valley due to very thick ice accumulations.

• Expect 4-7″ new snow in most of the metro area today/this evening.
• Most of the precipitation should stay as snow in the metro area
• Some freezing rain is possible in the metro area by evening, definitely possible during the overnight hours

Heavy freezing rain will develop in the Willamette Valley and snow will change to freezing rain from Salem up into the far southeast suburbs of the metro area during the afternoon.  Lots of thick ice developing and power outages!

Note the WRF-GFS forecast of snowfall in the metro area today…a much juicier storm than the last two over the metro area:

 

Chief Meteorologist Mark Nelsen