December 2016 Observations and Model Discussion for the Pacific Northwest

[Heavy Snow]

That is going to go east. Montana and east.

 

It looks like a shortwave is starting to dig S/SW. The Arctic air just can't set up shop just north of the Canada-US border all Winter long, eventually it will drop on down.

[TT-SEA]

Good news is that after a couple annoyingly dry days... the copious daily rains starts up again in earnest.   

 

That will be comforting since its been raining constantly for over 2 months now. 

[Kayla]

 

Current PDX forecast from Rod Hill. He's not worried of any frozen precipitation for the over-running event.

 

SUNDAY: Much colder air with afternoon snow levels for snow accumulation near 1,500 feet. Morning rain, heavy at times will break into showers. 24-hour rainfall will exceed .50 inches. Chilly northwest winds 10-25 mph. Temperatures will hold steady in the low to mid 40s.

 

MONDAY: Likely morning rain or a snow mix with temps in the 30s. Portland may see only rain, but a snow mix is possible. Metro hills near 500' and above could see flurries to 4" of snow accumulation. Showers with low snow levels will continue into the afternoon. Total liquid moistre of .25 inches.

 

TUESDAY: Morning showers with a possible snow mix at the lowest elevations. Metro hills may see up to an inch of snow. Becoming dry with partly cloudy skies late day.

 

WEDNESDAY: A HARD FREEZE, early metro temps 25-34 degrees. East winds will be gusty 10-35 mph. Windy areas may hold above freezing. Partly cloud skies with increasing cloud cover during the day.

 

WEDNESDAY NIGHT: Likely precipitation with gusty east winds. Watch for freezing rain or sleet in the gorge and other spotty areas where cold air may be trapped. Portland should hold above 32 degrees and see rain.

 

THURSDAY: Watch for possible icy spots early, especially near the gorge. A rainy day with .50" of rain or more expected. Gusty east winds continue.

 

http://www.portlandweather.com/portland-metro-7day

What maps is he looking at?? No way that forecast verifies for Wednesday night and Thursday. At the very least we are looking at a ZR event with temps well below freezing with the onset of precipitation. Most likely all snow to start with a quick transition in the afternoon on Thursday.

[Heavy Snow]

Rod hill is one of the worst forecasters in the lower 48. He is just a raging nam reading alcoholic.

 

I agree. I remember back in early January 2004 when he worked for KATU. He kept on saying day after day after day that the warm air should push out the cold air over PDX but it never happened until way later than he expected.

[Heavy Snow]

What maps is he looking at?? No way that forecast verifies for Wednesday night and Thursday. At the very least we are looking at a ZR event with temps well below freezing with the onset of precipitation. Most likely all snow to start with a quick transition in the afternoon on Thursday.

 

I have no idea. He must be thinking that because the models(mostly GFS) are showing 925mb temps turn positive when precipitation arrives that we should see all rain. He's not factoring in the cold pool in the Columbia Basin and the strong East winds. Yeah, we should definitely start off as snow. KING EURO has been consistent in showing below freezing temperatures run after run. 

[MossMan]

Sure, but a good 12-18 hours later than GFS. And north of Seattle is still in the -4 to -5C range at day 5.

That works...I'm good with that.

[Jbolin]

Oooo new mascot! like it... Hmmm funny thing is looks like some of my neighbors

Bonney Lake, need I say more?

[MossMan]

I cannot wait for frozen ground...even if it's just for a few days.

[Brennan]

What the long range Euro is showing at the end of the run reminds me of January 8-11 1991... i think thats the exact dates. Lots of snow in whatcom county (1-2 feet) and rain/40s everywhere south.

[Bryant]

Good news is that after a couple annoyingly dry days... the copious daily rains starts up again in earnest.   

 

That will be comforting since its been raining constantly for over 2 months now. 

 

That's good news indeed! 

[MikeInEverett]

06z gives Portland a snowstorm at hour 216.

http://www.tropicaltidbits.com/analysis/models/gfs/2016120406/gfs_mslp_pcpn_frzn_nwus_36.png

[MikeInEverett]

And FWIW, everyone gets in on the fun by hour 252.http://www.tropicaltidbits.com/analysis/models/gfs/2016120406/gfs_mslp_pcpn_frzn_nwus_41.png

 

http://www.tropicaltidbits.com/analysis/models/gfs/2016120406/gfs_z500_mslp_namer_42.png

[Timmy]

06z alert

[Phil]

I have no idea. He must be thinking that because the models(mostly GFS) are showing 925mb temps turn positive when precipitation arrives that we should see all rain. He's not factoring in the cold pool in the Columbia Basin and the strong East winds. Yeah, we should definitely start off as snow. KING EURO has been consistent in showing below freezing temperatures run after run.

Hard to stay snow with 925-950mb temps above freezing. That'd be closer to a graupel or sleet sounding if it's just confined to that layer.

[Phil]

06z GFS looks great (and more sensible) to me, as far as the pattern progression is concerned.

[TT-SEA]

Snowing here now... grass is turning white.

 

33.5 degrees.

 

Its been absolutely nuking snow at Snoqualmie Pass all night... can't wait to see their totals this morning.  

 

 

[ShawniganLake]

Snowing here now... grass is turning white.

 

33.5 degrees.

 

Its been absolutely nuking snow at Snoqualmie Pass all night... can't wait to see their totals this morning.

 

Have you even had a freeze yet?

[seattleweatherguy]

So far NWS just missing my elevation winter weather advisory for 500 feet

[TT-SEA]

Have you even had a freeze yet?

 

 

Nope.    Roses were still actively blooming yesterday.

[ShawniganLake]

Nope. Roses were still actively blooming yesterday.

31F here. But not precipitating of course.

[TT-SEA]

31F here. But not precipitating of course.

 

 

Had a few bursts of heavy snow when it was really accumulating... but then when the precip lets up it goes back to drizzle/snow mix.  

 

Got down to 32.3 and now back up to 33.    

 

Grass is white but roads are just wet with a little slush.

[westcoastexpat]

06Z GFS now showing what the Euro has been toying with -- another cold blast, quicker but colder mid month.

[Shadow]

Mix of snow here, 33.4 degrees.

Can anyone tell me how to change my weather link in my signature? I changed weather stations.

[Brennan]

Nope. Roses were still actively blooming yesterday.

It's so odd to me that roses are stil blooming this late. My parents garden still has several rose bushes with beautiful roses in mid bloom. They just continue to thrive in mild and wet conditions.

 

Pic of snow at your house!!!

[TT-SEA]

It's so odd to me that roses are stil blooming this late. My parents garden still has several rose bushes with beautiful roses in mid bloom. They just continue to thrive in mild and wet conditions.

 

Pic of snow at your house!!!

 

 

Waiting for daylight.

 

And it is really odd... the blooms are so nice here too.   Some better looking than in the summer.  

[TT-SEA]

[MossMan]

Hopefully my view will be changing to white by tomorrow!

Down to 39 degrees!!

[Brennan]

Windshield is frozen and there is some sort of frozen precip on it from earlier. Still mostly cloudy.

[FroYoBro]

The passes are getting destroyed with snow this morning. Nice to see.

[TT-SEA]

Windshield is frozen and there is some sort of frozen precip on it from earlier. Still mostly cloudy.

 

 

I saw a little band come through Bellingham on the radar just before 6.

[FroYoBro]

Looks like the cold front is passing through Portland right now judging by the radar. 

[MossMan]

Temp down to 38!

So nice to see a northerly wind this morning (a cold northerly) almost time to bust out the gloves!

[MossMan]

[FroYoBro]

12z shows that heavier moisture doesn't move through the Portland area until a little later in the afternoon on Monday. Definitely doesn't look good our small snow chances. 

[SilverFallsAndrew]

12z shows that heavier moisture not moving through the Portland area until a little later in the afternoon on Monday. Definitely doesn't look good our small snow chances. 

 

Best chances are probably actually tomorrow evening as things dry out. I think most people will see flakes in the air during the day tomorrow though. Nothing sticking below 500-1000' though. Thursday looks more like a classic 1-2" overrunning situation. The timing at this point looks perfect. Early morning. If we can get east winds pumping for a day or two I think it will start as snow Salem-north. 

[TT-SEA]

Not much... but at least it looks like winter.    Air seems to be drying out now.  

 

[HardDrinkinLincoln]

34° here and rain is now changing to snow.

[snow_wizard]

Snow mixed with rain falling here now with 36 degrees.  I knew the snow level would be lower than what was being shown.

 

On another note the Euro really did poorly with the precip for this area last night.  Hopefully that will continue to be the case.

[FroYoBro]

Best chances are probably actually tomorrow evening as things dry out. I think most people will see flakes in the air during the day tomorrow though. Nothing sticking below 500-1000' though. Thursday looks more like a classic 1-2" overrunning situation. The timing at this point looks perfect. Early morning. If we can get east winds pumping for a day or two I think it will start as snow Salem-north. 

 

Yep, I'm guessing there may be some light snow showers Monday night before we dry out. 

[MossMan]

I am currently having an unknown mix! Chunky splatters while moving my truck!