January 2017 Observations and Model Discussion for the Pacific Northwest

[Heavy Snow]

sledding in the rain... Might be possible.

I might have to settle for a little snow and then freezing rain. It's better than nothing.

[Deweydog]

True, and you'll note I didn't say battle, but instead interaction.

 

I could be wrong, but it seems like the further offshore the northern shortwave cuts off, the slower the WAA actually is. The 18z seems to show a fairly lengthy transition, at least for points north of Portland.

 

It'd definitely be less dynamic further offshore.  If it retrogrades another 750 miles or so we could easily be in a fake cold setup.  

[Heavy Snow]

Who do we ask?

Ullr

[Front Ranger]

Are we looking at the same 18z. Looks horribly quick to me.

 

925s stay below 0 with precip for quite awhile. Basically from hour 117 to hour 132 for much of western WA/lower BC.

[Front Ranger]

It'd definitely be less dynamic further offshore.  If it retrogrades another 750 miles or so we could easily be in a fake cold setup.  

 

Do you think it would be better (for a prolonged snowfall event) for the northern shortwave to completely cutoff/bombout way offshore, or to stay weaker and closer to the coast?

[luvssnow_spokane]

Are we looking at the same 18z. Looks horribly quick to me.

I agree, I am not seeing any kind of slow transition. It looks like a lightening quick one and back to climo. So sad to have had such a great block for what was a decent period of time and have all go to hell in a hand basket. AND this may be our last shot for the winter to get that kind of setup again.

[TT-SEA]

925s stay below 0 with precip for quite awhile. Basically from hour 117 to hour 132 for much of western WA/lower BC.

 

 

Seahwawks game is between hours 126 and 132 right now.

[luvssnow_spokane]

I might have to settle for a little snow and then freezing rain. It's better than nothing.

I have higher standards since I have been pretty much snow starved since 2012... lol

[Deweydog]

I have higher standards since I have been pretty much snow starved since 2012... lol

 

Wouldn't it be smarter to lower them in that case?  

[BLI snowman]

The interaction between the northern/southern streams over the weekend will be pretty interesting to watch.

 

Most recent trend has been to hold the northern shortwave further north, which opens the door to more southern stream influence...which could provide a better opportunity for a widespread, slower transition event.

 

Looks like about 12 hours of ice at this point, probably a bit less for Seattle.

[MR.SNOWMIZER]

I agree, I am not seeing any kind of slow transition. It looks like a lightening quick one and back to climo. So sad to have had such a great block for what was a decent period of time and have all go to hell in a hand basket. AND this may be our last shot for the winter to get that kind of setup again.

Looks like a 12-18 hr time frame to me for possible frozen precip.

[Front Ranger]

FWIW...low res, I know. Potential is there, especially since models almost always scour out low level cold too quick.

 

[FroYoBro]

I have higher standards since I have been pretty much snow starved since 2012... lol

 

               

[Deweydog]

Do you think it would be better (for a prolonged snowfall event) for the northern shortwave to completely cutoff/bombout way offshore, or to stay weaker and closer to the coast?

 

If it bombs further offshore you reduce precipitation and increase 500mb heights/thicknesses, and ultimately warm the mid and upper levels.  It's kind of a no-win setup unless you like what could be a fairly prolonged ice event near the gorge.  

[Front Ranger]

If it bombs further offshore you reduce precipitation and increase 500mb heights/thicknesses, and ultimately warm the mid and upper levels.  It's kind of a no-win setup unless you like what could be a fairly prolonged ice event near the gorge.  

 

I would think whatever scenario would make a southern tracking low more likely would be preferred. You don't see any way that happens?

[ShawniganLake]

925s stay below 0 with precip for quite awhile. Basically from hour 117 to hour 132 for much of western WA/lower BC.

Looks like very little precip before hour 120 and Seattle has 850s above freezing by 126. Maybe hood canal holds on longer. I am obviously not seeing what you are. 1-2" in Seattle would seem like a reasonable expectation.

[luvssnow_spokane]

Wouldn't it be smarter to lower them in that case?  

Probably... Hard to let go! 

[Deweydog]

I would think whatever scenario would make a southern tracking low more likely would be preferred. You don't see any way that happens?

 

Not really, a southern low in a pattern like that would likely bomb to some degree and track northbound in the SW'erly flow.  There's nothing left at that point to suppress the jet as the offshore ULL kicks up the downstream ridge.  

 

Best case with the players we have right now would be to have a scenario like late 1992 where a block and strong Arctic ULL bombed just offshore, slowly nudged its way inland and elongated, suppressing the jet.  

[Front Ranger]

Looks like very little precip before hour 120 and Seattle has 850s above freezing by 126. Maybe hood canal holds on longer. I am obviously not seeing what you are. 1-2" in Seattle would seem like a reasonable expectation.

 

It's definitely close. Too far out to say much else now. At face value the GFS generates some widespread, decent accumulations.

[Front Ranger]

Not really, a southern low in a pattern like that would likely bomb to some degree and track northbound in the SW'erly flow.  There's nothing left at that point to suppress the jet as the offshore ULL kicks up the downstream ridge.  

 

Best case with the players we have right now would be to have a scenario like late 1992 where a block and strong Arctic ULL bombed just offshore, slowly nudged its way inland and elongated, suppressing the jet.  

 

So basically root for the northern stream shortwave to make more progress further south and bomb out later.

 

Unfortunately, that's not the trend at this point.

[Front Ranger]

Seahwawks game is between hours 126 and 132 right now.

 

What did the Euro show for that time frame?

[Fircrest]

I have to give you credit for your earlier call that some parts of the Vancouver would do well. This is the most snow we have had around here since 2008.

 

IMG_1488.JPG

We were up in your area on the 29th and 30th and were surprised at the snow that was on the ground then.  You must have gotten a lot more since!  Very lucky.  I have only had about 2" total for all of December in Fircrest--west of Tacoma.

[ShawniganLake]

So basically root for the northern stream shortwave to make more progress further south and bomb out later.

Unfortunately, that's not the trend at this point.

I am Watching for this with every model run the past 2-3 days. Has left me disappointed roughly 8 times per day.

[Deweydog]

So basically root for the northern stream shortwave to make more progress further south and bomb out later.

 

Unfortunately, that's not the trend at this point.

 

Yeah, at this point once that thing kicks west of Juneau or whatever, the rest is kind of history.  An upper level feeding frenzy!

[Timmy Supercell]

Still only 1/2" on the ground. We had approximately 5-10 minutes of very light flakes around noon, then back to overcast with off and on filtered sun.

 

Now mostly sunny. Nice trolling from the NWS.

[SilverFallsAndrew]

Winter storm watch just posted for Central Oregon. 6-12" tomorrow night through Thursday morning. Unbelievable how much snow they are getting.

[Front Ranger]

Yeah, at this point once that thing kicks west of Juneau or whatever, the rest is kind of history.  An upper level feeding frenzy!

 

The only other possible, best-case scenario I can see would be for it to kick out and subsequently cutoff so far west and north that it never really teams up with the southern stream, and also allows more cold air to slide south after cutting off. Then a southern stream low moves in around Salem, pulling cold air in from the north, and a huge regional snowstorm ensues.

 

IT COULD HAPPEN. 

[SilverFallsAndrew]

Still only 1/2" on the ground. We had approximately 5-10 minutes of very light flakes around noon, then back to overcast with off and on filtered sun.

 

Now mostly sunny. Nice trolling from the NWS.

Looks like you are supposed to get hammered tomorrow

[Deweydog]

The only other possible, best-case scenario I can see would be for it to kick out and subsequently cutoff so far west and north that it never really teams up with the southern stream, and also allows more cold air to slide south after cutting off. Then a southern stream low moves in around Salem, pulling cold air in from the north, and a huge regional snowstorm ensues.

 

IT COULD HAPPEN. 

 

Somewhere in there Hillary wins the electoral college too, I believe.  

[Deweydog]

Holy ******* , though...

 

It's been an "interesting" month or so of looking at weather forecast models.  

[Front Ranger]

Somewhere in there Hillary wins the electoral college too, I believe.  

 

I'd put the odds about the same as we gave Trump to win the election.

[Deweydog]

I'd put the odds about the same as we gave Trump to win the election.

 

Let's hope the polls (every forecast model I can think of) are off!!!

[SilverFallsAndrew]

I still haven't given up on Wednesday for PDX

[MR.SNOWMIZER]

So funny to look at the 18z and imagine what it would be like if that low floated around 500 miles further south.  It is amazing how close we come at times to some major events.

[FroYoBro]

I still haven't given up on Wednesday for PDX

 

I am also hoping to get a little out of that. The trend sure isn't great though. Looks very weak now. 

[Deweydog]

I still haven't given up on Wednesday for PDX

 

Way too dry and not nearly enough forcing.  Froyobro will have some flurries.  

[SilverFallsAndrew]

Mark Nelsen just released a MUCH WARMER 7day

[Timmy Supercell]

Looks like you are supposed to get hammered tomorrow

 

Yeah, half foot of snow with a chance of thunder. We'll see.. 

[Deweydog]

Down to 32 here!!!  

 

We're officially in the ice box!!!

[Deweydog]

Mark Nelsen just released a MUCH WARMER 7day

 

We had a long heart to heart last night.