November 2018 Weather in the Pacific Northwest

[Deweydog]

God d*mn. Ugliest euro weeklies I’ve ever seen. Not even gonna bother posting it.

 

I think the model might be mishandling upstream wavetrains following the Siberian high descent, but still not a pleasant thing to look at.

Haha.

[BLI snowman]

This is what I have read, you probably know a bit more, is this what you are thinking?

 

http://www.theweatherprediction.com/habyhints/278/

 

LIMITATIONS

 

Forecasting the surface high using the 850-mb temperature has been a popular forecasting technique. First I will go over the limitations of using this method:

 

1. Method does not work on cloudy days or days with afternoon precipitation

 

2. There is a tendency that temperature will be higher than predicted on days the wind is light and will be lower than predicted on days the wind is strong. This is because the low level wind effects the depth of mixing.

 

3. Method assumes air is mixed only between the surface and 850 mb. If the air mixes to a height significantly above or below 850 mb the technique will not work accurately.

 

4. Method does not account for elevation. High elevation regions have a greater chance of mixing air that is above 850 mb.

 

5. Daylight hours effect accuracy. There is a significant difference in daylight hours between the warm and cool season.

 

6. Method only works in a barotropic atmosphere. Fronts or differential advection will contaminate technique.

 

7. Method does not work well in regions with complex topography or near mesoscale temperature gradients such as coastal areas, very hilly areas, and areas near large lakes.

 

The method works best in locations near sea level, in the warm season, on barotropic days, with flat topography, on moderate windy cloud-free days. If any of these conditions are not met then take that into account on the temperature prediction.

 

 

850mb temps mean fairly little at face value in the month of December. This is the peak of our inversion season and the sun is too weak to disrupt a stagnant pattern. Surface pressure gradients are paramount and low level WAA is what determines the anomalies on valley floors. Most of our warmest 850mb airmasses in December have been quite cold at the surface.

[Front Ranger]

Maps. Ugh.

 

Haha! Ugh.

[BLI snowman]

Obviously.  

 

If it's so obvious then why do you still make a big deal out of the 850mb maps? 

 

[Jesse]

At least some scenic clouds today.

 

[BLI snowman]

Heads up, Salmon Creek!

 

Pretty moderately dark green little speck heading that way on radar!

[Front Ranger]

God d*mn. Ugliest euro weeklies I’ve ever seen. Not even gonna bother posting it.

 

I think the model might be mishandling upstream wavetrains following the Siberian high descent, but still not a pleasant thing to look at.

 

How'd they do with November? I don't remember them predicting major cold for the country.

[Jesse]

Lights rain here now.

[Timmy Supercell]

At least some scenic clouds today.

 

1B69A8B6-019B-4400-8AC0-C5546A4F1BE2.png

 

I liked the picture better when it was sideways.

[BLI snowman]

Lights rain here now.

 

Heads up!

[TT-SEA]

If it's so obvious then why do you still make a big deal out of the 850mb maps? 

 

 

WTF?   Big deal?    

 

I am just posting the maps for the benefit of other people on here who do not have access to WB.   

 

We are always tracking cold 850mb temps in the winter.     

[Jesse]

How'd they do with November? I don't remember them predicting major cold for the country.

I think the ones that came out in October were also the ugliest he’d ever seen.

[Phil]

How'd they do with November? I don't remember them predicting major cold for the country.

They did have an average/coolish pattern with a ridge near Alaska, but obviously they underestimated the amplitude.

[Brian_in_Leavenworth]

850mb temps mean fairly little at face value in the month of December. This is the peak of our inversion season and the sun is too weak to disrupt a stagnant pattern. Surface pressure gradients are paramount and low level WAA is what determines the anomalies on valley floors. Most of our warmest 850mb airmasses in December have been quite cold at the surface.

Yeah, during inversion that makes sense of course.  And also during an arctic outbreak where everything is cold the 850's will be a good indicator.  But still wondering about the CPC calling for below normal temps (not arctic) despite the 850's, and it is not an inversion pattern (slightly above normal precip).

[Phil]

I think the ones that came out in October were also the ugliest he’d ever seen.

Bull.

[Deweydog]

Heads up!

Wet heads!

[Jesse]

Bull.

Nah. You’ve been more of a bear this year.

[Phil]

[Jesse]

Another 1987-88 nod it appears.

[BLI snowman]

WTF?   Big deal?    

 

I am just posting the maps for the benefit of other people on here who do not have access to WB.   

 

We are always tracking cold 850mb temps in the winter.     

 

I think most people track snow opportunities, yes. Either way, the actual 500mb pattern is usually the most telling in determining what type of weather we might have. Fixating on 850mb is counterintuitive. 

[Phil]

That 1987/88 analog is a good one. A bizarre, early collapse of the niño then, with enhanced early season MJO activity, much like this year.

 

Also a nearly perfect QBO match.

[Jesse]

That 1987/88 analog is a good one.

 

Also a bizarre/early collapse of the niño, with enhanced early season intraseasonal/MJO activity (much like this year).

Of course, 1988-89 then went on to be a strong La Niña. Aren’t you predicting another warm ENSO epidosde next winter?

[TT-SEA]

Wow... just a little bit of rain here with that last band.  

 

https://vimeo.com/303157735

[Blizzard777]

At least some scenic clouds today.

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Backside of a huge cell that went through Happy Valley / Damascus area. Brother reported lighting/hail and heavy rain. Looked beautiful from my side over in lake Oswego near Bridgeport.

On nest cam looks like house back home is about to get hit by some good cells too

[MR.SNOWMIZER]

Not much melt on Snoqualmie. Trees are covered still and if we can manage some good showers next few days they could open next week i bet.

[Phil]

Of course, 1988-89 went on to be a strong La Niña. Aren’t you predicting another warm ENSO epidosde next winter?

Yes, because the OKW return is much later this year which almost precludes a clean low frequency break before the tropical tropopause starts warming/lowering with the descent of the +QBO/westerlies a few months from now.

[Blizzard777]

Wow... just a little bit of rain here with that last band.  

 

https://vimeo.com/303157735

Pressure washing drops!

[Jesse]

No, because the OKW return is much later this year which almost precludes a clean low frequency break before the tropical tropopause starts warming with the descent of the +QBO/westerlies a few months from now.

So you aren’t predicting warm ENSO next year.

[Phil]

So you aren’t predicting warm ENSO next year.

I am predicting a warm ENSO, unlike 1988/89.

 

Edit: Sorry, I meant to write “yes”, not “no”. I’m not sure how I screwed that up.

[TT-SEA]

I think most people track snow opportunities, yes. Either way, the actual 500mb pattern is usually the most telling in determining what type of weather we might have. Fixating on 850mb is counterintuitive. 

 

 

I am not fixating on anything.   I know tracking 850mb temps is very important to us all winter.    If we even get a hint of an arctic air mass coming then the 850mb temp maps will be flowing fast and furious on here.   

 

And the 5-10 day period actually shows cold 850mb temps... a map that was posted!   

[Deweydog]

So a strong la nino next winter???

[Jesse]

I am predicting a warm ENSO next year, unlike 1988/89.

 

Edit: Sorry, I meant to write “yes”, not “no”. Not sure how I screwed that up.

Yes worries. Happens to the best of us.

[Phil]

So a strong la nino next winter???

El Niña is more likely.

[TT-SEA]

Pressure washing drops!

 

Play with the sound all the way up.   

[Esquimalt]

An impressive band with 3 inch an hour returns coming through the juan da fuca strait right now.  

 

 

[Jesse]

Play with the sound all the way up.

Need that full horror movie experience.

[Phil]

[TT-SEA]

I’ve seen much heavier.

 

 

Well aware.

[Front Ranger]

That 1987/88 analog is a good one. A bizarre, early collapse of the niño then, with enhanced early season MJO activity, much like this year.

 

Also a nearly perfect QBO match.

 

Terrible match solar-wise, much stronger second year +ENSO, and completely different fall pattern. 

 

[Phil]

Well aware.

Just messing with you.

 

Definitely looks wet.