December Med/Long Range Discussion

[poolz1]

The trough near HI seems to be the key to giving us another "window" in the D8-12 timeframe.  Last two EPS runs keeps this trough N/NE of HI which promotes enough ridging in the west and shoves the PV to E Canada.  GEFS Keeps this trough NW of HI and therefore any gradient is well to our NW.  

 

If the eps is correct, I can envision a fast moving gradient type storm.  Over the past few days the GFS op has a few of these looks in fantasy range. 

 

[mitchnick]

1 hour ago, poolz1 said:

The trough near HI seems to be the key to giving us another "window" in the D8-12 timeframe.  Last two EPS runs keeps this trough N/NE of HI which promotes enough ridging in the west and shoves the PV to E Canada.  GEFS Keeps this trough NW of HI and therefore any gradient is well to our NW.  

 

If the eps is correct, I can envision a fast moving gradient type storm.  Over the past few days the GFS op has a few of these looks in fantasy range. 

 

Day 10 operational from 0Z, fwiw, has that signature written all over it.

[showmethesnow]

2 hours ago, Bob Chill said:

Euro ens cold again even though h5 doesnt look impressive. Take a look at the 15 day mean hi/low bar charts. Weird. Seems like cross polar flow keeps a good supply of cold air to our north so I think that even with so so heght patterns that cold is easily available. Strange times ahead. Not sure what to compare it to irt previous winter patterns. 

 

15 day mean is fairly impressive with the cold. Noticed that the spread between the members with the min/max temps jumps dramatically after day 6. That doesn't surprise me considering the helter-skelter look I noticed yesterday  between the members going into the extended.

[WinterWxLuvr]

15 minutes ago, mitchnick said:

Day 10 operational from 0Z, fwiw, has that signature written all over it.

If we had had that 1034 high today, we would have all been celebrating.

[WinterWxLuvr]

I feel like we are in a step down mode.  As we move further, obviously climo continues to get colder as well as moving to a better pattern, along with cold nearby in Canada.  I think our opportunities will improve.

[Bob Chill]

It's hard to make sense of the ens means right now down the line. H5 isn't supportive for cold at face value but when you look at the mid levels and surface it paints a slightly different picture. 

My take after looking carefully @ the 0z ens suite:

It seems like the pattern remains relatively repetitive in nature after our first cold shot and regardless of the apparent long range jumpiness, the underlying pattern is basically the same. The ops have been showing versions of that for a couple of days now. It can be frustrating getting legit winter air masses in place only have them to run like a scalded dog when the next precip chance come up. But that's sort of a normal winter pattern for us and has been for basically forever. Long standing snow patterns are few and far between. Feast or famine is our climo. We are who we are. 

The d10-15 period has been unusually volatile with the ens means. Seems like they step forward and back every 24 hours. I think it is more of a byproduct of timing within the members versus representing pattern changes. Sometimes the the majority agrees on trough in the east during the same general time frame while other runs agree that more ridging in the east is happening during the same time frame. 

When you look at the 0z h5 mean @ d15 from last nights GEFS it looks like heights have relaxed in our area and cold is more bottled in Canada. Which it is but the mid level and surface depiction shows the gradient is farther south on the means that a normal scan of h5 would imply:

 

 

 

Breaking down the mean into the members shows that really we are in the same pattern with cold fronts on the move but with differences in timing:

 

 

 

About an equal split between a cold trough or warm ridge in our area with a bias towards a colder solution at this point in time. But even the warm looks have a cold on the other side or middle of the country so it's no like winter isn't existing somewhere in the US at any given time which is far different than no winter existing in the Conus like we saw last year or other recent "disaster" decembers. 

 

Euro ens' main difference versus the GEFS is higher heights in the SW building. This would be good for us of course but the same general idea exists with the EPS. Winter on the move with cold always available to tap out of Canada.

This leads me to believe that we are entering an extended "above normal" chance for snowfall. Big snow? Doesn't look like it but chaos embedded within the constantly buckling flow could potentially present one of those "lucky" events. Zero reason to speculate about that until if/when it presents itself. Measurable snow? Yes, I believe that the longer we stay in the sort of pattern being advertised, chaos will increasingly add to our chances to put something down within the next 2-3 weeks. All it would really take is tight spacing (I said that before but it's important). It's an active and wet pattern in general so there is no reason to think that even though the pattern is kinda so-so that we can have things work in our favor.  

 

 

[mitchnick]

Whenever I hear BN temps but higher heights I get that bad feeling in the pit of my stomach that can only be described as the winter of 93/94.

[H2O]

12z is trying to pop a W coast ridge around the 13th-14th so with a very good -EPO there could be some fun times ahead.

[Wonderdog]

17 minutes ago, H2O said:

12z is trying to pop a W coast ridge around the 13th-14th so with a very good -EPO there could be some fun times ahead.

So is that the polar vortex coming down around that time?

[H2O]

1 minute ago, Wonderdog said:

So is that the polar vortex coming down around that time?

Yup.  you can see that the PAC gets its wavelength act together and the ridge in the Bearing sea punches a big ol PV down.  That pops a ridge off the WC.  

[showmethesnow]

Can't remember when the last time I have seen such a cold look for a good portion of the country. 

[mitchnick]

18 minutes ago, showmethesnow said:

Can't remember when the last time I have seen such a cold look for a good portion of the country. 

And that's Celsius too.

[WinterWxLuvr]

Remember somebody posting a GFS map of low temps for this weekend at and below zero?

Remember when we were getting a snow storm this weekend?

[H2O]

1 minute ago, WinterWxLuvr said:

Remember somebody posting a GFS map of low temps for this weekend at and below zero?

Remember when we were getting a snow storm this weekend?

remember when the vikings were undefeated?

[Bob Chill]

1 minute ago, WinterWxLuvr said:

Remember somebody posting a GFS map of low temps for this weekend at and below zero?

Remember when we were getting a snow storm this weekend?

Nope

[showmethesnow]

17 minutes ago, mitchnick said:

And that's Celsius too.

For such a long lead the GEFS is very impressive as well. Also of note is that the GEFS has the PV splitting @ 50 and 30 hPa  (10hPa is close) and bringing it down into west/central Canada around day 10/11. Think it might be the real deal because it not only has been showing this for quite a few runs but it also has been moving it forward in time.

[Kmlwx]

13 minutes ago, H2O said:

remember when the vikings were undefeated?

We need some burn ointment in here...

 

[usedtobe]

17 minutes ago, WinterWxLuvr said:

Remember somebody posting a GFS map of low temps for this weekend at and below zero?

Remember when we were getting a snow storm this weekend?

Jason just posted an article on CWG showing the sub zero temp forecast you mention and how the previous run it was 70 degrees warmer.     It's not worth focusing on any day 10 forecast.  The Euro had us in a big snowstorm on one of its forecast.  Day 10 forecasts as you know are like the Redskins defense,  might look good for an occasional play but basically stink.

 

[H2O]

Wes got jokes

[WinterWxLuvr]

16 minutes ago, H2O said:

remember when the vikings were undefeated?

Barely

[WinterWxLuvr]

Just now, usedtobe said:

Jason just posted an article on CWG showing the sub zero temp forecast you mention and how the previous run it was 70 degrees warmer.     It's not worth focusing on any day 10 forecast.  The Euro had us in a big snowstorm on one of its forecast.  Day 10 forecasts as you know are like the Redskins defense,  might look good for an occasional play but basically stink.

 

Exactly the point.

BTW, for you Redskin fans.... I think you've got a good team.  Hopefully they can get on a roll.  They've got talent.  As for my Vikings, done.

[WinterWxLuvr]

4 minutes ago, Kmlwx said:

We need some burn ointment in here...

 

That was a good one.

[showmethesnow]

7 minutes ago, usedtobe said:

Jason just posted an article on CWG showing the sub zero temp forecast you mention and how the previous run it was 70 degrees warmer.     It's not worth focusing on any day 10 forecast.  The Euro had us in a big snowstorm on one of its forecast.  Day 10 forecasts as you know are like the Redskins defense,  might look good for an occasional play but basically stink.

 

Good thing that was a day 9 forecast then. Guess I will pull my long undies out of the mothballs.

[usedtobe]

5 minutes ago, showmethesnow said:

Good thing that was a day 9 forecast then. Guess I will pull my long undies out of the mothballs.

Well you can hope for the Euro and GFS Dec 14th flurries or light snow behind the front with no wave to get a winter feel.  No need for long undies. 

 

[usedtobe]

The trouble with this pattern is the stronger waves go to our north so we have to hope for weak waves behind of front before it gets too far south.  Not a great pattern despite the cold but not one that precludes seeing light snow if we get lucky. 

 

[Bob Chill]

3 minutes ago, usedtobe said:

The trouble with this pattern is the stronger waves go to our north so we have to hope for weak waves behind of front before it gets too far south.  Not a great pattern despite the cold but not one that precludes seeing light snow if we get lucky. 

 

Totally agree Wes. Without a tight space and complete luck, organized LP is going to have a major uphill battle doing the right thing for our area. OTOH- as the euro op is showing, weaker waves riding the gradient could do it. An inch or 2 on cold ground would be more than an acceptable way to kick off the season. 

[psuhoffman]

5 minutes ago, usedtobe said:

The trouble with this pattern is the stronger waves go to our north so we have to hope for weak waves behind of front before it gets too far south.  Not a great pattern despite the cold but not one that precludes seeing light snow if we get lucky. 

 

Agree. To me the question is where do we go from here. Is this a step towards a better pattern later on. Or is this a sign were in for a struggle getting meaningful snow this year. I don't really have a good read on that yet. 

[showmethesnow]

4 minutes ago, usedtobe said:

The trouble with this pattern is the stronger waves go to our north so we have to hope for weak waves behind of front before it gets too far south.  Not a great pattern despite the cold but not one that precludes seeing light snow if we get lucky. 

 

The writing was on the wall when the models kept pulling the mean trough westward over the last week or so.

[H2O]

No comments on the Euro agreeing with the GFS on ridging out west starting in a week or so?

[mappy]

59 minutes ago, H2O said:

remember when the vikings were undefeated?