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December Medium/ Long Range


Terpeast
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23 minutes ago, WxUSAF said:

 

I’m seeing the l/w pattern as more of a clippers/LES pattern. We’ve had plenty of that in the past before the 2010s onward, and while it got cold it wasn’t that easy to get snow. But we’ll see whether there’s a well timed s/w that digs enough to give us a snowstorm. Far too early to tell, but so far we have dec 1-2 and dec 5-8 windows to track. 

It may be similar to this past Jan where we did not see those 2 minor storms coming until they were starting to dig east of the rockies, and the models kept trending south until they were right on our doorstep.

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2 hours ago, CAPE said:

You realize the HP there is a fixture every winter, right? That area is adjacent to/part of the hyper-continental climate of Siberia(and the Siberian High). It takes a specific longwave pattern to deliver the extreme cold southward into our part of the world from that region. A negative WPO/EPO in conjunction with the elongated TPV stretching southward over Hudson bay is the potential delivery mechanism in this case. With a different longwave pattern that cold HP still exists during every winter and it is largely irrelevant to our sensible weather. This is the case many more times than not.

Lots of lower pressure there during our winter drought. I follow it every season, you well may not,  and lots of blue shading for most winters lately . It’s observational and won’t ignore it. 
 

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16 minutes ago, Terpeast said:

I’m seeing the l/w pattern as more of a clippers/LES pattern. We’ve had plenty of that in the past before the 2010s onward, and while it got cold it wasn’t that easy to get snow. But we’ll see whether there’s a well timed s/w that digs enough to give us a snowstorm. Far too early to tell, but so far we have dec 1-2 and dec 5-8 windows to track. 

It may be similar to this past Jan where we did not see those 2 minor storms coming until they were starting to dig east of the rockies, and the models kept trending south until they were right on our doorstep.

Yea last januarys events did kinda show up on modeling  kinda late

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12 minutes ago, Terpeast said:

I’m seeing the l/w pattern as more of a clippers/LES pattern. We’ve had plenty of that in the past before the 2010s onward, and while it got cold it wasn’t that easy to get snow. But we’ll see whether there’s a well timed s/w that digs enough to give us a snowstorm. Far too early to tell, but so far we have dec 1-2 and dec 5-8 windows to track. 

It may be similar to this past Jan where we did not see those 2 minor storms coming until they were starting to dig east of the rockies, and the models kept trending south until they were right on our doorstep.

Clippers/ Sw's provided decent Snowfalls in January 2014 as I recall even east of Apps. Feb. 2015 was historic and was , as we all know +TNH and resultant + PNA . There should be somewhat of a Southern Stream since the Nina is so weak. Models may be underestimating it's presence. Hopefully we get deeper divers this time around as well. 

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24 minutes ago, WEATHER53 said:

Lots of lower pressure there during our winter drought. I follow it every season, you well may not,  and lots of blue shading for most winters lately . It’s observational and won’t ignore it. 
 

There is always a shallow area of HP there during the winter months. 100 percent of the time. If you are looking at h5, then I can understand your confusion.

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7 minutes ago, NorthArlington101 said:

00z GFS joins its ensembles in trying to get a coastal going Sunday, fails to get anything notable going but nice to see the OP hop on with the general idea.

It looks like a pretty ideal vort pass. Just need more juice.

It's weak sauce. There are 2 areas of vorticity, neither are particularly sharp on approach, and interaction happens too late. Low forms way offshore.

Some flakes flying and maybe a dusting in places is probably the upside.

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It's weak sauce. There are 2 areas of vorticity, neither are particularly sharp on approach, and interaction happens too late. Low forms way offshore.
Some flakes flying and maybe a dusting in places is probably the upside.

Thanks for the clarification. What I think I was trying to say, and still happy to be corrected on, was that this seems like a good spot for the pass, at least based off my memory. Definitely need stronger.

54abfc1deca44f6ddbddd94ed57bd426.jpg
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13 minutes ago, NorthArlington101 said:


Thanks for the clarification. What I think I was trying to say, and still happy to be corrected on, was that this seems like a good spot for the pass, at least based off my memory. Definitely need stronger.

54abfc1deca44f6ddbddd94ed57bd426.jpg

The southern piece is too broad. The northern piece is a bit sharper, but they remain separated until offshore. Strong divergence aloft occurs on the downstream side when the shortwave is sharper, and that initiates lift and induces low pressure at the surface.

1733076000-HGWbfOas57g.png

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1733108400-TPLx2F3P7DE.png

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14 hours ago, Benjamn3 said:

A warm Xmas week is usually a slam dunk. Fingers crossed we get a reprieve this year. 

Man 5" - 8" of cold powder on Christmas Day would be amazing. Follow by a reinforcing shot of cold air and a clipper New Years Eve. 

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17 minutes ago, Eskimo Joe said:

Man 5" - 8" of cold powder on Christmas Day would be amazing. Follow by a reinforcing shot of cold air and a clipper New Years Eve. 

 Man you’re gonna make me cry. lol all we can do is cross our fingers and hope for the best. 

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3 minutes ago, NorthArlington101 said:

All the ens are pretty much snoozers for the next 10 days. Enjoy the cold!

In past Decembers when it was cold, we tended not to cash in on the cold.  However,  the chill will lend to the holiday season.  

There is still potential beyond the 10 day period, I like the window from Dec. 7 th to the 10 th.   

 

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24 minutes ago, frd said:

In past Decembers when it was cold, we tended not to cash in on the cold.  However,  the chill will lend to the holiday season.  

There is still potential beyond the 10 day period, I like the window from Dec. 7 th to the 10 th.   

 

The NS flow is fast and busy with shortwaves flying around. Guidance is going to struggle with location/strength and timing of specific shortwaves in the LR. For now we appear to have a pattern than can bring below avg temps, so we keep monitoring for a discrete threat to materialize in the medium range. 

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7 minutes ago, CAPE said:

The NS flow is fast and busy with shortwaves flying around. Guidance is going to struggle with location/strength and timing of specific shortwaves in the LR. For now we appear to have a pattern than can bring below avg temps, so we keep monitoring for a discrete threat to materialize in the medium range. 

yeah, these fast split flow patterns with potent +PNA ridging can have strong NS shortwaves / phasing situations not even show up until days 4-7

ecmwf-ensemble-avg-namer-uv200_stream-3443200.thumb.png.3883606b3c37d08211ab493783e7320c.png

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17 minutes ago, brooklynwx99 said:

yeah, these fast split flow patterns with potent +PNA ridging can have strong NS shortwaves / phasing situations not even show up until days 4-7

ecmwf-ensemble-avg-namer-uv200_stream-3443200.thumb.png.3883606b3c37d08211ab493783e7320c.png

Probably need some interaction/partial phase between a NS shortwave and a piece of vorticity ejecting from the trough in the SW that's stuck underneath the ridge. Pretty much what the 12z Euro run did yesterday that produced an east coast winter storm on the 7th.

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48 minutes ago, CAPE said:

The NS flow is fast and busy with shortwaves flying around. Guidance is going to struggle with location/strength and timing of specific shortwaves in the LR. For now we appear to have a pattern than can bring below avg temps, so we keep monitoring for a discrete threat to materialize in the medium range. 

Obviously we could go through the whole cold pattern snowless, but I’d bet against getting totally skunked. But we could certainly  top out at a dusting or two. Saw a plot yesterday of EPS analogs for its D10-15 forecast (this was yesterday’s 0z run). Couple were essentially snowless at BWI with just a T or two. Several had a light event or two nearby in time (1-3” type deal). Best was 12/5/2002…the OG December 5th storm. 

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13 hours ago, CAPE said:

There is always a shallow area of HP there during the winter months. 100 percent of the time. If you are looking at h5, then I can understand your confusion.

You seem to want to pick a fight which would be a mistake 

i know what I specifically observe while you share what you feel your model dependency tells you to . 
it doesn’t work to tell someone they “see it wrong”!

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13 hours ago, CAPE said:

There is always a shallow area of HP there during the winter months. 100 percent of the time. If you are looking at h5, then I can understand your confusion.

The party that is confused is you

You are Not the spokesman Nor the self appointed corrector of others. The simple lact of  observation is that for many years that region in the winters has had considerably less strong, very cold high pressure in the winter.

i hope this  cures your confusion and your need to “correct” others observations.  

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