December Medium/ Long Range

[Kevin Reilly]

57 minutes ago, Benjamn3 said:

To much excitement and happiness in this group lady’s and gents. I’ll throw some buzz words to keep away the evil. Torch. S.E Ridge. Dry slot. Underperform. Can kick…There that should do the trick. 

Let me add a phrase... "No cold high up north".

[stormy]

3 hours ago, CAPE said:

It's an h5 snapshot from an ensemble mean for a specific time on a single day. The longwave pattern phase isn't stationary.

I understand that the chart is only a snapshot in time, but  folks new to this hobby need to understand that we usually do better with a trough axis to our west (Ohio Valley).

Case in point, the 18z GFS drops a 2 - 5 inch swath of snow across Virginia on Dec. 9 with a weak trough axis back over the western Ohio Valley.

Thanks Cape

[CAPE]

8 hours ago, stormy said:

I understand that the chart is only a snapshot in time, but  folks new to this hobby need to understand that we usually do better with a trough axis to our west (Ohio Valley).

Case in point, the 18z GFS drops a 2 - 5 inch swath of snow across Virginia on Dec. 9 with a weak trough axis back over the western Ohio Valley.

Thanks Cape

The western US ridge and the downstream trough orientation/axis have been discussed. The big picture as advertised on guidance is a pattern that can deliver anomalous cold. Plenty to nitpick should you choose to do so. Might end up cold and dry- that is a 'risk'. As I said in at least one post, it will probably take a significant NS shortwave to get a surface low to develop far enough south(and west) for the MA to cash in. A higher amplitude ridge with an axis further west would help to facilitate this.

[Weather Will]

Thanksgiving week WB 6Z EURO:

light showers east of the mountains Tuesday am. 

Rainy Thursday tapering off west to east in the afternoon to evening.  Nice soaker...

Cold, but dry settles in for the weekend.

Wishing you and your families a healthy and happy Thanksgiving!

[Chris78]

Would gladly take what the cmc is serving up around day 8/9. 

1 to 3 incher that gets everyone on the board.

[CAPE]

The Euro has been trying for several runs for around the 7th, and it gets to a pretty good outcome on the 12z run.

[WxUSAF]

GEFS has a little intrigue for next Sunday. Ops all show the wave, but mostly shear it apart. 

[NorthArlington101]

GEFS has a little intrigue for next Sunday. Ops all show the wave, but mostly shear it apart. 

Feels like something that’ll juice up in the short-range or not at all. Long as the ghost of the wave is still a thing I’m okay with where we stand to get some flakes in the air.

[WxUSAF]

12 minutes ago, WxUSAF said:

GEFS has a little intrigue for next Sunday. Ops all show the wave, but mostly shear it apart. 

Also showing some action around the 7th. Same time as euro op more or less. 

[Eskimo Joe]

51 minutes ago, WxUSAF said:

Also showing some action around the 7th. Same time as euro op more or less. 

The ridge of Alaska gets swept out around the 7th on the Euro and replaced with an ugly trough. Prepping our yearly Christmas torch?

[aldie 22]

5 minutes ago, Eskimo Joe said:

The ridge of Alaska gets swept out around the 7th on the Euro and replaced with an ugly trough. Prepping our yearly Christmas torch?

You missed the punch bowl 

[WxUSAF]

11 minutes ago, Eskimo Joe said:

The ridge of Alaska gets swept out around the 7th on the Euro and replaced with an ugly trough. Prepping our yearly Christmas torch?

Are you talking about the euro op or eps? If it’s the op, who cares? If it’s the eps, that would be a drastic change from the 0z run. 
 

But I always bet on a Xmas week torch. Easy money. 

[SnowGoose69]

1 minute ago, WxUSAF said:

Are you talking about the euro op or eps? If it’s the op, who cares? If it’s the eps, that would be a drastic change from the 0z run. 
 

But I always bet on a Xmas week torch. Easy money. 

Yeah Just the Op and even that is just a transient upper low riding the western edge of the ridge and just gets booted due north.  The GEFS some of its recent runs is semi concerning as its flattening the western ridge somewhat.  The GEFS has tended to be better with the pac the last few winters so we need to see if that continues

[WxUSAF]

5 minutes ago, SnowGoose69 said:

Yeah Just the Op and even that is just a transient upper low riding the western edge of the ridge and just gets booted due north.  The GEFS some of its recent runs is semi concerning as its flattening the western ridge somewhat.  The GEFS has tended to be better with the pac the last few winters so we need to see if that continues

Yeah GEFS seems to be waffling in the EPO domain more than EPS. But I actually like how GEFS and GEPS (to a lesser degree) show a WAR building in late in the run. That could help push the storm track back closer. 

[Terpeast]

7 minutes ago, SnowGoose69 said:

Yeah Just the Op and even that is just a transient upper low riding the western edge of the ridge and just gets booted due north.  The GEFS some of its recent runs is semi concerning as its flattening the western ridge somewhat.  The GEFS has tended to be better with the pac the last few winters so we need to see if that continues

IIRC the GEFS has always had a flatter pna ridge than the other models. GEPS the tallest/strongest, which gives us more cold but also more suppression risk

[Eskimo Joe]

30 minutes ago, SnowGoose69 said:

Yeah Just the Op and even that is just a transient upper low riding the western edge of the ridge and just gets booted due north.  The GEFS some of its recent runs is semi concerning as its flattening the western ridge somewhat.  The GEFS has tended to be better with the pac the last few winters so we need to see if that continues

Appreciate the insight!

[cbmclean]

1 hour ago, Eskimo Joe said:

The ridge of Alaska gets swept out around the 7th on the Euro and replaced with an ugly trough. Prepping our yearly Christmas torch?

First mention of Pac collapse.  Mark 2024-11-25 14:30 EST 

[CAPE]

22 minutes ago, cbmclean said:

First mention of Pac collapse.  Mark 2024-11-25 14:30 EST 

Ugly AK trough right here

[CAPE]

1 hour ago, Terpeast said:

IIRC the GEFS has always had a flatter pna ridge than the other models. GEPS the tallest/strongest, which gives us more cold but also more suppression risk

There might be a suppression risk, but a high amplitude ridge with a slightly west biased axis is going to give the best chance (imo) of a NS wave digging further south with enough space to allow a surface low to develop in time to affect us. A low amplitude/broader ridge most likely results in shortwaves tracking further north and/or scooting off the coast with LP development occurring offshore- too late. A delicate balance when almost all the action is occurring in the NS.

12z Euro run today H5 that results in a moderate snowstorm for the MA-

[Ralph Wiggum]

2 hours ago, WxUSAF said:

Yeah GEFS seems to be waffling in the EPO domain more than EPS. But I actually like how GEFS and GEPS (to a lesser degree) show a WAR building in late in the run. That could help push the storm track back closer. 

Love me some WAR when we need the storm track closer. Worked in our favor a couple of time last winter. 

[WxUSAF]

2 minutes ago, Ralph Wiggum said:

Love me some WAR when we need the storm track closer. Worked in our favor a couple of time last winter. 

It was key in 2013-14, which is getting tossed around a lot as an analog. WAR/SER was over us a lot, but with the arctic air to our northwest, we cashed in over and over.

[Ralph Wiggum]

3 minutes ago, WxUSAF said:

It was key in 2013-14, which is getting tossed around a lot as an analog. WAR/SER was over us a lot, but with the arctic air to our northwest, we cashed in over and over.

It is very early and hopefully we don't deplete the reserves up N, but it doesn't appear arctic air will be an issue. Now just need to time some of that with moisture. 

[WxUSAF]

Just now, Ralph Wiggum said:

It is very early and hopefully we don't deplete the reserves up N, but it doesn't appear arctic air will be an issue. Now just need to time some of that with moisture. 

I saw a January 2022 H5 chart today. Looked a lot like our upcoming pattern to my eyes and I would jump at a January 2022 redux…

[Benjamn3]

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

[stormy]

10 hours ago, CAPE said:

The western US ridge and the downstream trough orientation/axis have been discussed. The big picture as advertised on guidance is a pattern that can deliver anomalous cold. Plenty to nitpick should you choose to do so. Might end up cold and dry- that is a 'risk'. As I said in at least one post, it will probably take a significant NS shortwave to get a surface low to develop far enough south(and west) for the MA to cash in. A higher amplitude ridge with an axis further west would help to facilitate this.

I NEVER care to nitpick.

I only pray that the models evolve to a December 1962 or 2009 pattern.

I highly doubt this but a La Nada pattern gives me 20 inches compared to 10 inches...............

[WEATHER53]

Mongolian first release  gets here Saturday and Sunday with -15 or greater departures. Highs  around DC 35-40 and lows 23-27 

Low pressure placements can be messed around all the models want but if the cold air can’t arrive it means zero.  At least for a while the Mongolian connection looks is place 

[cbmclean]

1 hour ago, Ralph Wiggum said:

It is very early and hopefully we don't deplete the reserves up N, but it doesn't appear arctic air will be an issue. Now just need to time some of that with moisture. 

I was wondering the same thing; is it possible for a pattern to "drain the source regions" of cold?  Sort of like running out of hot water in the middle of a luxurious shower?

[BristowWx]

4 minutes ago, cbmclean said:

I was wondering the same thing; is it possible for a pattern to "drain the source regions" of cold?  Sort of like running out of hot water in the middle of a luxurious shower?

I would think if you cut off the cross polar flow and rely on regular  Canada cold source and without a decent snow pack to the north even a good pattern could yield marginal cold which we don’t do well with.  Have heard many times here it’s a great pattern just not cold enough.  That’s more painful than straight up warmth.  

[CAPE]

3 minutes ago, WEATHER53 said:

Mongolian first release  gets here Saturday and Sunday with -15 or greater departures. Highs  around DC 35-40 and lows 23-27 

Low pressure placements can be messed around all the models want but if the cold air can’t arrive it means zero.  At least for a while the Mongolian connection looks is place 

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.

[yoda]

12z EC-AIFS was interesting enough at range for the Dec 5 time period