December 2022 Medium-Long Range Disco

[Ji]

13 minutes ago, leesburg 04 said:

What the hell is delayed?

winter...i mean its already mid january

[Terpeast]

10 minutes ago, brooklynwx99 said:

EPS looks amazing after the 12-14th system... strong blocking remains over the Davis Strait and the Pacific is vastly improved. everything still looks on track for the 15th onward

Exactly what I wanted to see. Pushing that aleutian ridge east to get cold air east of the rockies… and here. Hope this holds. 

[WEATHER53]

1 hour ago, BristowWx said:

We all need to do a little day drinking

Stay on topic and off personalizations 

[WEATHER53]

59 minutes ago, leesburg 04 said:

What the hell is delayed?

It’s an essentially made up mechanism to try and dismiss the fact that a predicted pattern change did not occur at the forecasted time but will materialize at a later date.  Therefore, the forecast was not wrong but rather the timing was just off or delayed. 

Unfortunately, timing is part of a verified and accurate forecast

 

[psuhoffman]

2 minutes ago, WEATHER53 said:

It’s an essentially made up mechanism to try and dismiss the fact that a predicted pattern change did not occur at the forecasted time but will materialize at a later date.  Therefore, the forecast was not wrong but rather the timing was just off or delayed. 

Unfortunately, timing is part of a verified and accurate forecast

 

But 2 things can be true. Getting the timing wrong is a bust. Failed forecast. Yes. But there is also a difference between a pattern change taking longer to complete or a new pattern taking longer to mature then initially expected and it just not happening at all. Sometimes it’s just a total fail but sometimes it really is just a timing thing. And shouldn’t it be about where we go from here not lamenting what some already got wrong? 

[WxUSAF]

@griteater with the festive report

 

[CAPE]

Latest edition of the Weeklies. That h5 look should bring some decent cold for the end of the month heading into Jan.

[CAPE]

lol ninja'd

[WxUSAF]

1 minute ago, CAPE said:

lol ninja'd

Weeklies look good although I’m sure it’s missing the cutter that goes to Hudson Bay on the 23rd with 70F temps ahead of the front 

[Eskimo Joe]

Yea Dec 10 to 15 onward looks good. We're clearly moving that direction.

[H2O]

24 minutes ago, WxUSAF said:

Weeklies look good although I’m sure it’s missing the cutter that goes to Hudson Bay on the 23rd with 70F temps ahead of the front 

I think it will be tropical in nature. The MDR should wake up soon

[IronTy]

10 minutes ago, H2O said:

I think it will be tropical in nature. The MDR should wake up soon

A solid warm core storm no doubt.

[IUsedToHateCold]

34 minutes ago, Eskimo Joe said:

Yea Dec 10 to 15 onward looks good. We're clearly moving that direction.

Models have been pretty consistent with this for some time, even though there have been wobbles (as to be expected). I'd be very surprised if we're in a shutout pattern come Dec 18th. 

[BTRWx's Thanks Giving]

Anyone else concerned by the ensembles forecasting the NAO to break down?

https://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/teleconnections.shtml

[CAPE]

25 minutes ago, BTRWx's Thanks Giving said:

Anyone else concerned by the ensembles forecasting the NAO to break down?

https://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/teleconnections.shtml

I'll wait until it actually materializes before I start getting 'concerned' it might not last.  Besides, Chuck told us all a ++NAO is where it's at.

[WEATHER53]

45 minutes ago, IUsedToHateCold said:

Models have been pretty consistent with this for some time, even though there have been wobbles (as to be expected). I'd be very surprised if we're in a shutout pattern come Dec 18th. 

I dont see the consistency.  Around Thanksgiving the block was in place about 10Th, now it’s approaching 10 days later.  That trend must reverse quickly. 

[AtlanticWx]

25 minutes ago, BTRWx's Thanks Giving said:

Anyone else concerned by the ensembles forecasting the NAO to break down?

https://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/teleconnections.shtml

Research has shown that the "big dogs" in the East Coast typically happen when the -NAO begins to weak, and besides it looks to strengthen again so not really that worried.

[WxUSAF]

Ok, so is Lucy going to kick the football again?  Today's EPS was run out of JB's basement. That's worth some private time alone in a dark room right there. -AO/-NAO/-EPO/+PNA Yahtzee!  

But will it actually happen?  GEFS continues to be far less enthused about west coast ridging.  

And the GEFS has led the way with the current can kick.  What continues to concern me is that GEFS, already with a less impressive Pacific sector than the EPS continues to correct to a stronger -PNA.  Look at all this blue on the west coast in this gif.  This is the GEFS forecast trend continuing to trend toward -PNA and/or more +EPO at all time steps as we march forward in time.  

Past performance is not necessarily an indicator for future performance though and there continue to be reasons to think that at.some.point the Pacific will improve enough to put us in the game.  So what can we look at to distinguish between the EPS and GEFS solutions?  I think the big tropospheric PV over Siberia/Sea of Okhotsk is a big discriminator.  Below is the D8 depiction for both systems.  There *should* be notable skill at D8 to forecast the location of such major features at H5.  The EPS wants to push this farther east toward Kamchatka and the Aleutians, which eventually produces the pants tent depiction above as it continues eastward.  

GEFS lags it far behind and keeps it more over the Arctic Ocean and eastern Siberia.  Blue over Kamchatka above, orange over it below.  

By D11, EPS has troughing extending into the Aleutians and we have a pretty El Niño type NHEM pattern.

GEFS is following to some degree (notice the blue over Kamchatka now at D11), but still different enough to have some big sensible wx differences downstream for us.  

The EPS continuing to show an El Niño-like pattern in the midst of a La Niña and with the GEFS continuing to push more troughing into the West Coast are two things to give us some caution.  I certainly hope it happens obviously!  Got to watch how that Siberian PV moves and wobbles over the next few days.  

[psuhoffman]

1 hour ago, WxUSAF said:

Weeklies look good although I’m sure it’s missing the cutter that goes to Hudson Bay on the 23rd with 70F temps ahead of the front 

Thanks to the Dalton Minimum coinciding with Dickens writing we get to obsess over snow happening on one specific day every year. 

[Scarlet Pimpernel]

19 minutes ago, WxUSAF said:

Ok, so is Lucy going to kick the football again?  Today's EPS was run out of JB's basement. That's worth some private time alone in a dark room right there. -AO/-NAO/-EPO/+PNA Yahtzee!  

But will it actually happen?  GEFS continues to be far less enthused about west coast ridging.  

The EPS wants to push this farther east toward Kamchatka and the Aleutians, which eventually produces the pants tent depiction above as it continues eastward.  

 

Good discussion, thanks! Interesting how a +PNA/-NAO kinda looks like a pants tent shape!  But that could be my mind going all RR here!

Seriously though, we can hope the EPS evolution is more realistic. But it's clear how much uncertainty there is even among both sets of ensembles. 

[Scarlet Pimpernel]

10 minutes ago, psuhoffman said:

Thanks to the Dalton Minimum coinciding with Dickens writing we get to obsess over snow happening on one specific day every year. 

Bah, humbug! You may take the day, but be here all the earlier the next morning! (which is Boxing Day, and we don't talk about that in these parts!) 

[nj2va]

52 minutes ago, WxUSAF said:

Ok, so is Lucy going to kick the football again?  Today's EPS was run out of JB's basement. That's worth some private time alone in a dark room right there. -AO/-NAO/-EPO/+PNA Yahtzee!  

But will it actually happen?  GEFS continues to be far less enthused about west coast ridging.  

And the GEFS has led the way with the current can kick.  What continues to concern me is that GEFS, already with a less impressive Pacific sector than the EPS continues to correct to a stronger -PNA.  Look at all this blue on the west coast in this gif.  This is the GEFS forecast trend continuing to trend toward -PNA and/or more +EPO at all time steps as we march forward in time.  

Past performance is not necessarily an indicator for future performance though and there continue to be reasons to think that at.some.point the Pacific will improve enough to put us in the game.  So what can we look at to distinguish between the EPS and GEFS solutions?  I think the big tropospheric PV over Siberia/Sea of Okhotsk is a big discriminator.  Below is the D8 depiction for both systems.  There *should* be notable skill at D8 to forecast the location of such major features at H5.  The EPS wants to push this farther east toward Kamchatka and the Aleutians, which eventually produces the pants tent depiction above as it continues eastward.  

GEFS lags it far behind and keeps it more over the Arctic Ocean and eastern Siberia.  Blue over Kamchatka above, orange over it below.  

By D11, EPS has troughing extending into the Aleutians and we have a pretty El Niño type NHEM pattern.

GEFS is following to some degree (notice the blue over Kamchatka now at D11), but still different enough to have some big sensible wx differences downstream for us.  

The EPS continuing to show an El Niño-like pattern in the midst of a La Niña and with the GEFS continuing to push more roughing into the West Coast are two things to give us some caution.  I certainly hope it happens obviously!  Got to watch how that Siberian PV moves and wobbles over the next few days.  

Great post! La Nina can go eff itself. 

[WxUSAF]

Follow up from above…if 1 runs trends are your thing (and we know they are!), 18z GEFS with more west coast ridging and moves the Siberian PV more into the Aleutians. Then it does it too much lol but one issue at a time .

[Deck Pic]

I'm fine with the pattern materializing later than first progged.  Our climo is more conducive to snow the later we get in DEC.  

[Stormchaserchuck1]

19 minutes ago, WxUSAF said:

Follow up from above…if 1 runs trends are your thing (and we know they are!), 18z GEFS with more west coast ridging and moves the Siberian PV more into the Aleutians. Then it does it too much lol but one issue at a time .

18z GFS had a 588dm ridge on the West coast. 12z GEFS had nothing at all. 

With this subsurface-ENSO configuration, we aren't going to see a west-based -PNA in Jan and Feb, like we are seeing now in Dec. Jan 500mb could be similar to last year. 

 

[WeatherShak]

From Mike Thomas:

Updated analogs...

Pack patience on big pattern shifts. Models often too quick with it. Eyes still on mid/late DEC.

Dec 2009 is now low on the 6-10 day analogs. Not thinking big winter weather for DC next 10 days.

11-15 day more interesting with 2009 top match. For now.

Keep in mine only a FEW analogs in either period have big impact December overall. Although on that same note, only ONE of them has NO winter weather at all. Would be surprised if we get through this pattern without anything at all, but that doesn’t mean what we do get will end up being a blockbuster. Hope that makes sense!

[Stormchaserchuck1]

This is what happened last time we had a Kelvin Wave in La Nina in the Winter (Dec 20-Jan 5)

 

[NorthArlington101]

This is beginning to get closer than the medium range, but the 18z EPS held decently firm on the Friday-Saturday timeframe. Some decent members in there, especially for first flakes.

That said, a *deeper* look doesn’t show great news at the surface and the overall axis shifted a jog north, but I’ll enjoy “tracking” something that’s just a couple days away.

[Stormchaserchuck1]

-PNA has to shake, sometimes the EC storm threat will take over and dominate N. Hemisphere pattern (usually it trends back to -PNA in the last few days).

[clskinsfan]

3 hours ago, WxUSAF said:

Ok, so is Lucy going to kick the football again?  Today's EPS was run out of JB's basement. That's worth some private time alone in a dark room right there. -AO/-NAO/-EPO/+PNA Yahtzee!  

But will it actually happen?  GEFS continues to be far less enthused about west coast ridging.  

And the GEFS has led the way with the current can kick.  What continues to concern me is that GEFS, already with a less impressive Pacific sector than the EPS continues to correct to a stronger -PNA.  Look at all this blue on the west coast in this gif.  This is the GEFS forecast trend continuing to trend toward -PNA and/or more +EPO at all time steps as we march forward in time.  

Past performance is not necessarily an indicator for future performance though and there continue to be reasons to think that at.some.point the Pacific will improve enough to put us in the game.  So what can we look at to distinguish between the EPS and GEFS solutions?  I think the big tropospheric PV over Siberia/Sea of Okhotsk is a big discriminator.  Below is the D8 depiction for both systems.  There *should* be notable skill at D8 to forecast the location of such major features at H5.  The EPS wants to push this farther east toward Kamchatka and the Aleutians, which eventually produces the pants tent depiction above as it continues eastward.  

GEFS lags it far behind and keeps it more over the Arctic Ocean and eastern Siberia.  Blue over Kamchatka above, orange over it below.  

By D11, EPS has troughing extending into the Aleutians and we have a pretty El Niño type NHEM pattern.

GEFS is following to some degree (notice the blue over Kamchatka now at D11), but still different enough to have some big sensible wx differences downstream for us.  

The EPS continuing to show an El Niño-like pattern in the midst of a La Niña and with the GEFS continuing to push more troughing into the West Coast are two things to give us some caution.  I certainly hope it happens obviously!  Got to watch how that Siberian PV moves and wobbles over the next few days.  

Could be too much of a good thing. Squished storms maybe? Then we are back to waiting for the relax. Still love the next 3 weeks for the majority of us though.