December Medium/Long Range Discussion

[Dabuckeyes]

18z run must be good if we are comparing field goal kickers and long range tweets

[WxUSAF]

5 minutes ago, Dabuckeyes said:

18z run must be good if we are comparing field goal kickers and long range tweets

Actually looks closer to a CAD event for NYE. 

[cbmclean]

7 minutes ago, howrdcounty snow said:

yes partially agree but considering the last storm, the long range proved in accurrate, so in my view LR forecasting doesn't always pan out, yes that's weather forecasting, but thee are other factors to consider which I won't touch. TYVM for your responses.

I'm not sure about the statement that the long range was "inaccurate". The storm signal was there for like 10 days.   The existence and approximate location were never in doubt.  Yeah there was a time where it looked like DC was going to good snow, and that didn't happen but that was corrected.  The fact that we knew about the storm at all from 10 days out is a miracle of modern science.

[WinterWxLuvr]

1 hour ago, leesburg 04 said:

Man that Blair Walsh miss was from like 2 ft to beat Seattle in the playoffs, then the Gary Anderson miss against the Falcons to go to the superbowl….gah!!! I hate kickers

The Anderson miss is the stuff of Vikings legend. It’s a history of Viking football in a nutshell

[WxUSAF]

5 minutes ago, losetoa6 said:

Gefs has a cluster of CAD believers NYE . Sometimes these CAD events get better as we near . 

 Front end thumpin would be real nice 

Speed up that s/w or bring it out in pieces with that cold high up top and we’re in the game.

[WinterWxLuvr]

26 minutes ago, WxUSAF said:

Actually looks closer to a CAD event for NYE. 

Yeah that storm is far from any type of certainty IMO

[Anyweather]

19 minutes ago, cbmclean said:

I'm not sure about the statement that the long range was "inaccurate". The storm signal was there for like 10 days.   The existence and approximate location were never in doubt.  Yeah there was a time where it looked like DC was going to good snow, and that didn't happen but that was corrected.  The fact that we knew about the storm at all from 10 days out is a miracle of modern science.

I agree with this. I'm of the age where I remember that all you could get was a 3 day forecast. It was a BIG DEAL when they started to do 5 day forecasts! Yeah, long range is useful.

[Wonderdog]

Just now, WinterWxLuvr said:

The Anderson miss is the stuff of Vikings legend. It’s a history of Viking football in a nutshell

Yeah, it robbed Randall of a trip to the Super Bowl and a MVP.

[psuhoffman]

2 hours ago, cbmclean said:

Honest question, what kind of "in-house" model could possibly be of use in serious forecasting?  The big boys all run on huge government supercomputers.  How could a homebrew model even have a chance.  I'm not trying to criticize, just honestly curious.

 

[psuhoffman]

57 minutes ago, WxUSAF said:

Actually looks closer to a CAD event for NYE. 

Sooooo 2020 to end on a catastrophic ice storm .  If it happens you will forever be associated with it lol. 

36 minutes ago, losetoa6 said:

Gefs has a cluster of CAD believers NYE . Sometimes these CAD events get better as we near . 

 Front end thumpin would be real nice 

Best example of this and a good bust in some places was Feb 2015 when from 72 hours it looked like a rain storm and trended south so much that our area got 6-12” of snow despite a surface track to our NW.  but that has an Arctic high with sub 0 temps in front of it. 

[Scraff]

45 minutes ago, losetoa6 said:

Gefs has a cluster of CAD believers NYE . Sometimes these CAD events get better as we near . 

 Front end thumpin would be real nice 

We know @ravensrule likes it in the back end. Uhhhhh thank you very much. Don’t forget to tip your waiters and waitresses. 

[Prestige Worldwide]

Maybe a big dog somewhere out there?

[WinterWxLuvr]

2 minutes ago, Prestige Worldwide said:

Maybe a big dog somewhere out there?

I would rather have frequent events

[cbmclean]

1 hour ago, psuhoffman said:

 

Interesting, do any of those terms mean anything to you?  I am only vaguely familiar with NWP.  I was under the impression that it involves lots of non-linear partial differential equations.

[ravensrule]

5 hours ago, Scraff said:

We know @ravensrule likes it in the back end. Uhhhhh thank you very much. Don’t forget to tip your waiters and waitresses. 

I take it anyway I can get it. I’m not picky. 

[PivotPoint]

23 hours ago, psuhoffman said:

Is it...the blues out west look pretty close to this...

Remember blocking changes what works out west.   Without blocking that wouldn’t work.  With blocking you want that trough off the west coast to kick everything along and promote enough ridging over the CONUS to prevent suppression. If we had what we think of as a ideal pac with great blocking everything would get squashed. That’s a cold dry look.  On the plot you posted I don’t see a disaster. The WPO vortex backed off enough to allow some epo ridging. The system south of AK is far enough south not to flood pac puke across.  It’s part of the flow not detached. I’d like a little more pna but it’s not bad.  If we have blocking.

Look at my response above. I think some are looking for the “ideal” pac but what is ideal changes based on other factors. It’s a balance. What’s on one side changes what we want on the other. A full latitude EPO/PNA ridge at the same time as a -AO/NAO is really rare. First of all you almost need the tpv to either drop into the US or completely vacate our side to get that. And when we have gotten that mid winter it’s tended to be a cold dry look. Think Jan 1977. 

Imo the snow mean hasn’t responded yet because after the New Years storm it’s dry. And that’s to be expected with that blocking look. The New Years period is the HA storm on the front end as the blocking goes up. The wave break from those 2 systems help get the block into our canonical location. Once there though waves will likely slow down over the CONUS...blocking. We would then need the blocking to start to relax some. Or...the Feb 2010 option when a really strong stj wave attacked the blocking aided by a trough off the west to promote enough ridging (and the wave was strong enough not to shear out) to get that moisture to attack the block.  But waves will likely be less frequent after the blocking establishment 

I guess what I was getting at is the there is a mean 500mb trough off the west coast that with a fairly active PAC flow means that any PNA that does develop gets eroded quickly and frequently. I’m not saying that a brief ridge can’t develop and time us up, however I also know that see the intermountain west get hammered with snow is not usually a snow look for us.

To your point though, with a mega block we probably do want an active west and PNA matters less since our risk of cutters is greatly reduced by the significant blocking. I’m always suspect of these highly anomalous teleconnections (like a massive -NAO phase).

Additionally, most the literature I have read about the seasonal variability of blocking suggests a duration of 5-30 days being within a normal distribution. So if we have already been experiencing a-NAO on the mean, then each few days that pass we risk cycling out or losing that look altogether. Long and short, I’m very happy with the Atlantic but feel like the PAC could sour our snow chances but not completely shut it out.