December 2019 Med/Long Range Disco

[LP08]

2 minutes ago, losetoa6 said:

You can see a little bit why here at h5 . Ukmet ejects more of the sw energy quickly east on the heels of the front passage and Euro holds back a good bit 

 

Here are the precip panels and temp panels from the Ukie.  Seems like it still has some work to do.

 

 

[NorthArlington101]

Here are the precip panels and temp panels from the Ukie.  Seems like it still has some work to do.
 
 

Does the temperature map only go out to 132? Just curious, because maps don’t line up based on hour.

[LP08]

10 minutes ago, NorthArlington101 said:

 

Does the temperature map only go out to 132? Just curious, because maps don’t line up based on hour.

 

I’m a moron.

 

[WinterWxLuvr]

5 minutes ago, LP08 said:

I’m a moron.

 

LOL, yeah I wondered why you would post a rain picture. Trouble with me is I’m not smart enough to even look at the time stamp.

[WinterWxLuvr]

Wasn’t Dec 5, 2009 a wave of low pressure that formed along a cold front that had just passed through.

[LP08]

5 minutes ago, WinterWxLuvr said:

LOL, yeah I wondered why you would post a rain picture. Trouble with me is I’m not smart enough to even look at the time stamp.

Lol, trouble is I did and still messed it up.  Unfortunately with the limited Ukie maps it’s hard to tell if there is much follow up after 144.  

[Ji]

2 hours ago, stormtracker said:

Hope you like valley livin

well thats all we know...so

[frd]

I hope the "weaklies" are wrong. 

[cbmclean]

4 minutes ago, frd said:

I hope the "weaklies" are wrong. 

What, they are so spectacular that should that pattern ever materialize, we will all become so spoiled that nothing less than a BECS will satisfy?

[WinterWxLuvr]

6 minutes ago, frd said:

I hope the "weaklies" are wrong. 

They always are

[Chris78]

We are  getting there slowly for the anafrontal mid week. Looks better

[Yeoman]

4 hours ago, osfan24 said:

Can anyone recall when we got snow, particularly significant snow, from an anafrontal? I feel like these are always huge teases and never work out. 

March 1995, and previous to that Dec 1778

[psuhoffman]

53 minutes ago, frd said:

I hope the "weaklies" are wrong. 

More about AAM. I had that data from earlier filed away from a few years back when there was another debate wrt AAM and snowfall. But I wanted to look this up on a hunch. Low AAM is usually associated with a Nina and high AAM with a nino. So yes they do skew somewhat the way you would expect. But there may be some wag the dog going on there. If we take out Nina’s and cold neutral following Nina’s and only look at years similar to this one, neutral or weak warm enso following neutral or warm enso years...what would the results be for -AAM?

Well there have been 8 such years with a -AAM. 1960-61, 1961-62, 1962-63, 1966-67, 1967-68, 1981-82, 1993-94, 2013-14. 

 6/8 had above avg snowfall. And get this, the 2 that didn’t were 1962 and 1994. Both were barely below normal at DCA but above for most west of 95 and both were memorable winters for various reasons. None of the 8 were “bad”. 

Finally im not even sure how - the AAM is going to be. It was running historically low in the fall but has been on the rise and is near neutral now.

It’s also hard to predict. So using it as a predictor past 10-15 days is risky. 

Putting all that data together, I’m just not sure that one factor is worth much concern.  I see nothing to indicate a -AAM enso neutral NOT following a Nina year would be a bad thing wrt snowfall.  On the contrary the historical data says it’s good for snowfall.  Furthermore, I’m not even 100% sold the AAM stays low all winter.  

 

[WEATHER53]

The kings of record cold in there 

[aldie 22]

In December I'm ok waiting a little longer for snow....if I had my choice between the 13th or the 20th I'd be happy to wait until the 20th similar to the gfs op. At some point though I'd like to see more sn than ra on the quick look text output though

[CentralVaNATS]

Another instance of not trusting modeling beyond 5-7day range this season. I'm sure most are already on that train. 5 days ago we were torching

 

Sent from my SM-N960U using Tapatalk

 

 

 

 

[psuhoffman]

2 minutes ago, CentralVaNATS said:

Another instance of not trusting modeling beyond 5-7day range this season. I'm sure most are already on that train. 5 days ago we were torching

 

Sent from my SM-N960U using Tapatalk

 

 

 

 

The guidance, especially the euro, has continually tried to progress the pacific pattern and crash a trough into the west. In reality the Aleutian low keeps reforming and pumping the epo ridge. Any breakdown is brief. 

[WxUSAF]

Ggem has gives us snow from the Wednesday frontal wave. Gfs does for the N+W folks as well. Getting there. 

Issue I’m seeing right now for next weekend is that the models are picking up on a northern stream shortwave moving into the Midwest at the same time we want our storm. That both pushes the high pressure out faster and some, like the euro, try to phase it in which pulls the storm west. Still a very long way to go so things will change.

[LP08]

Overnight EPS was a little more favorable for the Dec 11/12 follow up wave compared to the OP.  The GEFS mostly agrees with the OP that there is potential for a 1-3 after the front clears.

 

EPS Above has a stronger push of the -EPO than 12z, resulting in the TPV stretching and pushing further south into the OH valley.

GEFS has the stronger EPO ridge but doesn't stretch the TPV as much, but notice in south TX as a piece is left behind from the cutter that precedes it.

I like these tables below because it tries to show clustering.  This is the "best look" so far that I have seen from them for the Dec 11/12.

[CAPE]

52 minutes ago, losetoa6 said:

What a storm depicted on the Euro for day 9/10 . Verbatim....it gets down to 990s while still in the ne gulf and is 970s sitting over central Va . That would be some serious wind driven rain here and bigtime Appalachian snows . Curious to see the various outcomes the coming days for that period.  

Snow mean approaching respectable between the 12th and the 20th on the EPS. 2" at DC.

Looks active with multiple chances, ofc the prospect of total failure is always there in a pattern like this.

[Scraff]

15 minutes ago, losetoa6 said:

What a storm depicted on the Euro for day 9/10 . Verbatim....it gets down to 990s while still in the ne gulf and is 970s sitting over central Va . That would be some serious wind driven rain here and bigtime Appalachian snows . Curious to see the various outcomes the coming days for that period.  

We just need to push that storm out over Hatteras and crawl it NE. Can you please make that happen? And since I’m asking for gifts, throw in a nice cold H to the North as well. 

[MJO812]

1 hour ago, WxUSAF said:

Ggem has gives us snow from the Wednesday frontal wave. Gfs does for the N+W folks as well. Getting there. 

Issue I’m seeing right now for next weekend is that the models are picking up on a northern stream shortwave moving into the Midwest at the same time we want our storm. That both pushes the high pressure out faster and some, like the euro, try to phase it in which pulls the storm west. Still a very long way to go so things will change.

 

[pasnownut]

Looping the ensembles, gotta say thanks to the E PAC as there seems to be enough ridging and it really is trying to keep hope alive for use while we wait for the AO/NAO to get a better look to it. 

IMO as long as we keep that feature, we have a shot at something.  GEPS/EPS look similar so thats a + to me.  Mind you I'm just looking out to 10 days.  Like PSU stated a while back any unfavorable looks seem to be brief/transient.  

[Bob Chill]

@WxUSAF Eps starting to show the scand ridge pushing into GL D10-15 like the gefs. That could be the tipping point that turns a so-so but workable pattern into something pretty good. Get that going and we'll prob start seeing 50/50s and/or bn heights in the 50/50 region. 

[WxUSAF]

^excellent! At the moment I’m feeling reasonably confident of my low bar for December having a chance of clearance:

1. Less than 3F above normal

2. 1-2 accumulating snow events 

3. No 60F within 3 days of Xmas on either side 

 

[Bob Chill]

1 minute ago, WxUSAF said:

^excellent! At the moment I’m feeling reasonably confident of my low bar for December having a chance of clearance:

1. Less than 3F above normal

2. 1-2 accumulating snow events 

3. No 60F within 3 days of Xmas on either side 

 

We always need the little things to break right. Next week only needs some sort of transient block to keep hp from running east. Right now that's not looking too good and it's all at the hands of the progressive atlantic. Shove the mass of bn heights balled up over GL south and future cold highs to the north meet resistance.

Your short list seems reasonable to me. Just keep bringing the chances and it will accidentally snow here. 

[pasnownut]

15 minutes ago, Bob Chill said:

@WxUSAF Eps starting to show the scand ridge pushing into GL D10-15 like the gefs. That could be the tipping point that turns a so-so but workable pattern into something pretty good. Get that going and we'll prob start seeing 50/50s and/or bn heights in the 50/50 region. 

Thats what GEPS/EPS both show and part of what I mean by waiting.  Verbaitim that ridging needs to retrograde a bit to get to what you are suggesting, but its not far away from decent 

[frd]

9 hours ago, psuhoffman said:

More about AAM. I had that data from earlier filed away from a few years back when there was another debate wrt AAM and snowfall. But I wanted to look this up on a hunch. Low AAM is usually associated with a Nina and high AAM with a nino. So yes they do skew somewhat the way you would expect. But there may be some wag the dog going on there. If we take out Nina’s and cold neutral following Nina’s and only look at years similar to this one, neutral or weak warm enso following neutral or warm enso years...what would the results be for -AAM?

Well there have been 8 such years with a -AAM. 1960-61, 1961-62, 1962-63, 1966-67, 1967-68, 1981-82, 1993-94, 2013-14. 

 6/8 had above avg snowfall. And get this, the 2 that didn’t were 1962 and 1994. Both were barely below normal at DCA but above for most west of 95 and both were memorable winters for various reasons. None of the 8 were “bad”. 

Finally im not even sure how - the AAM is going to be. It was running historically low in the fall but has been on the rise and is near neutral now.

Awesome stuff here. Love it ! 

 

[frd]

21 minutes ago, Bob Chill said:

@WxUSAF Eps starting to show the scand ridge pushing into GL D10-15 like the gefs. That could be the tipping point that turns a so-so but workable pattern into something pretty good. Get that going and we'll prob start seeing 50/50s and/or bn heights in the 50/50 region. 

I don't recall the exact specifics, ( coffee still kicking in )  but reading over a post at 33 someone noted a similar evolution that did happen and triggered a negative  NAO which was one factor responsible for the Jan 2016 miracle that trended from a rain event many days prior to your victory of the winter.  Is that all true ?  

[frd]

@poolz1  keep an eye on this in the week or two ahead via BAMM , as well as what HM mentioned about the near splitting vortex, further down. Low chance but still of interest. 

Also seems like a bit of a spread with "maybe" an improving AO towards mid month and beyond.