December Med/Long Range Discussion

[CAPE]

11 minutes ago, WinterWxLuvr said:

Bob likes to say we hope to get something to show up in the medium range, and he's usually right, but right now we are going to have to get it to show up under about 72 hours.  There is huge volatility in the models right now beyond about 4 days.

Only long range threat that is legit worth consideration is mid next week. Anything beyond that doesn't warrant more than a heh or a meh. In this pattern day 6 or 7 is way out in la la land, but the signal for something wintry has pretty persistently been there, and it appears to be the first real shot at frozen for at least some of the region.

[poolz1]

GFS has some pretty robust CAD signatures on a lot of these waves in the MR - LR.  It does look like the midwest, OHV and PA will have a good blanket of snow...Cold highs over snowpack even in a not so ideal position can be stubborn and we know how the models handle these features.  I'd be good with all precip types as long as snow is somewhere in the mix.  So many waves and so much cold air...something is bound to line up our way.

[mappy]

CMC is warm too for Sun/Mon, but does drop 4-5" on the northern areas before it warms

also has snow to rain on wednesday, couple inches for northern areas before turning to rain

[Thanatos_I_Am]

FWIW, another good jump on the GEFS. Around 8" in DC and higher (in some cases much higher) North and West. Not bad

[yoda]

GEFS is okay 144-156.. I like through 180

 

[WinterWxLuvr]

54 minutes ago, Bob Chill said:

Crap, you guys must think I'm half blind or drunk...I meant the 0z euro. Not the 6z gfs. 

How's this lookin for good times? lol

This might look really good in an hour.

[WinterWxLuvr]

9 minutes ago, Thanatos_I_Am said:

FWIW, another good jump on the GEFS. Around 8" in DC and higher (in some cases much higher) North and West. Not bad
 

I still think that thing is useless unless you have a cluster of members showing a snow in the same time frame.

[yoda]

3 minutes ago, WinterWxLuvr said:

I still think that thing is useless unless you have a cluster of members showing a snow in the same time frame.

Around half have around a foot (or more) in the DC region

[yoda]

Darn... 1031 H in NE Quebec and it looks like we rain Sun night into Mon per 12z EURO

[mitchnick]

18 minutes ago, WinterWxLuvr said:

I still think that thing is useless unless you have a cluster of members showing a snow in the same time frame.

And support from the operational. 

[mappy]

Blah. Euro is cold, then sits at 33/34 (IMBY) when initial precip comes in Sunday. Then warms nicely into the 40s. 

[Bob Chill]

5 minutes ago, yoda said:

Darn... 1031 H in NE Quebec and it looks like we rain Sun night into Mon per 12z EURO

 

The 1031 near bermuda is doing it's dirty work. Not much we can do about it. The event has never really looked good so no biggie. Overnight timing could cause some ice in the northern burbs maybe but snow not looking good. 

[Thanatos_I_Am]

Around half have around a foot (or more) in the DC region

Yeah I was about to say, it seems like from D10-D14 almost all the members tick up the snowfall totals. Then again, it's been doing that for a while now.

[yoda]

EURO passes on the midweek chance again

ETA: Maybe not... 156 has some QPF...

lol cold rain on a southern slider (ninja'd by mappy)

[H2O]

theres a better CAD signal on the euro next week but things are moving too fast to crank

[mappy]

lol wednesday solution is now a southern slider. 

like some have been saying -- things are too volatile more than 3-4 days out

[psuhoffman]

41 minutes ago, WinterWxLuvr said:

I still think that thing is useless unless you have a cluster of members showing a snow in the same time frame.

I think people misuse it and then its useless but there can be "some" value to seeing the mean and spread.  For instance, yea none of these events coming up at the range we are at now are likely to hit.  I wouldn't put money on any single one of them.  And the ensembles bear that out because there is no cluster that hits on any one event with a majority.  But we have like 6 threats in the 2 week window coming up and you can also see that each has enough of a chance that if you add all the ensembles together at least one seems to hit our area on almost all of them.  They disagree on which one, but they agree the odds while low on any given event, are high that at least one works out.  its showing probabilities.  A bunch of low probability events together increase the odds one works out.  Like Russian roulette.  The odds of any one trigger pull ending in a shot are low, but if you pull the trigger enough times.....boom. 

[WxUSAF]

Crap ton of uncertainty for the next ten days. Euro does more of a gradient pattern and never strongly pushes the arctic air into our region. That's new vs past runs. Ends up with a whole lot of close but no cigar. Lots of fail or joy potential in that scenario. 

Euro is a lot closer for Sunday/Monday than the GFS. Still some potential there I think.

 

[Scraff]

17 minutes ago, psuhoffman said:

I think people misuse it and then its useless but there can be "some" value to seeing the mean and spread.  For instance, yea none of these events coming up at the range we are at now are likely to hit.  I wouldn't put money on any single one of them.  And the ensembles bear that out because there is no cluster that hits on any one event with a majority.  But we have like 6 threats in the 2 week window coming up and you can also see that each has enough of a chance that if you add all the ensembles together at least one seems to hit our area on almost all of them.  They disagree on which one, but they agree the odds while low on any given event, are high that at least one works out.  its showing probabilities.  A bunch of low probability events together increase the odds one works out.  Like Russian roulette.  The odds of any one trigger pull ending in a shot are low, but if you pull the trigger enough times.....boom. 

Click click... 

The happy hour GFS will be the draw. I'm laying money down.

[Snowless in Carrollton]

1 minute ago, WxUSAF said:

Crap ton of uncertainty for the next ten days. Euro does more of a gradient pattern and never strongly pushes the arctic air into our region. That's new vs past runs. Ends up with a whole lot of close but no cigar. Lots of fail or joy potential in that scenario. 

Euro is a lot closer for Sunday/Monday than the GFS. Still some potential there I think.

 

I couldn't help but to notice. Is that a typo where it says 3.2" for 2011-12 ? That's quite a range to go from 90" in 09-10 to 3" in 11-12.

[WxUSAF]

Just now, Snowless in Carrollton said:

I couldn't help but to notice. Is that a typo where it says 3.2" for 2011-12 ? That's quite a range to go from 90" in 09-10 to 3" in 11-12.

Nope. Life in the mid Atlantic. 

[pasnownut]

48 minutes ago, mappy said:

Blah. Euro is cold, then sits at 33/34 (IMBY) when initial precip comes in Sunday. Then warms nicely into the 40s. 

fixed

 

Lots of moving parts.  sunday may be bad for most of us, but I think like stated by otheres, we have chances, and it beats the heck out of last year.

 

Nut

 

[BristowWx]

It's not Dec 15 so looks good to me.  Xmas could be cold so that is my only wish.  Anything else gravy on top

[Eskimo Joe]

12z GFS for Dec 12th at 12z at DCA.  50 kt winds flooding the region with warm air.  Kiss the Sunday night threat goodbye.

 

[pasnownut]

10 minutes ago, BristowWx said:

It's not Dec 15 so looks good to me.  Xmas could be cold so that is my only wish.  Anything else gravy on top

at 500mb, GFS seems to keep the pattern reloading until 12/23ish  then takes on a more s/w component which would melt our white Christmas dreams away.  Too far out to hang a hat/ring or anything on but that's what I see....for now.

 

Nut

 

[midatlanticweather]

Wes' article 

 

https://www.washingtonpost.com/news/capital-weather-gang/wp/2016/12/08/next-weeks-arctic-blast-could-mean-two-bouts-of-wintry-precipitation-in-washington/?postshare=9271481225586360&tid=ss_tw&utm_term=.765ec3fa3611

 

If already posted! Sorry! 

[psuhoffman]

GEFS analysis....This is all centered on DC.   I separated the events into 5 time periods.  Next Monday, the midweek wave, the 12/17 threat, the 12/19 threat, and then the post 12/20 period.  That last period actually covers two shortwaves but separating them at that range is useless so I just lumped that window together but keep in mind that skews the numbers a little bit.  I considered over 1" at DC to be a hit.  Remember this is out of 21 individual members

Monday: 1 hit

Midweek: 9 hits

12/17: 10 hits

12/19: 11 hits

12/20-12/24: 13 hits

DC Mean 8", Mode 6", worst member 1", best member 18"

members with.... 0 hits 1, 1 hit 5, 2 hits 7, 3 or more 8

Other trends... lots of members with 10"+ but they get there mostly with several hits not one big snowstorm. 

So my take away, the model likes later in the period more then earlier.  The ensemble continues to be way more bullish then the operational...not sure what to make of that. Given this is the 4th run in a row with a LOT of members showing big snow totals it would be nice to get one of the op runs to show something like that soon.  We are unlikely to see a BIG event, but multiple smaller hits is possible.  The ensemble would make it seem likely one of these threats hits but I would feel better if we got some op support soon. 

[pasnownut]

4 minutes ago, psuhoffman said:

GEFS analysis....This is all centered on DC.   I separated the events into 5 time periods.  Next Monday, the midweek wave, the 12/17 threat, the 12/19 threat, and then the post 12/20 period.  That last period actually covers two shortwaves but separating them at that range is useless so I just lumped that window together but keep in mind that skews the numbers a little bit.  I considered over 1" at DC to be a hit.  Remember this is out of 21 individual members

Monday: 1 hit

Midweek: 9 hits

12/17: 10 hits

12/19: 11 hits

12/20-12/24: 13 hits

DC Mean 8", Mode 6", worst member 1", best member 18"

members with.... 0 hits 1, 1 hit 5, 2 hits 7, 3 or more 8

Other trends... lots of members with 10"+ but they get there mostly with several hits not one big snowstorm. 

So my take away, the model likes later in the period more then earlier.  The ensemble continues to be way more bullish then the operational...not sure what to make of that. Given this is the 4th run in a row with a LOT of members showing big snow totals it would be nice to get one of the op runs to show something like that soon.  We are unlikely to see a BIG event, but multiple smaller hits is possible.  The ensemble would make it seem likely one of these threats hits but I would feel better if we got some op support soon. 

that sounds aLOT better than what i posted about the GFS op at 500.

 

lets run w/ your's....:)

 

Nut

 

[WinterWxLuvr]

13 minutes ago, psuhoffman said:

GEFS analysis....This is all centered on DC.   I separated the events into 5 time periods.  Next Monday, the midweek wave, the 12/17 threat, the 12/19 threat, and then the post 12/20 period.  That last period actually covers two shortwaves but separating them at that range is useless so I just lumped that window together but keep in mind that skews the numbers a little bit.  I considered over 1" at DC to be a hit.  Remember this is out of 21 individual members

Monday: 1 hit

Midweek: 9 hits

12/17: 10 hits

12/19: 11 hits

12/20-12/24: 13 hits

DC Mean 8", Mode 6", worst member 1", best member 18"

members with.... 0 hits 1, 1 hit 5, 2 hits 7, 3 or more 8

Other trends... lots of members with 10"+ but they get there mostly with several hits not one big snowstorm. 

So my take away, the model likes later in the period more then earlier.  The ensemble continues to be way more bullish then the operational...not sure what to make of that. Given this is the 4th run in a row with a LOT of members showing big snow totals it would be nice to get one of the op runs to show something like that soon.  We are unlikely to see a BIG event, but multiple smaller hits is possible.  The ensemble would make it seem likely one of these threats hits but I would feel better if we got some op support soon. 

Now THIS is useful.

[WinterWxLuvr]

41 minutes ago, Eskimo Joe said:

12z GFS for Dec 12th at 12z at DCA.  50 kt winds flooding the region with warm air.  Kiss the Sunday night threat goodbye.

 

You're assuming it's modeled correctly.  

Big assumption lately.