December Pattern Disco- 2013

[Ginx snewx]

The last storm (the big QPF event) it had multiple days of me getting a foot and had a run as high as 18" I think.

It's well over-done, as are most of those snowfall products can be. Maybe at 24 hours out its closer to reality, but we aren't 24 hours out.

Any model is wrong days away, it nailed VT totals the day before. If It's overdone day 4 then it's overdone day 1, the parameters do not change.

[moneypitmike]

Looks like I get the cooler air in IA as I fly out on Thursday and then will welcome it back to New England when I fly in from Philly on Friday evening.  Perhaps in the midst of a few flakes and then some additional over the weekend. 

 

Not too bad a look I don't think.

 

33.3/30

[weathafella]

Happy birthday to one of the most respected posters on the boards over the years.love Jerry, he gets away with some stuff though.

It's the age before beauty factor...

[weathafella]

Meanwhile, I got caught in a chilly downpour about 30 minutes ago.

[CT Rain]

anecdote, science please, hard facts, numbers, statistics, you know like you tell me all the time.

Lol ok

Us meteorologists can tell a snow map is bogus pretty easily. Those maps aren't even a close call. Believe what you want though.

[Ginx snewx]

Lol ok

Us meteorologists can tell a snow map is bogus pretty easily. Those maps aren't even a close call. Believe what you want though.

Lol on you, I never said I believe either way, anecdotes don't cut it. Anecdotaly they have been good at times, blizz 13, March retro, been bad at times. Just looking for facts

[TauntonBlizzard2013]

Down pouring here still.

[Ginx snewx]

GFS looks very enticing. Getting excited for this setup.

[ORH_wxman]

anecdote, science please, hard facts, numbers, statistics, you know like you tell me all the time.

 

 

The wxbell snow maps do not support soundings from the Euro grid. I think the wxbell snow algorithm is quite crude and probably needs refining.

[Typhoon Tip]

Interesting appeal by the GFS and some of the other ..perhaps lesser reliant model types, re the boundary south, with periodic waves spreading overrunning across next weekend.   

 

I don't see this week a "torch" or whatever ...  It appears it would transiently warm at best Thursday and Friday, but it also depends on the guidance one is using. The GFS' displaces the boundary SE of our region early in the game and the Euro's belated passage until early Friday, allows for a balmy day ( I think that's suspect ).   Otherwise much of the time appears seasonal ... maybe slightly above, but not 'warm'

 

Just at a glance some impressive EPO-related cold loading takes/took place N and -30C and lower NW Territory on a lot of guidance is impressive -- though not sure how much below normal that is for that region, it doesn't matter;  it's a hefty source for having a NW mid level flow in Canada.   

[Ginx snewx]

Euro Ens are darn cold post fropo days 6-10. 850s -8 to -12

[N. OF PIKE]

Is black ice or ice on roads expected to be an issue anywhere tmrw am? Leavin at 530 for work thru woburn stoneham wakefield .

[weathafella]

GFS has the PV rollling around James Bay.  Lett did that.

[Met1985]

It's the age before beauty factor...

Happy birthday Jerry! I always come here to read about some great info on the pattern upcoming from the  mets up here and  I love your passion for snow man that is great.

[OceanStWx]

Always read on here the Wxbell Euro snow maps are wrong, seems purely anecdotal. Rather than recording Kevs totals somebody should do an analysis for 24 hours before a snow storm, final totals versus Wxbell Euro output. Right now it's pure anecdote and the popular line.

 

One problem I see is that you have two options, either the run total snow or the snow depth product. If you use run total, it's obviously including previous snow that the model forecast. If you use snow depth you have to infer what fell to get those values, plus you have no idea what the model may have melted off in that time.

 

Plus WeatherBell doesn't have any data on how it's produced. I search the site and the forum without any luck. Given their 6 hour time steps, I'm left to assume they are averaging over that time step and spitting out a snow amount. We well know that in a SWFE that averaging over 6 hours can be plenty of time to have the atmosphere warm and change ptype.

 

To be fair I'm not sure how AWIPS does it either, but I don't bother with model snow forecasts. I prefer to get the QPF close to right and work snowfall out in my grids hour by hour. I get a more accurate sense of snowfall and ice accumulations that way. In most cases we convert those hourly totals back to 6 hourly, and those go to the website.

[OceanStWx]

Thanks. Yeah I think people hear favorable and think automatic snow, but then if it doesn't happen..it's always a fail. However, if we discuss that even though it's "favorable" snow still may not happen...we sound wishy-washy and unsure. The fact of the matter is, we aren't totally sure and it's difficult to convey probability. A pattern like this may work out 6 or 7 out of 10 times...but who's to say where this ends up?  My gut is that I do feel 1 maybe 2 deals are in the cards from that 7-15 timeframe...but I can't say if it's all snow or not. There is a low prob it is cold and dry..but my feeling isn't sold on a totally dry deal.

 

Isn't that the biggest problem though? What is a fail? If you say a pattern is favorable and CON gets 25" this month but ORH whiffs is that a fail because Will's backyard saw a favorable pattern produce nothing? What about if ORH gets 25" and PVD 0"? Someone will always be unhappy and call the pattern a bust.

 

People need to realize that when we discuss patterns that we have some skill when it comes to temps, precip, and snowfall. In that order. It's a lot easier to infer temps from a forecast pattern, but we can also correlate to precip as well. However, those precip producers are too small a scale to be seen with ensembles. So to get snowfall right not only do you need the right temps, but you need to resolve individual shortwaves. Good luck at day 15. Just be happy that temps look cool enough that we have chances.

[tmagan]

Interesting appeal by the GFS and some of the other ..perhaps lesser reliant model types, re the boundary south, with periodic waves spreading overrunning across next weekend.   

 

I don't see this week a "torch" or whatever ...  It appears it would transiently warm at best Thursday and Friday, but it also depends on the guidance one is using. The GFS' displaces the boundary SE of our region early in the game and the Euro's belated passage until early Friday, allows for a balmy day ( I think that's suspect ).   Otherwise much of the time appears seasonal ... maybe slightly above, but not 'warm'

 

Just at a glance some impressive EPO-related cold loading takes/took place N and -30C and lower NW Territory on a lot of guidance is impressive -- though not sure how much below normal that is for that region, it doesn't matter;  it's a hefty source for having a NW mid level flow in Canada.   

The GFS MEX has Havre, Montana at ten degrees below zero or lower for virtually all of Thursday and Friday, how often does that occur during the first week of December there?

[OceanStWx]

The GFS MEX has Havre, Montana at ten degrees below zero or lower for virtually all of Thursday and Friday, how often does that occur during the first week of December there?

 

Definitely more common to see sub-zero low temps there, but a high below 0 this time of year has happened only a handful of times in the last hundred or so years on those calendar days.

[CoastalWx]

Isn't that the biggest problem though? What is a fail? If you say a pattern is favorable and CON gets 25" this month but ORH whiffs is that a fail because Will's backyard saw a favorable pattern produce nothing? What about if ORH gets 25" and PVD 0"? Someone will always be unhappy and call the pattern a bust.

People need to realize that when we discuss patterns that we have some skill when it comes to temps, precip, and snowfall. In that order. It's a lot easier to infer temps from a forecast pattern, but we can also correlate to precip as well. However, those precip producers are too small a scale to be seen with ensembles. So to get snowfall right not only do you need the right temps, but you need to resolve individual shortwaves. Good luck at day 15. Just be happy that temps look cool enough that we have chances.

Yep you hit the nail on this head, but weenies only think IMBY so if it doesn't happen there, it's a fail. It's not easy to convey all those aspects you bring up although we do out best.

[powderfreak]

Yep you hit the nail on this head, but weenies only think IMBY so if it doesn't happen there, it's a fail. It's not easy to convey all those aspects you bring up although we do out best.

Your SWFE is still there on the 00z ECM for a week from now. Looked like not much fan fare over the weekend with that over-running along the polar boundary, although some spots in both NNE/SNE may be able to end as a little wet snow or sleet. Hard to tell exactly on the wunderground graphics.

[Damage In Tolland]

As some on here discussed...the SE ridge will not be denied and Euro takes away snow/ice for the mid atlantic and brings it up here Dec 9..That looks like a decent storm

[powderfreak]

As some on here discussed...the SE ridge will not be denied and Euro takes away snow/ice for the mid atlantic and brings it up here Dec 9..That looks like a decent storm

 

Keep  moving it north?

 

[CoastalWx]

Interesting 11-15 day. At first glance you'd think the euro ensembles look good with great dateline ridging and ridging into Greenland, but the cold is back near the Canadian front range ad there is just enough troughing in the plains to force some ridging in the east.  It's really a dicey pattern because a few hundred miles makes all the difference and good luck figuring that out when you are two weeks or so away. GEFS look a little more east with the ridging and less of a trough in the eastern GOA. I thought the ensembles looked a bit better, but I'm still concerned about the cold being locked in Canada on the euro ensembles. I think we can work with the GEFS..hopefully they compromise.

[heavy_wx]

Interesting 11-15 day. At first glance you'd think the euro ensembles look good with great dateline ridging and ridging into Greenland, but the cold is back near the Canadian front range ad there is just enough troughing in the plains to force some ridging in the east.  It's really a dicey pattern because a few hundred miles makes all the difference and good luck figuring that out when you are two weeks or so away. GEFS look a little more east with the ridging and less of a trough in the eastern GOA. I thought the ensembles looked a bit better, but I'm still concerned about the cold being locked in Canada on the euro ensembles. I think we can work with the GEFS..hopefully they compromise.

 

The main lobe of the stratospheric polar vortex looks like it moves from the north pole to northern Canada/Greenland by day 10 on the Euro. The position of the PV at 500 hPa is similar based on the day 10 Euro ensemble mean.

 

 

That would appear to be more favorable as far as keeping colder air nearby but any trough over the central US could warm things in the east as you mentioned.

[weatherwiz]

Interesting 11-15 day. At first glance you'd think the euro ensembles look good with great dateline ridging and ridging into Greenland, but the cold is back near the Canadian front range ad there is just enough troughing in the plains to force some ridging in the east.  It's really a dicey pattern because a few hundred miles makes all the difference and good luck figuring that out when you are two weeks or so away. GEFS look a little more east with the ridging and less of a trough in the eastern GOA. I thought the ensembles looked a bit better, but I'm still concerned about the cold being locked in Canada on the euro ensembles. I think we can work with the GEFS..hopefully they compromise.

 

The exact position of the troughing/ridging will certainly be key but at this range it's really nice to see that there is potential out there.  We'd also have to watch that area of high pressure (for the 8-9th) as if it ends up being stronger than modeled that could certainly be a positive for us.

[ORH_wxman]

Keep  moving it north?

 

 

 

 

That's the preceding wave for the end of this week. The GGEM has the 12/9 wave offshore well south

[40/70 Benchmark]

Yep you hit the nail on this head, but weenies only think IMBY so if it doesn't happen there, it's a fail. It's not easy to convey all those aspects you bring up although we do out best.

Well, one must also consider the what exactly the term "fail" entails; is it really an idictment of the forecaster, or of the pattern's ability to deliver the goods at any given locale?? 

 

I know of some mets ( one in particular) who are a bit on the defensive side, which seems to be a trait endemic to this profession given the inexact nature of it, and tend to overreact when faced with public consternation.

I think this is even more prevalent on this particular medium because the stakes are higher, owed to an elevated emotional investment of both sides, thus both parties are more prone to project/misdirect their displeasure towards each other when forced to endure a 32.00000000001 rainer, or a cold, biting cirrus shield.

 

The average hobbyist/poster is more likely to blame the met as a byproduct of frustration, despite being consciously aware of the fact that snowfall in their BY was a casualty of a minescule, meteorological nuance within a sea of chaos. The forecaster, pissed himself that it didn't snow, and already on guard, sensitive to a perceived misconception on the part of the masses regarding his/her forecating ability, is eager to boisterously convey the complexity of this grossly inexact science that the world knows as simply "forecasting".

 

The issue is more a manifestation of folks' psychological maladaptations, than it is a misunderstanding of how chaotic our atmosphere is, and accordingly, how malleable the sensitve weather is in Joe-$hit-the-rag-weenie's BY at any given microsecond.

[Tropopause_Fold]

Interesting 11-15 day. At first glance you'd think the euro ensembles look good with great dateline ridging and ridging into Greenland, but the cold is back near the Canadian front range ad there is just enough troughing in the plains to force some ridging in the east.  It's really a dicey pattern because a few hundred miles makes all the difference and good luck figuring that out when you are two weeks or so away. GEFS look a little more east with the ridging and less of a trough in the eastern GOA. I thought the ensembles looked a bit better, but I'm still concerned about the cold being locked in Canada on the euro ensembles. I think we can work with the GEFS..hopefully they compromise.

ec ens are close to getting the cold air down into the lower 48 in that period but just not quite enough of a southward push. so instead canada is in the icebox. the height rises from Scandinavia into W greenland are promising but we need more than that. 

 

i agree it's pretty dicey. you could argue solid points for both warm or cold dominating at our latitude.

 

verbatim, seems like the euro ens are still fairly mild and the mean ll stearing flow across the conus is WSW. 

[40/70 Benchmark]

ec ens are close to getting the cold air down into the lower 48 in that period but just not quite enough of a southward push. so instead canada is in the icebox. the height rises from Scandinavia into W greenland are promising but we need more than that. 

 

i agree it's pretty dicey. you could argue solid points for both warm or cold dominating at our latitude.

 

verbatim, seems like the euro ens are still fairly mild and the mean ll stearing flow across the conus is WSW. 

 This is going to seem simplistic because it is...hopefully not overly so, but I don't see this evolving into a truly hopeless pattern anytime soon at this latitude because there is in fact an abundance of cold on this side of the globe. How long do we search for the mechanism to drive it into our fannies is the million dollar question.

[powderfreak]

Well, one must also consider the what exactly the term "fail" entails; is it really an idictment of the forecaster, or of the pattern's ability to deliver the goods at any given locale??

I know of some mets ( one in particular) who are a bit on the defensive side, which seems to be a trait endemic to this profession given the inexact nature of it, and tend to overreact when faced with public consternation.

I think this is even more prevalent on this particular medium because the stakes are higher, owed to an elevated emotional investment of both sides, thus both parties are more prone to project/misdirect their displeasure towards each other when forced to endure a 32.00000000001 rainer, or a cold, biting cirrus shield.

The average hobbyist/poster is more likely to blame the met as a byproduct of frustration, despite being consciously aware of the fact that snowfall in their BY was a casualty of a minescule, meteorological nuance within a sea of chaos. The forecaster, pissed himself that it didn't snow, and already on guard, sensitive to a perceived misconception on the part of the masses regarding his/her forecating ability, is eager to boisterously convey the complexity of this grossly inexact science that the world knows as simply "forecasting".

The issue is more a manifestation of folks' psychological maladaptations, than it is a misunderstanding of how chaotic our atmosphere is, and accordingly, how malleable the sensitve weather is in Joe-$hit-the-rag-weenie's BY at any given microsecond.

perfectly stated. It's the emotional investment in snow by everyone which leads to the issues. No one cares if someone misses a forecast in May and only get 0.41" of rain instead of 0.94"....but people sure as h*ll care if they get 4" of snow when they were thinking 8-10.