January 2016 Pattern Disco

[mahk_webstah]

There really isn't a big Archambault signal...NAO stays positive mostly until really late in the period and the PNA rises early on but then stays there.

 

We shift colder in the means with perhaps a relaxation for a day or two around 1/5-1/7...but storminess may be more likely after the first week of the month.

PerhAps we stay dry till past the 7th but that seems a long time. Maybe the relax produces a bit. Grasping art straws but thanks for the explanation

[OSUmetstud]

Hence why westerly flow over the Berks is terrible. You can't just modify a deep layer cold airmass from conduction of heat over a small area of water.

Id personally bet latent heat release is a bigger contribution than sensible. Well mixed boundary layers dont warm much sensibly from the lakes.

However, nw flow was the ideal direction for cold in buf. Way more so than west or southwest.

[Ginx snewx]

Cohens PV model is performing very well this year.

[ORH_wxman]

Cohens PV model is performing very well this year.

 

That monster Kara block basically slices the PV into two halves and they get shoved on opposite side of the NH. Pretty impressive actually to loop the ensembles. It is even severely stretched up at 50-100mb.

[codfishsnowman]

Dr Greg on TWC says its a 50/50 shot of a cold pattern....hes says it will def be cooler but not necc cold. He showed the spaghetti plots and he said the members are evenly split

[codfishsnowman]

That seems odd that they dont want to alarm the public, must be bc of all the severe weather recently

[dmillz25]

Dr Greg on TWC says its a 50/50 shot of a cold pattern....hes says it will def be cooler but not necc cold. He showed the spaghetti plots and he said the members are evenly split

Postel? And yeah of course they are calling for it to be 50/50 because their forecast calls for a warmer than average winter.

[SnowGoose69]

Postel? And yeah of course they are calling for it to be 50/50 because their forecast calls for a warmer than average winter.

Yeah it's way more than 50/50. Last night 10 of the 12 GFS members at 300-384 had a massive trof in the east. And only 1 of the 2 that didn't had a pattern that was remotely mild. The models definitely rushed the change a bit. I've felt the 10th onward was the best shot south of SNE. Many models and ensembles initially thought we could get it by the 3rd or 4th but were likely a week too early.

[Drz1111]

The Great Lakes are not a huge area filled with water. Maybe if you had a small pocket of cold right over the lakes, but air masses are large and would only get an influence from more westerly flow. When you look at the air masses that modify on west flow, it's usually from downsloping as the greatest influence. 850 temps won't modify much and you can actually lose the lake modifying influence as you move east, just like you would with a chinook wind.

I think you are confusing direct heating with latent heat.  The lakes don't modify temp that much but that add a ton of moisture to cold, dry air, which is then lifted and condensed over the Tug Hill, Catskills, Greens, Berks, etc.  It's that latent heat release that "warms" New England on a westerly flow.  It's still colder than the preceeding airmass, normally (given that those preceeding airmasses are generally maritime or _{tropical), so you get CAA on a W or NW flow and its a cold downslope, but that doesn't mean its not warmed by latent heat release.}

 

_{Put differently, given that elevations on the west sides of the NE mountains are ~500ft or less in pretty much all directions, latent heat release has to be the primary reason that the coast is warmer on W or NW winds than inland locations at similar elevations.} 

 

_{If there was a large, warm plateau near us that a ridge could sit over, then you might have a point that dry adiabatic warming (plus insolation on the plateau) would be enough to warm the coast - i.e., akin to a Santa Ana (which isn't a Fohn wind because its not warmed by latent heat release, it's dry adiabatic and warmed up in the Mojave and Southern Great Basin by insolation warming the ground which warms the airmass (relatively), so that a cool airmass that warms to 65 degree in Lancaster, CA (elevation 2350) downslopes to 77 in Malibu.  But we don't have a high desert plateau nearby, and that's not how we warm.}

 

_{Put differently - a parcel of air that never reaches saturation does not warm going up and down over a mountain range.  Most of our arctic airmasses are bone dry because they've already partially modified before they hit the Lower 48.  If not for the lakes, they'd go up, down, modify a little more bc of the trajectory over lower-latitude ground, and but fundamentally wouldn't change from origin to here.  The lakes are what modify those airmasses meaningfully.} 

[TheCloser24]

FWIW, 12z OP GFS shows an impressive west based -NAO mid month.

[Typhoon Tip]

I think you are confusing direct heating with latent heat.  The lakes don't modify temp that much but that add a ton of moisture to cold, dry air, which is then lifted and condensed over the Tug Hill, Catskills, Greens, Berks, etc.  It's that latent heat release that "warms" New England on a westerly flow.  It's still colder than the preceeding airmass, normally (given that those preceeding airmasses are generally maritime or _{tropical), so you get CAA on a W or NW flow and its a cold downslope, but that doesn't mean its not warmed by latent heat release.}

 

_{Put differently, given that elevations on the west sides of the NE mountains are ~500ft or less in pretty much all directions, latent heat release has to be the primary reason that the coast is warmer on W or NW winds than inland locations at similar elevations.} 

 

_{If there was a large, warm plateau near us that a ridge could sit over, then you might have a point that dry adiabatic warming (plus insolation on the plateau) would be enough to warm the coast - i.e., akin to a Santa Ana (which isn't a Fohn wind because its not warmed by latent heat release, it's dry adiabatic and warmed up in the Mojave and Southern Great Basin by insolation warming the ground which warms the airmass (relatively), so that a cool airmass that warms to 65 degree in Lancaster, CA (elevation 2350) downslopes to 77 in Malibu.  But we don't have a high desert plateau nearby, and that's not how we warm.}

 

_{Put differently - a parcel of air that never reaches saturation does not warm going up and down over a mountain range.  Most of our arctic airmasses are bone dry because they've already partially modified before they hit the Lower 48.  If not for the lakes, they'd go up, down, modify a little more bc of the trajectory over lower-latitude ground, and but fundamentally wouldn't change from origin to here.  The lakes are what modify those airmasses meaningfully.} 

 

_{I lived in the western lower Michigan the first half of my life and I can tell you ... a 0F Wisconsin air mass has no hope of being 0F after crossing Lake Michigan ... when/if the Lake is relatively free of ice.}   

 

_{Now I don't know what you call that ... but it definitely IS modifying the air mass some how} 

[CoastalWx]

I think you are confusing direct heating with latent heat. The lakes don't modify temp that much but that add a ton of moisture to cold, dry air, which is then lifted and condensed over the Tug Hill, Catskills, Greens, Berks, etc. It's that latent heat release that "warms" New England on a westerly flow. It's still colder than the preceeding airmass, normally (given that those preceeding airmasses are generally maritime or _{tropical), so you get CAA on a W or NW flow and its a cold downslope, but that doesn't mean its not warmed by latent heat release.}

_{Put differently, given that elevations on the west sides of the NE mountains are ~500ft or less in pretty much all directions, latent heat release has to be the primary reason that the coast is warmer on W or NW winds than inland locations at similar elevations.}

_{If there was a large, warm plateau near us that a ridge could sit over, then you might have a point that dry adiabatic warming (plus insolation on the plateau) would be enough to warm the coast - i.e., akin to a Santa Ana (which isn't a Fohn wind because its not warmed by latent heat release, it's dry adiabatic and warmed up in the Mojave and Southern Great Basin by insolation warming the ground which warms the airmass (relatively), so that a cool airmass that warms to 65 degree in Lancaster, CA (elevation 2350) downslopes to 77 in Malibu. But we don't have a high desert plateau nearby, and that's not how we warm.}

_{Put differently - a parcel of air that never reaches saturation does not warm going up and down over a mountain range. Most of our arctic airmasses are bone dry because they've already partially modified before they hit the Lower 48. If not for the lakes, they'd go up, down, modify a little more bc of the trajectory over lower-latitude ground, and but fundamentally wouldn't change from origin to here. The lakes are what modify those airmasses meaningfully.}

_{I know what latent heat is. I talk about tropical forcing all the time. But like Will said, I don't think lake modification is the big reason for the air masses on westerly flow into SNE, modify. Compressional heating can occur when air is not saturated.}

[Damage In Tolland]

Lots of Twitter talk today about no pattern change and transient cold shot this weekend then warmth continues.

[JC-CT]

Lots of Twitter talk today about no pattern change and transient cold shot this weekend then warmth continues.

 

Really? Looks like the pattern is changing to me on the ensembles

[Damage In Tolland]

Really? Looks like the pattern is changing to me on the ensembles

Qyite a few mets aren't convinced it's permanent

[WinterWolf]

I'll listen to the METS and knowledgeable people here, before I believe some of the garbage on Twitter.

[JC-CT]

Qyite a few mets aren't convinced it's permanent

 

Define permanent

[Damage In Tolland]

Define permanent

Like setting in next week. They all agree late month looks good

[SouthCoastMA]

Like setting in next week. They all agree late month looks good

I've read the pattern gets really good between 1/7-1/14, with a relaxation prior to that for a few days next week.

[Ginx snewx]

I've read the pattern gets really good between 1/7-1/14, with a relaxation prior to that for a few days next week.

have no idea where Kev gets this stuff. I mean just look at the Euro Ens, just a classic East Coast Storm setup Jan 11-13 - way BN heights, 850s and a cranking STJ. Cant look any better really.

[Ginx snewx]

Like setting in next week. They all agree late month looks good

so a couple of days transition period before an excellent period is your worry? :weenie:

[WinterWolf]

Typical Twitter BS..that's all that garbage is. Can't stand social media. One never gets the real info on sites like that.

[Typhoon Tip]

Kevin likes to create straw-man arguments ... just to probe and taunt others/mets etc to talking about it. 

 

I've heard the opposite on social media, ... a growing meme that winter is about to finally arrive.  

[Damage In Tolland]

Just going by a discussion between a bunch of mets I saw on Twitter. Some in Jersey, some in energy sector etc. no one was ruling it out,just expressing ideas that it may not lock in

[weathafella]

Well Kevin should post what he's reading. The first 10-14 days of January is not a cold pattern to me either but thereafter look out!

[CT Rain]

Just going by a discussion between a bunch of mets I saw on Twitter. Some in Jersey, some in energy sector etc. no one was ruling it out,just expressing ideas that it may not lock in

You're also not very good with reading comprehension we've noticed. Stick to posting your own thoughts and let mets post themselves if they want to.

[Damage In Tolland]

You're also not very good with reading comprehension we've noticed. Stick to posting your own thoughts and let mets post themselves if they want to.

None of them post here. It's not a big deal. Just rehashing their disco

[ORH_wxman]

The initial PNA ridge "folds over" into central Canada, and that's where we warm up a bit at the end of week 1 in January...but after that we reload even bigger it looks pretty damned good for a winter wx pattern.

[Ginx snewx]

Well Kevin should post what he's reading. The first 10-14 days of January is not a cold pattern to me either but thereafter look out!

Mon Tues look cold

[Zeus]

The initial PNA ridge "folds over" into central Canada, and that's where we warm up a bit at the end of week 1 in January...but after that we reload even bigger it looks pretty damned good for a winter wx pattern.

 

Don't call it a pattern. Call it a motif.