I have an idea - let's start a new talking points thread

[Tropopause_Fold]

Oh I was talking about the 180 hour threat lol post-frontal

yeah my bad. i didn't look closely at what you said. i thought you were referencing that 80 knot llj sunday night

[Damage In Tolland]

Looking at this 12z NAM solution over the deep south and southeast for 66 hours out, and look toward Florda: that is a hugely compressible field - meaning, there is almost no resistance at all to dig heights into that area. This may be why we are seeing some of this recent E adjusting.

I covered this a couple days ago, regarding this often hidden factor - it's easy to slip beneath the radar considerations because it is an excruciating albeit important detail, however one that should not be ignored.

At this point the big issue with the GFS/UKMET solutions - and yes Scott, there was a trend E in the Euro (don't get me wrong, Kevin should be liberally made fun of j/k Kev), it just wasn't demonstrative. Lovable Kevin just exaggerates where needed.

Anyway, there is a lack of nascient positive PP N of, or in the area. We really need that to budge back some boundary layer forcing, or we WILL do a primary over, tripple point under type scenario given the blend of the GFS and UKMET.

The fact that the ECM showed the east twitch (uh oh 'it moved') I think also hearkens to the earlier discussion regarding the longitudinal component of the overall domain from off the West Coast to the west Atlantic. There is a hidden W-E coordinate bias in there, and that means that the best trough amplitude as it comes east may do so with a somewhat of a anomalously long wave length (have to remember that these are not immovable objects and that the aspects such as wave-lengths are highly mutable in the atmosphere) relative to the typical R scheme. If the ridge out W pops higher in latitude, we shorten the w-length and the system will avail of this poorly time moderation of the NAO and cut under that circumstance.

Barring that, the combination of a erstwhile SE compressibility prior to the amplitude arriving east of the MV, combined with the limited meridional aspect of the large scale synoptic domain et al really does offer room to nudge this east. I don't feel confident enough of that to go out on a limb and forecast it, but if I were tailoring a forecast for the public these points would and should give rise at least some consternation.

Why deeper concern? Because one thing this synoptic event brings with it is sick gradients pre and post baroclinic translation. I have limited experience using the DGEX Franbenmodel but it's mid range depiction of 5F at ALB while it is 50F on the Cape is staggering, and although that may not verify verbatim the general idea will. Thermal gradient challenged this system shall not be! That has huge implications for threat because you really have big wind potential; there is a going to be some impressive short duration PP changes anyway, which can and does often produce the isollobaric response, but when the gradient is large you do over-turning and mix your llv jets very proficiently. As well, there will be abrupt transition zones where you have ephemeral warmth and mist versus winter harshness across small distances. simply put, a forecaster's nightmare.

As we thought

[Tropopause_Fold]

I wish it wouldn't phase at all, but yeah I agree with that. The euro looked weaker with the Pac energy in the Midwest, but the whole ana thing is a long shot for most of us.

it might be damned if you do, damned if you don't anyway. if it didn't phase...we'd be waiting with a crappy marginal airmass anyway.

[CoastalWx]

Looking at this 12z NAM solution over the deep south and southeast for 66 hours out, and look toward Florda: that is a hugely compressible field - meaning, there is almost no resistance at all to dig heights into that area. This may be why we are seeing some of this recent E adjusting.

I covered this a couple days ago, regarding this often hidden factor - it's easy to slip beneath the radar considerations because it is an excruciating albeit important detail, however one that should not be ignored.

At this point the big issue with the GFS/UKMET solutions - and yes Scott, there was a trend E in the Euro (don't get me wrong, Kevin should be liberally made fun of j/k Kev), it just wasn't demonstrative. Lovable Kevin just exaggerates where needed.

Anyway, there is a lack of nascient positive PP N of, or in the area. We really need that to budge back some boundary layer forcing, or we WILL do a primary over, tripple point under type scenario given the blend of the GFS and UKMET.

The fact that the ECM showed the east twitch (uh oh 'it moved') I think also hearkens to the earlier discussion regarding the longitudinal component of the overall domain from off the West Coast to the west Atlantic. There is a hidden W-E coordinate bias in there, and that means that the best trough amplitude as it comes east may do so with a somewhat of a anomalously long wave length (have to remember that these are not immovable objects and that the aspects such as wave-lengths are highly mutable in the atmosphere) relative to the typical R scheme. If the ridge out W pops higher in latitude, we shorten the w-length and the system will avail of this poorly time moderation of the NAO and cut under that circumstance.

Barring that, the combination of a erstwhile SE compressibility prior to the amplitude arriving east of the MV, combined with the limited meridional aspect of the large scale synoptic domain et al really does offer room to nudge this east. I don't feel confident enough of that to go out on a limb and forecast it, but if I were tailoring a forecast for the public these points would and should give rise at least some consternation.

Why deeper concern? Because one thing this synoptic event brings with it is sick gradients pre and post baroclinic translation. I have limited experience using the DGEX Franbenmodel but it's mid range depiction of 5F at ALB while it is 50F on the Cape is staggering, and although that may not verify verbatim the general idea will. Thermal gradient challenged this system shall not be! That has huge implications for threat because you really have big wind potential; there is a going to be some impressive short duration PP changes anyway, which can and does often produce the isollobaric response, but when the gradient is large you do over-turning and mix your llv jets very proficiently. As well, there will be abrupt transition zones where you have ephemeral warmth and mist versus winter harshness across small distances. simply put, a forecaster's nightmare.

There was no east trend. At 06z Monday, the front was over the Hudson river...same as 12z. The difference is at H5, where the 00z run develops a low and allows backside snow to eastern NY and western NE.

[Typhoon Tip]

I wish it wouldn't phase at all, but yeah I agree with that. The euro looked weaker with the Pac energy in the Midwest, but the whole ana thing is a long shot for most of us.

A Scott -

hm, you know, taken fwiw, my experience with ANA depictions is that it is more like an ensemble spread within a single model run, and really indicates the model is having difficulty resolving cyclogen kinematics within the complexity of the evolving baroclinicity of the given system. In future runs, the given ANA either evaporates, or the model commits to "kinking" boundaries and playing out deterministic cyclogenesis.

That said, obviously ANA events happen though - it's just from my experience they are not typically well-predicted by modeling.

[CT Rain]

yeah my bad. i didn't look closely at what you said. i thought you were referencing that 80 knot llj sunday night

lol that won't mix down... the 80 knot LLJs are a dime a dozen

[Tropopause_Fold]

lol that won't mix down... the 80 knot LLJs are a dime a dozen

yeah i know...that's why i made mention to the direction

[Typhoon Tip]

There was no east trend. At 06z Monday, the front was over the Hudson river...same as 12z. The difference is at H5, where the 00z run develops a low and allows backside snow to eastern NY and western NE.

It is interesting you make this observation; I was using PSU's E-Wall source so perhaps it is for a difference in product coverage. But ... the 12z run yesterday clearly had a stem-wound deep primary over AZO in Michigan, and the 00z never translates the primary through Michigan.

Again, it may be that we have different resolutions at our disposal - if so, oh well. Anyway, the weaker primary also is equally telling, too.

[Typhoon Tip]

As we thought

Eh, based on just sharing a post or two with Scott - sounds more like you guys were arguing about two different things anyway.

[CT Rain]

I wish it wouldn't phase at all, but yeah I agree with that. The euro looked weaker with the Pac energy in the Midwest, but the whole ana thing is a long shot for most of us.

To start getting exciting I think we need the PV to remain detached for as long as possible and keep the Pac energy weaker, strung out, and suppressed. If the thing can wait til the last possible minute to phase and the best forcing remains south and not up the OH River Valley our chances for something increase.

[CT Rain]

yeah i know...that's why i made mention to the direction

At what speed should we get excited about a LLJ? 120 knots? lol

[weathafella]

Witch's titty night on the way.

[Tropopause_Fold]

At what speed should we get excited about a LLJ? 120 knots? lol

for a S or SE flow...yeah probably. LOL.

any other direction on the compass and we'd be boarding up windows a couple times a month.

[CoastalWx]

A Scott -

hm, you know, taken fwiw, my experience with ANA depictions is that it is more like an ensemble spread within a single model run, and really indicates the model is having difficulty resolving cyclogen kinematics within the complexity of the evolving baroclinicity of the given system. In future runs, the given ANA either evaporates, or the model commits to "kinking" boundaries and commits to playing out deterministic cyclogenesis.

That said, obviously ANA event happen though - it's just from my experience they are not typically well-predicted by modeling.

I agree it could happen...I even mentioned it this morning and agree that the flow is compressible across the southeast, meaning the s/w could dig. I just want some more runs to confirm this, because these type of situations just aren't all that common over the east coast, for snow. I'm not being a downer...just want to see more evidence that it is possible. This will probably be a longitude thing if it does happen, so there is hope for Pete and Moneypitmike etc.

[CoastalWx]

To start getting exciting I think we need the PV to remain detached for as long as possible and keep the Pac energy weaker, strung out, and suppressed. If the thing can wait til the last possible minute to phase and the best forcing remains south and not up the OH River Valley our chances for something increase.

Violently agree, that's what the euro hints at.

[CoastalWx]

It is interesting you make this observation; I was using PSU's E-Wall source so perhaps it is for a difference in product coverage. But ... the 12z run yesterday clearly had a stem-wound deep primary over AZO in Michigan, and the 00z never translates the primary through Michigan.

Again, it may be that we have different resolutions at our disposal - if so, oh well. Anyway, the weaker primary also is equally telling, too.

Yeah it actually starts out further se than 12z. What happens is that it eventually responds to the s/w forcing and corrects north, but the southern part of the s/w energy dives se and helps spawn the second low. So, it's kind of weird in that it does start out farther se than the 12z run, but eventually corrects itself...or I should say responds to the forcing from the nrn part of that s/w.

[Typhoon Tip]

To start getting exciting I think we need the PV to remain detached for as long as possible and keep the Pac energy weaker, strung out, and suppressed. If the thing can wait til the last possible minute to phase and the best forcing remains south and not up the OH River Valley our chances for something increase.

lol - obviously your eyes are going to roll when you read this (and rightfully so...) but you'd like the 84 hour NAM depiction.... It argues strongly ...or rather extrapolates is probably a better term, toward a later phase, allowing the southward impulse to gain more east longitude before that subtending PV fragmentation can come down and subsume - this (oy vei) solution would definitely go far toward mending Kevin and Scotts troubled relationship

[CT Rain]

lol - obviously your eyes are going to roll when you read this (and rightfully so...) but you'd like the 84 hour NAM depiction.... It argues strongly ...or rather extrapolates is probably a better term, toward a later phase, allowing the southward impulse to gain more east longitude before that subtending PV fragmentation can come down and subsume - this (oy vei) solution would definitely go far toward mending Kevin and Scotts troubled relationship

lol yeah I saw that too... if we can get everything slower and weaker MAYBE just MAYBE we eek something out

[CoastalWx]

LOL, nah we're good. It's tough because euro products on the web are limited, so the in between things that happen get missed.

[moneypitmike]

Lots of optimistic mets in other threads

The Rochester, NY group is stoked.

Cold. 21.9/9, gusts to 28mph. Even had a few flakes. Trace ftw

[SnowlieSnowstormson]

Hello SNE friends! Thought this would hit close to home for everyone:

[Damage In Tolland]

Hello SNE friends! Thought this would hit close to him for everyone:

LOL. that is about right for most of our svere wx...Nice screen name lol

[Baroclinic Zone]

To start getting exciting I think we need the PV to remain detached for as long as possible and keep the Pac energy weaker, strung out, and suppressed. If the thing can wait til the last possible minute to phase and the best forcing remains south and not up the OH River Valley our chances for something increase.

I agree with this and even than without a 50/50 low to lock in the cold we're at the whim of the track.

[Zeus]

There was no east trend. At 06z Monday, the front was over the Hudson river...same as 12z. The difference is at H5, where the 00z run develops a low and allows backside snow to eastern NY and western NE.

As we thought.

[Damage In Tolland]

As we thought.

There was initially and we explained why

[weathafella]

The Rochester, NY group is stoked.

Cold. 21.9/9, gusts to 28mph. Even had a few flakes. Trace ftw

ROC has had 25 inches of snow during this 1st week of December.

[CoastalWx]

I agree with this and even than without a 50/50 low to lock in the cold we're at the whim of the track.

It's too bad we have a garbage airmass ahead of the low. Even if that low somehow goes south of us, a ton of warmer air would get pulled in. Just loop the 850 temps and you'll see what I mean. However, on the backside...the arctic awaits. The ultimate weenie solution would be for that energy that Ryan, John, and I are referencing to.....have it really dig off the se coast and have the wave develop along it. So in terms of sensible wx, you would have a fropa come through, but then rapidly falling temps and snow develops. That's what the euro has for eastern NY state.

[Zeus]

There was initially and we explained why

I'm going to buy you a dunce cap for Christmas.

[CT Rain]

It's too bad we have a garbage airmass ahead of the low. Even if that low somehow goes south of us, a ton of warmer air would get pulled in. Just loop the 850 temps and you'll see what I mean. However, on the backside...the arctic awaits. The ultimate weenie solution would be for that energy that Ryan, John, and I are referencing to.....have it really dig off the se coast and have the wave develop along it. So in terms of sensible wx, you would have a fropa come through, but then rapidly falling temps and snow develops. That's what the euro has for eastern NY state.

Yup... that would be very very nice lol

If things phase just right there's enough cold lurking to the northwest of the low to make things fun but it's the ultimate threading the needle. No room for error with a garbage airmass in place.

[CT Rain]

I'm going to buy you a dunce cap for Christmas.

You're my new favorite poster