Inverted Trough/ Redeveloper Disco Jan 7-9

[CoastalWx]

AccuCast

the orientation/configuration will be something similar to this with the first surge of instability in the inverted trof. The NAM really had a second surge of instabilty setup from about BOS on north late Saturday into Sunday as second solid shot of strong PVA is whipped around anchored 504dam vortex in PA...which is certainly possible given all the maxes getting whipped around the closed vortex. The GFS shows a similar redevelopment as well...would think AccuMap would need additional coverage of snow in NE Mass/SE NH/Maine at the expense of some of the 3-6 coverage in eastern CT/RI/SE Mass. I really think that the initial surge of instability with the inverted trof will be impressive, and stall out east of NYC in western CT and Hudson Valley. Then redevelop up north with renewed vort max. Again these are details that will prolly change several times from here on out, so maybe I shouldnt waste me time, lol. Have to pass the day with a my first cold of the season some how I guess, lol.

I kind of agree with that. I think that area of se NY and perhap sw CT along the pivot point..may do well. Sometimes where the band initially develops are the winners. It may change, and there is a pretty good bust potential down there, but I could see that.

Question is, what happens up here. I still like my ideas of maybe the orh hills and up through ne mass into sw me, but it's early in the game.

[Damage In Tolland]

I kind of agree with that. I think that area of se NY and perhap sw CT along the pivot point..may do well. Sometimes where the band initially develops are the winners. It may change, and there is a pretty good bust potential down there, but I could see that.

Question is, what happens up here. I still like my ideas of maybe the orh hills and up through ne mass into sw me, but it's early in the game.

Guess where this leaves the screw zone

[Tropopause_Fold]

This thread is starting to suck at an above normal level.

[bobbutts]

Feeling somewhat humbled.. Nothing of value to post (not that my usual post has much value). Would like to just lock in 12z nam and be done with this, but after reading above that seems very unlikely.

[Baroclinic Zone]

Can we stop the my penis is bigger than yours model talk? And get back to figuring out how much snow we're gonna get

Amen Rev!

[CoastalWx]

Feeling somewhat humbled.. Nothing of value to post (not that my usual post has much value). Would like to just lock in 12z nam and be done with this, but after reading above that seems very unlikely.

Honestly, it's probably going to change a few times. Today will probably be the day where we try to narrow the areas that have the best potential, but that's about it.

[40/70 Benchmark]

We are in great shape....general light snow this wknd....possible bomb next week and snowpack for the foreseeable future.

I don't see anything frustrating about that......lets focus on this.

[CoastalWx]

Guess where this leaves the screw zone

Well it could shift east too..just saying I could see that because it makes sense to a point. I don't really care about down there..I'm more worried about here.

[Baroclinic Zone]

Well it could shift east too..just saying I could see that because it makes sense to a point. I don't really care about down there..I'm more worried about here.

As am I. Looks like I may be caught between the inv. trough and coastal redev.

[Clinch Leatherwood]

This thread is starting to suck at an above normal level.

Where were you 90 minutes ago when we had two pages of skiing posts?

At least it's somewhat relevant to the upcoming situation re model talk.

---

NCEP model diagnostic has noted what we're already talking about which is the lack of continuity/weakening of that key feature since 0z. They don't offer an opinion yet on whether or not the change is right but pretty clearly it is.

I'd just like to better understand how it can be getting an init wrong unless something in how it processes data, or the data itself is bad and how much of that is being passed to the CMC and Euro.

[40/70 Benchmark]

Well it could shift east too..just saying I could see that because it makes sense to a point. I don't really care about down there..I'm more worried about here.

Just plan on a festive winter mood and if you hit the 6"snowfall megamillions, then great.

[Tolland Death Band]

Guess where this leaves the screw zone

We are in the screw zone, no getting around it. We'll be lucky to eek out 2" while Fairfield gets 10".

Gold coast winter

[CCPSUSuperstorm2010]

I am feeling good vibes Phil from the trends in the H5 setup around 72-84 hours. As John has mentioned in previous pages, the H5 low strengthens now as it passes through our longitude, however the NAM tracks it over our heads instead of to the south of the region. Intense vorticity roads the base of the vortex and moves right through the Cape and Islands, perhaps a reason the lack of QPF over our area. However if this can shift southward in time we could be dealing with an actual storm say in another 24 hour span of model runs. The speed of the lead shortwave energy at hour 30 over our region on the 12z NAM and the progressive trends in the northern stream energy at hour 30 over SD will greatly determine if SE MA and RI can get in on any of the fun this weekend. Right now timing of the passage of the H5 low continues to be problematic for the models. The strength and track will always be a problem with a highly anomalous H5 pattern, however in regards to this setup if this tracks over or just south of the 40n latitude, and actually intensifies as the NAM shows from 510dm to 504dm, we could have an intense surface low not so far to the southeast of ACK. however NAM currently shows this low over the Gulf of Maine at hour 72.

[nutmegfriar]

Just plan on a festive winter mood and if you hit the 6"snowfall megamillions, then great.

I agree. I'm hoping to have snow falling (tail end) while watching the Jets suffer the Agony of Defeet.

[CCPSUSuperstorm2010]

Now that the 00z CMC shows CC and SE MA and RI in the jackpot of the inverted trough, I expect it now to be in eastern coastal ME/NH/NE MA Friday evening through Saturday and in SE NY/Long Island/SW CT and most of central NY as well as maybe NYC, although they may be too far to the southwest.

[Clinch Leatherwood]

I am feeling good vibes Phil from the trends in the H5 setup around 72-84 hours. As John has mentioned in previous pages, the H5 low strengthens now as it passes through our longitude, however the NAM tracks it over our heads instead of to the south of the region. Intense vorticity roads the base of the vortex and moves right through the Cape and Islands, perhaps a reason the lack of QPF over our area. However if this can shift southward in time we could be dealing with an actual storm say in another 24 hour span of model runs. The speed of the lead shortwave energy at hour 30 over our region on the 12z NAM and the progressive trends in the northern stream energy at hour 30 over SD will greatly determine if SE MA and RI can get in on any of the fun this weekend. Right now timing of the passage of the H5 low continues to be problematic for the models. The strength and track will always be a problem with a highly anomalous H5 pattern, however in regards to this setup if this tracks over or just south of the 40n latitude, and actually intensifies as the NAM shows from 510dm to 504dm, we could have an intense surface low not so far to the southeast of ACK. however NAM currently shows this low over the Gulf of Maine at hour 72.

Problem is the moisture has been booted not once but twice.

We can hope for an eventual later evolution because we're certainly not getting consistency out of the GFS as it would appear.

[Clinch Leatherwood]

LOL at the NC system at 36 hours. Been hinting for a few runs.

Full blown closed contour low over western NC?

[Damage In Tolland]

Well it could shift east too..just saying I could see that because it makes sense to a point. I don't really care about down there..I'm more worried about here.

i'd just like 2-4..I'd be completely happy with that..snow on the ground..cold temps..and then hopefully Big poppa comes calling next week just deliver me 2-4

[CoastalWx]

Looks like Tip past out on the keyboard, talking about compressible flow.

[dendrite]

Where were you 90 minutes ago when we had two pages of skiing posts?

At least it's somewhat relevant to the upcoming situation re model talk.

No one should be afraid to report posts when they get excessively off topic for a prolonged period. I've tried to be extra lenient with the moderating in these threads, but I've always asked everyone to do their best to keep it mostly to weather (and on topic) when a threat is imminent or occurring.

If people want to get off topic about skiing, sports, or something try to keep it to the general obs thread.

[Damage In Tolland]

Now that the 00z CMC shows CC and SE MA and RI in the jackpot of the inverted trough, I expect it now to be in eastern coastal ME/NH/NE MA Friday evening through Saturday and in SE NY/Long Island/SW CT and most of central NY as well as maybe NYC, although they may be too far to the southwest.

Only problem is it didn't show that. it had .50 from HFD North. not your area

[Typhoon Tip]

Ray, gen thumb: < or = 580dm over MIA, and balanced geostrophic wind speed < or = 45kts, prior to trough passing east of 100W (for standard wave lengths; size and strength can skew).

The problem here is that the pattern at large can mask any inhibitory nature/characteristic of a given flow. Moreover, these values above are not thesis tested, but is based on 15 years of modeling behavior versus verificaiton - existentially derived assumptions do carry some merit, but it should be formally written and refereed.

That said, part of the reason why March 2001 skrewed the pooch in the MA is because all that negative anomaly was squeezed out E and could not detonate cyclogenesis sooner, because the flow was so compressed under that deep anomaly. Prior to that SPV subsuming into the OV, the heights and wind speeds were in violation of the above ...exceeding 582dm over MIA and having balanced winds moving along well above 50kts (this is just one example)

What happens in conceptual terms: if the arriving troughs wind max's dy/dx (where dx is the balanced geostrophic velocity) is not above a certain threshold, they will fail to excite necessary warm air advection response in the critical ~700mb level (depending on the given set-ups sigma level). That warm ingest is the fuel for pseudo-adiabatic latent heat release that adds to synoptic scale lift - when DP advection gets underway, this then rides up and over the baroclinic axis where it forms cloud material (looK up baroclinic leaf for fun), signaling this process is taking place.

As a result in March 2001, the best WAA came off the Atlantic at higher latitudes, where by nature of the flow there was less compression and better dy/dx, and it ended up being a central New England sort of affair (along and N of Rt poop up in Mass, too, I believe)

[CoastalWx]

The other thing too people, is that ratios will be quite good. This will not be 10:1, so don't think 0.2" = 2" of snow.

[Clinch Leatherwood]

No one should be afraid to report posts when they get excessively off topic for a prolonged period. I've tried to be extra lenient with the moderating in these threads, but I've always asked everyone to do their best to keep it mostly to weather (and on topic) when a threat is imminent or occurring.

If people want to get off topic about skiing, sports, or something try to keep it to the general obs thread.

I don't mind at all and I'd never report a post, to me that's childish. I'm a grown man I have the ability to ignore what's written. These guys are friends if they want to talk about skiing or whatever that's cool. I think everyone here knows when to say when and right now 2 days out....no harm no foul.

I think the idea that a thread with this many members can stay on T is pretty impossible and complaining about it is dorky.

BUT I do appreciate that you give everyone a long leash and are willing to listen to those that do complain, that's cool

GFS is off onto a totally new solution.

Nothing like a new Hatteras low thrown in.

[Wx4cast]

I kind of agree with that. I think that area of se NY and perhap sw CT along the pivot point..may do well. Sometimes where the band initially develops are the winners. It may change, and there is a pretty good bust potential down there, but I could see that.

Question is, what happens up here. I still like my ideas of maybe the orh hills and up through ne mass into sw me, but it's early in the game.

I like your reasoning and Gibbs' too.

Here's what we're thinking for now but like Gibbs stated it will probably change a few times between now and tomorrow:

[snywx]

The other thing too people, is that ratios will be quite good. This will not be 10:1, so don't think 0.2" = 2" of snow.

I would think 15:1 is a good starting point. I dont see ratios any higher then 10:1 or 12:1 on the immediate coast.

[Clinch Leatherwood]

So per the GFS we miss(ed) the first storm, will miss the second, and miss the third probably strong system per it's evolution.

By 48 we're all dry slotted.

[Clinch Leatherwood]

54 it's still too far out to sea, nice big donut hole over most all of SNE.

[subdude]

I kind of agree with that. I think that area of se NY and perhap sw CT along the pivot point..may do well. Sometimes where the band initially develops are the winners. It may change, and there is a pretty good bust potential down there, but I could see that.

Question is, what happens up here. I still like my ideas of maybe the orh hills and up through ne mass into sw me, but it's early in the game.

I hope your prediction verifies, I would be happy to see 4-6" in the ORH Hills out of this storm.

[CCPSUSuperstorm2010]

Only problem is it didn't show that. it had .50 from HFD North. not your area

Really, my bad.

Ray, gen thumb: < or = 580dm over MIA, and balanced geostrophic wind speed < or = 45kts, prior to trough passing east of 100W (for standard wave lengths; size and strength can skew).

The problem here is that the pattern at large can mask any inhibitory nature/characteristic of a given flow. Moreover, these values above are not thesis tested, but is based on 15 years of modeling behavior versus verificaiton - existentially derived assumptions do carry some merit, but it should be formally written and refereed.

That said, part of the reason why March 2001 skrewed the pooch in the MA is because all that negative anomaly was squeezed out E and could not detonate cyclogenesis sooner, because the flow was so compressed under that deep anomaly. Prior to that SPV subsuming into the OV, the heights and wind speeds were in violation of the above ...exceeding 582dm over MIA and having balanced winds moving along well above 50kts (this is just one example)

What happens in conceptual terms: if the arriving troughs wind max's dy/dx (where dx is the balanced geostrophic velocity) is not above a certain threshold, they will fail to excite necessary warm air advection response in the critical ~700mb level (depending on the given set-ups sigma level). That warm ingest is the fuel for pseudo-adiabatic latent heat release that adds to synoptic scale lift - when DP advection gets underway, this then rides up and over the baroclinic axis where it forms cloud material (looK up baroclinic leaf for fun), signaling this process is taking place.

As a result in March 2001, the best WAA came off the Atlantic at higher latitudes, where by nature of the flow there was less compression and better dy/dx, and it ended up being a central New England sort of affair (along and N of Rt poop up in Mass, too, I believe)

Great post John. It would appear that our main problem is the amount of shortwaves in the upper level trough. Models cannot depict which one will become dominant if any at all. Right now our best chance at accumulating snowfall is to get the H5 low to intensify as it passes to our south. If not then most of SNE will not see any snowfall until next WED maybe, although I will be gone by then in San Antonio, TX. Right now my best chance to see the models trend for the better with the H5 low passage. 00z EURO showed this to a degree, but it still tracked the low overtop of SNE. Still some time to resolve this pattern and determine if the right trend continues with the third surface low. It appears that the areas I have previously mentioned in my last post would be getting the heaviest snows from this inverted mess.