Inverted Trough/ Redeveloper Disco Jan 7-9

[ctsnowstorm628]

It doesn't look good for verifying warning totals. Maybe 0.30ish.

Its dangerous to issue watches in these types of setups.

what would ratios be like?

[40/70 Benchmark]

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)

Thanks, John....

[Clinch Leatherwood]

How close does it come to me?

Close enough that's it's a much larger concern than the goofy trough if it's a legitimate feature.

[Tropopause_Fold]

It doesn't look good for verifying warning totals. Maybe 0.30ish.

Its dangerous to issue watches in these types of setups.

as a whole...when we look at the entire region, i don't think the forecast is very challenging...it's when we try to break it down into specific locales that this one is an ass pain. i'd still place a relative jackpot someplace in the high spots inside an ORH to EEH to ASH triangle. warning criteria there with advisory type snows for most everyone else?

[HIPPYVALLEY]

It doesn't look good for verifying warning totals. Maybe 0.30ish.

Its dangerous to issue watches in these types of setups.

And over a significant area. WSW goes from the Ct coast up to Windham Co. VT. Big bust potential to the point of Warning criteria snows verify nowhere on that map.

[40/70 Benchmark]

Pedestrian event no more no less

I'm fine with it.

Trying not to litter the threads, myself, but others complaining doesn't really bother me.

[cpickett79]

It doesn't look good for verifying warning totals. Maybe 0.30ish.

Its dangerous to issue watches in these types of setups.

the watch warning criteria really doesn't fit well with a dual mandate of accuracy and preparing people for potential dangerous travel conditons when it comes to a NORLUN event.

but if i was of the opinion that Some areas would see heavy snow in my forecast area and i was only catering to the general population i would say TO HELL WITH the defintion for a warning and look on the practical side .....well the majority prob wont get warning criteria but those who will will be thankful and prepared a warning was issues and those that don't ....and they are the people that say "the weather man is always wrong" anyway.

But if you have clients who have plowing demands and schedules to set up this is just a real nightmare forecast. i mean they only put up watches anyhow.

[Clinch Leatherwood]

It's a watch not a warning not sure how it has bust potential

[nutmegfriar]

It's a watch not a warning not sure how it has bust potential

I agree and I am not sure why erring on the side of caution is a bad thing for the NWS.

[dryslot]

I'm fine with it.

Trying not to litter the threads, myself, but others complaining doesn't really bother me.

Yes, With decent ratios 3-5" maybe 4-8" nothing to sneez at.

As Bill B says, It is what it is..

[ORH_wxman]

the watch warning criteria really doesn't fit well with a dual mandate of accuracy and preparing people for potential dangerous travel conditons when it comes to a NORLUN event.

but if i was of the opinion that Some areas would see heavy snow in my forecast area and i was only catering to the general population i would say TO HELL WITH the defintion for a warning and look on the practical side .....well the majority prob wont get warning criteria but those who will will be thankful and prepared a warning was issues and those that don't ....and they are the people that say "the weather man is always wrong" anyway.

But if you have clients who have plowing demands and schedules to set up this is just a real nightmare forecast. i mean they only put up watches anyhow.

Watches tend to set the expectation of a big snow...so that's why I think they are a bit bullish. A lot of people won't be seeing big snow. But I understand the bust potential in this....and also understand they aren't warnings.

But regardless...not my call and not my problem. I've told my clients that a plowable snow is likely, but most likely the 2-4" variety.

[HIPPYVALLEY]

It's a watch not a warning not sure how it has bust potential

I was just about to post that. I've seen many watches turn into non-events.

[leesun]

With high ratios, that IMO warrants a WSW

Edit- not taking duration into concern

It doesn't look good for verifying warning totals. Maybe 0.30ish.

Its dangerous to issue watches in these types of setups.

[CoastalWx]

With high ratios, that IMO warrants a WSW

Edit- not taking duration into concern

High ratios allow it to be easier on the roads. With temps in the upper 20's...throw a little salt on the main roads, and they should be ok. Now if you get caught in band of s+..that may be different.

[dryslot]

I wish I could see it, what about the Portland, ME area?

.25" qpf

[leesun]

Plus, people that may live in an area that gets sub warning snows may be traveling in areas that does. It' a no win situation. Think it's better to have the watch than not to have it

the watch warning criteria really doesn't fit well with a dual mandate of accuracy and preparing people for potential dangerous travel conditons when it comes to a NORLUN event.

but if i was of the opinion that Some areas would see heavy snow in my forecast area and i was only catering to the general population i would say TO HELL WITH the defintion for a warning and look on the practical side .....well the majority prob wont get warning criteria but those who will will be thankful and prepared a warning was issues and those that don't ....and they are the people that say "the weather man is always wrong" anyway.

But if you have clients who have plowing demands and schedules to set up this is just a real nightmare forecast. i mean they only put up watches anyhow.

[rivers]

well upton did specify in this mornings discussion that when and where the trough sets up they will have a handle on who goes to warning and the rest of the area under advisory.so def not looking for the entire area going to warning .

[mattlacroix4]

.25" qpf

So I could get anywhere from 1-3, 2-4, 3-6, 4-8, 5-10? I will try and 'count' on the average of 3-6.

[moneypitmike]

the intersting thing to watch will be who will be the one under a WSW forecast to get X inches of snow and ends up with 80% Less and jumps off the cliff.

i don't think i will be under any sort of modeled jackpot or warning away from the coast and away from the E slope......but i hope MPM scores on this one....otherwise he will probably be biting his nails drinking 24 diet cokes as we watches the bands set up 15 miles to his west.

Lol. I'll actually be catching glimpses from my hotel in Annapolis wondering if it will get up here. Hoepfully, Chris, Pete, and others out in GC can keep tabs on how things are accumulating.

[cpickett79]

interesting little finger of clouds stretching NW to about the s. coast of Central long island from the offshore low. also interesting posters in NYC area were reporting flakes falling for about 15 min an hour ago.

looks like nice SN- shwr over/NE of torrington, ct shows up decent on visible as well.

[Mr Torchey]

I think putting out watches due to mesoscale snows is a bit bullish, after all this is not a general 4-8 6-12 synoptic snow event, and this is New England. The morning of the 27th, after 16 inches of snow, and 60 pmh wind gusts I was driving on I95 and the highway was totally clear as well as main roads, sure side roads had some snow, but we should all be able to navigate in snow living in sne.

I would imagine issuing a waa with sws pinpointing regions that were being affected by mesoscale banding would suffice.

[ag3]

interesting little finger of clouds stretching NW to about the s. coast of Central long island from the offshore low. also interesting posters in NYC area were reporting flakes falling for about 15 min an hour ago.

looks like nice SN- shwr over/NE of torrington, ct shows up decent on visible as well.

NAM has had this type of feature for the past 3-4 runs:

Here it is on today's 12z run. 7:00p.m. tonight.

[Clinch Leatherwood]

I think putting out watches due to mesoscale snows is a bit bullish, after all this is not a general 4-8 6-12 synoptic snow event, and this is New England. The morning of the 27th, after 16 inches of snow, and 60 pmh wind gusts I was driving on I95 and the highway was totally clear as well as main roads, sure side roads had some snow, but we should all be able to navigate in snow living in sne.

I would imagine issuing a waa with sws pinpointing regions that were being affected by mesoscale banding would suffice.

I have no problem with the watches.

They may need to re-evaluate later pending the 18z/0z.

I'm about as confident as ever that the big show is going to come from the ocean south and not a trough. The NAM had the right idea but the wrong s/w (12z yesterday run)....there's some pretty huge potential for the third system and it's time to get on the CT Blizz bus

...JET STREAK RACING SE FROM NRN PLAINS TO NC...

PREFERENCE: GFS/CANADIAN/ECMWF/UKMET

THE VORT LOBES REACHING THE MID ATLANTIC COAST THE FIRST PART OF

FRI DESCRIBED IN THE NAM EVALUATION WILL ROTATE N LATER FRI AND

BECOME ABSORBED IN THE CIRCULATION BY FRI EVE AROUND THE MAIN

VORTEX SINKING SE ACROSS THE GREAT LAKES. AS THESE INITIAL VORT

LOBES FADE OUT OF THE PICTURE...A NEW JET STREAK WILL RACE SE OUT

FROM THE NRN PLAINS/ UPPER THE MIDWEST INTO SRN PORTIONS OF TN/NC

BY FRI EVE. THE GFS IS SHOWING MORE REFLECTION AT THE SURFACE WITH

THIS JET STREAK THAN THE NAM...ALONG WITH SOME LIGHT SNOW IN THE

LEFT EXIT DIVERGENT REGION OF THE JET STREAK. MOST OF THE SN WILL

FALL IN THE SRN APPALACHIANS. WE BELIEVE THAT THE 12Z NAM IS TOO

WEAK WITH THIS JET STREAK AND ITS DYNAMICS...AND A QUICK LOOK AT

THE NEW 12Z UKMET/CANADIAN AND THE 00Z ECMWF PLACES A WEAK SURFACE

LOW FRI EVE OVER THE CAROLINAS IN RESPONSE TO THE UPPER DYNAMICS

[Tropopause_Fold]

Nmm really hits NYC and nw hard. Also has a max in ne ma

[moneypitmike]

I have no problem with the watches.

They may need to re-evaluate later pending the 18z/0z.

I'm about as confident as ever that the big show is going to come from the ocean south and not a trough. The NAM had the right idea but the wrong s/w (12z yesterday run)....there's some pretty huge potential for the third system and it's time to get on the CT Blizz bus

...JET STREAK RACING SE FROM NRN PLAINS TO NC...

PREFERENCE: GFS/CANADIAN/ECMWF/UKMET

THE VORT LOBES REACHING THE MID ATLANTIC COAST THE FIRST PART OF

FRI DESCRIBED IN THE NAM EVALUATION WILL ROTATE N LATER FRI AND

BECOME ABSORBED IN THE CIRCULATION BY FRI EVE AROUND THE MAIN

VORTEX SINKING SE ACROSS THE GREAT LAKES. AS THESE INITIAL VORT

LOBES FADE OUT OF THE PICTURE...A NEW JET STREAK WILL RACE SE OUT

FROM THE NRN PLAINS/ UPPER THE MIDWEST INTO SRN PORTIONS OF TN/NC

BY FRI EVE. THE GFS IS SHOWING MORE REFLECTION AT THE SURFACE WITH

THIS JET STREAK THAN THE NAM...ALONG WITH SOME LIGHT SNOW IN THE

LEFT EXIT DIVERGENT REGION OF THE JET STREAK. MOST OF THE SN WILL

FALL IN THE SRN APPALACHIANS. WE BELIEVE THAT THE 12Z NAM IS TOO

WEAK WITH THIS JET STREAK AND ITS DYNAMICS...AND A QUICK LOOK AT

THE NEW 12Z UKMET/CANADIAN AND THE 00Z ECMWF PLACES A WEAK SURFACE

LOW FRI EVE OVER THE CAROLINAS IN RESPONSE TO THE UPPER DYNAMICS

A Cape Scraper that hits ME?

[cpickett79]

I have no problem with the watches.

They may need to re-evaluate later pending the 18z/0z.

I'm about as confident as ever that the big show is going to come from the ocean south and not a trough. The NAM had the right idea but the wrong s/w (12z yesterday run)....there's some pretty huge potential for the third system and it's time to get on the CT Blizz bus

...JET STREAK RACING SE FROM NRN PLAINS TO NC...

PREFERENCE: GFS/CANADIAN/ECMWF/UKMET

THE VORT LOBES REACHING THE MID ATLANTIC COAST THE FIRST PART OF

FRI DESCRIBED IN THE NAM EVALUATION WILL ROTATE N LATER FRI AND

BECOME ABSORBED IN THE CIRCULATION BY FRI EVE AROUND THE MAIN

VORTEX SINKING SE ACROSS THE GREAT LAKES. AS THESE INITIAL VORT

LOBES FADE OUT OF THE PICTURE...A NEW JET STREAK WILL RACE SE OUT

FROM THE NRN PLAINS/ UPPER THE MIDWEST INTO SRN PORTIONS OF TN/NC

BY FRI EVE. THE GFS IS SHOWING MORE REFLECTION AT THE SURFACE WITH

THIS JET STREAK THAN THE NAM...ALONG WITH SOME LIGHT SNOW IN THE

LEFT EXIT DIVERGENT REGION OF THE JET STREAK. MOST OF THE SN WILL

FALL IN THE SRN APPALACHIANS. WE BELIEVE THAT THE 12Z NAM IS TOO

WEAK WITH THIS JET STREAK AND ITS DYNAMICS...AND A QUICK LOOK AT

THE NEW 12Z UKMET/CANADIAN AND THE 00Z ECMWF PLACES A WEAK SURFACE

LOW FRI EVE OVER THE CAROLINAS IN RESPONSE TO THE UPPER DYNAMICS

what are you saying... a bomb is back on the table? after the inv. trough stuff fri pm and overnite into erly sat am.

[#NoPoles]

what are you saying... a bomb is back on the table? after the inv. trough stuff fri pm and overnite into erly sat am.

[Clinch Leatherwood]

what are you saying... a bomb is back on the table? after the inv. trough stuff fri pm and overnite into erly sat am.

I'm saying the map below is ridiculous. IF IF this model camp is right and the NAM is wrong (we don't eject the s/w) I think we're going to see a steady evolution towards an important coastal low and less interest in the trough. In a lot of ways that's already occuring I think in the models as they shift around which to me is a signal. A signal that they're struggling with what should be a 3rd low.

IMO it doesn't get away or really even shear out if this is the real deal, it ends up being absorbed/phases with the main PV and we probably end up seeing a more definitive cut out under SNE and it stalling at all levels somwhere SE of the Cape up to about where it's modeled now. Impossible to say where. Like I said the NAM toyed with this with the 2nd pulse and it was a phantom and gone. The fact that almost every model is onto this now at 48-72 is very interesting and with all this energy coming into the picture and the knowledge that it's going to stall somewhere close anyway....

for some the trough talk will be more interesting because it will more directly impact them in all probablity, but I really like the idea of a coastal.

Again even though many models show it I'm not buying it until we see a cycle of the 18z and 0z show similar...ie we don't eject the s/w which kind of seems like a garbage idea with that much of a PV coming down anyway.

EDIT: In other situations we'd have people correctly stating there should be a low pressure somewhere out south of us, east of the delmarva developing rapidly in response to the incoming energy.

[moneypitmike]

That deserves a couple more.

:weenie:

[cpickett79]

great explanation. thx

rombowski can you believe i didn't get more votes for the WOTY...i'll be whining about that for months.