Thanksgiving Eve SECS/MECS Discussion II

[chietanen]

The last several runs of the HRRR have been pretty consistent in showing that at least 2-3 hours of heavy snow make it as far south as NE NJ, the Bronx and possibly Manhattan by 10-11 am (prior to a changeover). Based on obs and radar trends, seems like that idea is not far off.

[mikeysed]

already sticking at 36 degrees in southern morris county

[earthlight]

The initial push of dynamic cooling is occurring as a result of 700mb frontogenesis, which is currently oriented from southwest to northeast throughout our area. This lift for heavy precipitation is cooling the column and allowing for snow to push toward Northeast NJ and NYC. This may make it as far as the coastal plain for a period of time later this morning. Probably not Southern Brooklyn or Queens, but at least Manhattan and the Bronx.

 

Just a few short hours later, near term forecast soundings are in good agreement that southerly winds will strengthen between 650-700mb. As the 700mb low passes from Southeast PA to Northeast NJ, warm air advection will begin at that level. Temperatures could warm 4-6 degrees C by 2pm in that small sliver of the atmospheric column. This will melt snow flakes as they fall from the snow growth region. The depth of this warm layer is greater near the coast, so it will probably simply be all rain there. This is unfortunate because it occurs in conjunction with some very strong lift. 

 

After 2pm a dry slot should move in for a period of time with the 700mb low passing by and killing precipitation production at that level. But precipitation will wrap around again later this afternoon as it moves to our northeast. We will have to see how the thermal profile cools behind the passage of the H7 low and if we could see another hour or two of frozen precipitation behind it. 

[Brian5671]

nice update earthlight.  Thank you.

[Dosh]

So that's it??? Party over?  I go to sleep with a WSW and 6-8" on the way and wake up with a WWA and 1-3????   Boy I am p'od!!!!

 

Welcome to winter along I-95

[Ericjcrash]

34/34 rain, mangled flakes, and sleet.

[earthlight]

Welcome to a winter storm in November along I-95 with marginal thermal profiles, a +AO and a +NAO

 

fixed it for you bud

[REDMK6GLI]

The initial push of dynamic cooling is occurring as a result of 700mb frontogenesis, which is currently oriented from southwest to northeast throughout our area. This lift for heavy precipitation is cooling the column and allowing for snow to push toward Northeast NJ and NYC. This may make it as far as the coastal plain for a period of time later this morning. Probably not Southern Brooklyn or Queens, but at least Manhattan and the Bronx.

Just a few short hours later, near term forecast soundings are in good agreement that southerly winds will strengthen between 650-700mb. As the 700mb low passes from Southeast PA to Northeast NJ, warm air advection will begin at that level. Temperatures could warm 4-6 degrees C by 2pm in that small sliver of the atmospheric column. This will melt snow flakes as they fall from the snow growth region. The depth of this warm layer is greater near the coast, so it will probably simply be all rain there. This is unfortunate because it occurs in conjunction with some very strong lift.

After 2pm a dry slot should move in for a period of time with the 700mb low passing by and killing precipitation production at that level. But precipitation will wrap around again later this afternoon as it moves to our northeast. We will have to see how the thermal profile cools behind the passage of the H7 low and if we could see another hour or two of frozen precipitation behind it.

What a waste of a Miller A john, wouldve been nice to of had some blocking and a fresh banana HP with this then all would be happy on this board most likely

[earthlight]

What a waste of a Miller A john, wouldve been nice to of had some blocking and a fresh banana HP with this then all would be happy on this board most likely

 

Wait until mid Dec

[REDMK6GLI]

Wait until mid Dec

Yea mid to late december we should start seeing some wholesale changes for the better over greenland and el nino better establishing its dominance in the overall pattern on the pacific side. not worried one bit, its november hard to be pissed about losing snow in a month where it is climatologically unlikely to occur as measurable precip anyway

[wthrmn654]

Temperatures are already upper30s eastern long island..when forecasts to be middle 40.

[Brian5671]

The good news is that we have the storms (active pattern)  Once we get deeper into winter, we should be in business.

[mikeysed]

Earthlight,

 

Any change or will all places 30 miles west/north of NYC go to mix later? Where do you see the cutoff points now with current temps, low development, etc?

[alwaysready126]

Yea mid to late december we should start seeing some wholesale changes for the better over greenland and el nino better establishing its dominance in the overall pattern on the pacific side. not worried one bit, its november hard to be pissed about losing snow in a month where it is climatologically unlikely to occur as measurable precip anyway

Ill ask the same question i asked in another forum.....with this current storm (Thanksgiving Eve), not only was the GOM open for business but the flow of moisture was such that it originated from the Pacific, through Mexico and then through the gulf and up the coast. If this happens during the winter months with just a bit of blocking.....man we will have some historical storms. My question is this.... is that a result of a weak el nino and if so, can we expect more of that over the next couple of months?

[earthlight]

Earthlight,

 

Any change or will all places 30 miles west/north of NYC go to mix later? Where do you see the cutoff points now with current temps, low development, etc?

 

I'm pretty sure the H7 warming will get past the Watchung Mountains in NJ if that's a good reference point there. I expect it to get as far north as BDL too in CT. The southerly jet at 650-700mb won't be denied. 

 

In NJ, I don't think it will make much progress past MMU if it even gets there. 

[PB GFI]

Kudos and congrads to ISOTHERM . Tom never bought the 3 inch amounts at KNYC and I think that ends up being the right call   .

 

That was a very good call in the face of some of the modeling and WSW that were up .

[wkd]

John, fantastic updated analysis of the 700mb. layer.

[Brian5671]

Kudos and congrads to ISOTHERM . Tom never bought the 3 inch amounts at KNYC and I think that ends up being the right call   .

 

That was a very good call in the face of some of the modeling and WSW that were up .

yep...also, no cold air source, a weaker low pressure system and climo said this was a long shot for the coast.

[Doorman]

700mb temp advection 

@ 1400Z   {9:00am edt}

 

 

 

http://www.spc.noaa.gov/exper/mesoanalysis/s16/7tad/7tad_sf.gif?1417014307820

[SnoSki14]

yep...also, no cold air source, a weaker low pressure system and climo said this was a long shot for the coast.

I don't know about climo, if the low was some 50-75 miles further east we probably would've done pretty well. It's more of a bad track and poor antecedent air mass than climo.

[Stormlover74]

I don't know about climo, if the low was some 50-75 miles further east we probably would've done pretty well. It's more of a bad track and poor antecedent air mass than climo.

Yeah with this setup we do bad even in January even with the colder Atlantic

[Brian5671]

I don't know about climo, if the low was some 50-75 miles further east we probably would've done pretty well. It's more of a bad track and poor antecedent air mass than climo.

I'd buy that too.   Poor medium range performance by models which had us cashing in until yesterday's 18z runs

[Stormlover74]

I'd buy that too. Poor medium range performance by models which had us cashing in until yesterday's 18z runs

Didn't the Nam first pick up on the 700mb warming?

[Brian5671]

Didn't the Nam first pick up on the 700mb warming?

yep...as someone said, the NAM is good with thermal profiles and once it picked up on the warming yesterday, looks like it will be correct in the end

[rossi]

Snowing/sleet Manalapan, NJ 35 degrees

 

Rossi

[earthlight]

Didn't the Nam first pick up on the 700mb warming?

 

Euro first

[BxEngine]

Can someone w access post some of the short term stuff for when the warming moves in aloft? Trying to time it but my phone is wonky, got it wet.

[Lord Snot]

I'm pretty sure the H7 warming will get past the Watchung Mountains in NJ if that's a good reference point there. I expect it to get as far north as BDL too in CT. The southerly jet at 650-700mb won't be denied. 

 

In NJ, I don't think it will make much progress past MMU if it even gets there. 

Hey, Steve D is saying the track is east of guidance and the 700mb should follow resulting in a colder solution - why then is everyone - including you - so confident this event is a fail (for the areas noted).

[Brian5671]

Hey, Steve D is saying the track is east of guidance and the 700mb should follow resulting in a colder solution - why then is everyone - including you - so confident this event is a fail (for the areas noted).

He has a cold bias. 

[earthlight]

Hey, Steve D is saying the track is east of guidance and the 700mb should follow resulting in a colder solution - why then is everyone - including you - so confident this event is a fail (for the areas noted).

 

Not sure what he's looking at..the H7 low is right over DC/Baltimore like it is forecast to be