Dec 16-20 Snow/Mix events - Going over like a fart in church

[Clinch Leatherwood]

Decide for yourself which is colder.

Top image is 12z NAM at 81hr, bottom image is 18z NAM at 75hr, both valid at 21z SUN. Courtesy PSU Meteorology.

The time point may be the same but the 18z is slower so there's less warming at that point and less QPF to some degree. And besides it's the NAM long range.

[Damage In Tolland]

Hate to have to do this

That was definitely a colder run vs 12z on the NAM. CAD held a bit more stout that run.

It trended colder...just not enough for your area. It helps out interior MA though...but this is just a snap shot in time. The verbatim solutions mean relatively little right now.

Hate to have to do this

[ctsnowstorm628]

Decide for yourself which is colder.

Top image is 12z NAM at 81hr, bottom image is 18z NAM at 75hr, both valid at 21z SUN. Courtesy PSU Meteorology.

The timing is also different. 18z bring it in later, and the WAA aloft is just starting in CT at h75..h78 would probably be a better representation vs 12z.

[Damage In Tolland]

i don't think anything I have laid out is extreme, outlandish or crazy. I've laid out a reasonable forecast/expectation for my specific area and that i think ORH north ends up mostly or all snow. I've explained the reasons why ..and reasons how it won't work if certain conditions aren't realized.

We still have 2 days for this to trend colder or to blow up in my face like Tip's mom when she yells down into the basement and he doesn't wake up in the morning

[40/70 Benchmark]

right , he knows this, all the mets have said they are def less confident for tolland then for ORH and esp comp w/ . the Monads .

i honestly hope he gets a 31 F ice storm to enjoy, i know i have no real shot of ice where i am in NE mass. and honestly for most of interior NE mass) , unless you get out west of say 495.

i wonder if there is much hope that the Mid levels in NE mass stay below 0c into the wee hours mon am, bc i know i have no real shot of icing and the only shot i guess would be for some high rates and cooler mid levels and like a 33-34 snow paste job

This.

I'm not getting ice.....the hope is that we can hold the mid levels and keep the 2m under, say 35.....

[Quincy]

The timing is also different. 18z bring it in later, and the WAA aloft is just starting in CT at h75..h78 would probably be a better representation vs 12z.

There's no clean way of comparing it.

12z NAM was MUCH wetter across the Hudson Valley at 75hr and in return, colder. We're talking about 3hr precipitation of 0.42" vs 0.15" in 3 hours, which will significantly impact 2m temperatures, especially with the expected dew-points.

The evolution of the system has changed. Courtesy PSU Meteorology.

[Clinch Leatherwood]

Hate to have to do this

Hate to have to do this

It's come to you posting about the NAM at 70 hours.

The NAM at 84 hours had most of the precip exiting. the 0c at 8h wandered from north of boston to north of the pike crossing into VT. The 18z 78 hour has precip still back into PA and the 0c line a little further south than the earlier run. You win it's colder at the same moment in time but the system itself is slower. By the time the low is out south of Block on the 18z run the 0c line has cleared all of MA, versus earlier it was just about in the same position at 81.

There's really no debate on what the 18z GFS shows.

[hammerz_nailz]

If it rains I'm hoping it doesn't come down to hard. I did my final lawn mowning today nice and short towing the sweeper. Put down Lecso 18-0-18 so will be nice and green in march. Yard looks awsome. I think they need to move the zones on the fertilzer bags a little north. Nice little blanket of snow before the ground freezes would be perfect.

[N. OF PIKE]

i'm starting to think the ice threat will be minimal in SNE. the good thing will be mid levels may hold off enough for someone to see a good qpf thump while 850's are below 0 c. im not sure how strong winds are progg'd to be out of the E or Ne on sun aft/ eve over Ema/ SNh, but this will prob determine how far away from coast BL is torched. I hope we can get a good qpf thump with a secondary development but i'd favor Weenie ridge up thru the monads for the snow thump, with the caveat that many details are left to be decided.

[CT Rain]

The time point may be the same but the 18z is slower so there's less warming at that point and less QPF to some degree. And besides it's the NAM long range.

Correct. Worthless comparison lol.

If you look at 75 hours on the 12z NAM there is a large area of 2M temps in the 20s during the height of the storm in NW CT. The 18Z NAM is not nearly as cold at the surface during heavy QPF.

THis really isn't a question here not sure what the debate is.

There's certainly a cold appeal from ORH points NE but really not down here.

[Damage In Tolland]

I wouldn't say SNE torches...probably M-U30s coast, ice distincly possible interior.

Snow to rain for coast, snow to sleet/zr interior. North of a PWM-CON line it's all snow.

Actually there is

[CT Rain]

i don't think anything I have laid out is extreme, outlandish or crazy. I've laid out a reasonable forecast/expectation for my specific area and that i think ORH north ends up mostly or all snow. I've explained the reasons why ..and reasons how it won't work if certain conditions aren't realized.

We still have 2 days for this to trend colder or to blow up in my face like Tip's mom when she yells down into the basement and he doesn't wake up in the morning

I'm hoping the whole thing trends colder and we can get a thump of snow.

You cutting your expectations in half from earlier today shows where things have trended.

From 1-3 or 4.... to a measley 1-2.

[ctsnowstorm628]

There's no clean way of comparing it.

12z NAM was MUCH wetter across the Hudson Valley at 75hr and in return, colder. We're talking about 3hr precipitation of 0.42" vs 0.15" in 3 hours, which will significantly impact 2m temperatures, especially with the expected dew-points.

The evolution of the system has changed. Courtesy PSU Meteorology.

Yeah, I agree. Been bogged down with my junior core and haven't looked at everything extensively, but I think there is a wintry threat that exists for northern CT...to what extent, who knows. Elevation will help too I think.

[Damage In Tolland]

I'm hoping the whole thing trends colder and we can get a thump of snow.

You cutting your expectations in half from earlier today shows where things have trended.

From 1-3 or 4.... to a measley 1-2.

I 've always thought for our area..ice was going to be the bigger threat..and that even includes you in the valley. I tweeted that like 3 days ago and I've said it on here when I started posting after my hiatus. The 2-4 covered all of SNE...I've always thought a few inches here then the rest is ice.

i liked the trends today overall.

I will be very surprised if we don't see the Euro come in colder tonight and tomorrow especially. as it locks in the ageo north drain from the 2ndary

if we don't..then this disco is all for naught

[CT Rain]

I 've always thought for our area..ice was going to be the bigger threat..and that even includes you in the valley. I tweeted that like 3 days ago and I've said it on here when I started posting after my hiatus. The 2-4 covered all of SNE...I've always thought a few inches here then the rest is ice.

i liked the trends today overall.

I will be very surprised if we don't see the Euro come in colder tonight and tomorrow especially. as it locks in the ageo north drain from the 2ndary

if we don't..then this disco is all for naught

Besides a brief period of glaze... meh.

While weak low south of Long Island may develop a weak northerly ageostrophic component I highly doubt it's enough for us.

[CoastalWx]

Be careful about "forecasting" what models will do.

[N. OF PIKE]

i don't think anything I have laid out is extreme, outlandish or crazy. I've laid out a reasonable forecast/expectation for my specific area and that i think ORH north ends up mostly or all snow. I've explained the reasons why ..and reasons how it won't work if certain conditions aren't realized.

We still have 2 days for this to trend colder or to blow up in my face like Tip's mom when she yells down into the basement and he doesn't wake up in the morning

mainly agree

alot depends on how cold u are by sun am. (how cold the antecedent air mass is and where/if the coastal pops, i put the over/under for 5am tolland temp @ 28F

[Quincy]

One last thing and I think we're splitting hairs here.

http://68.226.77.253/text/NAMSFC/NAM_KBDL.txt 18z NAM

http://68.226.77.253/text/NAMSFC/NAM_KBDL.txt 12z NAM

Temperatures about the same - no clear trend. Yeah, the 18z max temp is 1F cooler, but that's not a big deal. 1000-500mb thicknesses max out at 544dm on both runs, no difference.

In hindsight, I'm not sure why I'm even spending this much time analyzing an 18z run of the NAM at day 3.5.

[Damage In Tolland]

mainly agree

alot depends on how cold u are by sun am. (how cold the antecedent air mass is and where/if the coastal pops, i put the over/under for 5am tolland temp @ 28F

Well i saw one poster say temps would be above freezing Sunday morning.

But yeah if it's 30 then ice longevity diminishes greatly.

if it's 26/20..then it's weenie on

[ineedsnow]

watching that movie now and I cant stop laughing

Mostly because you've done such a great job sniffing out snow and cold threats I am no longer needed. Plus I lost the RUC which was my Ted.

This thread and others like it remind me of this scene from Analyze This:

http://www.anyclip.c...angry/#!quotes/

[Clinch Leatherwood]

Well i saw one poster say temps would be above freezing Sunday morning.

But yeah if it's 30 then ice longevity diminishes greatly.

if it's 26/20..then it's weenie on

In your eagerness to post you misunderstand the difference between people discussing a modeled outcome at a point and time and personal predictions. You excel at personal predictions many days in advance. Most of us are speaking within the confines and context of particular model runs as they've come out and are at least a day away (42-48 hrs to onset) from making specific predictions like you have for the last two days.

[powderfreak]

18z GFS ensembles looked nice for NNE on the whole... and definitely looking better for SNE on the second storm.

Days and days of snow? Its got like 3 straight days of measurable. Much better looking than the OP.

[moneypitmike]

No worries Dave.

There's the mathmatical/modeled atmosphere and then there is the observable atmosphere. The models will continue to sort the mathmatical atmosphere out over the next few days.

As far as the observable atmoshere it's been cold here the past month, it's 29/24 imby currently. Local Wunderground stations will support that the cold has held it's own in the Rt 2 corridor and N the past month. My feeling is that the cold is going to be stronger than the models are indicating at present.

There's stormy weather coming into some cold air even if it's not a high parked perfectly to our NW. There is still no doubt in my mind that you and I and a lot of CNE/NNE posters are going to see meaningful frozen precipitation in a few days. How it all unfolds is tbd but it should be some exciting winter wx to track. So sit back and relax and enjoy winter is my motto.

I'm worried. And it's not about qpf.

i'm starting to think the ice threat will be minimal in SNE. the good thing will be mid levels may hold off enough for someone to see a good qpf thump while 850's are below 0 c. im not sure how strong winds are progg'd to be out of the E or Ne on sun aft/ eve over Ema/ SNh, but this will prob determine how far away from coast BL is torched. I hope we can get a good qpf thump with a secondary development but i'd favor Weenie ridge up thru the monads for the snow thump, with the caveat that many details are left to be decided.

Agreed.

Be careful about "forecasting" what models will do.

We've resorted to modeling models.

[HoarfrostHubb]

Mike, what are you worried about? Temps?

[HoarfrostHubb]

Matt Noyes seems to be reading the KURO

Good swath of "at least" 2"

NH, VT have a lot of "at least" 4"

This is by 8AM Monday

[HoarfrostHubb]

And why is everyone so pissy? Santa Blizz is coming

[powderfreak]

And why is everyone so pissy? Santa Blizz is coming

The pattern is getting to some

[ineedsnow]

All I want to see is an inch of snow the last couple of events we had ive been in NY for and it would be nice to see some snow falling longer then 10 minutes

And why is everyone so pissy? Santa Blizz is coming

[Tropopause_Fold]

In your eagerness to post you misunderstand the difference between people discussing a modeled outcome at a point and time and personal predictions. You excel at personal predictions many days in advance. Most of us are speaking within the confines and context of particular model runs as they've come out and are at least a day away (42-48 hrs to onset) from making specific predictions like you have for the last two days.

Yes. Totally agree. I don't get what the deal is. How many times were phrases like "based on the trends today" or "as modeled" and so on used.

[moneypitmike]

Mike, what are you worried about? Temps?

Yup. The antecedent cold is so meh, that even if the rare condiitions that can lead to icing events take place, the initial temps have so little room to shift for this to go from early snow to rain.

And why is everyone so pissy? Santa Blizz is coming

Yup--people sure are crabby.