NYC/PHL December 24-27 Potential - Part 2

[Alpha5]

So the GGEm is a scraper?

[ag3]

Yeah. The 108 map I posted is today's. I took down the 120 hour map.

[ag3]

So the GGEm is a scraper?

No. It misses us. It scrapes extreme eastern LI. And a little better in eastern NE.

[Zir0b]

who caress if it misses us. it's closes to nailing us at 500, just need to phase slightly earlier and tilt that trough in the negative direction a bit

[Chris L]

The GGEM trough isn't negative orienated. Its more neutral, which is likely the reason why it misses. A classic negative tilted trough (line slants from) is from southeast to northwest. On the GGEM it simply doesn't show that.

[eduggs]

Then why, eduggs, does HPC continually have better error verification than any model? Why does NHC have better track forecast error verification than any model? Why do private forecast companies exist? Think carefully about your answer.

That's kind of my point. Better than "any one model." HPC uses the statistical tools that I'm talking about. They don't eyeball charts. Even so, HPC is outperformed by various composites and superensembles.

[Maximum lawman]

I think people here don't really understand how statistical models work. Even deterministic models have error, from bad input, from impecfectly modeling physical processes, from the randomness of the universe, from resolution, etc. Take the resolution for an intuitive explanation. The models, in effect, smooth across areas at a defined geographic unit, a little larger on the GFS than the Euro. Now the real weather obviously varies within that area, so that variance will effet the next period in terms of what actually will happen, but while that variation can be incorporated in a staochastic model, it can't be incorporated in a deterministic model. Obviously, small error compound over time, which is why the models perform better in the short-term. An experienced observer can detect when the solution, even a deterministic one, is unlikely. And unlikely is the key word - all these sources of error create uncertainty and that's not reflected in any models solution - but it is reflected in your actual forecast, e.g., a 50% chance of snow on Sunday.

[SACRUS]

12z Recap

NYC QPF

GFS : 0.15

Ensembles : 0.20

UKMET : 0

GGEM : 0

[SRRTA22]

Did the 00z Euro continue what it was showing yesterday or did it trend towards a miss?

[hazwoper]

No. It misses us. It scrapes extreme eastern LI. And a little better in eastern NE.

Yes, but like the GFS, it has shifted towards the Euro from last night. This is the key point at this time, not that it misses us.

[Sn0waddict]

Did the 00z Euro continue what it was showing yesterday or did it trend towards a miss?

Yes, it's been a hit for 3-4 straight runs now.

[hazwoper]

Did the 00z Euro continue what it was showing yesterday or did it trend towards a miss?

It was a massive hit for the big cities.

[NortheastPAWx]

Based on these runs and its ENS, I think we see the EURO shift east and fall in line with the other models.

[ARyan]

I think people here don't really understand how statistical models work. Even deterministic models have error, from bad input, from impecfectly modeling physical processes, from the randomness of the universe, from resolution, etc. Take the resolution for an intuitive explanation. The models, in effect, smooth across areas at a defined geographic unit, a little larger on the GFS than the Euro. Now the real weather obviously varies within that area, so that variance will effet the next period in terms of what actually will happen, but while that variation can be incorporated in a staochastic model, it can't be incorporated in a deterministic model. Obviously, small error compound over time, which is why the models perform better in the short-term. An experienced observer can detect when the solution, even a deterministic one, is unlikely. And unlikely is the key word - all these sources of error create uncertainty and that's not reflected in any models solution - but it is reflected in your actual forecast, e.g., a 50% chance of snow on Sunday.

Forecast POPs are not model uncertainties. They are based off of coverage. Using your example, 50% chance of snow means 50% of that area will receive snow.

[SRRTA22]

Yes, it's been a hit for 3-4 straight runs now.

It was a massive hit for the big cities.

Thanks alot guys! Thats good to hear. If the euro starts to lose it at 12z, then I'll get worried.

[eduggs]

Could be some consensus building today. GFS, GFES, GGEM converging on offshore, but highly threatening, coastal track. Same idea as UK, and Euro ensembles. Last night's GGEM ensembles were further SE and obviously the OP Euro is further SW.

The 12z GFS ensembles look better than they have in days, with the 84hr mean chart getting QPF back to WV, and clearly the presence of westward members in later charts.

[am19psu]

Forecast POPs are not model uncertainties. They are based off of coverage. Using your example, 50% chance of snow means 50% of that area will receive snow.

This is wrong. When the NWS forecasts a 50% POP, that means half the days with a 50% POP issued will see precipitation. It has nothing to do with area.

[jasonli18t]

Based on these runs and its ENS, I think we see the EURO shift east and fall in line with the other models.

you think the EURO will fall in line with the others??? the others are falling in line with the euro. even if the euro goes east, it is in no way falling in line with the awful GFS.

[Mr. Windcredible!]

Really???!!!

So the GGEM, UKIE and GFS take a massive step towards the EURO while the EURO stands pat and you forsee the Euro will shift east. Would love to know your rationale for this (my guess is you have none)

he gave his reasoning...0z Euro ensembles were a good deal east of the op. Add in the fact that last nights Euro came east and was a bit less wound up...and I tend to agree it may take another shift east.

[Stormlover74]

Who's to say they took a step towards the Euro? Maybe they are taking a step towards the correct solution and the Euro will also do the same. Again, most of the major models and ensembles are showing a near miss/scrape/coastal hit with the exception of the Euro operational at this juncture. I'm not saying it won't show what its been showing but I would say theres an equal chance it shift towards the current consensus

Really???!!!

So the GGEM, UKIE and GFS take a massive step towards the EURO while the EURO stands pat and you forsee the Euro will shift east. Would love to know your rationale for this (my guess is you have none)

[hazwoper]

he gave his reasoning...0z Euro ensembles were a good deal east of the op. Add in the fact that last nights Euro came east and was a bit less wound up...and I tend to agree.

OK, so 100-126 out we expect all models to come into agreement, is that what you are saying?

Also, the GFS ens shifted well west as well. Look, I am not saying he is incorrect, I just think with the majority of the models shifting west a good bit I wouldn't expect the Euro to come in line, but meh, that's JMHO and I am no met, so take MO for what it's worth.

[HSNN4]

Can I make the respective request to the boards moderators that if a someone writes something that has nothing to do with the original thread that it gets deleted.

I for one use this board to summit my observations and for situational awareness,

Thank You.

[pazzo83]

Can I make the respective request to the boards moderators that if a someone writes something that has nothing to do with the original thread that it gets deleted.

I for one use this board to summit my observations and for situational awareness,

Thank You.

So I guess this post should be deleted?

[jasonli18t]

Can I make the respective request to the boards moderators that if a someone writes something that has nothing to do with the original thread that it gets deleted.

I for one use this board to summit my observations and for situational awareness,

Thank You.

I really think we are taking things too seriously here. There will always be debate, and one-off comments. Why can't we be human beings? It doesn't mean take the thread wildly off topic, but if someone has something to say, even if it isn't necessarily meteorological, we are out for blood, and it runs counter to the spirit of what message boards are all about. I think we need to loosen up, not tighten up. You can't even make a joke in one of these threads without the post being deleted and getting warned. We take ourselves a bit too seriously.

[ag3]

12z Recap

NYC QPF

GFS : 0.25

Ensembles : 0.20

UKMET : 0

GGEM : 0

Not to nitpick but soundings show .13" for NYC off the 12z GFS.

[Feb]

So I guess this post should be deleted?

oops, mine too!

[Mr. Windcredible!]

OK, so 100-126 out we expect all models to come into agreement, is that what you are saying?

Also, the GFS ens shifted well west as well. Look, I am not saying he is incorrect, I just think with the majority of the models shifting west a good bit I wouldn't expect the Euro to come in line, but meh, that's JMHO

well bottom line is no one can really predict how a model is going to come out before its even initialized...so we're all just basing it on gut anyway. part of my gut has a tendency to expect disappointment from the models as a means of protection. but the Euro has been the western extreme and is not infallible...so all I'm saying is we shouldn't be surprised if it continues to back off its HECS scenario a bit. Even if it does, we're all still very much in the game for at least a light to moderate event seeing as we're still a good 4-5 days out. plenty of time for things to shift one way or another.

[hazwoper]

well bottom line is no one can really predict how a model is going to come out before its even initialized...so we're all just basing it on gut anyway. part of my gut has a tendency to expect disappointment from the models as a means of protection. but the Euro has been the western extreme and is not infallible...so all I'm saying is we shouldn't be surprised if it continues to back off its HECS scenario a bit. Even if it does, we're all still very much in the game for at least a light to moderate event seeing as we're still a good 4-5 days out. plenty of time for things to shift one way or another.

I agree with this post completely!

[Kevin Druff]

So I guess this post should be deleted?

No one else will get this, but since Chris is being a dick, I'm going to say it anyway.

Weller's giving you the glare over her reading glasses, dude. Don't be a prick.

Edit: and, yes, I get to call him a prick because I've known him for almost a decade and a half.

[pazzo83]

No one else will get this, but since Chris is being a dick, I'm going to say it anyway.

Weller's giving you the glare over her reading glasses, dude. Don't be a prick.

LMAO, that brings back some memories. OK OK, back on topic.