December 18-20 Talking Points - Part 2

[NorEaster27]

HPC says...don't dismiss the GFS!

12Z GFS REMAINS THE MOST AGGRESSIVE MODEL WITH ITS STRONGER

SHORTWAVE AMPLIFICATION AS IT APPROACHES THE EAST COAST SATURDAY.

ITS MID LEVEL CONFIGURATION BY DAYS 4-5 FITS THE 00Z ECMWF ENS

MEAN PATTERN. ITS EXACT TRACK IS CRITICAL TO PCPN CHANCES AND

AMOUNTS ALONG THE NORTHEAST COAST ESPECIALLY NEW ENGLAND. GOOD

AGREEMENT BY THE 12 GFS ENS MEAN AND 12Z CMC BUT CONTINUED FLAT

AND WELL AT SEA BY THE UKMET AND 12Z ECMWF. UNCERTAINTY CONTINUES

WITH TWO SEPERATE CAMPS. RAPID OFFSHORE DEEPENING SCENARIO BY THE

GFS RUNS SEEMS MORE LIKELY AS THE SHORTWAVE AND DEVELOPING SFC LOW

ENCOUNTER AN UNSTABLE MARINE ENVIRONMENT WITH INCREASED

BAROCLINICITY FROM THE CURRENT STRONG COLD ADVECTION FLOW OVER

RELATIVELY WARM OCEAN WATERS.

HPC is going to get burned going against the Euro, the statement bolded above is laughable. What does the current CAA have anything to do with a storm 96 hours away where we are going to have WAA in the same places that have CAA now. I know they are the experts but that is a pretty ridiculous statement.

[jm1220]

SREF's out to 72 look a lot like 12z nam and gfs

There's definitely some piece of data our models are ingesting that perhaps the foreign models aren't or are interpreting differently. There's definitely a defined wave present on the GFS/Nam and not present at all on the Euro.

[IsentropicLift]

A general comprimise would give eastern areas a few inches and a very narrow miss for the rest. Not a bad place to be four days out especially with things trending more favorably even with models that are OTS. As I stated before, Euro was step in the right direction with the PV. Step backwards with the strength of the shortwave, something that I think will be corrected at 00z. Others have stated, Euro doesn't make big jumps. This gradual change is in our favor. I would be very worried if the Euro was slowly changing in the opposite direction.

[GD0815]

the thing that is concerning to me is that the Euro has not vacillated from the OTS solution in 3 days, I would feel much better about any storm chances if it had been all over the place like the GFS.

[Kaner587]

There's definitely some piece of data our models are ingesting that perhaps the foreign models aren't or are interpreting differently. There's definitely a defined wave present on the GFS/Nam and not present at all on the Euro.

and at 87hr its obvious the result is different than the euro on the SREF's but I agree, and I'm really not big on this threat but you can't just dismiss model agreement from NAM/SREF/GFS. Granted the SREF and NAM are related but saying the EURO is king=its always right is just wrong. EURO does happen to be right most times though so seeing it be flat and progressive is definitely a red flag, but declaring the threat dead BECAUSE of the euro is not prudent yet. Tomorrow if it holds and the models are still separated it will lend credence to the idea that maybe its onto something, if todays run didn't already lead us in that direction.

in case that explanation was a little confusing...

euro=best model we have available

euro does not equal infallible however.

[IsentropicLift]

the thing that is concerning to me is that the Euro has not vacillated from the OTS solution in 3 days, I would feel much better about any storm chances if it had been all over the place like the GFS.

The Euro is all over the place with regards to the different players. The location of the low itself has remained OTS but at different degrees.

[Chris L]

HPC is going to get burned going against the Euro, the statement bolded above is laughable. What does the current CAA have anything to do with a storm 96 hours away where we are going to have WAA in the same places that have CAA now. I know they are the experts but that is a pretty ridiculous statement.

HPC forgot more than we'll ever know....

[atownwxwatcher]

Maybe I wasn't looking at the whole east coast but my recollection of the Euro runs were that all of its 00z runs did not have a hit, well in our area this post I believe is true.

These images were posted as well by Tom

Then this

So yep the ECM definitely showed a HIT!

[jm1220]

and at 87hr its obvious the result is different than the euro on the SREF's but I agree, and I'm really not big on this threat but you can't just dismiss model agreement from NAM/SREF/GFS. Granted the SREF and NAM are related but saying the EURO is king=its always right is just wrong. EURO does happen to be right most times though so seeing it be flat and progressive is definitely a red flag, but declaring the threat dead BECAUSE of the euro is not prudent yet. Tomorrow if it holds and the models are still separated it will lend credence to the idea that maybe its onto something, if todays run didn't already lead us in that direction.

in case that explanation was a little confusing...

euro=best model we have available

euro does not equal infallible however.

Once it's all on the N. American continent, we'll see all the model chaos collect into one solution, but if that wave does come ashore into CA, there will more than likely be a significant storm here. If not, it'll probably be a flat, strung out low. It's that simple and seemingly the only real point of disagreement right now.

[SRRTA22]

What do the colors represent? It'd be nice to have some sort of key on those maps.

[phlwx]

So yep the ECM definitely showed a HIT!

It hasn't shown a hit in at least 5 runs (going back to Monday 12z....might not have even shown it at 0z so that would be 6).

It's been much, much more consistent with this storm than the GFS.

[Kaner587]

Once it's all on the N. American continent, we'll see all the model chaos collect into one solution, but if that wave does come ashore into CA, there will more than likely be a significant storm here. If not, it'll probably be a flat, strung out low. It's that simple and seemingly the only real point of disagreement right now.

don't you find it odd though that the Euro can just miss this ? It would be a huge fail on its part if that were the case. Also I'm assuming you're still in Long Beach? If so we're both in better locations, albeit not the best, for a better hit from this if something like the GFS were to verify, I just don't see that happening at this juncture though.

[phlwx]

The Euro is all over the place with regards to the different players. The location of the low itself has remained OTS but at different degrees.

...and the GFS has been consistent? In the end, if there's no storm it won't matter much how the players have played out.

[Feb]

It hasn't shown a hit in at least 5 runs (going back to Monday 12z....might not have even shown it at 0z so that would be 6).

It's been much, much more consistent with this storm than the GFS.

Agreed. We are also getting into it's dead zone time wise so it better make a move tonight or 12z tomorrow or the fat lady can start singing.

[atownwxwatcher]

What do the colors represent? It'd be nice to have some sort of key on those maps.

Those were prior images from the ECM QPF not current....it was from 6 inches or less to as much as a foot plus that the ECM was showing at one point!

[jm1220]

don't you find it odd though that the Euro can just miss this ? It would be a huge fail on its part if that were the case. Also I'm assuming you're still in Long Beach? If so we're both in better locations, albeit not the best, for a better hit from this if something like the GFS were to verify, I just don't see that happening at this juncture though.

I definitely like our position here on Long Island more than people in western NJ and PA, but I still think that we either get a significant snow event or very little. The difference is wave vs. no wave, the models with that wave develop into a major storm and the ones without don't. I don't even think the Euro gives us more than a cirrus deck. GFS would probably be an 8-12" kind of storm for Long Island and probably more in SNE.

[earthlight]

The SREF mean is definitely more amplified than it's 09z and 03z runs...doesn't really mean much right now.

[Kaner587]

...and the GFS has been consistent? In the end, if there's no storm it won't matter much how the players have played out.

you're right and the GFS hasn't exactly been consistent but you're simplifying things saying the euro has been consistent because its shown no storm since sunday night or whenever. First it showed no storm because of awful PV orientation but decent to good southern stream s/w and recently its been great PV orientation and NO southern stream s/w. hardly consistent if you ask me.

[Chris L]

Agreed. We are also getting into it's dead zone time wise so it better make a move tonight or 12z tomorrow or the fat lady can start singing.

I actually disagree with this Bob, and normally we agree 99.9% of the time.... this is just the mere .1%.

I think we can wait until Thursday at 0z before we throw it out... too many issues on the table here.

[atownwxwatcher]

It hasn't shown a hit in at least 5 runs (going back to Monday 12z....might not have even shown it at 0z so that would be 6).

It's been much, much more consistent with this storm than the GFS.

Thats not the point that i was making ..I was making a point on the ECM was the first to show what the GFS started showing later. 4 runs in a row that the ECM did this... before it started backing off and if you look at its means versus the operational run the means are more consistent with what the GFS has been showing then what the OP ECM has been showing...

The ECM is deadly 48 and under...NOT before hand..its fallible just like any other model prior to 48 hrs...

[IsentropicLift]

...and the GFS has been consistent? In the end, if there's no storm it won't matter much how the players have played out.

didn't say the GFS was however....to say the EC has been is quite incorrect! Don't just look at the end result, look at how it got their.

[am19psu]

The ECM is deadly 48 and under...NOT before hand..its fallible just like any other model prior to 48 hrs...

Where did this old wives' tale come from?

[Kaner587]

Where did this old wives' tale come from?

lol I've heard deadly from 96 on not 48, in fact, I've heard its best in the medium range and not necessarily in the short term, but I might be wrong on that.

[A-L-E-X]

I actually disagree with this Bob, and normally we agree 99.9% of the time.... this is just the mere .1%.

I think we can wait until Thursday at 0z before we throw it out... too many issues on the table here.

Chris, tomorrow is Thursday bro.  I say give it until Thursday 12z because the players arent in the well sampled area until then.  Until then its a crapshoot.

[Feb]

I actually disagree with this Bob, and normally we agree 99.9% of the time.... this is just the mere .1%.

I think we can wait until Thursday at 0z before we throw it out... too many issues on the table here.

I'm not discounting any late minute shifts but i would at least like to see it TREND better the next run or two.

[CooL]

Nam out to hr 36, PV slighlty west of 12z...s/w in the southwest pretty much the same as 12z, not much change..

[Feb]

lol I've heard deadly from 96 on not 48, in fact, I've heard its best in the medium range and not necessarily in the short term, but I might be wrong on that.

[am19psu]

lol I've heard deadly from 96 on not 48, in fact, I've heard its best in the medium range and not necessarily in the short term, but I might be wrong on that.

Over the long run, the Euro is the best model, period. It falls off in accuracy monotonically in time. For individual events, the Euro has the best probability of being correct, but for any one storm, the GFS or the UKM or the GEM might "win." The whole deadly thing doesn't make a lot of sense to me.

[goombatommy]

just to summarize...we have the following:

gfs - hit (for eastern sections)

ggem - hit (for eastern sections)

ukmet - out to sea

euro - out to sea

kma - out to sea

jma - out to sea

being west of the cities, i've thrown in the towel but i guess for those along i-95 and east (especially coastal sections) still have a shot at a few inches.

I agree for the most part however, this was never really our storm to begin with. I think we may scrape by with 1 - 2" absolute max with those sharp QPF gradients - and that's if anything comes to play out of this.

[Kaner587]

Nam out to hr 36, PV slighlty west of 12z...s/w in the southwest pretty much the same as 12z, not much change..

it really looks like it wants to amplify the first storm once its gets off the coast and that be the reason for our PV trending west.