And we're off - first threat for a few mangled flakes

[earthlight]

two storm systems to keep an eye on towards the end of the week.

the first one is a long shot but looks to provide the chance for a few wet flakes north and west as the system wraps up later thursday. this system will undoubetly have more profound snow potential in northern new england. thinking of driving up to my place in south central vermont wednesday evening. we will see.

second system is a beast for this time of year -- mid level height falls are very impressive on the euro specifically for three runs in a row now. the gfs is less enthused (what a surprise as it flattens the mid level ridge allowing the trough to de-amplify eastward).

i will say this -- if the upper air pattern on the euro is correct, we could see snow into the immediate suburbs. i think it's going to be harder than anticipated to get snow falling in the city or east with warm air still very much in place. we will need perfect timing and a strong system for that.

we will see. and that's what this thread is for. the beginning of another marathon. I hope the usual crew begins to trickle in over the next few days. it's good to be back with y'all. we are going to have a fun 5 months.

[uncle W]

this is a great sign if this storm plays out like the models say it will...Is this what the storm track will look like at times this year?...

[tmagan]

A bit surprised to see that Central Park has had only three Octobers with accumulating snowfall and the last was 59 years ago.

[Edge Weather]

I am looking forward to the potential of this weekend's storm. I have been tracking this one using the GFS since Saturday the 15th.

[TheTrials]

its literally euro and ukmet vs. the world. Not even a gfs ensemble member showing something close to the euro solution.

[Neblizzard]

Sure looks like an interesting setup for the weekend storm. Pretty robust +PNA ridge over the west, major nor'easter is certainly a good possibility....

[earthlight]

some euro maps from last night during deformation snows. by the way it has a period where even the city gets 1-2" in a 3 hour period.

mslp & precip | 850mb temps/heights | 2m agl temps

[snywx]

its literally euro and ukmet vs. the world. Not even a gfs ensemble member showing something close to the euro solution.

HPC seems to like the Euro/Ukmet idea..

http://www.hpc.ncep.noaa.gov/discussions/hpcdiscussions.php?disc=pmdepd

[TheTrials]

HPC seems to like the Euro/Ukmet idea..

http://www.hpc.ncep....php?disc=pmdepd

They always favor Euro in the long range, and rightly so with its verification. I mean, last night was the perfect track for NYC N and W, what's the chances that stays locked in?

Regardless, I would take this 500mb setup any day of the week, so let the chips fall where they may.

[earthlight]

i still think the euro has to be considered a wild outlier solution, despite some support amongs its ensemble members. one thing to be considered is that the gfs "bias" per se doesn't really work fully into this specific event as it is right now. the gfs isn't shearing out any shortwave or phase--it's simply not digging the trough as it crosses the international border.

the progressive nature of the ridge axis over the rockies has a whole lot to do with this as it rolls eastward and the shortwave diving south takes a southeast heading and then slides through the northeast under the upper air trough to the north of new england. the euro allows for much greater amplification (we're talking hundreds of miles farther south) than the gfs. the gfs and its global ensembles just have a very flat look to them--and the synoptic setup looks just a hair flat to me just eyeballing it.

something will give eventually--but the big wound up wet snow bomb on the euro is still an outlier for sure right now.

[Jefflaw77]

Oh boy.. The battle of the models is beginning to take shape.. As Earthlight stated- the next 5 months should rock.. Whether they'll live up to last years craziness is still up in the air.. Hoping to see a few flakes before we usher in the month of November should provide a touch of winter in everyone's mind and create havoc for the general public... ))

[earthlight]

here's the amplification of the upper air trough on the euro valid at 120 hours from the 00z run last night (valid 00z sunday). go check out the gfs 00z or 06z run for the same valid time if you want a real laugh. not even in the same ballpark.

[Edge Weather]

JMA has the exact same solution as the Euro. And JMA is probably better than the GFS

its literally euro and ukmet vs. the world. Not even a gfs ensemble member showing something close to the euro solution.

[supermeh]

12z NAM 500 mb

http://mag.ncep.noaa.gov/NCOMAGWEB/appcontroller?prevPage=Model&MainPage=indexℑ=&page=Param&cycle=10%2F25%2F2011+12UTC&rname=UPPER+AIR+PARMS&pname=500_vort_ht&pdesc=&model=NAM&area=NAMER&cat=MODEL+GUIDANCE&fcast=084&areaDesc=North+America+-+US+Canada+and+northern+Mexico&prevArea=NAMER&currKey=model&returnToModel=&imageSize=M

6z GFS 500 mb

http://mag.ncep.noaa.gov/NCOMAGWEB/appcontroller?prevPage=Model&MainPage=indexℑ=&page=Param&cycle=10%2F25%2F2011+06UTC&rname=UPPER+AIR+PARMS&pname=500_vort_ht&pdesc=&model=GFS&area=NAMER&cat=MODEL+GUIDANCE&fcast=090&areaDesc=North+America+-+US+Canada+and+northern+Mexico&prevArea=NAMER&currKey=model&returnToModel=&imageSize=M

[TheTrials]

I like the look of the NAM at 84 hours, even though its way at the end of its useful range.

As to JMA vs. GFS, JMA is a very good model inside of 3 days, but GFS beats it at 5 days, even though JMA is 4DVAR.

[TheTrials]

Look at the nam at the end of its run, heights are aplifying out ahead of the vorts pretty good with a nice return flow out of the GOM. Southern vort is much more potent, like the euro.

It's not there yet, but it looks better than the gfs right there.

[Isotherm]

Can't pinpoint an exact time, but I recall many storm threats the past couple years in which the Euro was our only hope, then ended up caving to the others as we approached the time frame. We need to see some consistency from run to run and more model support.

[supermeh]

Look at the nam at the end of its run, heights are aplifying out ahead of the vorts pretty good with a nice return flow out of the GOM. Southern vort is much more potent, like the euro.

It's not there yet, but it looks better than the gfs right there.

That vort in TX at the end of the NAM run looks good.

[jm1220]

I would really favor inland areas, places above 500 foot elevation, etc in terms of ACCUMULATING snow from this. It's just very hard to get cold enough air into shore regions when water temps are still near 60 or even above. Dynamics will be key-if we have massively crashing heights as this thing develops off NJ or the Delmarva, there could be a burst of snow anyway for everyone. But I don't see it happening unless a CCB develops as the low bombs away. If it's more of an overrunning type situation without dynamic banding, I don't see it benefitting many near NYC proper. I know it's been mentioned in the SNE thread and elsewhere, but even a few inches of snow can cause a lot of tree damage this time of year. I remember seeing trees and limbs down back in Oct 2005 when we had 3-4" of snow at Penn State (there was a lot in Oct 2009 when they had something like 6-8"). Most trees here still have leaves and can easily take damage.

[CooL]

here's the amplification of the upper air trough on the euro valid at 120 hours from the 00z run last night (valid 00z sunday). go check out the gfs 00z or 06z run for the same valid time if you want a real laugh. not even in the same ballpark.

the models are already in winter mode..euro has a violent s/w dropping from n - s in the plains, then rounds the trough and boom. GFS is way different. I agree with you, something will eventually give

http://www.meteo.psu.edu/~gadomski/AVN_6z/f90.gif

[Eskimo Joe]

12z NAM 500 mb

http://mag.ncep.noaa...el=&imageSize=M

6z GFS 500 mb

http://mag.ncep.noaa...el=&imageSize=M

Look at the placement of the southern stream energy. NAM has it over Texas, while GFS is over Florida. HUGE geographic difference.

[ag3]

I would really favor inland areas, places above 500 foot elevation, etc in terms of ACCUMULATING snow from this. It's just very hard to get cold enough air into shore regions when water temps are still near 60 or even above. Dynamics will be key-if we have massively crashing heights as this thing develops off NJ or the Delmarva, there could be a burst of snow anyway for everyone. But I don't see it happens unless a CCB develops as the low bombs away. If it's more of an overrunning type situation without dynamic banding, I don't see it benefitting many near NYC proper. I kniw it's been mentioned in the SNE thread and elsewhere, but even a few inches of snow can cause a lot of tree damage this time of year. I remember seeing trees and limbs down back in Oct 2005 when we had 3-4" of snow at Penn State (there was a lot in Oct 2009 when they had something like 6-8"). Most trees here still have leaves and can easily take damage.

There has to be a storm first. Euro and its sister, Ukie, are the only models that have it right now.

[TheTrials]

Can't pinpoint an exact time, but I recall many storm threats the past couple years in which the Euro was our only hope, then ended up caving to the others as we approached the time frame. We need to see some consistency from run to run and more model support.

well, we are approaching the time frame where the euro loses a solution, only to find it again closer to the event. All these vorts are in regions that are not sampled well and as we have seen time and time again, regardless of how many people say it shouldn't matter, when the vorts hit the denser sounding networks things can change drastically.

[Isotherm]

Can't pinpoint an exact time, but I recall many storm threats the past couple years in which the Euro was our only hope, then ended up caving to the others as we approached the time frame. We need to see some consistency from run to run and more model support.

As depicted right now, the PNA ridge out west isn't that impressive (somewhat flat). Also, phase 2 MJO wave is in the process of rapidly de-amplifying, which lends support for a weaker trough in the East and thus lower probabilities of a big coastal storm. We'll see, but atm I don't believe the second system will come up the coast ala the Euro.

[jm1220]

There has to be a storm first. Euro and its sister, Ukie, are the only models that have it right now.

I like the fact that the Euro has ens support right now, and has some support from the UKMET. There's quite a potential for a storm (huge temp contrast between water and land) if we can somehow buy a phase, and it did happen last year despite the stronger Nina then (although we had nice blocking to help depress south the northern stream. It's hard to trust what the GFS says about this at 100 hrs out anyway.

Whether it happens or not, it's all good practice for prime time, and perhaps it can be a good foreshadowing of what's to come.

[Edge Weather]

I have been tracking this storm on model runs since October 15. It has been on one model or the other every day since then. I remember starting to track it using the GFS which was showing this storm starting on October 15. I find it extremely difficult to believe that it won't happen. I think the GFS will pick it back up soon.

[TheTrials]

As depicted right now, the PNA ridge out west isn't that impressive (somewhat flat). Also, phase 2 MJO wave is in the process of rapidly de-amplifying, which lends support for a weaker trough in the East and thus lower probabilities of a big coastal storm. We'll see, but atm I don't believe the second system will come up the coast ala the Euro.

It will do, we have had coastals pop with lesser ridges, even -PNA. It may even be a good thing here as the blocking is transient and too much amplification would be an inland runner.

IMHO it is more about the strength of the vorts in the split stream and the potential for phasing.

[earthlight]

As depicted right now, the PNA ridge out west isn't that impressive (somewhat flat). Also, phase 2 MJO wave is in the process of rapidly de-amplifying, which lends support for a weaker trough in the East and thus lower probabilities of a big coastal storm. We'll see, but atm I don't believe the second system will come up the coast ala the Euro.

Agreed. The Euro has a couple of things occuing which all play a major role. We both discussed them...the ridge is stronger and farther west, the northern stream digs very far south, and the southern stream phase occurs at the right time. All of these events, while possible, arent likely.

Let's also throw in there that the event occurs at 00-12z when things are coolest. What a perfect run, huh? Jesus.

[tornadojay]

northern stream energy certainly looks better on the GFS compared to 6Z

[TheTrials]

northern stream energy certainly looks better on the GFS compared to 6Z

it's having a terrible time with the southern vorts and the hurricane. It certainly made some improvements.