The PHL/NYC Medium Range Thread - Part 2

[Atlas]

Earthlight,

Looking at some of the patterns showing up in the long raneg it does seem like some kind of overrunning event could be in the cards. With the NAO going negative again what do you think about a potential ice storm in Early-Mid Jan. I think this type of pattern might support it , thoughts? For instance, I could see an ice to rain type of storm. Like Am19psu said in this thread the storm track in early Jan could be west, but that doesnt mean that the storms wont start out frozen in our area.

[Rainshadow]

This is all WAGing on my part. I don't see any blowtorch pattern setting up for the foreseeable future (through Mid Jan at the least). It looks like the gwo is cycling more toward ninaish but for the first half of the month it looks like we will have a -nao repeat and then the wpo is forecast to go negative that is going to bring cross polar flow on this side of the hemisphere.

[am19psu]

This is all WAGing on my part. I don't see any blowtorch pattern setting up for the foreseeable future (through Mid Jan at the least). It looks like the gwo is cycling more toward ninaish but for the first half of the month it looks like we will have a -nao repeat and then the wpo is forecast to go negative that is going to bring cross polar flow on this side of the hemisphere.

I'm with you Tony. I haven't looked at anything today, but when I went through everything at work this week, the blocking signal in the stratosphere looks to continue through the end of January, imo.

[Rainshadow]

I'm with you Tony. I haven't looked at anything today, but when I went through everything at work this week, the blocking signal in the stratosphere looks to continue through the end of January, imo.

Happy New Year!

Yeah, it looks like the Siberian Ridge takes the place of the -nao and I wouldn't discount another -nao ridge forming again either. Only difference it appears, the west gets in on it also this time. MJO dead in the water, GWO hanging close to neutral, love your sub-title yeah some nina.

[am19psu]

Happy New Year!

Yeah, it looks like the Siberian Ridge takes the place of the -nao and I wouldn't discount another -nao ridge forming again either. Only difference it appears, the west gets in on it also this time. MJO dead in the water, GWO hanging close to neutral, love your sub-title yeah some nina.

The -EPO setting up is going to be one for the ages. It looks like a 1060mb high is going to drop down from the Yukon into the Northern Plains by next week. I wouldn't be surprised to see records broken.

That means the primary storm track, if any sort of southern stream develops, should be from the SW to Middle MS Valley. Nothing is showing up in the models yet, but I'd bet on some nasty weather centered somewhere in an area bounded by OKC/OMA/STL/MEM next week.

For us, I haven't really changed my opinion. We should remain mostly cold and dry, punctuated by 1-2d warm ups prior to fropa from Jan 7-15.

[Rainshadow]

The -EPO setting up is going to be one for the ages. It looks like a 1060mb high is going to drop down from the Yukon into the Northern Plains by next week. I wouldn't be surprised to see records broken.

That means the primary storm track, if any sort of southern stream develops, should be from the SW to Middle MS Valley. Nothing is showing up in the models yet, but I'd bet on some nasty weather centered somewhere in an area bounded by OKC/OMA/STL/MEM next week.

For us, I haven't really changed my opinion. We should remain mostly cold and dry, punctuated by 1-2d warm ups prior to fropa from Jan 7-15.

Maybe we get a "break" here that the angle of the cold is nor direct, LOL at another -NAO ridging forming in baffin island.

[CAT5ANDREW]

We could be looking at a FEB 2007,JAN 2009 period of cold here starting this weekend.Despite DEC 2010 being well below normal,we did it without any arctic air and the brunt of the cold going West and South of us.Perhaps NYC sees temps between 4 and 8 degrees for lows.

[Rainshadow]

The -EPO setting up is going to be one for the ages. It looks like a 1060mb high is going to drop down from the Yukon into the Northern Plains by next week. I wouldn't be surprised to see records broken.

That means the primary storm track, if any sort of southern stream develops, should be from the SW to Middle MS Valley. Nothing is showing up in the models yet, but I'd bet on some nasty weather centered somewhere in an area bounded by OKC/OMA/STL/MEM next week.

For us, I haven't really changed my opinion. We should remain mostly cold and dry, punctuated by 1-2d warm ups prior to fropa from Jan 7-15.

Looking at the 12z ensembles, the dead on arrival mjo, the un-ninalike gwo, don't see any end in sight for a predominately cold pattern until maybe the last week of january at the earliest. Probably next week I'll type until maybe the first week in Feb at the earliest. Still looks like the first surge of arctic cold relatively speaking is going to be more west of the appalachians than east, then when the pna forecast to rise late, beyond day11 the angle of the cold gets fresher farther to the east.

The naefs pops are already greater with system2 about Jan11th than they are for system1 late this week around here, so we'll see how that works.

[am19psu]

Looking at the 12z ensembles, the dead on arrival mjo, the un-ninalike gwo, don't see any end in sight for a predominately cold pattern until maybe the last week of january at the earliest. Probably next week I'll type until maybe the first week in Feb at the earliest. Still looks like the first surge of arctic cold relatively speaking is going to be more west of the appalachians than east, then when the pna forecast to rise late, beyond day11 the angle of the cold gets fresher farther to the east.

The naefs pops are already greater with system2 about Jan11th than they are for system1 late this week around here, so we'll see how that works.

I really can't envision a scenario where you are wrong about the cold. There doesn't look to be a good MJO pulse for a while and there is no stopping the blocking.

I was just peeking at today's 8-14d analog, and it shows the precip max in the Mid-South/OH Valley. That jives with what I saw at H5 in the models today. I was trying to figure out why both the GFS and Euro wanted to spring everything to the coast (reacting to the natural baroclinic zone?). It's clearly still possible we could get something around the 12th, particularly if the northern stream shortwave is faster, but the H5 pattern in the models this afternoon looked to me like it should cut up.

[Jet-Phase]

I really can't envision a scenario where you are wrong about the cold. There doesn't look to be a good MJO pulse for a while and there is no stopping the blocking.

I was just peeking at today's 8-14d analog, and it shows the precip max in the Mid-South/OH Valley. That jives with what I saw at H5 in the models today. I was trying to figure out why both the GFS and Euro wanted to spring everything to the coast (reacting to the natural baroclinic zone?). It's clearly still possible we could get something around the 12th, particularly if the northern stream shortwave is faster, but the H5 pattern in the models this afternoon looked to me like it should cut up.

Wouldn't it be hard to cut up with the PV as strong as it is?

[CoastalWx]

Tony or Adam,

Do any of you have that sheet that had the GWO either daily or weekly?? I saw it posted a couple of weeks ago, but I can't find it anywhere. I think you may have been using it as a reference for Philly storms. Thanks again!

[am19psu]

Tony or Adam,

Do any of you have that sheet that had the GWO either daily or weekly?? I saw it posted a couple of weeks ago, but I can't find it anywhere. I think you may have been using it as a reference for Philly storms. Thanks again!

I'm not sure if this is what you're asking for, but you can get the daily text file here: http://www.esrl.noaa.gov/psd/map/clim/gsdm.composites.shtml

[am19psu]

Wouldn't it be hard to cut up with the PV as strong as it is?

In its current location, yes. But look at the modeled upper level pattern around 168 in the models today. The polar vortex, if you want to call it that, is well east.

The thing I might not be taking into account is the magnitude of the low level CAA across the Midwest. It really causes heights to crash right about the time where it looks like the low should cut (e.g. T+162 in the ECM or T+168 in the GFS).

EDIT: Both ensemble means are implying a Miller B with a cut up west of the Appalachians, then transition to the coast off Jersey. That's reasonable.

[Rainshadow]

Tony or Adam,

Do any of you have that sheet that had the GWO either daily or weekly?? I saw it posted a couple of weeks ago, but I can't find it anywhere. I think you may have been using it as a reference for Philly storms. Thanks again!

This was a spread sheet from Ender:

[CoastalWx]

This was a spread sheet from Ender:

http://www.americanw...post__p__166303

Ahh yes, that was it. Thank you both Adam and Tony.

-Scott

[Rainshadow]

In its current location, yes. But look at the modeled upper level pattern around 168 in the models today. The polar vortex, if you want to call it that, is well east.

The thing I might not be taking into account is the magnitude of the low level CAA across the Midwest. It really causes heights to crash right about the time where it looks like the low should cut (e.g. T+162 in the ECM or T+168 in the GFS).

EDIT: Both ensemble means are implying a Miller B with a cut up west of the Appalachians, then transition to the coast off Jersey. That's reasonable.

Hopefully this is the extreme left (north) end of all possible solutions, it would be tough at our latitude to stay all snow if the initial low gets that far north. I guess we'll have to see what occurs this weekend, because how much that low lingers over the maritimes will have a bearing on system #2.

[tombo82685]

the mjo looks like it wants to go into favorable territory next week

[am19psu]

Hopefully this is the extreme left (north) end of all possible solutions, it would be tough at our latitude to stay all snow if the initial low gets that far north. I guess we'll have to see what occurs this weekend, because how much that low lingers over the maritimes will have a bearing on system #2.

Clearly, my forecast for the surface low to go up west of the Appalachians could bust horribly if the PV lingers over the GL like the 0z/12z Euro and 0z GFS showed. However, ensemble guidance still shows a ton of spread. Looking at the NAEFS members from 0z, the spread still encompasses everything from a Lakes Cutter to an OTS solution. With the cold high dropping down the lee of the Rockies, my favored solution is still an early turn to the north, since the low level CAA should lower heights and allow for a strong baroclinic zone to form across the MS Valley or Midwest. That doesn't preclude Miller B-like redevelopment off the coast, but likely too late for PHL southward. Of course, if the PV hangs on like what the models showed yesterday, forget about it.

[am19psu]

the mjo looks like it wants to go into favorable territory next week

Euro and UKM are still pretty meh.

[NJwinter23]

Clearly, my forecast for the surface low to go up west of the Appalachians could bust horribly if the PV lingers over the GL like the 0z/12z Euro and 0z GFS showed. However, ensemble guidance still shows a ton of spread. Looking at the NAEFS members from 0z, the spread still encompasses everything from a Lakes Cutter to an OTS solution. With the cold high dropping down the lee of the Rockies, my favored solution is still an early turn to the north, since the low level CAA should lower heights and allow for a strong baroclinic zone to form across the MS Valley or Midwest. That doesn't preclude Miller B-like redevelopment off the coast, but likely too late for PHL southward. Of course, if the PV hangs on like what the models showed yesterday, forget about it.

I tend to believe that a solution such as the 1/4 12z gfs which would bring sleet to the coastal plain is the furthest left solution we will see with this pattern (save the ggem run from yesterday that showed a lakes cutter). The reason being the block which looks like it is in central Canada somewhere by this time. The 12z gfs yesterday amplified/closed off the system so far west that it normally would have cut into the Plains. But the block kept our heights just low enough even with the 50/50 largely on its way out and it kept opening up and shifting south until it reformed offshore. It was crawling too and trying to amplify. I haven't looked terribly into it, but I would tend to believe that a solution scooting south and out to sea is more likely than a lakes cutter on Jan 11-12th.

[am19psu]

I tend to believe that a solution such as the 1/4 12z gfs which would bring sleet to the coastal plain is the furthest left solution we will see with this pattern (save the ggem run from yesterday that showed a lakes cutter). The reason being the block which looks like it is in central Canada somewhere by this time. The 12z gfs yesterday amplified/closed off the system so far west that it normally would have cut into the Plains. But the block kept our heights just low enough even with the 50/50 largely on its way out and it kept opening up and shifting south until it reformed offshore. It was crawling too and trying to amplify. I haven't looked terribly into it, but I would tend to believe that a solution scooting south and out to sea is more likely than a lakes cutter on Jan 11-12th.

If I had to make a deterministic forecast right now, I'd probably develop the low in OK/AR and aim it at CMH, then redevelop a coastal low east of DOV/WWD, but that's still a WAG 6-7 days out. I'm not buying off on the polar vortex that's in the ops models from yesterday because there is nearly zero ensemble support for it. Maybe the ops are onto something, but I can't find an ensemble member with a similar evolution across the GLs.

I'm not sure what the high heights over Hudson Bay mean to the synoptic forecast across the CONUS, since it's not really doing anything to the synoptic flow at that time, other than funnel cold air southward, which does lower heights across the Midwest. Can you go deeper into your thoughts re: the Central Canada block?

[NJwinter23]

If I had to make a deterministic forecast right now, I'd probably develop the low in OK/AR and aim it at CMH, then redevelop a coastal low east of DOV/WWD, but that's still a WAG 6-7 days out. I'm not buying off on the polar vortex that's in the ops models from yesterday because there is nearly zero ensemble support for it. Maybe the ops are onto something, but I can't find an ensemble member with a similar evolution across the GLs.

I'm not sure what the high heights over Hudson Bay mean to the synoptic forecast across the CONUS, since it's not really doing anything to the synoptic flow at that time, other than funnel cold air southward, which does lower heights across the Midwest. Can you go deeper into your thoughts re: the Central Canada block?

I just think the placement of it retrograding from Greenland right now to I guess near Hudson Bay by 11th-12th will keep the heights down near the 50/50 spot too even if there isnt a true closed 50/50 present anymore. Or at least I think it is blocking this storm from cutting so far northwest to the point that were getting blasted with a warm rainstorm on current model runs. And Iike I said a lot of what I was talking about was based solely on the 12z/00z gfs runs. I do not disagree with the track you layed out in bold there at all actually. I just tend to think right now that a solution like that would be more on the left side of possibilities I guess. I could be wrong in my interpretation of all of this though.

[am19psu]

I just think the placement of it retrograding from Greenland right now to I guess near Hudson Bay by 11th-12th will keep the heights down near the 50/50 spot too even if there isnt a true closed 50/50 present anymore. Or at least I think it is blocking this storm from cutting so far northwest to the point that were getting blasted with a warm rainstorm on current model runs. And Iike I said a lot of what I was talking about was based solely on the 12z/00z gfs runs. I do not disagree with the track you layed out in bold there at all actually. I just tend to think right now that a solution like that would be more on the left side of possibilities I guess. I could be wrong in my interpretation of all of this though.

Nope, that's cool. I just wanted to get your take on it. I see the 50/50 being a more important consideration than the high heights over Hudson Bay, but we're basically saying the same thing.

And again, it's all moot anyway if the PV evolves the way the 0z ops models (except the UKM) showed last night.

[Porsche]

Any word on the EURO ens from last night anyone? Or maybe there is a link?

Thanks

[Rainshadow]

Nope, that's cool. I just wanted to get your take on it. I see the 50/50 being a more important consideration than the high heights over Hudson Bay, but we're basically saying the same thing.

And again, it's all moot anyway if the PV evolves the way the 0z ops models (except the UKM) showed last night.

I really don't think the UKMET solutions @ 144 have come close this winter at all. I don't trust the GFS MJO solution either, but its a moot point either its in a cold phase and we're cold, or its the valley of death and we are cold.

[NJwinter23]

Nope, that's cool. I just wanted to get your take on it. I see the 50/50 being a more important consideration than the high heights over Hudson Bay, but we're basically saying the same thing.

And again, it's all moot anyway if the PV evolves the way the 0z ops models (except the UKM) showed last night.

Understood and agree. I haven't gotten a great chance to look at the pattern evolution in depth for every model and run either so my realm of possible tracks may be too gfs-based. I was just surprised yesterday at how the storm was amplifying and closing off in the Intermountain region on the 12z gfs and yet still managed to scoot south/ redevelop in time for all snow/sleet DC north. I saw the blocking pattern in Canada as the culprit, but that was just the op run.

And I see what you are talking about with that PV forming over the Great Lakes on 00z runs last night, kind of stealing the show from the system. Definitely looks like a bit of a sketchy feature to me.

[am19psu]

Any word on the EURO ens from last night anyone? Or maybe there is a link?

Thanks

It's hard to get a good read on Earthsat because the 540dam height line at H5 is so important to this forecast, and they only give spag charts at 552 and 528, but it looks like it has a large spread like the NAEFS I talked about above. The ensemble mean shows lots of sagginess to the isobars at 144 from OH to the Bahamas.

Questions still >> answers.

[am19psu]

I really don't think the UKMET solutions @ 144 have come close this winter at all. I don't trust the GFS MJO solution either, but its a moot point either its in a cold phase and we're cold, or its the valley of death and we are cold.

Agree. The UKM really been awful over the Eastern CONUS this cold season, for whatever reason.

Re: the MJO, the Roundy progs show an evolution to what would be P7/P8 if convection would form over the dateline, but he still has +OLR anomalies there despite the MJO wave progressing.

[am19psu]

I really don't think the UKMET solutions @ 144 have come close this winter at all. I don't trust the GFS MJO solution either, but its a moot point either its in a cold phase and we're cold, or its the valley of death and we are cold.

Tony, I'm a little sketchy on my wintertime MJO stuff, but isn't the importance of going to P8 that it enhances the PNA ridge through subtropical forcing, allowing an easier time for systems to come up the Atlantic Seaboard?

[NJwinter23]

I know phase 8 for it's hypothesized/peer reviewed connections to the -NAO phase