Re: Long Range Thread 13.0

[jmanley32]

Frank 12z 31st system thats just to south and bombs a little late?

[aiannone]

TWC's Tom Nizol just said, winter weather lovers in the east and especially Northeast should stay tuned to this pattern change. He likes clippers turning into Northeast snowstorms as they hit the coast.

[Frank_Wx]

Looks like threats after the 5th have a better shot once the baroclinic zone lifts N&W. Not discounting anything before then though. Great pattern coming up.

[SNOW MAN]

I was watching the Pro/Mets out at Penn State last night and they mentioned a possible storm off the coast for Monday/Monday night. Is there a possibility of this ? I also watched their 30 day outlook last week and they said what Frank has been telling us for a while, that there will be a pattern change to normal and below temperatures. And their feeling was that there would be more below normal temps. They said there would be a lot of cloudy days, but the one thing they didn't mention was anything about snow chances in that 30 day period. I just thought that was odd because usually when they do their outlook they always give you an idea on what the precip chances are for that time frame. I'm hoping it was just an oversight on their part. The period goes from 1/18/17 to 2/15/17.

[nutleyblizzard]

After looking at the 6z GFS, there are some threats out there in the long range including a doozy a couple days after the Super Bowl. We'll see. My hopes are not very high at the moment though. We really need a blockbuster February to salvage this winter.

[skinsfan1177]

I thought their is a threat around 1/30-2/2 timeframe and last model runs showed a close hit if spacing between vorts was better

[skinsfan1177]

From another weather board.

gefs finally showing a lot of atlantic improvement with a nice Neg ao nao bridge for 2/1

[CPcantmeasuresnow]

From another weather board.

gefs finally showing a lot of atlantic improvement with a nice Neg ao nao bridge for 2/1

Skins we received 4.3 inches of sleet with a little snow mixed in there during the night.

I would guess your family 20 miles north of me did receive a little more snow. Reports I saw from that area on other boards was about 5 inches of combo sleet and snow.

[Frank_Wx]

Very excited for the upcoming pattern 1st half of February. I will have a video out tomorrow. Resurgence of North Pacific ridging will be the first domino to fall as a result of a potent MJO wave propagating through phases 8 and 1. A Stratospheric Warming Event will take place the first couple days of February which will displace, but not destroy, the 10hPa PV to Europe and the 50hPa PV to Asia. Higher heights at the 500mb level are expected to dominate the Arctic and North Atlantic as we get deeper into February, especially after the 5th. The Baroclinic zone may be too far S&E from January 29th-5th but I am not ruling out any winter storms at this time. I feel one of those Alberta Clippers could try to re-develop off the coast though I admit the lack of blocking early on will make it challenging. There is a ton of PVA advertised on guidance and if we can get better spacing, or one to dig into the central part of the country and allow heights to rise along the EC, then we could see a snowstorm out of it. A projected -WPO/-EPO/-AO/-NAO pattern should increase chances of a Godzilla affecting the area. The pattern change has been talked about extensively, but it's nice to see it will come to fruition. Now let's see if we can get it to deliver...

[amugs]

Very excited for the upcoming pattern 1st half of February. I will have a video out tomorrow. Resurgence of North Pacific ridging will be the first domino to fall as a result of a potent MJO wave propagating through phases 8 and 1. A Stratospheric Warming Event will take place the first couple days of February which will displace, but not destroy, the 10hPa PV to Europe and the 50hPa PV to Asia. Higher heights at the 500mb level are expected to dominate the Arctic and North Atlantic as we get deeper into February, especially after the 5th. The Baroclinic zone may be too far S&E from January 29th-5th but I am not ruling out any winter storms at this time. I feel one of those Alberta Clippers could try to re-develop off the coast though I admit the lack of blocking early on will make it challenging. There is a ton of PVA advertised on guidance and if we can get better spacing, or one to dig into the central part of the country and allow heights to rise along the EC, then we could see a snowstorm out of it. A projected -WPO/-EPO/-AO/-NAO pattern should increase chances of a Godzilla affecting the area. The pattern change has been talked about extensively, but it's nice to see it will come to fruition. Now let's see if we can get it to deliver...

Frank great news and yes talked about this for sometime. IMHO I would rather a disturbed and elongated PV casue we take chances with a split like 2011-12 where it set up shop in Europe. Looking forward to 29-30 - I'll take an appetizer to get us going. Could be a 1978, 2015 set up incoming.

[skinsfan1177]

Hearing latest gfs isn't good

[jmanley32]

Ar only thing it shows surface is a cutter changing to snow at end around 6th. But that's fantasy land and who knows if there will b a storm and even harder where it will b.

[sroc4]

Its not much in the way of the LR any more but we need to keep a close eye on Jan 29th-1st.  All three global models are not that far off to a decent system developing when you look at H5.  Forget the surface.  

The CMC is the closest as of now,  with most of the working parts still not yet on the playing field.  And once again with every other system with so many working parts it wouldn't take much shifting to create a nice system at the surface.  Lets look at the 12z CMC followed by 12zGFS then 00z Euro(12z not out yet as of this write up).

First important piece is cold air.  The frontal boundary that swings through around Friday set us up with fresh cold air.  All models agree on this.  

Next look out west on the map.  We have a +PNA spike agreed upon on all three global models the axis of which looks to be in decent position.  THIS IS KEY IF THIS THREAT COMES TO LIGHT.  

However, look in SE Canada at the area labeled 1.  If this upper level system centers itself a tad further SE from wherethe CMC has it verbatim it may act as a 50/50 upper level block.  

As of now the area labeled 3 associated with southern stream energy remains stung out and separate from the N energy diving in out of N Canada on the Eastern flank of the +PNA ridge.    






Here are a few scenarios we may want to see to have this all come together.
1)IF The energy labeled number 1 trends a tad further S&E it may act as a temporary block to slow down the S Branch.  If the N Branch can phase with the the S ( 2 with 3) then a slightly better positioned number 1 would leave room to raise heights out ahead of the phased energy and a LP system has room to come up the coast.  If you look at the CMC image above I drew in what that might look like.

2)  IF number 2 is a bit faster and it phases with number 3 earlier same deal there may be enough time to raise heights out ahead leaving room for a LP to come up the coast.  

Normally one might say that the pattern doesn't support this as the flow remains progressive on the modeling as of now; however, if you look a little more closely the NAO takes a little dip into negative territory between the 26th-28th before headed towards positive/neutral again by around the 29th-30th.  The last 5 runs of both GFS and European models have trended stronger and stronger with this signal.  Ive said this before and Ill say it again, when you see a -NAO headed towards positive that tends to be a signal for a storm.  This idea held true for the system on the 7th.  Coordinate that with a healthy +PNA spike which is also agreed upon across the board in the modeling, and well we have to keep our eyes out for this time frame.  

One last though about the GFS and the Euro on the 500mb images I show above.  Both models have known biases.  GFS tends to be a progressively biased model with southern stream energy, and it is currently the most progressive soln keeping the southern stream a long strung out mess.  The European model has a known bias of holding back energy in the west, which it is doing on the image above.  So if you take that into acct I expect both models to come back towards a soln in the middle similar to what we see on the CMC which increases our chances of phasing with the N branch if it can trend a tad faster, and or if we can get a transient 50/50 LP block in place.  We shall see if todays 12z Euro comes in line with what I'm thinking.  Even with model bias correction there is of course no guarantee that what I'm hoping for comes to fruition.   A seperate thread will go up immediately IF we see any positive trends over the next 24-36hrs.  

We track!!

[skinsfan1177]

Its not much in the way of the LR any more but we need to keep a close eye on Jan 29th-1st.  All three global models are not that far off to a decent system developing when you look at H5.  Forget the surface.  

The CMC is the closest as of now,  with most of the working parts still not yet on the playing field.  And once again with every other system with so many working parts it wouldn't take much shifting to create a nice system at the surface.  Lets look at the 12z CMC followed by 12zGFS then 00z Euro(12z not out yet as of this write up).

First important piece is cold air.  The frontal boundary that swings through around Friday set us up with fresh cold air.  All models agree on this.  

Next look out west on the map.  We have a +PNA spike agreed upon on all three global models the axis of which looks to be in decent position.  THIS IS KEY IF THIS THREAT COMES TO LIGHT.  

However, look in SE Canada at the area labeled 1.  If this upper level system centers itself a tad further SE from wherethe CMC has it verbatim it may act as a 50/50 upper level block.  

As of now the area labeled 3 associated with southern stream energy remains stung out and separate from the N energy diving in out of N Canada on the Eastern flank of the +PNA ridge.    






Here are a few scenarios we may want to see to have this all come together.
1)IF The energy labeled number 1 trends a tad further S&E it may act as a temporary block to slow down the S Branch.  If the N Branch can phase with the the S ( 2 with 3) then a slightly better positioned number 1 would leave room to raise heights out ahead of the phased energy and a LP system has room to come up the coast.  If you look at the CMC image above I drew in what that might look like.

2)  IF number 2 is a bit faster and it phases with number 3 earlier same deal there may be enough time to raise heights out ahead leaving room for a LP to come up the coast.  

Normally one might say that the pattern doesn't support this as the flow remains progressive on the modeling as of now; however, if you look a little more closely the NAO takes a little dip into negative territory between the 26th-28th before headed towards positive/neutral again by around the 29th-30th.  The last 5 runs of both GFS and European models have trended stronger and stronger with this signal.  Ive said this before and Ill say it again, when you see a -NAO headed towards positive that tends to be a signal for a storm.  This idea held true for the system on the 7th.  Coordinate that with a healthy +PNA spike which is also agreed upon across the board in the modeling, and well we have to keep our eyes out for this time frame.  

One last though about the GFS and the Euro on the 500mb images I show above.  Both models have known biases.  GFS tends to be a progressively biased model with southern stream energy, and it is currently the most progressive soln keeping the southern stream a long strung out mess.  The European model has a known bias of holding back energy in the west, which it is doing on the image above.  So if you take that into acct I expect both models to come back towards a soln in the middle similar to what we see on the CMC which increases our chances of phasing with the N branch if it can trend a tad faster, and or if we can get a transient 50/50 LP block in place.  We shall see if todays 12z Euro comes in line with what I'm thinking.  Even with model bias correction there is of course no guarantee that what I'm hoping for comes to fruition.   A seperate thread will go up immediately IF we see any positive trends over the next 24-36hrs.  

We track!!

Great write up and easily to understand

[jmanley32]

Thanks sroc glad to hears there's at least some potential in sr.

[oldtimer]

Sroc Thanks for all your understandable stuff Maybe you can help me on this If a upper level low catches surface low, does that mean the system can't intensify further? Does it begin to weaken? Would that be one of the reasons the wind backed off late afternoon? Pressure gradient weakens

[sroc4]

Sroc  Thanks for all your understandable stuff   Maybe you can help me on this   If a upper level low catches surface low, does that mean the system can't intensify further?  Does it begin to weaken?  Would that be one of the reasons the wind backed off late afternoon?  Pressure gradient weakens    

To a degree yes. Initially upper level divergence is created by the vorticity embedded within the trough out ahead of it and this is where a surface low gets generated. However, When that vorticity closes itself off to create an upper level LP center as the trough gets negatively tilted the track of the surface low begins to shift N and even NW if there is enough negative tilt. If the ULL pivots over top, or catches the surface low for which it originally created it will effectively cap it off. Once the ULL is right over top the surface LP the ULL the surface LP is now subject to upper level "Convergence" associated with the Upper level LP over top.

IMO this was the reason for winds letting up some throughout the middle of the day yesterday, because the primary low became occluded, synonymous with what we just described. Now bear in mind there was still strong upper level divergence ahead of our ULL within a negatively tilted trough so the primary didnt just disappear, but rather what we saw was a period of several hrs where the primary surface low weakened as it began to transfer off the coast. At its peak the primary was at about 987-988mb over the eastern Tenn valley before it began to transfer off the DELMARVA coast at which time the center was no longer a small compact tight center. Instead during the transfer off the DELMARVA it was a much broader, elongated at times, circulation and weakened to between 992-994mb during the transfer. Once the primary low that was beneath the ULL was completely snuffed out the new primary off the coast took over. Iit then began a similar evolution the original primary had and that was to become condensed and compact center that began to intensify beneath upper level divergent conditions once again and winds picked back up into the early and late eve.

The best analogy to help you visualize is to think of a wood burning stove. With the flue wide open the fire burns bright. However by closing the flue you effectively prevent the warm air from rising up and out through the chimney effectively preventing the rising air. The result is the fire gets dampened.

Hope that helped

[Math23x7]

So much for cold weather in early February...



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