Long Range Discussion 20(20) (Ha!)

1-3 to 4 storm is ALIVE!!

Sudden stratospheric warming is underway! Here's a selection of radiosonde ascents from Russia & Mongolia at 12Z today, which captured the warming in the mid-stratosphere. https://t.co/zaxvOFTGnM pic.twitter.com/ig7zgioj5G

— Simon Lee (@SimonLeeWx) December 29, 2020

HOUSTON WE HAVE IGNITION!!

amugs wrote:1-3 to 4 storm is ALIVE!!

Yeah.  I see two things conditions that could make this interesting for a light/moderate event.

The trough starts to go negative as it hits the coast.
The ULL stays south and east of the area.  

It's thread the needle since we don't have a good antecedent air mass and we are hoping for a low latitude departure of the ULL.  I could see LI getting into some action though if the storm intensifies quickly enough.  You never know quite honestly.

Tnis is what I was talking g about above in how the NAO and AO will help push the LP out of western Canada and AK and promote a Negative EPO

Tonight's GEFS Ext Ens thru Jan in 7 day increments. Getting the Urals ridging in NW Asia to calm down is a good first step to look for to change the Pacific pattern. As that happens, the heavy low pressure in AK and Gulf of AK weakens...time will tell if the ideas here r correct pic.twitter.com/gk995BwY6R

— griteater (@griteater) December 30, 2020

I mean it’s not a grade A threat but I’m with you heehaw and mugs. The 1/3-1/4 threat continues to gain traction. Wave spacing between the 1st-2nd ice threat and this time frame just might be perfect. The first system lifts out into the 50/50 vicinity and just enough confluence might be there along the coast as the energy emerges from the south. Gfs looks really close but south and east. CMC has a beast of a storm hugging the coast. We are just about under 100hrs where the details will start to reveal themselves. Again not a grade A chance but def worthy of the mention.

GFS out to lunch as usual with the 3rd/4th chance and will play catch up once again. I would go with a Euro/cmc blend for now. I think there will be a storm but cold air is limited especially in NYC metro.

Thr block looks stout the issue is tge pacific and the epo. We don't seem to have a cold air source.

amugs wrote:Tnis is what I was talking g about above in how the NAO and AO  will help push the LP out of western Canada and AK and promote a Negative EPO

Tonight's GEFS Ext Ens thru Jan in 7 day increments. Getting the Urals ridging in NW Asia to calm down is a good first step to look for to change the Pacific pattern. As that happens, the heavy low pressure in AK and Gulf of AK weakens...time will tell if the ideas here r correct pic.twitter.com/gk995BwY6R

— griteater (@griteater) December 30, 2020

Nice post. The models are definitely hinting at heights rising in EPO and PNA regions as we head towards January 10. It's a delicate and fine dance to get the PAC to become consistently better. However, the higher heights in the arctic and NAO region really appear to have staying power.

sroc4 wrote:I mean it’s not a grade A threat but I’m with you heehaw and mugs. The 1/3-1/4 threat continues to gain traction. Wave spacing between the 1st-2nd ice threat and this time frame just might be perfect. The first system lifts out into the 50/50 vicinity and just enough confluence might be there along the coast as the energy emerges from the south. Gfs looks really close but south and east.  CMC has a beast of a storm hugging the coast. We are just about under 100hrs where the details will start to reveal themselves. Again not a grade A chance but def worthy of the mention.

The 06Z GFS would be a decent hit if the energy was a just a bit more consolidated at the 850/700 levels. I think just a hair more neutral trough would have done it. The energy latitude looked good to your point on the confluence. Interesting to say the least.

Wow.  I'm a buyer for wintry events with this kind of rooted signal. This doesn't appear ephemeral to me.  People will debate each teleconnection fervently, but for my money this is the one I'm most interested in for our area.  Of course we need to get the PAC air flushed out of the area, but the bottom line is slight adjustments are all that is needed to do that.  Having this anchored allows for these gyrations in the PAC to occur and then you have a much higher probability of an event when things line up.

Frank_Wx wrote:

aiannone wrote:Models such as the euro eukie and cmc coming around to the idea of a coastal on Sunday. Gfs is last to the party. However until you get up far NW of NYC looks like cold air will be absent.

Was just coming to say I may have spoken too soon when I stated “no snow” first ten days of January, but you’re correct in saying the cold air is lacking and it would take a stronger storm to pull the cold air into the coast (manufacture cold air through dynamics). Given its early January it won’t take much!

You of all people Frank to make such a definitive statement as "no snow" lol  Unless of course its a bit of a reverse psychology tactic then well played sir. Obv there is still a ways to go but if you look at the evolution in the modeling for this time frame its getting really interesting.  Again the wave spacing with the first system ahead of it from a timing stand point is just about what we would need to make it happen.  The mid month storm had the same needs with the Monday storm setting up a bit of a block for our main event on Wed eve into Thursday. Obv thats just one aspect of what needs to happen but with the Pac the way it is a 50/50 or pseudo 50/50 low that provides some form of confluence as it heads that way is key for any sort of chance.  

Heehaw there is your neutral to neg tilt compliments of todays 12z GFS.  

sroc4 wrote:

Frank_Wx wrote:

aiannone wrote:Models such as the euro eukie and cmc coming around to the idea of a coastal on Sunday. Gfs is last to the party. However until you get up far NW of NYC looks like cold air will be absent.

Was just coming to say I may have spoken too soon when I stated “no snow” first ten days of January, but you’re correct in saying the cold air is lacking and it would take a stronger storm to pull the cold air into the coast (manufacture cold air through dynamics). Given its early January it won’t take much!

You of all people Frank to make such a definitive statement as "no snow" lol  Unless of course its a bit of a reverse psychology tactic then well played sir. Obv there is still a ways to go but if you look at the evolution in the modeling for this time frame its getting really interesting.  Again the wave spacing with the first system ahead of it from a timing stand point is just about what we would need to make it happen.  Obv thats just one aspect of what needs to happen but with the Pac the way it is a 50/50 or pseudo 50/50 low that provides some form of confluence as it heads that way is key for any sort of chance.  

Heehaw there is your neutral to neg tilt compliments of todays 12z GFS.  

Great post. This is getting interesting for sure. The antecedent air mass is not good, but if the storm can consolidate quickly and stay south of us then it will snow.

heehaw453 wrote:

sroc4 wrote:

Frank_Wx wrote:

aiannone wrote:Models such as the euro eukie and cmc coming around to the idea of a coastal on Sunday. Gfs is last to the party. However until you get up far NW of NYC looks like cold air will be absent.

Was just coming to say I may have spoken too soon when I stated “no snow” first ten days of January, but you’re correct in saying the cold air is lacking and it would take a stronger storm to pull the cold air into the coast (manufacture cold air through dynamics). Given its early January it won’t take much!

You of all people Frank to make such a definitive statement as "no snow" lol  Unless of course its a bit of a reverse psychology tactic then well played sir. Obv there is still a ways to go but if you look at the evolution in the modeling for this time frame its getting really interesting.  Again the wave spacing with the first system ahead of it from a timing stand point is just about what we would need to make it happen.  Obv thats just one aspect of what needs to happen but with the Pac the way it is a 50/50 or pseudo 50/50 low that provides some form of confluence as it heads that way is key for any sort of chance.  

Heehaw there is your neutral to neg tilt compliments of todays 12z GFS.  

Great post.  This is getting interesting for sure.  The antecedent air mass is not good, but if the storm can consolidate quickly and stay south of us then it will snow.  

Yeah there are def several key things that need to fall into place ala "baby bear," just right. But like you've been saying if you get that trough to tilt towards neg you get a deepening low which will drag down and make its own cold air. Key is of course when and where. With the time of year in our favor climatologically speaking, marginal temps can be overcome with the right spark much more easily compared to early and/or late in the season.

If you look at the 12Z CMC the track of the 850 mb low is favorable.  The problem is it's letting the 500 low get a bit too far north as it warms the mid-levels.  Just slightly earlier transfer and keep that trough negative as it hits the coast.  Maybe this turns out to be a miss, but it won't miss by much.

sroc4 wrote:

Frank_Wx wrote:

aiannone wrote:Models such as the euro eukie and cmc coming around to the idea of a coastal on Sunday. Gfs is last to the party. However until you get up far NW of NYC looks like cold air will be absent.

Was just coming to say I may have spoken too soon when I stated “no snow” first ten days of January, but you’re correct in saying the cold air is lacking and it would take a stronger storm to pull the cold air into the coast (manufacture cold air through dynamics). Given its early January it won’t take much!

You of all people Frank to make such a definitive statement as "no snow" lol  Unless of course its a bit of a reverse psychology tactic then well played sir. Obv there is still a ways to go but if you look at the evolution in the modeling for this time frame its getting really interesting.  Again the wave spacing with the first system ahead of it from a timing stand point is just about what we would need to make it happen.  The mid month storm had the same needs with the Monday storm setting up a bit of a block for our main event on Wed eve into Thursday.  Obv thats just one aspect of what needs to happen but with the Pac the way it is a 50/50 or pseudo 50/50 low that provides some form of confluence as it heads that way is key for any sort of chance.  

Heehaw there is your neutral to neg tilt compliments of todays 12z GFS.  

Sroc this 50/50 low makes this so tempting for me to bite and I think it's going to really limit the progression of the northern extent of the ULL.  A better air mass and I'd be salivating.  Expect a lot of 50/50 lows in the future though if this blocking verifies.  

I think it's about time our guy heehaw gets a title under his name.

crippo84 wrote:I think it's about time our guy heehaw gets a title under his name.

If you follow the legend on the home page, you will see that his name in green assigns him to be an advanced forecaster,so he don't need no stinkin' badges.

But if you insist, might I suggest "The Long Ranger"

Pardon the banter...

If we miss out on 1/3 other chances will come.  Maybe sooner than later quite honestly.

This is from today's 12Z Euro Operational.  When you see big digging troughs like this tilting negative at that latitude it's a good thing.  

Frank_Wx wrote:Signs as of now point to a coastal storm on the 3rd but lacking cold, which obviously would mean rain. I rather it go out to sea!

You're probably right Frank. I'll say this sometimes models don't appreciate the -NAO until very late in the game even though it's east based now.  I've seen this before whereby the spacing between systems gets disturbed just enough to shunt energy sooner than modeled.  Pay particular attention to how fast the departing storm moves out to the 50/50 area.  If you see it taking longer than modeled then that will raise a flag.

I see some pros/cons.  Probably Friday it's going to be known for sure if we are in the game or not, but I'll err on the side of NO for now mostly due to the air mass.

Cons
1.  Poor antecedent air mass.  Huge weight.
2.  Track of the ULL before it transfers. Huge weight.

Pros
1.  The 50/50 low albeit not extremely strong
2.  The -NAO albeit east based
3.  Tracks of the mid-level lows could be favorable.
4.  Climatology for snow.

Frank_Wx wrote:Signs as of now point to a coastal storm on the 3rd but lacking cold, which obviously would mean rain. I rather it go out to sea!

Hey now, we have a chance of seeing some snow north of 84.

Frank_Wx wrote:Signs as of now point to a coastal storm on the 3rd but lacking cold, which obviously would mean rain. I rather it go out to sea!

Coast is always at play for rain without a cold air injection.
GFS has this for the levels of atmosphere

925


850

Look at all the LP over Canada, West Coast adn Ak regions gets rooted by the nd of the run


Orangy/red/tello wcolros mover across the NA continent into the AK region to help buckle the flow

This is something that is super long range but also interesting to note that our currents are changing in the oceans as they always have. This can lead to sudden or moderate cooling of the land as the arctic ocean current spills fresh cold water into teh Northern Atlantic and this shunting or retracting the Gulf stream waters lower in latitude.

Yes that looks like cold to Arctic. Over 90% of Arctic heat is coming from Norwegian current.

If heat transport from Atlantic decreases so much it will mean cold Arctic at future. Of course heat transfer/freezing up have years to time lags. I say ~10 years https://t.co/rv8buhbYE7 pic.twitter.com/IcBvaG5pdu

— peikko763 (@peikko763) December 27, 2020

AMOC - Atlantic Ocean Multidecadal Oscillation

Yes that looks like cold to Arctic. Over 90% of Arctic heat is coming from Norwegian current.

If heat transport from Atlantic decreases so much it will mean cold Arctic at future. Of course heat transfer/freezing up have years to time lags. I say ~10 years https://t.co/rv8buhbYE7 pic.twitter.com/IcBvaG5pdu

— peikko763 (@peikko763) December 27, 2020