Long Range Discussion 20(20) (Ha!)

amugs wrote:Well this is interesting by GFS for 1/1 NNJ, HV and EPA

Looks like another nice, cool rain storm for me. Awesome!

amugs wrote:Well this is interesting by GFS for 1/1 NNJ, HV and EPA

With a better track this would be warning level snowfall as there is a CAD with high pressure in Quebec. With WAR in place the ULL just gets shoved right through Detroit. Expect surface cold to hold on much longer than mid levels and if the precip can come in fast and hard enough then a few inches could be possible in those areas. It's also possible CAD could be stronger than currently modeled but with a track like that there are hard limits to any potential.

Last nights EURO continued to show an official SSWE taking place on or about January 5th. On this map that is shown by the negative U winds (mean zonal winds) of -2.0 m/s at 60N 10hPa. Also from this map you can see the EURO successfully splits the PV through Wave 1 warming - one HP over Siberia.



This a top down warming event, meaning the wind reversals to easterly begin at 1 hPa and propagate down toward the mid levels of the strat. The deep blue at 1 hPa and 70N suggest an anomalous warming event which is why the EURO is able to split the PV with just one wave.



Heat flux is pointing poleward and growing with time. The attack on the SPV is real, and evidence is mounting that it may not be able to withstand the attack and we’re beginning the process of permanently displacing the SPV.



No change from the GFS. In fact, it’s taking the wind reversal to another level outside of the 30 year average. Questions that remains:

1. Will there be a wave 2 warming event? Some models like the GFS only displace the SPV and the split doesn’t occur until January 12th when there are two warming events happening simultaneously (one High in the PAC/US side and another in the ATL). Our area would benefit most from seeing a SPV split through Wave 2 warming not just Wave 1.

2. What does this do to our pattern at the trop and when will we begin seeing the affects? I don’t think models will properly recognize the SSW until the New Year, and there is going to be wild swings in long range forecasts until that happens. Snow chances from now until Jan 10th will be limited and/or minor. We need to turn the NAO block from east to west based, but most importantly, break the +EPO pattern that’s hogging all of the cold air. It’s possible the SSW acts as a domino and we begin seeing tropical activity (MJO) develop around Jan 10th. This forcing should be enough to remove the lower heights over Alaska and bring them into the CONUS.

Frank I was going topmost the above maps but you did a more eloquent job explaining tjis. Very exciting. Later when I getbsime time I am going to share what resaercher has about the arctic ocean and currents. Interesting for sure.

Anyway I'd say we have an East Based Nina developing?? Which would mean a colder than normal winter possible, other factors at play as well.

Ring in 2021 any better than 2020??

With a -AO there will be many such CAD signatures that occur and ice is a threat for NYD.  These Highs will consistently get pushed down to Quebec and New England to supply cold air.  There is evidence on the modeling that the -NAO will push more westward to Baffin Bay and that will make it much less likely for storms to cut to our west.  The PAC will be work in progress but I believe it will ridge from time to time in the PNA and EPO areas.  The pattern being a work in progress is a scenario we're all used to by now.  It can be slow and frustrating, but as I have said if the AO can stay negative we will get our chances as other things become a bit more favorable.

And btw there continues to be a threat for 1/3 for a potential coastal system.

Get this trough to go a bit negative and we'd be in business. This is a 6+ days out and there will be adjustments.

Regarding the threat window for 1/3 this is today's 0Z Euro.  That's a pretty potent shortwave ULL in a favorable location for us.  What's it's missing is a negative tilt, but definitely worthy of watching.  

I understand this is para GFS and take it with a grain of salt, but this is what you'd want to see for 1/3 if it were to materialize.

heehaw453 wrote:I understand this is para GFS and take it with a grain of salt, but this is what you'd want to see for 1/3 if it were to materialize.

Does this mean we may have a chance, even if it is a slim chance

heehaw453 wrote:I understand this is para GFS and take it with a grain of salt, but this is what you'd want to see for 1/3 if it were to materialize.

Does this mean we may have a chance, even if it is a slim chance

phil155 wrote:

heehaw453 wrote:I understand this is para GFS and take it with a grain of salt, but this is what you'd want to see for 1/3 if it were to materialize.

Does this mean we may have a chance, even if it is a slim chance

I would put the threat level at low right now. Let's see what guidance shows on Wednesday.

heehaw453 wrote:

phil155 wrote:

heehaw453 wrote:I understand this is para GFS and take it with a grain of salt, but this is what you'd want to see for 1/3 if it were to materialize.

Does this mean we may have a chance, even if it is a slim chance

I would put the threat level at low right now. Let's see what guidance shows on Wednesday.

Wait and hopefully we will have something to track

Look at the latest AO projections just absolutely tank.  If true it will just take a little movement of the NAO and PAC ridging to make for some very interesting times. You also get the feeling with these kinds of deviations that it may have some staying power.

heehaw453 wrote:Look at the latest AO projections just absolutely tank.  If true it will just take a little movement of the NAO and PAC ridging to make for some very interesting times.  You also get the feeling with these kinds of deviations that it may have some staying power.

Hopefully it doesnt lead to suppression depression. Sometimes too much of a good thing can be a bad thing.

From what I'm hearing today it looks like the SPV will be severely weakened and displaced but not split which is what we want as a split usually favors Eurasia. It looks like guidance may now be catching on to this as blocking up top is dropping to levels we haven't seen in over a decade. If the pac wasn't a total mess I dare to say that we would be cold and dry with a lot of suppressed systems with that look. The new Euro weeklies are out and beginning about January 10th the PAC looks to improve and the AO and NAO stay negative right into February. Weeks 3 and 4 building Aleutian Ridge and a trough across the whole continental US with blocking up top could be some fun times ahead we shall see

How about this!


griteater
@griteater
Current Siberia High showing at 1076mb, not far off the world record high of 1084mb on Dec 31, 1968. Maybe this is a sign (ha) as Jan-Mar 1969 went on to be one of the all-time great Greenland Blocking winters

Sayaka Mori
@sayakasofiamori
Siberia's #Oymyakon had -57.2C (-71F) on Monday due to a significantly developed Siberian High. Its central #pressure now is 1076hPa. Though it is lower than the world's highest pressure of 1083.8hPa recorded in #Siberia in 1968, it's definitely amazing.

NY storm looking icy for NW regions and ticking S. CAD being recognized.






The upcoming pattern with the W based Greenland Blo k it retrograde over the top and kicks rhe LP out of western CAN and AK to thus promoting a PNA and N EPO. Time will tell but if you keep that Ural HP as grittier tweeted about i. That spot you will reinforce the N NAO. Time will tell but let's see. Jan 4th storm is on the table as pe EURO to help kick things off.

Age of Aquarius peeps!!

We had our big ice storm last year and lost power, all set with another ice storm.  That does not look good at all.  But whatever we get is out of our control I guess, is there anyway this can be snow or are we looking at potetially a moderate ice storm? BTW thats one huge area of frz, usually its a small strip, that would cause a mess across most of NY and new england, if it drops anymore than 0.25 over that large an area it would be awful.

Stratosphere information
Massive heat flux


Huge wind reversal

Are the above graphs indicative of a sswe?

I think we have a long way to go before we should be getting excited. It seems to me that because of the state of the Pacific, both tropically and in the mid-latitudes, as our Atlantic blocking develops and matures it’s just going to end up linking with an eastern North American ridge in the time-mean. What does this mean? Rinse,wash, repeat with warm, cutter, cold, warm, cutter, etc. A negative AO/NAO will not be enough to change this, IMO, and the only way to stop this is through a favorable stratospheric disruption, but from what I’m seeing, that’s not likely right now. The disruption/destruction of the vortex is, but favorable location/orientation isn’t.

I'll continue preaching patience with regards to the long range. The first 10 days of January do not look good. Expect average to above average temperatures and no snow. The second week of the month will be the 'transition' thanks to the SSWE. It looks like there will be a stout -NAO, potentially anomalous one at that, but the Pacific is in shambles. The Wave 1 SSWE will be enough to displace/elongate the PV but we need to follow that up with a Wave 2 warming event which would SPLIT the PV and send one lobe south into Canada. This would ensure we have a cold air mass to work with - along with a -NAO. Models are gung-ho on Wave 1 SSWE but not yet on a Wave 2.

Sunday is threat window especially for NW interior.  The ULL has been placed all over the place by the models and some models are back and forth.  If it's this far north and east before transfer to coastal then it's a New England threat mostly.  If it's lower latitude before transfer then we'd be in the game. Expect a lot of changes on placement and transfer of the low.

Weak MJO pulse into phase 2 and 3

I think we need to be patient but the latest model run suits for the past cycle (4 runs) are getting stronger with the block. The PAC is a mess yes BUT the heights from teh AO and NAO will slowly push those Low heights out of Western BC and Alaska.

This map show these heights in orange for the Greenland Region spread over the top of CANADA into Alaska. So lets see what the next few days of runs show with this.
It is exciting to see and also to see the SSWE occurring. There is a coupling with the stratosphere and troposphere from model runs - EURO saying Jan 4 - GEFS say JAN 10 so time will tell.



Sorry but this is exciting to see - no storm is going into that block - suppression maybe but cutters - ain't happening - the storms are going to head North/Northeast when they feel the press. Maybe head North and then East - again time will tell.

Sunday into Mon is on the table as Haw said and I have been harping on the ICE ICE baby for NYD for N of I 80 and NW NJ - Orange, Rockland Cts.

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!!