February Obs & Discussions

nutleyblizzard wrote:Nam coming in colder for the early week storm. Good start to the 0z runs.

Feeling the NAO ocl baby! What a trend. See that up in Maine! Bring it baby!

Big day of tracking, friends. I know many won’t believe the digital snow until they shovel it, and I get that! But let’s real this sucker in!

10 degrees, partly cloudy, calm winds.White on the ground from yesterday's .75 inch and a winter storm watch out for 5 to 7 inches tomorrow and Tuesday.

00Z Euro ULL closes off as it hits the coast.  LoL. Can only hope.

On the 06Z Euro watch the mid-levels close off.  How quickly consolidation can occur will have a bearing on the snow amounts.  The faster it closes off the more it will cool the column. If that continues it bodes well for North Central NJ, NYC, LI and EPA. All I can say is the Euro has been very consistent run over run. Maybe consistently wrong but I don't think so.

heehaw453 wrote:On the 06Z Euro watch the mid-levels close off.  How quickly consolidation can occur will have a bearing on the snow amounts.  The faster it closes off the more it will cool the column. If that continues it bodes well for North Central NJ, NYC, LI and EPA. All I can say is the Euro has been very consistent run over run. Maybe consistently wrong but I don't think so.

So heehaw, if you throw in the CNJ and the Jersey Shore, that's whole forum! How about it? (Especially, the Jersey Shore! )

No seriously. Any chance for S and E of 95 and 195 to get in the game for either this week or next weekend? Or is it already a fait accompli ( )?

Morning Folks.  Lets get right into it.  I'm pretty confident we are going to see accumulation snow Monday night into Tuesday morning if you live north of, draw a line SW to NE, between say Trenton NJ to Sandy hook out to Montauk point.  South of there will struggle.  

A few key points:  
1) We have needed to see our 500mb energy stay south of Long Island.  All models have trended to this soln; however, there are still subtle differences to just how far south and how strong and concentrated vs more strung out is it between models.  (Below is GFS and Euro 500mb vort maps.  Notice these differences)




2)  Point two:  If you have been following along this past week I have wanted to see the SOI remain negative through the weekend.  Reason for this is that all winter it has remained in mod positive territory which is a La Nina base state.  Combined with the MJO prev running through warm phases 3-4-5-6, this base state of the atmosphere typically allows any energy coming out of the SW CONUS to amplify over the center of the country which pumps the SE ridge, allowing the energy to bully its way into the great lakes; flooding the entire NE region with warm air ahead of our systems.  




Unfortunately the SOI has trended back into positive territory over the past 3 days after only spending 3 days in the negative.  https://www.longpaddock.qld.gov.au/soi/.  My concern with this would be that if nothing else changed then the prev atmospheric forcing pattern that has been entrenched all winter would settle back in allowing this Mondays potential to trend right back to the GL cutter soln.  BUT hold on because even though the SOI isnt ideal there are afew other big picture items that are likely to allow this to happen for Monday AND maybe even allow for the potential for the March 3rd-4th come to fruition as well.  One at a time though.  

3) Take a quick look back at the last two maps and notice the big circle to our NE.  This is our 50/50 low. If you look at the Anomaly map notice just how green the colors are in the center.  Also note the Reds to the north(our -NAO).  Up until now with the aforementioned pattern entrenched, La Nina base state and MJO in warm phases, anything that has resembled a 50/50 low in the past had been easily booted as our system amplified over the central CONUS an the SE ridge flexed.  But this time is def diff.  Reason?  the Stratospheric warming that has occurred.  That's right Mugsy had been talking about this quite a bit a few couple of weeks ago, and its effects are clearly going to help us here.  

Lets explore just how real quick.  How exactly does a strat warm event help?  This illustration is somewhat oversimplified but gets the main point across.  Here is a little mind exercise.  I want you to pretend you are an alien hovering high above earth centered over the north pole looking down and this is what you see.  



What you are looking at here is the temp profile for the strat at about 50mb or approx 63,000 feet above sea level.  Now I want to think about the fact that when air warms it expands, and when it cools it contracts.  Ok.  Still looking straight down at this map from space pretend that that the circle is a balloon filled with air in the stratosphere.  Immediately below the balloon is another balloon over the north pole in the troposphere.  Now I want you to take your space ship from hovering directly over the top of the north pole and now fly it such that you are now hovering centered over the equator.  Now we are perpendicular to the north pole.  So what we are visualizing here is two balloons stacked directly on top of one another centered over the north pole.  

Now when we have a strat warming event I want you to visualize the fact that the air within the strat balloon is going to expand.  now reference the image below.  As the strat balloon expands it cannot expand further out higher in altitude because its out into space.  So instead it begins to expand outward and down.  As it expands down in height you can now visualize that the result is going to be to compress the tropospheric balloon below it.  As you press on the center of the trop balloon, since it can compress into the surface of the ground you can imagine the balloon only being able to expand outward.  (Put a balloon on a table and press down into the center of the balloon with a fist.  You can see the balloon expand outward right?).  



With this visual, understand that when the strat warms over the N pole like this it in essence dislodges pieces of the tropospheric polar vortex(arctic and polar air masses) southward in latitude because of the downward pressure exerted on it by a warming and expanding strat Polar vortex.  Again keep your balloon analogy in mind here.


So how does this tie into our discussion about Mondays snow potential?  Despite the fact that the SOI, or more appropriately put the Trop Pac forcing is still less than ideal, the DEEP 500mb trough in our 50/50 region combined with the -NAO is NOT going to budge much because of the force exerted on the troposphere from above.  




 THIS right here is a fundamental difference and key factor as to why this is different setup with a likely different outcome than what we've seen all winter and why accumulating snow is going to happen for many of us on this board.  

So to bring this back around instead of our amplifying system over the central CONUS pumping the SE ridge and bullying its way into the GL its going to run into this 50/50low/-NAO block that isnt going to move much due to the forces exerted on it from the Strat.  The result is our closed ULL w'll head into the Ohio valley before running into the block, opening up, and forced ESE, and exit the coast S of Long Island.  At least thats the current consensus on the models.






Its a comlpex set up as you can see by the three LP look.  There is a HP to our north with exceptionally cold air to work with as seen by this 850mb temp anomaly map.  This air mass is Arctic in origin and as you can see is about 12-20*C below normal at its center.    



Some of the finer details that need ironing is the fact that the surface and low mid levels will have a SE and ESE wind flow which will likely keep the surface temps above freezing along the coastal plain.  Just how deep this above freezing layer is will dictate just how far away from the 10:1 snow ratio will be.  I would strongly urge you all to reference the Kuch-era snow maps instead of the 10:1 maps as it is likely giving a better representation of the 6:1-8:1 ratios for the coastal plain.  Once you get N of the Ct Coast the ratios are going to go up.  Its still possible that we get even worse ratios along the coastal plain if the soln is closer to the GFS than Euro regarding strength and position of the energy.

Obviously no amount of snow is going to change my outlook on winter, but I am at least a little excited of the prospects of enough snow to cover my grass.  

WE TRACK!!!!
 

SENJsnowman wrote:

heehaw453 wrote:On the 06Z Euro watch the mid-levels close off.  How quickly consolidation can occur will have a bearing on the snow amounts.  The faster it closes off the more it will cool the column. If that continues it bodes well for North Central NJ, NYC, LI and EPA. All I can say is the Euro has been very consistent run over run. Maybe consistently wrong but I don't think so.

So heehaw, if you throw in the CNJ and the Jersey Shore, that's whole forum! How about it? (Especially, the Jersey Shore! )

No seriously. Any chance for S and E of 95 and 195 to get in the game for either this week or next weekend? Or is it already a fait accompli ( )?

Hi!  Next Friday has a much higher ceiling POTENTIAL for most folks here. That is very uncertain this far out obviously and depends on interactions with the NS.  IMO JS is just a bit too close to the mid-level and ULL for decent accumulations for Monday night.  I think 195 is a decent delineator in NJ.

25* low and a delicate frost on the grass this morning..

Excellent analysis Scott. I'm pretty sure I can't top that, so I'll just give my quick thoughts on the down and dirty of what we'll end up seeing here in different spots. This of course is subject to change as additional model runs come in today and tonight (12zs about to rev up).

I'm feeling pretty good about a measurable snowfall Monday night at this point for many people on this board. I think there is something to be said not just for the Euro's consistency, but the fact that the last several GFS runs have seemed to bring it more in line with the Euro with the NAM not far off. When one model stays consistent and the others start moving toward it, that's a good sign.

I think as this comes closer into focus we're looking at something like this (just a preliminary thought of course):
North of I-78 and all of LI: Mostly all snow with amounts in the 4-6" range.
North of I-195 (Trenton to Belmar) to I-78: Snow, mixing briefly in the middle with sleet/frz, before maybe ending as just snow with amounts in the 2-4" range.
South of I-195 (or the line from Trenton to just south of LI). A slushy inch or two of snow before mixing with sleet/frz, and then rain limiting any further accumulation.

Those are my early thoughts based on current models. Subject to change of course as there are many dynamics at play here, and in some ways we may not know where we stand until we see where the coastal actually forms.

12z GFS nice and cold and more QPF!

Trend is our friend!

aiannone wrote:12z GFS nice and cold and more QPF!

Looking at the 12z GFS it has come almost completely into line with the Euro for the most part. The NAM is the last holdout with a slightly north bias at this point. If this energy comes off the coast where the GFS and EURO now have it -- near the Delmarva -- and organizes there, this will be a good event as outlined above. Let's see if the NAM gets more in line with the GFS/Euro as it gets inside of 24 hours later today.

aiannone wrote:12z GFS nice and cold and more QPF!

Notice the snowfall maps.  When you see it dip like that on the western side it usually means closing off the mid-levels.  Dragging colder air into the system.

GFS:

Euro:

jmanley32 wrote:Wheres frank? Him not being here tells me he may b thinking this isnt go work out. Judging by our other experts looks like it is a good shot. Is tgat 6 to 8 accurate around nyc area on tge gfs or should that b dropped like scott said to 8:1

I don't want to answer for Frank, but I wouldn't read too much into his absence. He has been a very busy guy the last several months and I think that probably has more to do with it, although truthfully I don't know what his thoughts are on this particular event so I wouldn't speculate either way.

I think the 6-8" around NYC might be a bit overdone (see my post above about my best guess accumulations). However, if the dynamics of this system pan out, I could see where it could overperform in some areas.

billg315 wrote:GFS:

Euro:

Yeah now they're very close.  The Euro is slightly lower latitude on the ULL, but at this point it's noise IMO. My guess is the ULL passes between ACK and DE.  If the ULL closes off as it approaches the coast then sig snow is possible for aforementioned areas North CNJ, LI/NYC/EPA.  If it doesn't then 2-4" sounds good for most folks in those areas.

Here in Albany, I had 1.8" of snow yesterday, putting the 2022-23 seasonal snow total at 29.6". Models are currently indicating 6-10" of snow here for Tuesday. If ALB gets at least 6.9" of snow then, it will surpass it's 2021-22 seasonal snow total of 36.4". And for a good chunk of that winter, it was cold with most systems being suppressed, especially in January.

I’m not completely convinced just yet that this will be more than a nuisance 1-2” snowfall for NYC. But, given how winter has gone maybe a couple of inches of accumulation is worth bragging about. I think N&W is in prime position for a significant event. Probably a general 3-6” across NW NJ, NEPA and those north of the City. The extent of the CAD is hard to predict. Will the cold air be strong enough to withstand the primary low? Some models say yes, others not so much. I do LOVE the timing of how this mostly comes when the sun is down. By Tuesday morning I think a lot of the storm will be done with.

The 500mb picture is sloppy though. The second is disorganized. The 500mb/700mb energy is rampant. A preliminary call is 1-3” across CNJ through NYC and Long Island (from SW to NE). Those north of that gradient (figure most of NNJ) are probably more in a 2-4” range. NW NJ and all those N&W could see 6” or more given the amount of moisture this storm is coming with. Regardless it is a winter storm. We haven’t had one of these this year. It’s truly amazing in the worst way possible. I’ll provide an update again later today.

Frank_Wx wrote:I’m not completely convinced just yet that this will be more than a nuisance 1-2” snowfall for NYC. But, given how winter has gone maybe a couple of inches of accumulation is worth bragging about. I think N&W is in prime position for a significant event. Probably a general 3-6” across NW NJ, NEPA and those north of the City. The extent of the CAD is hard to predict. Will the cold air be strong enough to withstand the primary low? Some models say yes, others not so much. I do LOVE the timing of how this mostly comes when the sun is down. By Tuesday morning I think a lot of the storm will be done with.

The 500mb picture is sloppy though. The second is disorganized. The 500mb/700mb energy is rampant. A preliminary call is 1-3” across CNJ through NYC and Long Island (from SW to NE). Those north of that gradient (figure most of NNJ) are probably more in a 2-4” range. NW NJ and all those N&W could see 6” or more given the amount of moisture this storm is coming with. Regardless it is a winter storm. We haven’t had one of these this year. It’s truly amazing in the worst way possible. I’ll provide an update again later today.

Completely agree with this, but the only way I see 6+" for anyone is if the ULL closes off right before hitting the coast.  I think it's possible, but really difficult to predict. Also if it does close off then North Central NJ/NYC/LI probably get 3"+. But that's a big IF.

Weather channel just posted a warning 3-5” for Islip

Question what models are you guys looking at that show the primary goes to far North after the 12Z run that will cause this to be a nuisance type storm for anyone N of I80? I am seeing a sl=olid 3-5". NYC and a bit South a nuisance maybe but the CAD is darn hard for the models to pick up on. Seasonal trends and FEAR of are the only two aspects that I see becasue every major model shows the press of the NAO and confluence over the NE region incerasing since Thursday aagin for I78 N. It was a HV storm that has trended a good 100 miles south since then. If that is not a trend?? I do not know what is. CMC shows what I am talking about in the GIF and the EURO has been on this for days now and all models are coming around to it...cough cpough GFS, NAM. My .02 here but the potential is exciting from what we have had fro NYC on N. Coastal plain sorry folks, the spoils of the last 20 years are put on hold. MAYBE the MARCH 3rd storm will deliver. Time will tell.

CMC from CCB 33n rain



Here is your HREF that is a darn good SR model - composite of all SR models. Great starting point for this. Elevations will be doing better and their maybe a warm nose around I78 to I80 but N of their it looks to be mostly snow.

18Z HRRR is COLD!



Also good video from Bernie. Talks about NYC metro in great detail
https://www.youtube.com/watch?v=i4Dv3_dY4YQ&t=18s

aiannone wrote:18Z HRRR is COLD!



Also good video from Bernie. Talks about NYC metro in great detail
https://www.youtube.com/watch?v=i4Dv3_dY4YQ&t=18s

The 18Z HRRR has a closed off 850mb low.  That's what it's going to take for amounts > 4".  Fast consolidation and slow movement.