Jump to content
  • Welcome to American Weather

    Register now to gain access to all of our features. Once registered and logged in, you will be able to contribute to this site by submitting your own content or replying to existing content. You'll be able to customize your profile, receive reputation points as a reward for submitting content, while also communicating with other members via your own private inbox, plus much more! This message will be removed once you have signed in.

BxEngine

1/23-24 Randytastic Snowstorm Part 2 STORM MODE THREAD

Recommended Posts

Get ready for thundersnow over NYC if this verifies. That is some intense lifting.

 

namFLT_700_vvel_030.gif

Those are some of the strongest 700mb VV's I've ever seen. That would definitely be a 3-4"/hr band. And at some point it will stop progressing north and sit over one area and rot. That could be a jackpot zone for sure. 

Share this post


Link to post
Share on other sites

Warmer waters helping out big here. Much like last Sundays snow showers, you can essentially see where the barclinic zone sets up.

I've been doing this for a living for a while now, but these bowling ball ULs rarerly seem to miss southward. Models gave a scare, but I think we're starting to see the reality of how close to 96 this storm could very well be, especially in Philly.

Share this post


Link to post
Share on other sites

Good trends overnight and so far this morning. This storm looks like an absolute behemoth on satellite too. I think the prospect of "miss" for Rockland/Westchester and south is much, much diminished, and I'd probably go with 10-15" for NYC/LI/up to I-80 in NJ based on the trends overnight and this morning. Where that deform band can sit and the pivoting keeps heavy snow overhead, watch out-that's where someone here can grab 18 or 20". I'm still not ready to say this will be as good for around DC yet for NYC, but the first major part of the battle-getting the heavy snow up to the area, looks to be won. Hopefully the banding acts more like the NAM shows than the GFS. I still think the NAM is too far north and you can see is slowly settling south with how far it gets the heavy snow banding. At least it didn't collapse, which is what I feared it would do after its insane 0z run. 

 

North of I-84, unfortunately it still looks to be too little, too late. South from there to White Plains is the real area to watch to see how far north the real snow can get. 

 

One key to how much you receive is how soon this second low takes over well offshore and starts shutting down the very heavy snow. If it takes over sooner, snow will begin to diminish and also won't make it as far north. That's where models like the GFS (still up to a foot in parts of NYC and Long Island as well as I-78) will be more right.

Norh of 84 sees warning level snows according to Nam... Pretty far north of 84 actually...

Share this post


Link to post
Share on other sites

Gonna be awesome to watch this thing transfer to the SC coast and ride up along the Gulf Stream. Holy moisture transport, Batman! Congrats, guys. Looks like that f-gen banding is gonna smoke you down there.

Share this post


Link to post
Share on other sites

I am starting to suspect that the series of very strong warm eddies along 38N - they are very, very anomalous for this time of year, some of them have 24-25degC water - is this issue here.  I don't think they're being properly resolved by the globals, and what's happening is that the eddies are being expanded by the resolution b/c they extend over multiple grid spaces.  So the globals see gigantic chunks of  23degC+ water at 38N, and that generates massive convection and pulls the low to where the warmer SSTs are.

 

That's not entirely a false solution, since the warm water is going to draw the low toward where the boundary is, but I think that the globals are overplaying it.  There's also plenty of anomalously warmish water just offshore of LI and south of the Islands - ~10degC water south of Long Island and ~8degC water south of Nantucket.  I think the fine details of SST are going to be relevant here.

Share this post


Link to post
Share on other sites

This blows my mind more Than anything... The SREFS are updated, and so VERY well within 12-24hrs.. And no they are not as scewed by the ARW as you may think.. Most NMM members are in board as well..... I'm throwing the challenge on these globals

 

GFS and ECMWF are by their very definition "medium-range" models. They are less useful in the short term. Hence why we have the NAM, SREF, HRRR, RAP, etc. The OP Euro kept the heavy snow west during Juno even after the NAM had bailed. It held out to the end. Even the GFS failed to get the details right during that storm, despite its QPF output being fairly accurate.

Share this post


Link to post
Share on other sites

Yes I was just about to say that.... this is probably a little more realistic. 

 

Agreed. It shows about ~60% of the 12km NAMs totals which is inline with the so-called "rule of the NAM" to expect half of what it outputs.

Share this post


Link to post
Share on other sites

Is anyone else concerned about the fact that the precipitation shield has dropped south 2 runs in a row now? It's fine now but if it continues?

It's honing in as we get closer to the start time. As yanks fan has said south of 84 you should be fine

Share this post


Link to post
Share on other sites

GFS and ECMWF are by their very definition "medium-range" models. They are less useful in the short term. Hence why we have the NAM, SREF, HRRR, RAP, etc. The OP Euro kept the heavy snow west during Juno even after the NAM had bailed. It held out to the end. Even the GFS failed to get the details right during that storm, despite its QPF output being fairly accurate.

Let's not forget the RGEM in that list... let's see how it comes in for 12z. I'd strongly prefer to have it on our side.

Share this post


Link to post
Share on other sites

Is anyone else concerned about the fact that the precipitation shield has dropped south 2 runs in a row now? It's fine now but if it continues?  

Don't worry yourself, there are no runs left, it's nowcast time for what should be a spectacular storm for those under it.

Share this post


Link to post
Share on other sites

Could we see a huge bust on the low or is it high side. My 10-14" could in fact have to be doubled if many of those models are correct.

Also the winds are going to be absolutely ripping if this storm tucks and is as strong as the Nam implies.

Share this post


Link to post
Share on other sites

expect it to contiune moving south on future runs. Final correction last model run prior to the start of snow in the metro area.

Just model noise, the actual Low was north of 06z and stalled in a better spot... Deciphering 10-20 mile shifts in precip shield is NOT a good idea.. Gonna pull ur hair out

Share this post


Link to post
Share on other sites

As a non-weather person who's interested in models, I do have this question for you fine folks: Why are the local NOAA offices (both Mt Holly and Upton), with their 9:30 updates to the point/click weather, still saying only about 7-ish inches for my area (Rockaway, Morris County) and 6-ish inches for Mahwah,NJ area even though all these newer model updates are spewing much more than that amount?

Share this post


Link to post
Share on other sites

Is anyone else concerned about the fact that the precipitation shield has dropped south 2 runs in a row now? It's fine now but if it continues?  

Going to come down to the banding for us.  If there is a mega band just to our south, we could get stuck in a subsidence zone.  Still think we're good for 4-8 up here with chance for more.

Share this post


Link to post
Share on other sites

As a non-weather person who's interested in models, I do have this question for you fine folks: Why are the local NOAA offices (both Mt Holly and Upton), with their 9:30 updates to the point/click weather, still saying only about 7-ish inches for my area (Rockaway, Morris County) and 6-ish inches for Mahwah,NJ area even though all these newer model updates are spewing much more than that amount?

Because making a forecast is not just taking the model with the highest qpf and then taking snow maps verbatim

Share this post


Link to post
Share on other sites

As a non-weather person who's interested in models, I do have this question for you fine folks: Why are the local NOAA offices (both Mt Holly and Upton), with their 9:30 updates to the point/click weather, still saying only about 7-ish inches for my area (Rockaway, Morris County) and 6-ish inches for Mahwah,NJ area even though all these newer model updates are spewing much more than that amount?

If the rest of the 12z suite comes in further north then they will up those totals this afternoon, and then again possibly for some areas when we get an idea of where the mesoscale features are setting up. Remember last year a forecast for 2-3 feet busted with 9in at KNYC, that mistake will not be made again. If you're looking for a non moving target forecast, try to reach out to Mitch Volk, he forecasts for NYC's san dept and thus has to provide a non wavering forecast 24 hours out in order for the City to prepare snow removal, etc. resources.

Share this post


Link to post
Share on other sites

GFS and ECMWF are by their very definition "medium-range" models. They are less useful in the short term. Hence why we have the NAM, SREF, HRRR, RAP, etc. The OP Euro kept the heavy snow west during Juno even after the NAM had bailed. It held out to the end. Even the GFS failed to get the details right during that storm, despite its QPF output being fairly accurate.

A medium range model is "less useful" in the short term?...........what?

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Recently Browsing   0 members

    No registered users viewing this page.

×