OBS-NOWCAST for the first moderate to high impact snowstorm of the 21-22 season, along and south of I95 3AM-7PM Monday January 3, 2022

[HeadInTheClouds]

19 minutes ago, Brasiluvsnow said:

JT I have zero shot at this one I am in Rockland but I am looking at the radar ( have been for a while) and by all reports what the radar is showing is not snow in some places 

Forget about any snow in Rockland. Too far north. 

[psv88]

RH in the city and metro is in the low 40s, on the island its mid-50s to low 60s. 

[Rjay]

6 minutes ago, MJO812 said:

I would be happy if the gfs is right

 

Over 3 inches here for my area 

 

[eduggs]

9 minutes ago, MJO812 said:

I would be happy if the gfs is right

 

Over 3 inches here for my area 

That's not the GFS. That's a 3rd party interpretation of the GFS output.

Plus the GFS is showing -38C at 750mb at the peak of the "precipitation" near NYC. I think we should look more at the model forecast soundings and mid-level charts and less at 3rd party snow maps.

[ForestHillWx]

27/15 currently. Cold and gray. Enjoy the snow south Jersey weenies!

[forkyfork]

1 minute ago, Rjay said:

 

i have no idea why the precip maps are spitting out those totals. ridiculous 

[HeadInTheClouds]

1 minute ago, eduggs said:

The GFS was right a few days ago when it started strengthening and sharpening the southern stream wave and signaling a greater separation and storm threat. The model caught this feature earlier than other guidance.

But the GFS also appears to have a problem with its QPF parameter that has been observed several times this winter season, and notably today. It shows precipitation at the surface that would actually sublimate or evaporate before reaching the ground. Simulated radar reflectivity maps look pretty good, but QPF is way off.

The dry lower-mid level air was very well modeled with this storm. In fact it appears that, outside of the QPF parameter, the GFS did very well.

Yes, but the QPF parameter is the most important to snow lovers. Most other models gave nothing to very little for NYC metro especially mesos. GFS is a POS. 

[psv88]

4 minutes ago, Rjay said:

 

Yup. Not expecting more than 1/2" here

[eduggs]

2 minutes ago, forkyfork said:

i have no idea why the precip maps are spitting out those totals. ridiculous 

The obvious answer is the near saturated lower levels. But that seems too simple to be right.

I don't recall the GFS having this problem to this degree in previous years. And this is not the first time it's been observed this winter.

[eduggs]

2 minutes ago, HeadInTheClouds said:

Yes, but the QPF parameter is the most important to snow lovers. Most other models gave nothing to very little for NYC metro especially mesos. GFS is a POS. 

The GFS might be a great model with a very minor glitch in the algorithm used to model surface precipitation.

[eduggs]

3 minutes ago, HeadInTheClouds said:

Yes, but the QPF parameter is the most important to snow lovers. Most other models gave nothing to very little for NYC metro especially mesos. GFS is a POS. 

That's why we have meteorologists to interpret model output. Otherwise we wouldn't need people to forecast the weather. The GFS was actually showing something very similar to other guidance once you took the dry air into consideration.

[HeadInTheClouds]

2 minutes ago, eduggs said:

That's why we have meteorologists to interpret model output. Otherwise we wouldn't need people to forecast the weather. The GFS was actually showing something very similar to other guidance once you took the dry air into consideration.

The other models weren't showing anything really for NYC metro. The GFS has consistently been a poor model. For instance it has nothing for the 7th threat while other globals like Euro, CMC, UKIE have been showing a legit threat. Guess who my money is on. 

[dseagull]

3 minutes ago, HeadInTheClouds said:

The other models weren't showing anything really for NYC metro. The GFS has consistently been a poor model. For instance it has nothing for the 7th threat while other globals like Euro, CMC, UKIE have been showing a legit threat. Guess who my money is on. 

 

I'd go with the GFS for the 7th, but let's get past this threat and revisit the models when this thing exits the N. Maritimes.    50 miles south, and you would be cashing in.  When we are talking deviations of less than 100 miles, it's all just noise.  The GFS nailed this storm (besides QPF), when all others were out to lunch.   Gotta give credit where it is due. 

[Rjay]

The EPS had an 8" mean for Philly yesterday and a few inches for NYC too.  This isn't a gfs only thing.   The gfs/euro/sref were brutal.  

[eduggs]

5 minutes ago, HeadInTheClouds said:

The other models weren't showing anything really for NYC metro. The GFS has consistently been a poor model. For instance it has nothing for the 7th threat while other globals like Euro, CMC, UKIE have been showing a legit threat. Guess who my money is on. 

Only the QPF parameter was off on the GFS. And that is the least accurate model parameter. If you simply used the 50% humidity at 700mb to mark the precipitation shield, it lined up very well with the EC and CMC/RGEM. In fact the EC might have been even further NW than the GFS.

My appreciation for the GFS model has increased after this event, with the major caveat that its QPF parameter along the boundary with a cold, dry airmass cannot be trusted.

[eduggs]

3 minutes ago, Rjay said:

The EPS had an 8" mean for Philly yesterday and a few inches for NYC too.  This isn't a gfs only thing.   The gfs/euro/sref were brutal.  

The SREFs were way too far NW yesterday, which they often are with coastal events. I don't recall the EPS showing an 8" mean and PHL. Maybe for one run with an extremely sharp cutoff? The EC did end up a little too far NW with precipitation... but I don't have access to the soundings to determine if the placement of features was too far NW or just the surface QPF.

[HeadInTheClouds]

8 minutes ago, dseagull said:

 

I'd go with the GFS for the 7th, but let's get past this threat and revisit the models when this thing exits the N. Maritimes.    50 miles south, and you would be cashing in.  When we are talking deviations of less than 100 miles, it's all just noise.  The GFS nailed this storm (besides QPF), when all others were out to lunch.   Gotta give credit where it is due. 

Good luck with that. It's ridiculous to say the GFS nailed this storm except for the QPF. Thats like saying a goalie has good form and is square to the puck but then can't stop a beachball. I understand the precip gradient was always going to be very tight but nearly every other model had it much different. GFS brought some precip up to HV. It's a lousy model. 

[Stormlover74]

Just now, HeadInTheClouds said:

Good luck with that. It's ridiculous to say the GFS nailed this storm except for the QPF. Thats like saying a goalie has good form and is square to the puck but then can't stop a beachball. I understand the percip gradient was always going to be very tight but nearly every other model had it much different. GFS brought some precip up to HV. It's a lousy model. 

It's still printing out a quarter inch of liquid that it thinks is falling right now

[jm1220]

I’d say it’s now or never for us getting snow for NYC/LI. Snow is shifting east in the DC area. 

Unfortunately the issue isn’t only surface dry air, there’s also dry air aloft that’s hurting our chances. 

[jm1220]

1 minute ago, Stormlover74 said:

It's still printing out a quarter inch of liquid that it thinks is falling right now

The GFS is bonkers, and it’s had this issue in the past where it prints out snow where the air is too dry. 

[winterwx21]

9 minutes ago, Rjay said:

The EPS had an 8" mean for Philly yesterday and a few inches for NYC too.  This isn't a gfs only thing.   The gfs/euro/sref were brutal.  

RGEM did a good job. It consistently showed the significant snow staying just to our south, but wasn't ridiculously far south early on like the NAM was. I've always found RGEM to be a very good model.

[eduggs]

Just now, jm1220 said:

I’d say it’s now or never for us getting snow for NYC/LI. Snow is shifting east in the DC area. 

Unfortunately the issue isn’t only surface dry air, there’s also dry air aloft that’s hurting our chances. 

The issue is not surface dry air. It's 850mb - 700mb.

[eduggs]

I expect flakes in the air in places like Sandy Hook, NJ and along the south shore of LI etc over the next few hours. Whether they accumulate is still unclear.

[dseagull]

9 minutes ago, HeadInTheClouds said:

Good luck with that. It's ridiculous to say the GFS nailed this storm except for the QPF. Thats like saying a goalie has good form and is square to the puck but then can't stop a beachball. I understand the precip gradient was always going to be very tight but nearly every other model had it much different. GFS brought some precip up to HV. It's a lousy model. 

I did a poor job articulating myself.  Let me try again.  It outperformed and signaled at something that most models lost entirely for a period of time.  Consistency is a valuable asset for any model.  I'm not lauding the performance of the GFS, I'm simply giving credit where it is due.  I'd like to look into the parameters once this system exits.   Something to learn from.  

 

OBS -  31/31 Barnegat NJ. Light/mod SN.  Winds starting to howl N @ 20-25 G to 35.  2.6" on the board. Still expecting less than 5", but the roads have gone to crud quickly.  Going to make bird hunting impossible today, unless it lets up soon here on the Northern Fringe. 

[Rmine1]

4 minutes ago, jm1220 said:

I’d say it’s now or never for us getting snow for NYC/LI. Snow is shifting east in the DC area. 

Unfortunately the issue isn’t only surface dry air, there’s also dry air aloft that’s hurting our chances. 

Never is pulling away with every passing moment. 

[Gravity Wave]

So far this winter is reminding me of 2018-19, where one big storm slid just south of us due to bad luck early on and we came up with snake eyes the rest of the season. I think the highlight of the year was getting 2 inches of slush in late February.

[Rjay]

11 minutes ago, eduggs said:

The SREFs were way too far NW yesterday, which they often are with coastal events. I don't recall the EPS showing an 8" mean and PHL. Maybe for one run with an extremely sharp cutoff? The EC did end up a little too far NW with precipitation... but I don't have access to the soundings to determine if the placement of features was too far NW or just the surface QPF.

Sorry it was the OP Euro.  The EPS had a 6" mean for Philly. 

 

[dseagull]

1 minute ago, Rjay said:

Sorry it was the OP Euro.  The EPS had a 6" mean for Philly. 

 

Thanks for sharing. Totals are definitely busting low even further south.  I'm curious to see where the axis of max accumulated snow sets up. just east of hammonton, NJ is looking prime for jackpot.  Maybe a line from Millville to  New Gretna.  

[psv88]

Looks like snow is back in off the ocean from east to west in eastern suffolk, esp south fork. Let's see how far west that can get.

[NEG NAO]

3 hours ago, jm1220 said:

Yep. Unless it makes a pretty good north jump in the next few hours I’m just not seeing it. Dewpoints in the low teens aren’t helping. It’s hitting the wall of dry air up here and you can tell there’s virga from the Mt Holly radar. 

agree haven't seen 1 flake yet on the Union/Middlesex County border - they prinned and salted the roads here believe it or not....