Re: Long Range Thread 26.0

[Quietace]

Euro 18Z Control. Storm undergoes bombogenesis. Again it may be too far offshore for a mega hit, but it's certainly close enough for intrigue. Certainly some CCB interest.

heehaw, correct me if I'm wrong...but isn't that exactly the image what a Jersey Shore coastie wants to see? I mean that's a 984 low, which is fairly strong, and the red freezing line is WAY offshore. Or no? Am I just looking at this through rose colored/bourbon altered glasses?

Low levels are going to torch with the strong east component to the wind. With the lack of any heavy precip, most southern areas even in a set up like that will likely not see accumulating snowfall. The set up this weekend is not conducive for snow in CNJ south.

A latitudinally transversing 500 hPa ULL, with strong WAA and southerly flow that leads to an overhead transfer (PA to off the JS for both the 850 hPA and 500 hPa lows) to an offshore, where all the favorable cyclogenic forcing is also offshore once temperatures cool via CAA from the wind shift, will not lead to any significant snows in the region. Once the coastal low is developed enough to form a mature precipitation shield, it is far to east to impact the region.

In fact, the overrunning from the initial ULL approach will likely drop more snow than this coastal storm unless significant changes occur on guidance.

[Frank_Wx]

Very much agree that Saturday will be difficult to see accumulating snow from CNJ and points south. It looks like even parts of NNJ including NYC may struggle, but still a little time to iron out specifics. I think NW NJ and N&W of NYC are in line for a light snowfall event.

The Monday-Tuesday storm has a chance to be special, but we’re dealing with some hiccups in the pattern. For one, the Saturday storm tries to “blow up” offshore and tries to become the 50-50 Low for the Monday storm. We have to watch this. The EURO amplifies heights along the EC enough to allow a northern and southern s/w phase, while GFS shows flatter heights as a result of Saturdays storm which keeps the Monday storm to our S&E.

The other thing to watch is western ridge. Currently one is being modeled but if it’s too quick to slide east or be too flat we’ll have issues with phasing, or this turns out to be a northern stream driven event which will only bring impact to areas N&W of NYC

[SENJsnowman]

Thanks everyone for the feedback. Right after I posted last night, I looked at the Euro's temp profiles. 850 looked great. 700- great. That last one- the 2m surface temps told me the bad news right away:




And heehaw even mentioned parallels to the Jan/Feb '21 storm which brought a nice 5-6" front end dump down to the Shore, but then as the storm approached, it brought the rains I think all the way up a little north of 195.

OK...disappointing but not a bit surprising.

[dkodgis]

Talking about N&W, what will Fri am bring?

[heehaw453]

Thanks everyone for the feedback. Right after I posted last night, I looked at the Euro's temp profiles. 850 looked great. 700- great. That last one- the 2m surface temps told me the bad news right away:




And heehaw even mentioned parallels to the Jan/Feb '21 storm which brought a nice 5-6" front end dump down to the Shore, but then as the storm approached, it brought the rains I think all the way up a little north of 195.

OK...disappointing but not a bit surprising.

Yeah. This will be west of the fall line for accumulating snows. Beginning of next week would afford better potential for coastal plain, but that has way too much to iron out as the exact phasing mechanisms will determine if snow occurs. As usual I would favor interior for that too because we don't have a huge dome of cold air to work with IMO.

edit
what I meant by the 500mb comparison was for the next several waves not necessarily this one.

[sroc4]

Euro 18Z Control. Storm undergoes bombogenesis. Again it may be too far offshore for a mega hit, but it's certainly close enough for intrigue. Certainly some CCB interest.

heehaw, correct me if I'm wrong...but isn't that exactly the image what a Jersey Shore coastie wants to see? I mean that's a 984 low, which is fairly strong, and the red freezing line is WAY offshore. Or no? Am I just looking at this through rose colored/bourbon altered glasses?

Low levels are going to torch with the strong east component to the wind. With the lack of any heavy precip, most southern areas even in a set up like that will likely not see accumulating snowfall. The set up this weekend is not conducive for snow in CNJ south.

A latitudinally transversing  500 hPa ULL, with strong WAA and southerly flow that leads to an overhead transfer (PA to off the JS for both the 850 hPA and 500 hPa lows) to an offshore, where all the favorable cyclogenic forcing is also offshore once temperatures cool via CAA from the wind shift, will not lead to any significant snows in the region. Once the coastal low is developed enough to form a mature precipitation shield, it is far to east to impact the region.

In fact, the overrunning from the initial ULL approach will likely drop more snow than this coastal storm unless significant changes occur on guidance.

I was coming on to make some similar points.  Specifically the ones involving the current consensus of where the transferred coastal low forms and the fact that as it stands now the only real snow opportunity exists via the warm air advection(WAA) from the initial primary to our west.  As the low transfers and reforms off the coast the trajectory is then E  to ESE from there instead of having any sort of northerly component.  This results in our area then sitting beneath the dreaded subsidence zone.  Thats why, if anyone out there has scrolled through the model loop you see an initial surge of precip(WAA), but very quickly it looks to dissipate over only a few frames as the secondary takes over, matures and forms a nice mature precip shield around it from your standard CAA mechanisms, and as Ace points out too far S&E to affect the area.  

And recall the discussion from yesterday.   I posted this map showing how the GFS had the ULL interacting with the polar branch of the jet effectively opening the door to a cold air source; also causing the slp to be tugged a bit farther N and hence the colder soln, ie: the maturing precip shield actually over the coastal plain becuse the slp was further N.





On the other hand the Euro map I showed had a ridge to the N of our ULL effectively cutting off tthe cold air supply meaning we are dealing with primarily modified pacific air.



Well over night the GFS has trended towards that soln.  


Up until yesterdays 12z models had trended more favorably; however, they still were still not ideal.  It appears they have reached a threshold as to how far they trended toward a more wide spread favorable snow fall type soln.  As it stands now it appears what snow does fall will be compliments of the initial WAA from the primary, followed by the secondary forming too far to the S&E to get any of us into the heavier precip shield that forms, and because the air mass is marginal at best, and because of the easterly fetch to the lower levels as the precip lightens up very quickly, esp over the coastal plain, we will likely see it transition to light rain or perhaps white rain as the mid levels do still look to remain cold enough.  As Ace points out with the marginal air mass involved we need to be under the heavier precip in order to cool the lower levels enough to accumulate.  

Im not quite ready to write off the system just yet, but the combo of the ridge over top, and the status/positioning of the 50/50 Low complex is such that it appears the ULL trajectory is too much in the ESE direction as it exits the coast which will make it very hard to get the secondary low to trend further N&W from where currently modeled.  Again I believe we have to see the ULL interact some with the northern branch for this to happen but not sure we have the time left to do so.

[heehaw453]

I wouldn't write off coastal effects just yet either. I've been fairly confident most of the snow comes for interior comes from the ULL diving underneath. But writing off a closed off ULL as it hits the coast is way too premature. Not saying there's going to be 6" blizzard for 3 hours, but certainly some snowfall is possible on the I95 and maybe locally heavy for a bit. This is 700mb vorticity and wherever that forcing sets up is going to thump.

[dkodgis]

Looks like mid -afternoon to rush hour?

[jmanley32]

Great analysis by all but I knew this wasn't going to work out at least for coast, not hyped but you all sounded super interested in this one, so I will assume Tuesday will be exactly the same and lose interest as we hit the weekend. I am ready for spring unless we can actually get a storm for the coast next week. After that I am done tracking, not reaching CP level stress (jk CP) but its just not really worth looking at and being let down what 20x this year?

[jmanley32]

Looks like mid -afternoon to rush hour?

Why does it matter sounds like yet another rain event, too warm.

[Frank_Wx]

Great analysis by all but I knew this wasn't going to work out at least for coast, not hyped but you all sounded super interested in this one, so I will assume Tuesday will be exactly the same and lose interest as we hit the weekend.  I am ready for spring unless we can actually get a storm for the coast next week. After that I am done tracking, not reaching CP level stress (jk CP) but its just not really worth looking at and being let down what 20x this year?

Looks like mid -afternoon to rush hour?

Why does it matter sounds like yet another rain event, too warm.

Bring your negativity and banter to the banter thread. Thanks!

[Frank_Wx]

The next two frames are only 6 hours apart, per the latest GFS for this Saturday's storm.

Check out this transfer of energy from western PA to off the coast. Pretty amazing how that works...





Yes the immediate coast is dealing with torched surface temps, but this looks like a nice snowfall for many areas.

[dkodgis]

I feel comfortable asking a question

[billg315]

12z NAM is predominantly snow northwest of a line from Doylestown PA to just N and W of NYC proper. In that area it looks like about a 2-4" snow event (basically NW NJ, far NNJ and the HV). By the time the secondary takes over and turns some of the rain south and east of that line to snow, it is too late to accumulate much, maybe a coating to an inch on the back-end in Central/parts of SNJ -- excluding coastal areas which get zippo. That is pretty much in-line with some of what you've read above.
12z GFS still looks like it wants to develop a more potent secondary closer to the coast, bringing the totals in the above-mentioned areas up more to the 3-5" range and bringing some accumulation (an inch or two) even down to the coast.

[billg315]

Not really a huge difference in the looks of the GFS/NAM right now other than how far south and east accumulations could get. NAM keeps it confined more N&W while GFS brings it a little further south and east.

[billg315]

Looks like mid -afternoon to rush hour?

You're looking at snow starting by you Friday evening at 6 or 7 p.m. and continuing to about mid-morning/midday Saturday. And you're likely in a 2-4" range on either model.

[hyde345]

Don't think the Friday night event is going to be very robust in terms of snow. For most it looks like a 1-2 inch type event with maybe isolated 3-4 inches NW Jersey and elevated areas in Orange county. Wave 2 looks a little more interesting in term of potential snowfall especially N and W.

[heehaw453]

If there's going to be a surprise this winter on the upside this Friday night/Saturday may be it. Closed off ULL you just never know.

[Grselig]

If there's going to be a surprise this winter on the upside this Friday night/Saturday may be it. Closed off ULL you just never know.

Hey. Tough winter for all of us. Thanks for staying on top of it. Really appreciate your insights. Hopefully Friday is a surprise.

[amugs]

EURO brings a nice snowfall 3-5" type to NNJ, HV, NWNJ and EPA.



Primary dies in OHV which is key - thanks to W NAO block:




Close Up

[essexcountypete]

mugs, I think your image links are broken. I've restarted my browser and checked the post on my phone and the images are not working on my end.

[Frank_Wx]

Monday Godzilla? EURO says YUP



Funny enough, 500mb looked a little sloppy this run. There was some southern energy trying to scoot too far ahead of the trough. Ultimately a phase happened and we saw the trough go negative.

The GFS is just very fast and flat looking. Nothing comes together.

[Frank_Wx]

The purple line is where the 12z EURO tracked the 500mb ULL Saturday through Monday morning. It's still A LITTLE too far north that would pose issues to coastal areas in terms of temperatures. The red line is the IDEAL 500mb path for the ULL. One that would bring a widespread Godzilla to our area, and minimize the risk for mixing. If we're able to get the western ridge to amplify more I think the red line is possible. But we're not seeing this on any modeling right now, unfortunately.

[amugs]

GFS says hello for a few inches Fri night into Sat.
GIF not uploading properly  argghhh!!

[heehaw453]

Monday night is not a snow storm setup in mid-March especially at the coast IMO.  No anomalously cold air with this setup and in March a system would have to be absolutely perfect at the coast to deliver sig snowfall without the cold air locked in. I'd buy it a lot more with cold 1040 H parked over Quebec. I'll be surprised if this is much snowfall outside of higher elevations and maybe CNE.

[Radz]

I’ll take next weekend if Mon/Tuesday doesn’t pan out lol

[Frank_Wx]

The EURO continues to show a prolific storm along the coast early next week. I'm not particularly impressed with 500mb, however.



I circled in purple the southern and northern short wave energies that are poised to phase near the east coast. WHERE and WHEN is very important in terms of keeping it cold for snow (or even out to sea like the GFS shows). Heights are rising along the coast (black arrow) and the western ridge is looking kind of defeated. Notice how the heights over Arizona look quite meridional but we're seeing a spike over Idaho. That is not a terrific look, or one that will put the phase where we need it to be.



Here we are Monday evening. The ridge looks a little better but it's already too late. The southern stream is AHEAD of the northern stream. We wanted this phase to happen by now. But the overall flow is a little too quick. Not enough blocking mechanisms to slow the pace down.

Ultimately, the EURO still shows a big storm and brings snowfall to the area. But you have to put some weight on the GFS which shows a low impact event, because if the flow is as fast as it suggests (and I just showed why that is), then it may be onto something.

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