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NYC/PHL Jan 25-28 Potential Threat Part 2


am19psu

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You are being blinded by snow goggles here. The 850 low basically goes over your head...that is not a snow track. You have hours of ranging E/SE winds in the boundary layer as the low climbs the coast.

You don't get snow because a sfc low goes east of you. You have to look at all levels and also how the sfc low gets there....if it was out in the ocean and came due north into LI, that would be a lot more favorable...but this low comes from Delaware, tracks over S NJ and then over LI....that type of track gives you a lot of SE flow in the boundary layer.

Yes, but every other model is way east, and the ECM is often too warm in the medium range. That's all I'm saying. I don't buy 975mb lows near Montauk that are all rain in the NW suburbs after a massive arctic outbreak. Sounds fishy to me.

I'm a pretty honest forecaster and always say when I think a set-up is bad. It means something when I'm not that worried. Let's just see what happens.

We don't see a flurry on any of the 0z GFS individual ensemble members. So that's another way this storm can end badly. But still 5 days out...

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At 120 hours the 540m line crashes near NYC with a 975mb low near Montauk...that's definitely changing over to snow.

That's where elevation and being outside the urban heat island, farther from the Atlantic comes into play.

Models are guidance. I generally go with a blend of them for my forecast, and that suggests a Nor'easter that's mostly snow, frankly. I am not going to take a warm-biased overamplified model verbatim at Day 5 considering the problems the ECM has had.

0z GFS ENS individual members are out...they are all out to sea, not a hit for NYC.

maybe you need a break bro because there are several huge hits.

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Surface conditions depicted on the 0z ECMMF are eerily similar to the Dec 12, 1992 event...big retreating high northeast of Caribou, deepening low near the Chesapeake Bay...that was a terrible time of year for snow...water temps in the 50's, etc...yet slightly elevated areas such as Greenwood Lake, NJ (just NW of NYC) were buried under heavy snow..and we all know what happened in the Berkshires and 5 miles inland from Logan...

William, it does have a lot of similarities...I wouldn't be surprised to see some type of solution like that in the end albeit a bit colder.

Verbatim the Euro is kind of ugly, but as for trying to figure what might actually happen rather than discussing the model verbatim, I wouldn't be surprised to see it come in a bit colder and snowier on future runs. A colder version of Dec '92 would be pretty remarkable.

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well, to be fair, he is at 440 feet, so his surface temp is probably 4.5C

Assuming a moist adiabatic lapse rate of 6C/1000M

440ft = 134.15 m

134.15* 6 = 804.67 / 1000 = .80467 ~.805

4.7 - .805 = 3.895 degrees C at the surface.

Yup, still heavy rain.

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Lol...dude, how can you just ignore the screaming southeast flow in the lower levels with the poorly positioned high pressure? Just to lay this to rest, HPN surface temp at 120 hours is still 4.1 C and your thickness is 542.

We had a crappy high pressure for the last storm and still had 2" snowstorm and then freezing rain. That's the power of having antecedent cold and some dynamics. This time, we're talking about more antecedent cold and much more dynamics from the low bombing into the 970s. Wet snow bomb in my opinion.

You don't put anything to rest...I have often been fooled by the Euro's warm bias. It's well documented. And all the other models are east. So take a couple degrees off the 850mb temps, shift the low 50-100 miles east, and you're golden. I'm starting to worry about the trough being too northern stream influence and this going out to sea.

That's my opinion. We'll just see how it plays out.

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I think his knee-highs are inside-out, tonight.

This will jump around so I'm not worried yet.

If his argument is that he thinks it will be a little too far east and the euro may be a little on the warm side, then that's different. However, it's "mild" solution makes sense when you look at how the storm evolves.

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This solution has NO blocking, strong easterly winds off the Gulf Stream with no cold high to the north and almost ALL rain for most coastal and I-95 sections. But that doesn't mean that this solution is the correct one. We have two distinctly different solutions on the table (this and GFS) and only time and future guidance will tell us which one is more accurate. Right now most likely, neither solution is exactly how this event is going to play out.

WX/PT

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I think it would be a wet snow here. But we'll see. I think the ECM has a warm bias and that the track is trending east. The 0z ECM was clearly east of the 12z ECM, and both the GFS and GGEM have been trending east. That's all I need to see to say it's game on for the NW suburbs.

Also, the low at 120 looks well east of JFK.

Exactly, my friend. It would be a mix with snow just inland.

I have to honestly say very few storms have taken that track and delivered rain here... That has major snowstorm written all over it for western Orange County..

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You don't put anything to rest...I have often been fooled by the Euro's warm bias. It's well documented. And all the other models are east. So take a couple degrees off the 850mb temps, shift the low 50-100 miles east, and you're golden. I'm starting to worry about the trough being too northern stream influence and this going out to sea.

Okay, but your original argument was that the Euro was too warm and that you predict things based on synoptics. Synoptically, this model evolution makes perfect sense.

You thinking this will end up east, less amplified, colder, whatever..is a different story.

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This will jump around so I'm not worried yet.

If his argument is that he thinks it will be a little too far east and the euro may be a little on the warm side, then that's different. However, it's "mild" solution makes sense when you look at how the storm evolves.

Exactly this is my argument...There's no point in discussing any model verbatim at Day 5. They're called "guidance" for a reason. None of these tracks is going to verify exactly, so a prudent forecaster takes a blend and that's mostly a snowstorm where I live. That's just how I see it.

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William, it does have a lot of similarities...I wouldn't be surprised to see some type of solution like that in the end albeit a bit colder.

Verbatim the Euro is kind of ugly, but as for trying to figure what might actually happen rather than discussing the model verbatim, I wouldn't be surprised to see it come in a bit colder and snowier on future runs. A colder version of Dec '92 would be pretty remarkable.

Will, I agree about a colder version of December 1992, that would likely be the benchmark for every snowstorm if it were to happen.

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This will jump around so I'm not worried yet.

If his argument is that he thinks it will be a little too far east and the euro may be a little on the warm side, then that's different. However, it's "mild" solution makes sense when you look at how the storm evolves.

His argument is that the model is spitting out incorrect information based on track alone, which is patently false (unless he changes his argument).

I completely agree with you that this is simply one piece of an evolving solution at ~4-5 days from an event, but this run is a good illustration of what can go wrong with a synoptic pattern like this.

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if you dont like it turn off sigs in settings...problem solved,thanks.

I'm rooting for the Steelers, but Isn't there enough acrimony, tension, concern, stress, on these boards without coming coming into the NY Form with that logo that is somewhat obnoxious and hard on the eyes when people want to look at models, maps, etc. Can't u at least find a somewhat smaller sig to show some respect -- especially since you are in the NY Board?

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William, it does have a lot of similarities...I wouldn't be surprised to see some type of solution like that in the end albeit a bit colder.

Verbatim the Euro is kind of ugly, but as for trying to figure what might actually happen rather than discussing the model verbatim, I wouldn't be surprised to see it come in a bit colder and snowier on future runs. A colder version of Dec '92 would be pretty remarkable.

Considering the base that we have laid down right now, I would argue that this would be just about unprecedented....I can't even comprehend that.

I have never seen an event of that magnitude with this great of a base leading in.

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Anyone care to share what the Euro depicts for KMDT precip wise and temp wise?

Thanks

Harrisburg...

Hard to be exact on amounts because phase change appears to occur between 6 hour data points, ballpark, inch of snow, inch of rain, and ballpark foot (plus) of snow with change to snow sometime between breakfast and lunch Wednesday, 850s drop from about -2º to about -5ºC, all with surface temps just over freezing, during a six hour period lunch to dinner where almost an inch liquid equivalent falls.

Guesstimate, rain, and then 15 inches. If the Euro was spot on 4 days out. Which is probably isn't.

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