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Models Advertising Late Month Storm And Cold Front


bluewave

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Agreed..especially over Central New York with the 20's. I think 30's are definitely possible throughout the Northeast...but the moderately large spread of 20's F temps is a little ridiculous.

thanks for moving things over John.. I was just about to agree with you and CoastalWx on the depicted 2M temps.. I mean, if this was in the middle of the night, then perhaps, but daylight hours in late October and having surface temps in the mid-upper 20's... I kind of doubt that... there really isn't a source of arctic air

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Agreed..especially over Central New York with the 20's. I think 30's are definitely possible throughout the Northeast...but the moderately large spread of 20's F temps is a little ridiculous.

I would think with pockets of between -5 and -7C at 850mb the higher terrain would have no problem maintaining temps in the 20's. The boundary layer can only warm up so much when you are already at 2,000+ feet with such cold temps aloft and moderate precip falling.

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I would think with pockets of between -5 and -7C at 850mb the higher terrain would have no problem maintaining temps in the 20's. The boundary layer can only warm up so much when you are already at 2,000+ feet with such cold temps aloft and moderate precip falling.

You'd need an airmass with dewpoints in the 20's. It looks like most of the major cities like ALB and BGM have forecasted dew points bottoming out around 30-ish...

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Well I think it may be picking up the 2500'+ spots which might be ok. My thing was that it has 100-850mb critical thickness line over BOS until 00z Friday when it collapses se. That seemed a little too cold for me, but maybe it's right.

It's pretty notorious for doing that in events like this. But notice how the 10m southwest flow never really gets north of the CT/MA border on the NAM. Here's the 54 hr map which is far N as that boundary gets. The surface low begins to develop and the winds are northerly..so the cold air is already being advected into those locations by 60 hr.

That being said, in these tight boundary events..I have seen the NAM be too cold by as much as 5-8 degrees on several locations. There were a few similar events a few winters back where I was just north of the boundary and it was just god awful with my thermal profile.

http://www.meteo.psu.edu/~gadomski/ETANE9_12z/f54.gif

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You'd need an airmass with dewpoints in the 20's. It looks like most of the major cities like ALB and BGM have forecasted dew points bottoming out around 30-ish...

What are dews like at 925mb? I'm thinking terrain north of say 2000 feet will have a lower dewpoint just from the fact that that elevation level in the column is cooler overall. Those are the places where I can see stay in the 20's albeit barely.

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Everyone should try, especially early in the cold season, to make sure you look at 925 temps and the 925 low. Its really good to see just how cold that level is and where the low sets up when we have a coastal system. Even later in the season its important with the more marginal events. I'm gonna post the 925 low from the NAM this morning and you can see how impt it is.

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What are dews like at 925mb? I'm thinking terrain north of say 2000 feet will have a lower dewpoint just from the fact that that elevation level in the column is cooler overall. Those are the places where I can see stay in the 20's albeit barely.

I'm not sure if the NAM outputs a good map for DPs.. the higher elevations would definitely be colder.. it just seemed that the NAM was a bit too widespread with the placement of the cold air.

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Everyone should try, especially early in the cold season, to make sure you look at 925 temps and the 925 low. Its really good to see just how cold that level is and where the low sets up when we have a coastal system. Even later in the season its important with the more marginal events. I'm gonna post the 925 low from the NAM this morning and you can see how impt it is.

The newbies should learn how many a snowstorm can be subdued via sleet and freezing rain intrusion by the pesky levels below the "popular" 850mb.

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through 84 hours on the gfs, its a non-event, and much warmer all over the NE than the NAM. There is some snow up into ORH and points north. However, the gfs has another vort in the split flow and this is what the euro keyed in on later in the period last night.

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The GFS doesn't seem to have nearly the cold air as the NAM does.. at least at the surface.

its not even close. GFS also had like .25 rain last week, so I don't know about this model, they both are sub-par at times.

Im really more interested in the second set of vorts.

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LOL, it is October, right?

Beautiful sub-pv in eastern canada funneling colder air in the NE with a split jet and vorts in both streams trying to phase at the trough goes negative.

And to top it off you have a PNA spike and height anomolies over the davis straights.

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LOL

18Z saturday 0C line off the coast (as in in the middle of the ocean) and its snowing in NYC.

Looks like a little weaker version of the euro last night.

This is hillarious.

925 temps barely above freezing and if the storm was a little better organized and closer to the coast dynamics would kick in.

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Its like a time warp. Unbelievable. That is as good as you can get this time of year. 850's -6!!!

and the sun will be setting as the storm gets going.

LOLZ.

it'd be shocking to get a coastal event bringing snowfall into NYC, proper, this time of year.... but if it lines up perfectly, it could happen.. the type of system I'd see bringing snow to the city would be a strong upper shorwave or clipper type system after a massive cold front has gone through.

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it'd be shocking to get a coastal event bringing snowfall into NYC, proper, this time of year.... but if it lines up perfectly, it could happen.. the type of system I'd see bringing snow to the city would be a strong upper shorwave or clipper type system after a massive cold front has gone through.

Hey, i just report what the map says. It's a long shot, but look at the 500mb setup Jay, you will do a double take.

Surface is warm, but that would be good enough for wet flakes, and any extra dynamics with the system would cool the column further.

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Hey, i just report what the map says. It's a long shot, but look at the 500mb setup Jay, you will do a double take.

Surface is warm, but that would be good enough for wet flakes, and any extra dynamics with the system would cool the column further.

I'm with you.. It's definitely about as good as you can possibly hope for October.. It's close.. real close.. I'm definitely not arguing against what you're saying...

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soundings show everything frozen until 925, so a lot of work to do. But also the gfs is weaker with the storm and further east. This would be a classic situation where dynamics would have one town as snow and another as rain, even to the coast. Further n and w into the hudson valley and jersey and higher elevations above 500 feet, accumulation is easy in that setup.

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soundings show everything frozen until 925, so a lot of work to do. But also the gfs is weaker with the storm and further east. This would be a classic situation where dynamics would have one town as snow and another as rain, even to the coast. Further n and w into the hudson valley and jersey and higher elevations above 500 feet, accumulation is easy in that setup.

Yeah but how good are dynamics going to be with a 1002mb low?

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