00:00Always beware of an Arctic air mass.
00:04You have an Arctic air mass coming your way, your antennas should go up for snow.
00:08And I think we're going to be looking at a sneaky snow situation.
00:11Will it be a snowstorm for the Northeast?
00:14It's not going to be that, but there's going to be an area between New York City and Boston
00:18where things are going to get very interesting late Friday night and into Saturday.
00:23I'm going to show you why here in a second, but it always begins with what?
00:27An Arctic injection.
00:28You know, when an Arctic injection comes in, Bernie's antenna goes up.
00:33And when you hear myself talk about myself in the third person, that's another clue.
00:36Let me show you what's going on here.
00:38We have an Arctic air mass.
00:39Here it is.
00:39You can see where it is.
00:40Well, it's up here in the Arctic.
00:42Watch it come on south.
00:43This is today.
00:44Watch this area.
00:45Here we go Friday morning.
00:46Here it comes.
00:47Here's the leaning edge of it right in here.
00:49Here's your Arctic boundary.
00:51Now, that's going to continue to come south.
00:53There's going to be a glancing blow for like Chicago and the Midwest.
00:57But the teeth of this Arctic air mass is coming into the northeast.
01:01This is Saturday.
01:02This is Sunday morning.
01:03And here it is.
01:04I mean, this is an Arctic air mass.
01:07Lots of areas are going to be below zero.
01:11Saturday morning and then Saturday night, Sunday night.
01:16So, Saturday morning, let's just say, Sunday morning, Monday morning.
01:22And this is going to get a little tricky as this Arctic air mass comes in.
01:26I want to show you this.
01:27Let's go to the 500 millibars.
01:29And here's what I'm looking at.
01:30I'm going to show you all the models here.
01:31Here's my concern.
01:33The time frame I'm looking at is late Friday night in the Saturday midday-ish.
01:38And here's why.
01:40Watch this trough coming on down.
01:42This is the European model.
01:44So, we're going to show all of them.
01:45Watch this come down.
01:46Friday night, Saturday, early, late Friday night, and then Saturday morning right here.
01:52Right here.
01:52Look what's going on.
01:53You've got a trough axis swinging through here.
01:55And it's what I call neutral about ready to go negative.
01:59And it goes negative late in the morning.
02:02Right there.
02:03Start going.
02:04That's a lot of energy coming in.
02:05Now, why do I care about a negative trough when that comes into the northeast?
02:09That means it's oriented like this, and you start backing the flow out of the south-southwest,
02:15and you start getting more moisture in the cold air.
02:18When you look at the surface map during that time, here's the 500 millibar.
02:22Here's that trough axis swinging through.
02:24Look what's going on in the surface map.
02:26You have no downsloping flow here.
02:28You don't see any lines coming in out of the west-northwest.
02:31Remember, you've got mountain ranges here in New York State and Pennsylvania.
02:35So when you get a west-northwest flow, that downslopes along the I-95 corridor and it dries out.
02:41I don't see that.
02:42But what I do see is no downsloping flow, light winds, and this big trough axis coming through.
02:49And it even gets more curious to me at 1 o'clock Saturday because look at the surface map.
02:56You see you have these little isobars curved this way.
02:59That means you have what we call cyclonic curvature and weak upward motion at the surface with this upper level system coming through.
03:08That smells snow.
03:09I smell snow with this.
03:11That's the European.
03:13Let me show you the American model.
03:15Same thing Friday and Saturday.
03:17Look at this.
03:18Here comes the trough right there.
03:20Here it comes.
03:21Saturday morning, you've got this trough axis starting to go negatively tilted, right?
03:25Tilted like this.
03:26You're starting to back the flow out of the south.
03:30Look at the surface map during that time.
03:32No downsloping flow.
03:34And again, cyclonic curved isobars like this.
03:38Upward motion in the low levels.
03:40And then look, that swings through around 1 o'clock.
03:42And look at this.
03:43It's like, see that right in here?
03:46That tells me it's going to try to snow in there.
03:49Now, one more model.
03:50The Canadian, not as impressed.
03:52Because watch the trough axis.
03:55It's too positive there.
03:57You see, it's not oriented like this.
03:59It's kind of oriented like this.
04:01However, this would say, watch in eastern, like across eastern Massachusetts.
04:06And you can see some blue in here.
04:08The other thing to consider with this is that you have very cold, dry air.
04:13So you can get a high ratio of snow out of this.
04:15Now, I'm going to show you the European AI, close up picture.
04:19And you can get a better feel of what I'm talking about.
04:21Watch this trough coming down.
04:23This is late Friday night.
04:24Right here.
04:25Look at this.
04:26This is 7 a.m.
04:27You've got this trough axis here.
04:30Look at all of this energy in the form of wind.
04:33That's in the upper part of the atmosphere.
04:35So you're going to get upward motion.
04:37And then at the surface, see, again, you have no northwesterly flow.
04:43So nothing to dry out the atmosphere.
04:46Now, you're going to get some late snows.
04:48But I'm talking about here.
04:49This is the area I'm looking at.
04:51Between Boston and New York City, in here in the lower Hudson Valley, that's the area.
04:59And watch what happens at 1 o'clock.
05:00This is 7 a.m., 1 o'clock.
05:02That trough axis is swinging through.
05:04And look at this.
05:05Same story.
05:06You see how the isobars, lines of equal pressure, are coming in out of the north.
05:11That, and there's cyclonic, there's a cyclonic curvature with them.
05:16So they're going this way.
05:18Whoops, sorry.
05:19They're going this way, like this.
05:24That tells me it's going to try to snow in there.
05:28And when I look at the upper levels, what I see is this.
05:32All its energy in the form of wind.
05:34And you can even see the wind flow coming like this.
05:37You see this coming out of the south?
05:41It's going to snow in this area.
05:44I don't have any doubt about that.
05:45The question is, is how much?
05:48This is the area I'm looking for.
05:50I'll draw it again.
05:51I would include New York City in this and probably like this.
05:54This is an area where I think you're going to get a coating to an inch of snow.
05:59But somewhere in here, you can get four, five, six inches of snow.
06:05It's not going to be common.
06:07It's not going to be throughout the whole area.
06:09But a small area in here, you've got to keep an eye out for it.
06:14Now, where is it within this area?
06:16I'm not sure.
06:17But I'm starting to think it's somewhere south of Boston toward Providence and Hartford here.
06:27If it happens, it can happen anywhere in there.
06:30I don't think it's New York City or Boston.
06:32I'd worry about that area.
06:37Sneaky snowstorm.
06:38Again, coating to an inch in that area.
06:41Slippery travel Saturday morning.
06:42But don't be surprised if someone ends up with four, five, six inches of snow.
06:46And it won't be a surprise to you because you heard it on the feed.
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