In today's Forecast Feed, Geoff Cornish takes a look at the arctic air moving in this weekend and what impacts people in the Southeast and Northeast can expect to see.
00:00Here on the forecast feed as Arctic air charges back in, things are getting a little more interesting across the northeast and the southeast as well. I'm going to take a look at a couple of things, really three big things. One, briefly, I want to touch on a weak disturbance on Saturday.
00:22There could be a sneaky system that could produce maybe a couple of inches of snow in parts of the Lehigh Valley or the southern Poconos on Saturday. More eyes have been on a Sunday disturbance. We'll look at the potential for some snow in the southeast, even down into south Georgia, maybe a coating to a fraction of an inch there and into the Carolinas, not that far from the coast. We could see a coating to an inch of snow. And then could that impact the northeast? It'll be a close call.
00:49We'll see at least some snow in Cape Cod. How far west does it go? Do we see a coating to an inch in Boston? Probably. Do we see any more than that? We'll have to see. And then beyond that, we'll try to preserve a little bit of time to look a little farther down the line, just a little preview of late next week.
01:03So before we get into the main event here, I want to at least acknowledge that there is a disturbance on Saturday. This is not the storm that everybody's talking about in the southeast, but there's a little disturbance.
01:16And while the core of this storm system is up here, driving the surface low pressure system, there's also a secondary disturbance that's going to scoot through parts of the mid-Atlantic and into the northeast.
01:27And you can see we're talking about a rain-snow mix there in areas around Philadelphia and New York City.
01:32But I'm increasingly concerned about a little bit of accumulating snow on Saturday in some areas kind of near the interface between the pink and the blue on our map.
01:42I'll show you what I'm talking about here. Overall, this disturbance kicks through the northeast.
01:47And there's a little short-term, little hint of a kink there into parts of Ohio and into Pennsylvania here as this system lifts through the region here.
01:58It's a very subtle feature. It's responsible for this little dip. I'm kind of exaggerating it just for all intents and purposes, just to draw it out.
02:06But that disturbance that rotates around this system, look at what it does in a few of the computer models here.
02:11On Saturday, the GFS doesn't do much with it in the area that I'm concerned about.
02:17We're going to see rain that changes over to some snow in a few of these areas here.
02:22And I don't think we're going to see as much snow as more of a rain-snow mix for some.
02:26But in the NAM, it's going to be borderline temperature-wise a little farther west into areas near Allentown, PA.
02:33And this is the North American model here, also known as the Wharf.
02:36And this is going to bring a potential little burst of snow, maybe with some raindrops mixed in Saturday morning to midday.
02:45And you can see this hint of some slightly greater precipitation there.
02:49And the European, similar tune here.
02:52Again, this would be rain showers down to the south, but a potential for a little burst of snow for some.
02:58And take a look at this here, as we look at the explicit computer model forecast of snowfall.
03:03The GFS brings a small fraction of an inch, six-tenths of an inch, into an area near Trenton, New Jersey.
03:09Probably a pretty reasonable forecast.
03:11But there's potential in the NAM.
03:14Now, the NAM is probably over-forecasting snow.
03:16I think some of this is going to be melting and some rain on the front end.
03:20But there's potential on Saturday.
03:22You can see if you take it at face value, it produces 4.6 inches of snow in Allentown.
03:26I would bet under that.
03:27I would certainly bet under that.
03:29But there's potential maybe an inch or two here in a few areas.
03:32And again, trying to hit it 3 inches of snow in Harrisburg, I don't think we're going to see 3 inches.
03:36But I do think there could be an inch or two.
03:39And here's the European model.
03:41And this is forecasting, again, potential for maybe 2 or 3 inches in Allentown.
03:48And maybe an inch, inch and a half in Harrisburg.
03:50Some of this will be lost to rain.
03:52But I at least want to acknowledge that.
03:54And again, some of this in Connecticut and into areas around Worcester, Mass., and into the Berkshires.
04:00There's potential for some snow there.
04:02Some of this is actually a higher confidence forecast because of a little more elevation there into the Taconics and the Berkshires.
04:08But it's something to keep an eye on with that Saturday disturbance accompanying the actual front.
04:15Let's pull the map out here and look at the main event.
04:18This is what we're more concerned about on Sunday.
04:20This big, long wave, full latitude trough and the disturbance that rotates around the base of that, it becomes a little bit more of a neutral tilt here.
04:33Almost a neutral tilt.
04:34And it actually goes full neutral.
04:36And then it actually begins to kind of flex to more of a negative tilt once it goes offshore.
04:42Probably a little too late for big fireworks in the northeast.
04:46But as this disturbance pivots through the south, it's such a deep trough that you can see here in the European and the NAM.
04:53That's a really sharp, sharp trough.
04:55The short wave that rounds the base of the long wave trough.
04:59These are going to work in tandem with one another to produce some accumulating snow in some areas.
05:04Look at this.
05:05Now, we have concerns about the surface temperatures here on Sunday.
05:08North Florida, probably a mix of rain and snow.
05:10But if perhaps the precipitation comes down heavily enough, it can cool the whole column of the atmosphere, maybe near Tallahassee, maybe up at the Statesboro, Georgia.
05:19I think this is probably a more realistic depiction of precipitation type here.
05:23The NAM model, mainly rain in Florida, obviously.
05:26But some snow.
05:27Statesboro, Georgia is kind of an interesting spot here on the map.
05:30That's an area where we could see a little thump of snow.
05:34And here is the European.
05:36You're going to go from rain to rain, ending as snow.
05:38So, some of the blue here, some of that precipitation will be lost to rainfall.
05:43So, when it comes to an actual forecast of precipitation amounts, snow amounts, in the GFS, fraction of an inch for some.
05:50Nobody sees a full inch there.
05:51In the NAM, you can see Augusta to Statesboro.
05:56Maybe two inches of snow in a few areas.
05:58And in the European, maybe an inch or two of snow, I'd bet against an inch and a half there in Tallahassee.
06:04But that's the flavor of what we're talking about here.
06:07A rain-snow mix for some.
06:09And our actual forecast, this is what we're going with.
06:11A coating to an inch in the blue areas.
06:14And then, as this moves up into the East Coast, just a brief look at this.
06:18We did nudge the 1-3-inch line closer to Boston.
06:22So, in Boston proper, up to an inch.
06:241-3 inches in Southeast Massachusetts.
06:27So, I'm going to go back and end with a quick look at the Northeast.
06:30You can see the Sunday, Monday.
06:32It's a close call to the GFS.
06:34This is the biggest argument for big-time problems in Boston with maybe an inch plus.
06:38The NAM keeps it offshore.
06:39The European brushes Southeast New England.
06:42And again, that's how we landed at our forecast.
06:44Just keep in mind, late next week, late next week, we've got another storm system.
06:49And that's going to be something to track that could bring some snow to the Mid-Atlantic.
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