• 9 months ago
AccuWeather Chief Meteorologist Jonathan Porter looks at the complicated Northeast storm forecast, which is expected to bring significant snow to the region.
Transcript
00:00 There's lots of challenges with this forecast.
00:04 Let's take them one by one.
00:05 Yeah.
00:06 Cold air, not a lot, but some.
00:09 Just enough.
00:10 This is what we've been talking about.
00:12 There was an injection of cold air focused especially across the interior parts of the
00:17 Northeast.
00:18 But take a look at this map of high temperatures today.
00:20 50 in New York, 51 in Washington, 48 Pittsburgh.
00:23 There's not a lot of cold air to start with.
00:25 That's issue number one.
00:27 Number two, though, when you take a look at this, John, dew point temperatures, they're
00:31 low.
00:32 They're not in the teens, but they're dry enough for if you get heavy precipitation
00:38 for some snow.
00:39 That's right.
00:40 And that maybe is the key to what we've been talking about here over the last several days
00:43 because the air is drier, which means when you start to moisten it, those temperatures
00:47 will fall.
00:48 And you can see those dew points, 27 in New York and Boston, and they're in the mid-20s
00:52 from Northern Pennsylvania into interior Southern New England.
00:55 That's why we've always been concerned about those areas in terms of where the core of
00:59 the snow will be.
01:00 All right, let's talk about the storm itself.
01:02 So we have enough cold air for snow.
01:05 The question is now storm track.
01:07 And when you look at the radar, you're drawn to the Southeast because there's lots of lightning,
01:12 lots of rain.
01:13 But that is not the storm in itself.
01:15 No, that's part of it.
01:17 That's the associated moisture.
01:18 And there will be ample moisture surging up the East Coast to promote heavy precipitation
01:23 with this storm as it intensifies.
01:25 But here's the swirl Bernie.
01:26 This is what we've been talking about, this rotation here, the swirl in the clouds and
01:31 the rain and snow that are occurring across the Southern Plains.
01:34 That's the key to this, one of the keys to this forecast.
01:37 And you know, John, it was last week that, remember that map that we made, it had the
01:40 two areas of energy, the Northern piece and the Southern piece, how they interact with
01:45 each other.
01:46 That is the key.
01:47 Right.
01:48 Well, here they are.
01:49 And here's that storm.
01:50 That's the one we just pointed out swirling in the Southern Plains as we head toward later
01:54 tonight at 11 p.m. that moves up into the Ohio Valley.
01:58 That's part number one.
01:59 Here's part number two coming across the Great Lakes.
02:02 And the question has always been, how do these interplay in order to get a big storm?
02:07 It comes down to very small details into how these storms or how these two systems interact.
02:13 Looks like this storm is going to continue to make its way off to the north and east
02:15 here.
02:16 The question will be, does it come up the coast or take a little bit further of a southward
02:21 jog?
02:22 If that happens, then we're going to have to reduce the snow amounts as the storm will
02:25 be drawn further to the south.
02:27 It all comes down to the intensity of this jet stream disturbance coming across the Great
02:32 Lakes.
02:33 And our team of over 100 expert meteorologists are watching that minute by minute.
02:36 Now, let's take a look at future radar here quickly, John, and then we'll get into some
02:40 snow accumulations here.
02:42 Now, listen, it's starting his rain in New York City, Philadelphia.
02:45 No problem, Washington, D.C.
02:47 Let's start right here at around 7 o'clock in the morning.
02:52 John, take it over.
02:53 You'll notice that everything starts to change over to the snow.
02:56 See, look at the blue in here.
02:57 This is indicative of where the snow is going to be occurring.
02:59 And see how that collapses toward the coast as some of that colder air gets drawn into
03:03 the storm system.
03:04 And the rate of snowfall increases even close to the coast.
03:08 Now, as we get toward tomorrow morning, tomorrow afternoon, everything ends.
03:12 In New York City and Philadelphia, the tricky part is, does it precipitate hard enough to
03:18 accumulate?
03:19 Here's a big map, then we'll zone in.
03:21 Overall, north of Interstate 80, Pennsylvania, southern New England, that appears right now
03:26 where the air is cold enough for mostly all snow.
03:29 Right.
03:30 That's from the Poconos into northern New Jersey, the Catskills into interior southern
03:34 New England.
03:35 So Connecticut, northern Rhode Island, and much of Massachusetts, including Boston.
03:39 Pretty good snowstorm there.
03:41 Now, there's our Wintercast forecast for Boston, 6 to 10 inches of snow.
03:44 You'll notice there is a possibility of a little more than that noted by Wintercast.
03:50 That's correct.
03:51 And these details for your community available in the AccuWeather app for every location,
03:55 great resource to understand when it's going to start and how much may fall.
03:59 Now, there's New York City, and this is the real tough forecast, John.
04:02 That's right.
04:03 Look at how a sharp variation here, right in the city, could be dealing with 1 to 3
04:08 inches out to Long Island, but 3 to 6 just to the north.
04:12 Yonkers, the northern part of the Bronx up to Westchester County.
04:15 So that's the kind of sharp variation we're going to be talking about with these temperatures
04:19 very borderline for heavy snow.

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