00:00Well, there's plenty of fodder for travel trouble this week.
00:04Tuesday morning is going to be messy in many areas across the northeast,
00:08especially from I-95 north and west, with snow and ice for some.
00:13It's a relatively small-scale storm system in terms of the amounts of snow and ice
00:19that we're going to see near I-95.
00:21But you head north to Boston, you're going to have some snow-plowable amounts there.
00:25And then later this week, around the day after Christmas, Friday, we have another round.
00:31This one's going to come in with a little more firepower, and it's not your typical coastal storm,
00:36but it will bring more snow and ice, freezing rain, some sleet for some.
00:40It's going to be problematic.
00:41Let's look at this first round.
00:43Late tonight and into early Tuesday, you can see some snow is going to be scooting on in
00:49with also a pretty quick changeover.
00:52This is warm advection.
00:54We're going to actually, again, you have the center of low pressure flow around this.
00:57It's going to be driving warmer weather in.
01:00But we're starting cold, so we're going to be seeing some snow over to some sleet and freezing rain,
01:05and then eventually a changeover to rain.
01:07You can see, if I compare our Monday night forecast to the Tuesday forecast,
01:13just for comparison's sake, initially the rain-snow line here is going to be,
01:18well, at least the transition from snow to ice will be from near Bradford, PA, down to near Philadelphia,
01:25and rain and ice transition zone around northern Maryland.
01:29You get into the day Tuesday, and you can see we're going to be dealing with a warming trend.
01:34The ice-to-rain line is trimmed away from the city of Erie, pulls well north of the Maryland line.
01:40We're going to have still a mix transitioning over to rain, probably for the end of this in New York City.
01:45And the true snow and slop line will be a little farther north, up into areas near Poughkeepsie, New York.
01:52Overall, I'm going to show you the models in a moment,
01:53but our forecast for snowfall, just so you have perspective for the first round.
01:57This is the first storm of the week, late tonight through Tuesday morning.
02:02Late Monday night through Tuesday morning, we're looking at 1 to 3 inches of snow in areas like the Poconos,
02:08and 3 plus, 3 to 6, up into the Adirondacks, the Green Mountains, the White Mountains,
02:13and most of coastal Maine.
02:15Portland, you should see 3 to 6 inches all the way down to sea level there,
02:18into areas around Acadia National Park as well.
02:20Now, let's look over to the models, and we can show you that this first wave,
02:25it's a pretty muted one, there's not a big dip in the jet stream with it,
02:29it's just a relatively short wave that has kind of low amplitude,
02:33but you can see some of the troughiness here,
02:37and the overall measure of spin in the atmosphere of vorticity, those brighter colors,
02:40when the vorticity is moving in your direction, you're going to have extra lift in the atmosphere.
02:44The GFS kicks that through quickly, the European does something similar.
02:48It's mainly driven by warm advection, by warm air at the,
02:54in the low to mid-levels of the atmosphere, overrunning some shallow cold air.
03:00So, precipitation amounts south of I-80, relatively slim, not a whole lot,
03:06but it doesn't take much ice to cause big trouble.
03:08So, here we go into the nighttime hours, you can see this kind of almost just materializes,
03:13as opposed to being a storm that we could track from hundreds and hundreds of miles away.
03:17Precip from 7 p.m. to 1 a.m. late tonight, and then Tuesday, 1 a.m. to 7 a.m. Eastern.
03:22The pink zone is where we're going to see some ice, blue in the snow,
03:25that's where the column of the atmosphere is cold enough for snow,
03:27and then into the morning, 7 a.m. to 1 p.m.
03:31We've got snow falling in the Catskills, North Jersey, rain just south of I-78,
03:37and then this scoots into Maine, and more snow continues into Boston.
03:41It's probably going to be an entirely snow event in Boston.
03:43Here's the European model through the, well, the overnight hours.
03:49Limited, a little more limited in precip amounts,
03:52but it's going to be some light snow, some ice.
03:55It doesn't take much ice, that pink zone.
03:56And then during the morning hours, this is the concern, freezing rain
04:01and the snow moving into more of New England,
04:04and then into the afternoon, a pretty quick end to this southwest of New York City.
04:08So that's storm system number one, freezing rain.
04:12Now, the color coding here may make it look like regular rain.
04:16This is for a 24-hour window, how much freezing rain.
04:18And you can see a hint.
04:20This is coming down as liquid, glazing the surfaces that it lands on.
04:23Now, there's potential for two-tenths of an inch there in areas of maybe eastern Huntington County, PA,
04:28western parts of Mifflin County, PA, Juniata County.
04:33We don't want to take this too literally, but there's a message here.
04:36The shallow, cold layer of air right along the ground gets trapped in the central valleys
04:41of central Pennsylvania a lot of the time.
04:44Here's the NAM.
04:45It's a little more into the Laurel Highlands with some of that icing potential
04:48of two-tenths of an inch plus in the brighter yellow.
04:50And then the European, it's a little more fractured, but you can see hints of that
04:55in the Ridge and Valley region even down into parts of maybe eastern West Virginia.
05:02So that's storm number one.
05:03Regarding snowfall amounts, you can see that there could be a jackpot area.
05:07We have the three- to six-inch forecast, and it's pretty well placed, I think.
05:11Now, the GFS would say we might even see four-plus in Scranton, PA,
05:14and up into Binghamton, New York, and then a pretty good hit there in Portland, Maine
05:20with a jackpot 13.
05:21Now, we don't want to lock ourselves into a 13-inch snowfall forecast because look at the NAM.
05:26It brings only 1.5 inches there.
05:28Gives you a little bit of a window into some of the, if you just take a straight-up computer model
05:32and pump it out as a public forecast, it's not a good move.
05:35You need to have human application forecasting to keep things in check
05:40and also apply pattern recognition and years of experience and so forth,
05:45and that's what our team here at AccuWeather does.
05:47But, again, the message is that Portland, Maine, you're going to see some pretty decent snow out there,
05:52and that's how we land, again, on our forecast of, again, 1-3 and 3-6 inches,
05:57just going back to this briefly.
05:59Most likely area for 3-6 is coastal Maine and the Adirondacks.
06:02Now, behind that, we've got another mess on our hands at the end of the week,
06:06Thursday night, Christmas night, into Friday, and Friday night, the day after Christmas.
06:09Look at what goes on here.
06:11We're dealing with a pretty good round of another disturbance.
06:15This one's a little sharper.
06:16It's still a northern branch of the Jetstream feature.
06:19It's not going to have the amplitude of a big East Coast storm,
06:22but take a look at what this is able to do.
06:25We've got concerns Friday could be a heavier thump of snow and some ice.
06:31So snow and ice.
06:32New York City, you can see several inches of snow out of this.
06:34Philadelphia, you can see an inch or two changing over to ice.
06:37The freezing rain forecast, bigger numbers in southwest PA.
06:41Here's another model.
06:42Most of the interior northeast would see significant freezing rain
06:44and a quick window into snow.
06:46Potential for several inches, Philadelphia to New York.
06:49We've got to watch that one especially.
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