00:00In tonight's forecast feed, we do want to take a look at the potential for just a small crowd in the New England states and the Adirondacks,
00:11who may see just a little hint of some early November snow, or end of October snow here.
00:18You know, it was a few years ago that we had a little bit of a blitz of some light snow on Halloween night into early November 1st
00:24in parts of the Great Lakes and into the Northeast, and we may see something kind of similar this time around.
00:30This, however, will only impact the highest elevation.
00:33So here, as we take a look at the big picture, here's our forecast map for tonight into early Saturday.
00:38And the storm system that's been cruising through the region has been bringing some soaking rain.
00:43We saw record daily rainfall, wettest October 30th in the books on October 30th in parts of New York City at Central Park
00:51to areas LaGuardia, Newark, places like Williamsport, PA, broke records for rainfall specific to the October 30th timeframe.
01:00Now it's colder and most of the precipitation's out of here.
01:03You'll notice that the rain generally is restricted to areas near and west of the spine of the mountains.
01:10So the anatomy of the Northeast here with the highest elevations, generally the highest elevations here kind of separate those who see up-sloping
01:20versus down-sloping, areas on the west side of the mountains.
01:24The flow comes and actually increases it.
01:27It ascends from the elevation of the Great Lakes, a few or several hundred feet above sea level,
01:34up to the high elevations, around 3,000 or 4,000 feet, some of the high peaks of the Adirondacks.
01:39So it's a pretty good lift.
01:40Once you get east to the spine of the mountains, though, the atmosphere dries out.
01:45So that's why we tend to see brighter skies behind a cold front in Harrisburg, Philadelphia, New York, Baltimore, D.C.
01:52These areas, again, dry descending air is going to carve away any chance for precipitation.
01:57So you can see we are including a little bit of blue on the map here.
02:01In fact, we had a little bit of a dusting of snow in parts of eastern West Virginia this Friday morning, this Halloween morning.
02:05The Adirondacks, the Green Mountains, the White Mountains, you're going to see a little bit of light snow into Saturday morning.
02:12Snow showers.
02:13You notice that we are kind of being a little more restrictive with the true snow,
02:17where we're unabashedly just calling it snow as opposed to snow showers, mainly north of the St. Lawrence Seaway.
02:22So let's look at some models.
02:24And overall, here we have a big dip in the jet stream and that pouch of colder air upstairs.
02:29We'll focus this in on maybe the late night hours here, the late evening into the early part of the overnight.
02:35This big low pressure system aloft, that's where we find some colder air upstairs.
02:40And it's a puddle of cold air, again, cold enough to support some snow.
02:44So how high up do we need to go?
02:46Not necessarily above ground level, but how high up do we need to go above sea level to find anything that's cold enough for snow?
02:54By the way, this exits pretty swiftly here on Saturday afternoon.
02:58So the narrow window of opportunity for snow in some of these high elevations is limited.
03:04And again, this is not like a winter storm.
03:07This is not a snowplow situation except for maybe a few spots above 3,000 feet, way up above most of the towns and communities.
03:16So this is kind of a trivial point.
03:18But again, this time of the year, I think there's always a bit of interest here in the first flakes for some.
03:24You can see as we get deeper into the evening that the principle of generally precipitation being restricted to areas west of the Eastern Continental Divide being true.
03:34Where we're not going to see any rain in areas near Harrisburg, or even in Scranton tonight, or into areas near Poughkeepsie.
03:41But you need to be up to the northwest, up into areas near Warren, PA, or Bradford, PA, or up into areas near Oswego, New York, maybe into areas around Watertown.
03:50The west side of the mountains, closer to the Great Lakes, and then certainly the west slopes of Vermont and New Hampshire's mountains.
03:56That's where you're going to see some activity.
03:58You'll begin to notice that we do see that blue line here.
04:01This is the 540 thickness line, an old-fashioned rule of thumb in the world of meteorology.
04:06When the atmosphere is colder, and the 540 thickness line in decameters is basically the thickness of the atmosphere between one level of pressure and another level of pressure.
04:18When it gets constricted, that's a sign of colder air.
04:20When it expands, it's warmer air.
04:22When that blue line steps into your neighborhood, maybe begin to think about some snow falling if you're approximately near sea level.
04:29If you're above sea level by a big margin, you might get a little snow even when the blue line is to your north.
04:35But you'll notice a limited amount of precipitation on the backside of this north of the blue line.
04:40That's when you get into these snow showers here into Saturday, Saturday night in some areas.
04:44Now, this map here shows the freezing level in feet above sea level.
04:49As we get into this evening and tonight, when you get into the yellows, that's around 2,000 to 3,000 feet.
04:56In fact, 2,000 feet above sea level is where you're going to have the freezing line.
05:00Now, most cities and communities in the northeast are below 2,000 feet elevation.
05:05But if you're above 2,000 feet, you've got the chance of seeing a few snowflakes out there later on tonight.
05:11And a quick look here at our forecast.
05:15These are a couple of model forecasts here for snowfall amounts.
05:19Now, again, we can't take these too literally.
05:22Models don't do really, really, really well with snowfall forecasting on a hyper-local scale,
05:29partly because of the resolution of the models and the localized variation, far smaller in resolution in the real world.
05:37But here's the GFS model, and you can see some of those little purples up there in the high peaks of the Adirondacks.
05:42A hint that maybe, maybe, maybe atop Whiteface Mountain, there could be 3, 4, 5 inches of snow.
05:48Just up at the top, not at the parking lot.
05:50It varies so much.
05:51And some areas with more than 2 inches of snow, up where there are a few actual roads there,
05:56maybe a few of the passes through the Adirondack Mountains.
05:59That's one model depiction.
06:00Here's another one. This is the NAM.
06:02Here you can see some actual communities where in the highest elevations of the Green Mountains, the White Mountains,
06:07there's potential for 3 inches of snow up there, and then something kind of similar with the European model.
06:11So it is that time of the year where at least we can begin to think just a little bit about some high elevation snowflakes.
06:17I'll see you next time.
06:18Thanks.
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