The first half of December hit the Midwest and Northeast with multiple rounds of snow, but for the week of Christmas, chances of snow and ice will be small there while they ramp up in the West.
00:01In the forecast feed, we're going to look ahead to Christmas week, and there is a significant shift in the weather pattern and the location that's going to see the heavy snow.
00:09We're going to see feet of snow in the Sierra, and we won't see much in the Midwest or the Northeast, though there could be some ice at times in the New England states.
00:18Let's take a look at the big picture here for next week, Christmas week, as we show you the details and the headlines here.
00:24We have drenching, rain, and also, you could argue, welcome mountain snow, unless you're traveling through the passes into California.
00:32We need the snow because it's so important for water supply.
00:35It's like money in the bank as we get into the dry season with the slow timed release of that snowpack that helps to fill the reservoirs in the warm season.
00:44But also, it's good news for the ski resorts out there as well.
00:47We had a good start back in early November, and then things got really dry in California.
00:51There are two disturbances that could bring some snow and ice to New England, but neither of these are big storms.
00:57We need to keep an eye on them, though, as it doesn't take a whole lot of freezing rain to cause big problems out there.
01:02And then near-record highs will be moving through parts of the interior west and maybe even into the Midwest come Christmas Day.
01:10Let's look at the models, though.
01:11And as we take a look at the conditions aloft, let's go about 20,000 feet up into the atmosphere.
01:17Your 500 billi bar map showing that what was once a very amplified pattern, and you can see a bit of an amplified dip of the jet stream here early on with the late-week storm system scooting through,
01:29bringing us colder wind behind the departing cold front, and snow showers returning to many of us.
01:35It's going to be a more seasonable weekend.
01:40Chilly, cold, but not as cold as we had been.
01:43And you can see overall, in general, the jet stream, there's still a dip in the jet stream here, but in general, it's more linear.
01:50It's less amplified than it had been.
01:52Now, there's another system that kicks through this weekend.
01:55This one is kind of a low-amplitude trough.
01:57When I say low-amplitude, I mean the depth of this is kind of muted.
02:02It doesn't dig down into Georgia.
02:04The depth of the trough here is scooting across the Ohio Valley and the Great Lakes states.
02:08So what that will do is it'll serve to just reinforce the chill across the region.
02:12You can see there's very little moisture with this because it is a low-amplitude trough.
02:16There will be some lake-effect snow that follows it downwind of Lake Ontario.
02:20Won't be a whole lot on Sunday, but a little bit there to Rochester and Oswego, New York, and Syracuse.
02:26But what it will do is reinvigorate the chill out there, and again, reinforcing blasts of cold with a new cold front following that system.
02:36So it's going to keep our temperatures down at the end of the weekend.
02:39But then high pressure builds in, and we're going to begin to see a warming regime set up here.
02:44We are concerned about some ice in some spots.
02:47This could be a sneaky event, a little bit of snow over to freezing rain or sleep Monday night, Tuesday,
02:52that could be impactful into parts of maybe Pennsylvania and upstate New York, maybe western Maryland.
02:59We need to keep an eye on this.
03:00This is a relatively limited precipitation producer, but it just takes so little freezing rain to cause big trouble.
03:07That would be Tuesday morning.
03:09That's the GFS.
03:10How's the European look?
03:11Here you can see Monday into Tuesday.
03:14It has a similar signature, also bringing some freezing rain into the area of central Pennsylvania, up into the Poconos.
03:22A little bit of snow giving way to some ice.
03:24So because there's pretty good agreement between the GFS and the European, with that pink there on the map,
03:30and the overall setup of warm advection following a cold spell, warmer air building in,
03:35pretty good agreement there.
03:37Confidence is growing that we could see some ice Tuesday morning in the interior northeast.
03:42So that's a concern.
03:43That's concern number one for the northeast.
03:46Behind that, and there you can see there's that system.
03:49It's kind of a very muted dip in the jet stream.
03:51It's partly being driven by the winds near the surface and just a little bit above the surface there,
03:55that warming flow overrunning that colder air.
03:59Behind that, here comes another system into Christmas and the night following Christmas, Friday.
04:05This one also problematic for some.
04:07Here you can see a little dip in the jet.
04:09Not much of a dip, really.
04:10There's just some vorticity, some spin in the atmosphere,
04:13and there is going to be some troughiness there in the atmosphere tied to that.
04:18It's a very muted dip in the jet stream, just a little tiny hint of a mid-ridging little dip.
04:24I'm kind of exaggerating it just so you can see it a little bit.
04:27And that's going to be the next precipitation producer.
04:29Christmas Day, there could be some rain showers and a little bit of ice,
04:32but that system is actually this next one for Friday, following Christmas.
04:36And by then, we will have warmed up.
04:39That first system earlier in the week that could bring some ice on Tuesday,
04:42that's the agent of warming here.
04:45And behind that, we're going to be left in a milder position.
04:47That one brings in enough milder air that the following storm on Friday
04:51is going to be mainly rain south of Interstate 90.
04:55But we got snow and ice, and that could be heavier snow and ice up into New England on Friday.
04:59So we could have nasty travel weather from the Adirondacks to Vermont, New Hampshire,
05:03and virtually any part of Maine.
05:05A second opinion, the European showing that same system, but with less precipitation,
05:11and it would be a much more manageable storm,
05:14unless you're up in northern Maine with a little bit of ice.
05:16So again, there's some more uncertainty about the dynamics at play with that second one.
05:21Is it with the GFS, with stronger vorticity,
05:23or is it going to be more like the Euro, where the strong vorticity,
05:28the brighter colors, extra spin, way, way, way up there in north-central parts of Quebec?
05:34That would be the deciding factor. We'll have to see how that tracks.
05:36Now, along with all of this, before we get too far out,
05:39just to show you the snow forecast through the next several days,
05:44the European, it keeps most of the accumulating snow of an inch plus,
05:48mainly north of I-80, and some decent snow up into the Adirondacks
05:52and the Green White Mountains there with that late-week storm system.
05:56The GFS, similar story, but it's very much more of an ice event
06:01that we're concerned about for Tuesday, with some 1-3,
06:03and locally maybe 6-10 inches up in the high peaks of the Adirondacks.
06:09What I want you to notice, though, is as all this business is happening in the east,
06:12look at what goes on in the west.
06:14A trough gets deeper and deeper and deeper,
06:15and now, by Christmas Day, we're dealing with a deep trough
06:20driving all kinds of moisture into the southwestern U.S.
06:23So what does that do for us?
06:25That brings big snow to the Sierra late next week.
06:28You see in the greens, that's feet and feet of snow,
06:33and the GFS model kind of maximizing our color scale there into the pink zone.
06:38So overall, later next week, big shift in the storm track.
06:42We're going to see heavy rain, big-time mountain snow out there in parts of the southwest.
06:48So we'll close with a quick look at Christmas Day.
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