Loaded pattern: Cold, several opportunities for snow

AccuWeather

In today's Forecast Feed, AccuWeather's Geoff Cornish takes a look at the risk for cold and snow for some in the United States.

Transcript

00:00And here on the forecast feed on this Black Friday edition and moving through Thanksgiving

00:11weekend, we are dealing with a loaded pattern. We've got cold. We have multiple rounds of snow

00:17in the short term. The Midwest getting hit hard on Saturday, but we want to look a little farther

00:23down the line with the forecast feed to two additional storms that may put some of the

00:29Northeast and will put more of the Northeast in play for some accumulating snow. The plows will be

00:33out. Make sure that snow blower is ready. We'll look at a couple of graphics, some computer model

00:38data, and then back to a graphic or two to summarize things. But overall, looking at the big picture

00:43here, this next week, we have the first order of business, a storm moving from the Plains into the

00:50New England states Monday, Tuesday, and Wednesday. Tuesday is the bigger day for the Northeastern U.S.

00:56for the impacts from this system. On the southern side of this, there will be some scattered

01:00thunderstorms in the Southeast. And just in general, if you're north of I-40 and east of

01:05the Rockies, so if you're anywhere in the North Central Plains into the Midwest, the Ohio Valley,

01:12the Northeast, you have a cold pattern here. And the cold is going to be persistent. It comes in

01:17kind of like the tide, almost waves of cold behind every storm system. The winds reorient. We get that

01:23Northwest flow, and we chill back down. Now, let's take a look at some of the models here. And I'm

01:28going to jump past the weekend storm, which will be a high-impact event in the Midwest. Primarily a

01:35rain event for the Northeast. Interior Northeast, you're going to see a little bit of a mix over to

01:39some rain. With a storm track where it is, when a storm tracks over Eastern Michigan, especially this

01:45time of the year, you're going to get a changeover to rain in most areas east of I-81. And along I-81,

01:51it'll be a sloppy mix. But you can see, again, there's just too much warm advection here.

01:56And we're going to be dealing with a lot of rain showers that roll in after maybe a little bit

02:00of a transition period of time in between these two lines here on Sunday, where there could be a

02:05sloppy mix of snow to maybe a little bit of ice, then over to rain on Sunday. But what really has

02:10our attention is the next one behind that. Look at the GFS model for Tuesday. Monday into Tuesday.

02:17You can see, even before we go upstairs to the upper level flow, you can see the northern branch

02:22feature. You can see flow coming out of the Gulf. And these systems are going to work in tandem with

02:29one another, in phase with one another, to produce a pretty impactful storm. Now, we call it the QPF,

02:34the Quantitative Precipitation Forecast. How much rain or snow would fall? Pretty juiced up here

02:41in the GFS, perhaps the wettest of all these models. Now, the storm track is going to be hugging

02:48the coast. There's not a whole lot of well-established cold air in place. There is an area of high

02:54pressure, but you'll notice it scoots up and out. If it were anchored over eastern Ontario, western

03:02Quebec, and staying there, that would be a cold press, keeping the cold air with the circulation

03:07around it in place. That's not quite the case. So it's not the ideal position for cold to be

03:13sustained along I-95. There is a high pressure system to the north of this storm, but it's kind

03:19of transient and it moves out. And you can see, once it moves out to sea, there's no longer really much

03:26of a reinforcing push to keep that cold in place. And you can see with our low pressure system becoming

03:33the dominant driver here. There's just so much flow out of the southeast to drive warmer air in,

03:39and that high pressure system is nowhere to be found. It's way, way out east of the Canadian

03:43Maritimes. So for, say, New York City or Philadelphia, primarily a rain event. There could be a mix on the

03:48front end, but it won't be sustained. Now, if you're north and west of I-95, especially I-81, you got a good

03:55winter storm here early in the season. The European, not quite as wet. One thing I do want to point out,

04:01this is just Meteorology 101. When you have these isobars that are kinked down over the east side

04:09of the mountains here, that's a cold air damming signature. You can see it really well with the

04:13European model. That's a sign of cold air that's been dammed up against the east side of the

04:18mountains. And again, cold air is dense. It hugs the low elevations. You have the mountains there

04:24with elevations of 2,000, 3,000, 4,000 feet just to your west. Cold air gets stuck there and trapped.

04:28That's why we have such a proclivity for ice storms in areas like the Blue Ridge and the I-81

04:34stretch of western Virginia. We're going to see some ice there on Tuesday and some snow that could

04:39become heavy snow for southern New England on Tuesday afternoon. This becomes a powerful storm.

04:43996 low in the European, 994 low south of Block Island, Rhode Island in the GFS. Pretty good storm

04:50system. Similar 994 low in the Canadian. Pretty impressive stuff. Now, let's take a look at this

04:55storm system here. The only thing it doesn't fully have going for it in the argument for a big winter

05:01storm is that it's kind of progressive. It's kind of the trough is not fully tilted. It's tilted

05:08positively from southwest to northeast as opposed to negatively tilted northwest to southeast. So because

05:15it's going to be a fast mover, it's a decent storm. Anything this side of December 15th could be a win

05:21for the snow fans. So this is what we're forecasting. Again, it's a swift mover. I do think there will be

05:28some areas that exceed the one to three inch forecast in some of these areas, parts of central

05:34PA, western Maryland perhaps. There's going to be some ice down this way. Just be aware, some ice down

05:39here. But the snowfall forecast looks like this. And we do have a three to six inch. There is some

05:44potential that in southern New England, maybe just north of Hartford, we could get into something more

05:49than three to six. You can see our AccuWeather local store max, 12 inches. We got some time. We're

05:54going to be tweaking this with time. But that's the big idea. Pretty conservative first call from our

05:59forecast team here. I think we exceed some of these numbers in a few spots. But again, one to three

06:05inches likely for Reading, PA, Allentown, and three to six up into areas around Poughkeepsie, New York,

06:11and points north. A quick, quick word on the next storm. Quick word on the next storm. We go farther

06:18out. The one after that, you can see there's potential for either, here we have the GFS, a

06:25non-event next Saturday. But look at the European. Look at the European. Pretty interesting storm.

06:30And the Canadian, kind of between the two. So the difference here, we need to keep an eye on.

06:36If it's like the GFS, it's a pretty shallow wave. If it's like the European, look how deep that trough is.

06:41So there are some questions out there. But if the European is right, next weekend,

06:47we got chances for another significant round of snow. It depends on the depth of that trough

06:52and some other factors. That is your forecast feed.

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