While an atmospheric river hammers the Pacific Northwest this week, multiple rounds of rain and snow are moving through the mid-Atlantic and Northeast.
00:00It's feeding time here on the Forecast Feed, and here we're taking a look at two totally different weather patterns.
00:06We have an atmospheric river impacting the northwest with torrential rain, yards and yards of very high elevation snow.
00:13Some of you are actually seeing more than four or five feet of snow in the extreme highest elevations,
00:19but where the passes are, it's warm enough that it's mainly rain.
00:23Meanwhile, the southwest is warm and dry, near record highs this week, and in the east, the Arctic chill holds on.
00:29We're looking for opportunities for more snow.
00:32Richmond, Virginia, if you like snow and you live in the mid-Atlantic states, often a frustrating spot for the snow fans.
00:37You've had two accumulating snows in the past five days in southeast Virginia.
00:40Pretty impressive stuff.
00:41Let's start in the northwest.
00:42That is one storyline that's really impacting the northwest in a big way here.
00:47We have a couple of storm systems.
00:49So our storm right now continues to impact British Columbia, Washington, and Oregon.
00:54There's another one lined up here for Tuesday into Wednesday.
00:57And this atmospheric river is a big deal here.
01:00It really is continuing to impact many areas.
01:02Even in a midweek, we're going to see more moisture here impact the northwest,
01:06and also more cold here in the parts of the mid-Atlantic and northeast at times.
01:10Mid-Atlantic does get a brief warm-up into Wednesday.
01:12But let's take a look at that atmospheric river event.
01:15One of the best ways to see this, if not the best way to see it, is to look at the precipitable water.
01:20So if you wrung out all the moisture in the atmosphere, whether they be water vapor or in the form of liquid water in the clouds and rain and so forth,
01:30it's actively falling.
01:32Again, a lot of this would be water vapor.
01:34If you wrung it out and bring it down to the surface of the ground in one instantaneous moment,
01:38we'd have a lot of moisture out there in this ribbon that goes for thousands of miles across the north-central Pacific into the northwestern U.S.
01:47It really is a continuous band of really significant moisture.
01:51There's a storm system that kind of interrupts that here.
01:53I'm going to try to illustrate the flow around that.
01:55But overall, plenty of moisture out there coming into the Pacific Northwest.
01:59How does this evolve?
02:00You're going to see it continues Tuesday, Tuesday night.
02:04Wednesday, it lifts a little north into more of the state of Washington into Thursday.
02:10It does weaken a bit.
02:11It doesn't get dry, but it weakens.
02:14And then you can see this ribbon of moisture is oriented more south to north and kind of misses the land for a bit.
02:19So it gets interrupted, and then we see some more showers and rain return for the weekend.
02:23But it won't be anything like that high-octane fuel that we're facing right now.
02:27Now, one thing to keep an eye on is the altitude at which it's cold enough to snow.
02:33So the freezing level, if you were in a weather balloon or a helicopter, how high up do you have to go before you hit freezing?
02:39You have to go pretty high up right now.
02:41This is, again, a storm system that's being influenced by a ridge of high pressure over the southwest.
02:47And because of that, it's kind of inflating our temperatures here over the southwest.
02:53And it nudges even the warmth.
02:57It comes into more of the northwest as well.
02:59So the storm track differentiates.
03:01It separates the cold from the warm.
03:02And right now, the freezing levels are around 8,000 feet as we look to areas like Snoqualmie Pass.
03:09And, again, Snoqualmie Pass only around 3,000 feet, under 3,100 feet.
03:14So that's rain instead of snow there at Snoqualmie Pass.
03:18Heading into the future here, into Tuesday, there's a time when the snow levels drop below 5,000 feet.
03:24You see the 5 and the orange?
03:26That's 5,000 feet.
03:27It's in thousands of feet above sea level.
03:30So there's a time when the snow levels come down.
03:32And Stevens and White Passes, we might see a little snow mix in, around 4,000 feet for a time late Tuesday.
03:37But it's mixing with rain at times as well.
03:40And then just that fast into Wednesday, look at this.
03:43Snow levels rise to around 10,000 feet in southwest Washington.
03:47Maybe 7,000 to 8,000, 8,000 to 9,000 feet for some of those other passes.
03:50And they really creep up there, 8,000 to 9,000 feet above Snoqualmie Pass Wednesday night.
03:54So this is mainly a rain event for many of those areas.
03:56So you can see, again, the snow levels fluctuate.
04:00But regardless, the precipitation consistently comes in.
04:03And it is some really heavy rain.
04:05Monday night, Tuesday, this is that time when the snow levels drop a little bit.
04:09I suspect this is showing maybe a broader blob of blue than perhaps it should.
04:13Some of that's going to be rain-snow mix.
04:15It will snow for Stevens and White Passes at times.
04:18But we're looking at inches of snow and inches of rain there.
04:22Instead of feet of snow and inches of rain in the lower elevations.
04:25So a tremendous amount of rain.
04:27Then by Thursday, this does get disrupted.
04:29Thursday night, and the precipitation finally breathes a sigh of relief here as we see the
04:35precip lift north up into Canada.
04:37And just a quick snapshot at snow amounts.
04:40If you're way, way, way up there, you're going to see mainly snow.
04:44But you have to be above 9,000 feet or so.
04:46There's a 30-inch snowfall forecast.
04:48Some areas you can see in the extremely high elevation pixels, maybe 4 feet of snow.
04:53So, and again, the European model here, hinting at the same.
04:57You need to be way up there, above 6,000 feet for the substantial snow with this one.
05:02Now, elsewhere, we want to take you into the central and eastern U.S.
05:07A new reinvigorating blast of Arctic air accompanies this next front that dives all the way down into
05:12the Ohio Valley on Wednesday.
05:14But in advance of this one, some of you actually get flow from the southwest.
05:17So, it's a tricky forecast because some of you will warm up.
05:21And even in eastern Pennsylvania, we're going to see a rain-snow mix with this one.
05:25But cold air gets reinvigorated behind it.
05:28And then we look ahead to the next system.
05:30And there's a lot of noise in the models here.
05:33Another disturbance dips through for Friday.
05:36Again, there will be opportunities for some snow with this one.
05:39And then into Sunday, another chance for some snow with another dip in the jet stream.
05:43But none of these are positioned like you'd look for a major east coast winter storm.
05:49If you had a big dip in the jet stream all the way down, digging south into the interior
05:54southeastern U.S.
05:55So, again, we're going to see opportunities for snow.
05:57But none of these have the thumbprint of significant heavy snow for I-95.
06:04And you can see how this plays out.
06:05Here we go Wednesday.
06:06Again, we got that flow from the southwest in advance of this.
06:09And it's mild enough for Harrisburg to see a little bit of rain, a rain-snow mix in Allentown
06:15ending as snow showers.
06:17But by the time it gets cold enough for snow, the precip is beginning to fade into the weekend.
06:22This one has a little more potential.
06:23This one does have a little more potential.
06:25And, again, we would like to see, we would need to see this dip in the jet stream become
06:29a little more aggravated a little farther west and maybe dig into the mid-Atlantic a little
06:35deeper, you could see in the European GFS, the contrast there.
06:40We're going to see some snow out there, but I don't think we're going to see a whole lot
06:43in parts of the I-95.
06:46There is plenty more cold coming behind each of these waves.
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