Regional and Mesoscale Meteorology Branch

00:00:00:09 – 00:00:22:15
Speaker 1
Okay. Welcome to today’s, visit satellite chat. And, we’ll look at some real time data for today on, 18th December. And, first thing I want to highlight is the orographic cirrus clouds that are over, Colorado and portions of, Wyoming and up into Montana as well. Go ahead and let this air loop run here.

00:00:22:15 – 00:00:45:04
Speaker 1
And you can see during the overnight hours, some orographic series develops along and downwind of the Front Range. And this can play havoc in terms of the temperature forecast as you block out the insulation for, during the daytime hours, which, you know, during this time of year can play a big role, can keep it a lot cooler than, what Mars might be forecasting.

00:00:45:04 – 00:01:06:22
Speaker 1
So question is what guidance might be out there to help you out, in terms of forecasting this. And one of the things that you can use is, synthetic imagery from the various models that are out there. For example, we’ll go to the synthetic imagery from the, Nestle Wharf Air. And this is, initialized at zero.

00:01:06:22 – 00:01:28:00
Speaker 1
The so this is the waterfront initialized at zero. The on the 18th, the forecast goes from nine to, 36 hours. So this is the nine hour forecast. And you can see by nine it had developed these orographic cirrus along and downwind to the Front Range of Colorado. And the observed imagery they developed right around seven C.

00:01:28:01 – 00:01:50:28
Speaker 1
So just before the start of this model run here and, a few questions as you run this through here is you can see it persist through the day, which would be a concern here. How does it persist during the day and when does dissipate. Or you can begin to see dissipation by early afternoon. Here’s 20 and you can see over Colorado.

00:01:50:28 – 00:02:14:10
Speaker 1
Anyway, a lot of it has, dissipated or at least developed further to the south. And New Mexico. And you get into the later afternoon hours and it’s it’s mostly gone, but then it starts to come back again, right around, the evening hours here. Not as much as there was in the morning hours currently, but it does, at least is forecast to come back into the evening hours here.

00:02:14:10 – 00:02:43:00
Speaker 1
So this is one of the tools that’s out there in terms of, helping you to, forecast these are graphic series which can be a nightmare for, temperature forecasting and, of course, just like looking at any model, it’s good to look at, different models. If we go to, if we go to the page where these synthetic, loops are available here, and the, goes our proving ground freight here at Sierra.

00:02:43:02 – 00:03:01:29
Speaker 1
Another thing that you can look at is, just a different model. This is the Nam nest at, also at four kilometer resolution, same as the Nestle, worth. And, we’ll go ahead and see what, what, that was saying here. This is the forecast starting at nine. And you can clearly see it over Colorado here.

00:03:02:02 – 00:03:27:04
Speaker 1
And it does have it through the midday hours and then, not dissipating as much as the initial war. So, so this particular model has these orographic series kind of sticking around, particularly over Boulder and Denver for, most of the day here, which would obviously keep the temperatures down, considerably. And it keeps it through the evening hours here as well.

00:03:27:07 – 00:03:47:28
Speaker 1
So a couple different models to look at. And, you’re used to differences in models. And one thing you can do is just analyze that throughout the day, compare it to the Gos and see which one seems to be, handling this particular situation better. Let’s go on and switch gears here to lake effect snow.

00:03:48:00 – 00:04:00:24
Speaker 2
I’m actually down. Yeah. I got a question. Do you have, if if I take it, interrupt you? I do have, some high res imagery of the or graphics that are pretty interesting.

00:04:00:27 – 00:04:03:05
Speaker 1
Okay, let’s, switch it over to you here.

00:04:03:06 – 00:04:04:27
Speaker 2
They pass over to me.

00:04:04:29 – 00:04:12:04
Speaker 1
Check it out.

00:04:12:07 – 00:04:43:13
Speaker 2
Okay, here we are looking at the viewers, then, the day night band. We were. We see. Excellent. Excellent. This kind of, like, visible image at night because we are, we have illumination from the moon. That is, I think, at 100% or. And so we see the brightness of these orographic. Mounts on the day night band.

00:04:43:13 – 00:04:57:13
Speaker 2
If we compare, where do they look like on the I r image. If I do it mixed together and look at the corresponding I r image.

00:04:57:16 – 00:05:42:19
Speaker 2
If you look at just the EIR, it looks like you know, wow. The eastern end of this is still awfully cold. But when you look at it on the day night band, it can tell that it’s, you know, yes, it’s cold, but it’s sort of really not, that the, the high clouds are kind of those it’s a wispy, you know, they’re probably not much that would block out, any, heat from the ground for a low temperature or the eastern end might not be enough to, you know, block out enough to have much impact on, high temperature.

00:05:42:21 – 00:06:06:20
Speaker 2
However, this area out here that is, is looks like it’s, a, a denser area. And of course, it’s also a cold area. So I thought I’d just show what this looks like, on higher high res imagery. And it was pretty interesting and outline for the folks in Fort Collins. It looks like Fort Collins.

00:06:06:20 – 00:06:29:04
Speaker 2
You can see it there. Fort Collins band, the light coming through. And right there, they say that, I don’t know what it looks like, what time of this is. It’s kind of a wait and see. Yeah. So I don’t know what it looks like now, but it’d be interesting to see, you know, how the Cirrus is evolving, you know?

00:06:30:10 – 00:06:42:09
Speaker 2
But. Yeah. So they were in the clear, at least at that time. Okay. Right. And there, right. To see the night band and it’s neat. Thanks. Okay. Sure.

00:06:42:11 – 00:06:54:05
Speaker 1
Okay. I will go back to my screen here.

00:06:54:08 – 00:07:19:00
Speaker 1
By the way, here is the latest image 1545. And you can see the kind of the, the dissipation or at least the, advection of it off to the east there. So we’ll see if that, makes its way back. Or maybe the initial wharf was, on the right track here in terms of dissipating it by, by the, midday hours.

00:07:19:02 – 00:07:41:02
Speaker 2
Yeah, that that’s pretty neat case than where, you know, you have the two different models, for forecasts. Was that be a real. This is a great example of saying, okay, you got two different solutions in the short term. And you can already see it looks like maybe it it’s starting to move away or reduce. So maybe it leaning towards the which one was it.

00:07:41:02 – 00:07:41:16
Speaker 2
And that’s what.

00:07:41:20 – 00:07:42:23
Speaker 1
This will warm.

00:07:42:26 – 00:07:52:22
Speaker 2
Down by midday in this area. So I yeah. So it’s a great example. You can verify 1 to 1 model versus the other. Yeah.

00:07:52:24 – 00:08:14:19
Speaker 1
Okay. Let’s switch gears to, lake effect snow. So we’ll go to the Great Lakes region here, and I’ll, set this up with, some visible imagery along with some surface observations, just so you can see, the temperatures across the eastern Great Lakes here in the, 20s, for the most part, teens over, portions of Lake Ontario here.

00:08:14:19 – 00:08:42:01
Speaker 1
So pretty cold air mass over Lake Erie. We have pretty much a southwesterly flow, which is, favorable because it’s across the major axis of the lake. The longer, fact, you can see that, in here across Lake Erie. We’ll look at the radar here in a second. And, also over Lake Ontario, you can see a single band, over the major axis of that lake where we pretty much have west, southwest, flow across the lake here.

00:08:42:01 – 00:09:13:24
Speaker 1
So that’s, the snow that’s affecting land is on the eastern portion of, Lake Ontario. We can zoom in on this a little bit right here. And, you can see these pretty nicely here with the zoom in. They’ve had a lot of lake effect snow, particularly, off of Lake Ontario, where they had, five feet, earlier, in the week here, some, some, big, big events, or not earlier in the week, last week, I should say.

00:09:13:26 – 00:09:37:29
Speaker 1
And then there was a lot of snow off. Lake Erie as well. So you can see that’s how it looks. The zoomed in imagery. And another option that’s available is, the synthetic synthetic imagery that we’ve been talking about. This is the nasal warfare. And it’ll show these, lake effect snow bands here. Just a nice way to compare, I would say the I.R. imagery to see what the forecast is.

00:09:37:29 – 00:10:06:14
Speaker 1
So let’s get to the current time, which is, right around here, and you can see the depiction of the various, snow bands off the lakes here. Now that the the main, feature to point out here is that we introduce warmer air, a warm advection ensues here. By the end of the forecast. So right around here you can really see, say off Lake Erie, for example, right here, that, that warm advection really cuts off the lake effect snow.

00:10:06:14 – 00:10:23:15
Speaker 1
And then soon thereafter, over Lake Ontario here. So that’s basically, this evening here. So this won’t last terribly long at all. At all, occurs during the day. And then as we get into the evening hours, warm advection will kind of make these bands go away.

00:10:23:17 – 00:10:24:02
Speaker 2
Yeah.

00:10:24:04 – 00:10:25:00
Speaker 1
Yeah.

00:10:25:03 – 00:10:38:02
Speaker 2
Yeah. The question is like, static feature in the model. Back back to the model. Over. I think it was, Lake Erie. It’s like,

00:10:38:10 – 00:10:38:18
Speaker 1
Yes.

00:10:38:22 – 00:10:39:07
Speaker 2
Moving at.

00:10:39:07 – 00:10:49:05
Speaker 1
All. Yeah. Some ice, some ice. You can see that. Yeah. This is this is, Yeah, it is input into the model, the ice covered.

00:10:49:11 – 00:11:01:06
Speaker 2
So I didn’t know they had ice warm up yet. It really did. Okay. And also in the north, this section there, there’s another kind of a but it’s kind of straight edge the way they put it in.

00:11:01:08 – 00:11:05:09
Speaker 1
Yeah. You can easily see it over places like Saginaw Bay.

00:11:05:09 – 00:11:05:29
Speaker 2
Got it to.

00:11:06:00 – 00:11:30:01
Speaker 1
Michigan right western edge of, Lake Erie. So yeah, that’s the representation of of ice here in the models. And I saw it yesterday and the western edge of Lake Erie. And right now there’s some, cloud cover. So I’d have to go back to, earlier times. But I do remember seeing, yesterday and that when there was, less cloud cover over the lakes.

00:11:30:11 – 00:11:50:06
Speaker 1
The other thing just to show here is the radar reflectivity. This is from the Buffalo and Binghamton radar. Doesn’t include the radar on the eastern end of, Lake Ontario. So it doesn’t capture all of that. But you can easily see the band coming off of, Lake Erie. You remember they have a southwesterly flow here, which is very favorable.

00:11:50:06 – 00:12:01:02
Speaker 1
So areas just south of Buffalo are getting, pretty significant snow right now. Okay. That’s all I have on lake effect snow. And I believe Scott.

00:12:01:05 – 00:12:05:22
Speaker 2
I can I can interrupt you. I do have some some extra imagery also on that.

00:12:05:24 – 00:12:15:01
Speaker 1
That’s what I was going to say, that I knew you had some extra imagery, so I will I will pass it to you.

00:12:15:03 – 00:12:42:29
Speaker 2
So it’s in the evening time and you’re looking at the Erie imagery and it’s like, well, I really don’t see much indication of a band there. But again, if we look at the DNA. There and we just like put a variable image in the evening, why isn’t it toggling air? Oh, because it didn’t hit image target. All right.

00:12:43:01 – 00:13:24:21
Speaker 2
That’s the air from the piers is correct. And now we will compare that with the corresponding here’s day and night band. And now we can see a pretty good indication of a band that is beginning to, get its act a little more organized. And so you can, I think, make pretty good use of the DNA band act as a visible image in the evening to, to help you pick out some stuff that’s really not very obvious on the, I imagery.

00:13:24:23 – 00:13:25:18
Speaker 2
Okay. That is.

00:13:25:29 – 00:13:30:25
Speaker 1
Is there anything else you’d like to show or, I’ll turn it over to Scott Lindstrom at this time.

00:13:30:27 – 00:13:50:24
Speaker 2
Let’s go over to the other Scott. He’s probably gotten a lot more interesting things here. And I’ll just add for the East Coast, a day night band is usually overhead around 60, so it’s just something to keep in mind. Okay. I’m talking I’m going to talk a little bit about, air quality in the western part of the U.S.

00:13:51:23 – 00:14:20:26
Speaker 2
Both. Boise has been Boise has been sucked in for a couple of days, and there have been. So it’s been a dense fog advisory for several days, and there have been air quality advisories, in southwestern Oregon. Now, that’s that should clear up in the next couple of days as the system comes down from the north. But I just wanted to highlight a couple of ways to detect, the presence of this fog event in the snake River Valley through Boise.

00:14:20:26 – 00:14:40:11
Speaker 2
And what you have on the screen right now is from 1130 today. I have the, brightness temperature difference in the upper right because our fog and low Stratus products are on the left. So the IFR probability is in the upper left and the coast are cloud thickness. So the thickness of the highest liquid layer is in the lower left.

00:14:40:11 – 00:15:11:11
Speaker 2
And then I have the water just so regular old water vapor on the right. There’s a lot of high clouds coming in from the, from the Pacific, into the western part of the U.S and that’s making it very difficult for the traditional, method of detecting fog. Looking at the brightness temperature difference between 10.7 and 3.9 microns to have a signal, that the time I’ve chosen here at 1130, there happened to be a hole in the clouds.

00:15:11:11 – 00:15:32:20
Speaker 2
So here’s here’s Boise. And you do see a signal in the brightness temperature difference, and it shows up in the IFR probabilities as well. So it’s a very small region. But if the IFR probabilities have been high there, for the last, I believe, 36 or 48 hours, because the fog really is and is trapped in the valley.

00:15:32:22 – 00:16:07:21
Speaker 2
So that’s from 11 C if you look at the same thing from 15 C, it’s a little bit harder to see stuff. But we do we do still see a signal in the brightness temperature difference. In that region. And the IFR probably is also giving a signal. Now, one of the things that is a challenge is if you do not have, satellite data input into the IFR probability product because of high clouds, it’s only going to be using the rapid refresh.

00:16:07:21 – 00:16:35:06
Speaker 2
And that’s a 13 kilometer model. So the number of pixels in the model that have that are in this valley probably aren’t that large. So just like with the, You can use a day night band to get a feeling for the extent of the cloudiness as well. And the nice thing about the day night band is that if you have thin cirrus, you can still see the extent of the low cloudiness underneath it.

00:16:35:06 – 00:17:05:28
Speaker 2
And then the snake River Valley shows up very nicely in this image through southwestern, southwestern Idaho. This is from nine 4559. So for the West Coast, day night band is typically there around ten feet. And again, you’re seeing the low visibilities in the snake River Valley and the increased IFR probabilities in that region as well. And I also had the, I have the brightness temperature difference product from FEA.

00:17:05:29 – 00:17:27:27
Speaker 2
If it’s in the that’s in the bottom right, as well as just showing you that it’s, it’s giving you mostly the same region as, Picos images. But if it goes image goes, imagery does, you just get a better definition of exactly where the low clouds are. And you can also see some streaks of high clouds that are over the, low clouds.

00:17:27:27 – 00:17:54:25
Speaker 2
And of course, that interferes with the brightness temperature difference signal. And that also plays back into the IFR probability as well. So it’s a it’s a handy product to use when, because the IFR probably is a handy project to use when you’re trying to identify regions of low stratus and fog and you have, high clouds in the area which make it traditional method difficult to use.

00:17:54:25 – 00:18:17:23
Speaker 2
So with that, I will hand it back. Yeah. Scott. Yeah. Before you can, yeah. I think, am I saying it correctly? There is a fame running through the in the top right. Actually pretty close. Yes. This is, we have goes east on the to the right of that same in goes west to the left image thing.

00:18:18:02 – 00:18:40:29
Speaker 2
I don’t know, time. And at some point look to see what the cause was, the picture and would look like, for that same area. Right? Yeah. The difficulty is I’m localized for for Sullivan here, and, so, but that’s what I am. Yeah. Because the Boise people say, wait a minute. Yeah. What do you think out west?

00:18:41:00 – 00:19:04:21
Speaker 2
Yeah. Although I think the viewing angle is probably about equal. Yeah. And birds and still be good to do a little flip comparison. Oh, yeah. Absolutely. Yeah. That’s a good idea. I would say the high cloud now but that’s really I, I love that the zoom or not the zoom that the high res from on the bottom right.

00:19:04:21 – 00:19:27:11
Speaker 2
Yeah. But yeah. Okay. It really does say okay that break in between there. Right. Almost over the itself is actually high clouds. Right. There’s no doubt about it. Yeah. And and it looks like maybe there is a little fog over Salt Lake or not down there. Oh there’s I mean there’s a bit of a signal and both of them, if the there’s some haze there I guess.

00:19:27:24 – 00:19:39:16
Speaker 2
Okay. So that might be hard to see in the day night band, but there’s so many there’s so many city lights there that it’s kind of contaminating the theorem. Right? Right. Okay, great.

00:19:39:18 – 00:19:43:03
Speaker 1
Okay. Should I turn it over to Scott B here?

00:19:43:23 – 00:19:50:17
Speaker 2
I think I have, I’ve already had all my on all my. Oh, all my cool images thrown out there. So.

00:19:50:22 – 00:19:53:26
Speaker 1
Okay, well I’ve shown everything as well. So are there any other comments.

00:19:53:26 – 00:20:20:10
Speaker 2
Do we just show the water vapor loop showing that system coming down the West coast that’s going to impact the central part of the country next? Yeah I do, yeah, let’s do it. The experts say about which way is it going. We’ll have to cover kind of a vague the terrain, you know, I guess they’re obviously model the model and run a run changes and just how far that’s going to dig and how it’s going to make the turn right.

00:20:20:10 – 00:20:48:11
Speaker 2
So there it is right off. Right, right southwest of the Queen Charlotte Islands or Vancouver Island. So that’s the impulse that eventually, goes all the way around the long wave tromping trough and comes up through the central part of the US over the later part of the weekend. And some of the forecasts for O’Hara, for example, would be a real snarling of the, of that air hub.

00:20:49:02 – 00:21:16:02
Speaker 2
So, yeah. So I think the other interesting thing, though, is even though it’s it’s finally being kicked out, there was that other wave that was hanging off the coast of California, and that’s being picked up now, right? I don’t know, they’ll have much farther away, but I think that’ll be considered some some of the high clouds are developing out ahead of day out of that finally kicking out and could have a little bit of an impact over the out that comes across.

00:21:16:02 – 00:21:36:08
Speaker 2
And I think for us, I think most of that stand to our North. It’s mostly for, maybe the northwest corner of Colorado. And I don’t know, Brian, if you’ve seen what a local office is saying about that little wave kicking out ahead, it may the old fly in the ointment. It’s now so we be right out there.

00:21:36:08 – 00:21:52:07
Speaker 2
The other little wave that coming in? Yeah. I mean, that’s that first wave is supposed to give the upper Midwest, you know, a nuisance snow. And oh, I love that. I really think well, it’s just a couple inches, so. Yeah. Know. Yeah.

00:21:52:07 – 00:21:54:18
Speaker 3
But 500 miles worth of a couple of inches.

00:21:54:25 – 00:21:56:17
Speaker 2
Oh, is that some of it?

00:21:56:21 – 00:22:01:24
Speaker 3
Yeah. I, I’ve driven on I-80 through that one time. It was a it was endless nightmare.

00:22:01:26 – 00:22:11:27
Speaker 2
Well, you were driving us, right. You need to drive orthogonal to the I know exactly. Right. Yeah. It had a way I like it. What parents of new sense. They say what we hear term get it.

00:22:12:03 – 00:22:29:00
Speaker 3
And it was a nightmare. You know, after about 300 miles, I mean it there was no end. It was it was terrible. Oh yeah. But you’re right, Tony, that is a bit of a wild card. And I’ve been hoping that that interaction with the northern thing would occur over us instead of Cheyenne. I haven’t seen the very latest stuff, but.

00:22:29:11 – 00:22:57:01
Speaker 2
Okay. Yeah. And you’re going to say that and run and run. It’s been changing quite a bit in terms of finally, because, well, these features are off the coast. And those of us that look at satellite know that, okay, how well those are being captured is going to vary significantly until it does get. Now, although we do know the models are incorporating a lot of satellite data, maybe not all of it is the question.

00:22:57:01 – 00:23:23:15
Speaker 2
So as those both those features get closer in to the West Coast, you’ll see I think Phil, the some significant run around it. And if you want I can do an an image comparison of the coast versus a remote is on the the water vapor imagery. Sure. Why not?

00:23:23:18 – 00:23:49:02
Speaker 2
We got two minutes. All right, well, plenty of time. Plenty of. So here we can see that beautiful gradient of where that, pocket of the dry air is. And this is what it looks like at one kilometer using the Motus instrument. If we compare the corresponding cores image, it’s going to make sure it and on and look at those water vapor.

00:23:49:05 – 00:24:16:09
Speaker 2
Is that 11 zero. I’m like I can’t quite see the correct green sky okay. So if I toggle between here’s the goes and here’s a Morris boy, I got some slow connection there. I thought you guys had fast connection. Oh, that’s often the case. I don’t know what’s going on here. That was the surprise. And what it finally is down there that time.

00:24:16:09 – 00:24:50:25
Speaker 2
There you go. Yeah. And so, you know, you do. You can see the gradient and, you know, stuff of where the dry air is a lot better from the Morris estimate because it’s a one kilometer versus probably, what, eight kilometers up here at this high of a viewing angle. So and it’s also, looking more straight down versus, a slant light goes as it goes, has a significant slant there.

00:24:50:25 – 00:25:14:25
Speaker 2
So there’s going to be a little bit of limb brightening, versus the Motus image, which is more, Nader. That’s correct. And there is just a hint of some striping maybe. And that goes that not apparent at all. You know, especially if you look further at the northern part of that. You know, me, I always make up stripes, but I.

00:25:14:26 – 00:25:38:06
Speaker 2
Yeah, maybe it’s my eyesight. But, you know, as you get up into Canada, there in far northern part of it goes, it’s not there at all in the town. That’s true. So although and ago that interesting over to, western Montana, there is a nice little dry, air that that there would be a little wind, getting going there.

00:25:38:07 – 00:26:00:23
Speaker 2
And I think they do have some problems there of high winds. Yeah. Okay. And I mean that we we noticed that right away in Colorado. When we see that we know winds coming and it’s not here already. Okay. I just thought I’d have that little image comparison. I tossed it in. So that’s all I have.

00:26:00:29 – 00:26:07:10
Speaker 1
Okay. Do we have any questions or comments before we conclude?

00:26:07:13 – 00:26:21:08
Speaker 2
Yeah, just thanks again for great job you guys are doing. And I think, we’ll talk about it tomorrow, tomorrow. But I think, we’ve got some ideas, percolating about how to get this. There’s a cat at ten. It’s got a.

00:26:21:08 – 00:26:21:21
Unknown
Little more in.