Regional and Mesoscale Meteorology Branch

00:00:00:00 – 00:00:25:04
Speaker 1
Here. Welcome to today’s, visit, late chat. Today we’re going to lead off with talking about typhoon. Actually super typhoon long, long from, last week, it was a very intense system. And we’re going to look through some, imagery associated with that. And to help us out, we have the unique perspective of, Doctor John Neff, who is, here at Sierra.

00:00:25:04 – 00:00:40:20
Speaker 1
He’s a known as this employee and an expert on, tropical cyclones. So, without further ado, I’ll turn it over to John here.

00:00:40:23 – 00:01:22:17
Speaker 2
All right. Good morning. Just as an overview perspective, I put up the track. This is the operational best track from Typhoon von fog. And, as you can see, these are the intensities along the track. Kind of a flat period here of around 90 knots. And the estimates. And then somewhere around the, the this date time, which is, close, but this is the sixth, the, the storm rapidly intensified, and we have some viewers imagery for right in this time period here or where the storm both was intensifying very rapidly.

00:01:22:19 – 00:01:50:01
Speaker 2
And then as it reached a more steady state of around 155 to 145 knots. So, you know, in retrospect, we probably should have put, the, the corresponding image from, MT sat here. But, I think the important takeaways are that, this is during the intensification period on the seventh at about zero, four, 30 Z.

00:01:50:03 – 00:02:13:05
Speaker 2
And one of the things you can always see in, in intensifying storms is that the, the or often can see is that you can, see this ragged, and what this is really telling you is that there’s a tremendous amount of mixing going on in the, in the eyewall. That usually corresponds to a lot of mixing that’s going on in this, in the rain band region.

00:02:13:05 – 00:02:38:22
Speaker 2
But as the storm becomes more mature, the, convection at the top, the cold clouds here will become more, uniform lower standard deviation in and and ask me will sense in this I will oftentimes become, very, circular in nature. And that usually means that the storm has completed its intensification period or its rapid intensification period.

00:02:38:24 – 00:03:02:24
Speaker 2
And the storm is, is now at near steady state. So this was during the intensification period. If we if we went, if we go back to the previous time just to kind of show you where this was, in the greater scheme of things, that was right in this time period between where the storm was 105 and 125, so during the period of rapid intensification.

00:03:02:26 – 00:03:36:26
Speaker 2
So if we go to the next image, which is the visible of that, and this is this is a true visible during the day, you can see the evidence of these, mesoscale, mezzo vortices in the eye. And I don’t think that this is all that, evident in the MTC. It’s very smooth. And this may actually be more of a, a polygonal eye case where you have, kind of a square or, polygon, in the, in the imagery.

00:03:36:26 – 00:04:07:04
Speaker 2
And this has been pretty much noted in the, in the literature, polygonal walls. If you do a Google search, you can, you can find, quite a few papers discussing those, type storms. So moving on. This is on the seventh at 17 Z. This is during its, very intense period. And you can see that the, the relative lack of, of, eyewall, undulation or major vortices here.

00:04:07:04 – 00:04:36:10
Speaker 2
You can also see that the, the satellite is viewing from the west southwest. So, you’re getting, more of the eyewall viewed at this angle and less. But I think what’s somewhat remarkable in this case is how how axial, actually vertical. The, eye wall is typically this slope is a lot more severe, but you can see the upper upper, upper, cold cloud has become very uniform.

00:04:36:10 – 00:04:47:03
Speaker 2
But in the viewers imagery, we can see evidence of even striations of the, you know, transverse banding above the cold convection. So you really.

00:04:47:06 – 00:04:50:05
Speaker 3
Say is at three 75 meter or some 50.

00:04:50:29 – 00:05:15:27
Speaker 2
I believe this is 375, but, obviously it’s not, displayed at the highest resolution. We could probably zoom in even further in the, in the imagery. You can also see these individual cells out here and, the rain bands, if we went back to the original image, you can see that, that there appears to be a lot more, going on in the, in the outer rain bands here.

00:05:15:27 – 00:05:41:26
Speaker 2
So, if you were to do a at classification, the two things that you would be most interested in are the, the the the, coldness of this. And, at this time, it was in the, -170, close to -180 type. Temperatures. And the high temperature was somewhere around, 15 or so.

00:05:41:26 – 00:05:58:09
Speaker 2
See? And so those two things combined and the width of the, of this cold cloud kind of give you a rough, starting point for your and test intensity estimate. So, are there any questions thus far?

00:05:58:11 – 00:06:02:16
Speaker 4
Just to clarify, you meant 170 to 180 Kelvin, not -170.

00:06:02:19 – 00:06:10:00
Speaker 2
Oh, I, I did I say Kelvin, I meant minus minus is in the -70 to -80. Okay.

00:06:10:02 – 00:06:11:27
Speaker 3
I thought you said 170 and I was raised.

00:06:11:29 – 00:06:36:22
Speaker 2
Yeah. Wow. Yeah, yeah. I’m sorry. That’s that. That’s my, My bad. This is not an ideal, color enhancement for doing a Dvorak type, estimate, but, we’ll we’ll live with that. So this is at night, and then this next image is also at night. I think this is probably one of the most spectacular, nighttime visit.

00:06:36:27 – 00:07:03:04
Speaker 2
Visible images we’ve gotten, since verses has been up there. And you can see this. I mean, for all intents and purposes, this is what you’d see in during the day. So from that point, you can see a lot more going on in, in the eye wall at night in the visible imagery than you can say, per se in the, in the, previous, infrared image.

00:07:03:04 – 00:07:04:03
Speaker 2
So.

00:07:04:10 – 00:07:06:13
Speaker 3
So it was at the height of the full moon.

00:07:06:16 – 00:07:35:25
Speaker 2
It is it’s nearly at the height of the full moon. This is this is without, any, you know, day night band near constant contrast. So, like I said, one of the more spectacular, nighttime visible, if, we go forward, this is when the star has, has, this is the actually the next day, at, for Z.

00:07:36:00 – 00:07:56:15
Speaker 2
And this is when the storm has started and, it has sort of peak. And you can see the viewing angle here is from the east. It looks like the east almost. Well, little south of east viewing in this angle. And you can see that the slope of the eye wall is quite a bit more, quite a bit more sloped at this time period.

00:07:56:26 – 00:08:23:16
Speaker 2
You can’t even see any evidence of the slope here. A little Pelleas clouds moving in from the, from the eyewall or from the upper clouds into the inner eyewall. And I think when you blow in like this, you can see, it’s you can almost see that the the evidence that you got, cyclonic outflow in this, in this regime, because you can match up the, the striations in the, in the cirrus clouds here.

00:08:25:03 – 00:08:48:26
Speaker 2
And, it’s kind of unique in, in, in the world that you can get, cyclonic outflow at the upper level. So what typically happens is you get cyclonic going out like this, and then it’s some further radius out. And here it starts to turn and this cyclonic. So and that’s sometimes why you get this mote out here as because you’re, you’re forcing, descent.

00:08:48:28 – 00:09:14:09
Speaker 2
I’m sorry. I, went to the next image by accident, but you can see this this mote developing out here, and it’s nearly symmetric. So this is where this area is usually where the, the cyclonic outflow turns into a cyclonic. So sort of like that. And here’s a, here’s a further out image. And you can see evidence of, of where that mode is, a little bit better.

00:09:14:09 – 00:09:49:16
Speaker 2
You can also see the slope. And, you know, I have never seen a cyclone, that does not have, mezzo vortices or in this, in this what they call the hub cloud, in here, unless the eye is completely clear, which is usually, sort of at the end of, rapid intensification. So I, I don’t know if you guys have any more questions, but, I’ll pause for a second and, see if there is any, any comments from, anybody out there.

00:09:49:16 – 00:09:53:02
Speaker 3
This one is at nighttime and the previous one was daytime, correct? Yeah.

00:09:53:04 – 00:09:57:02
Speaker 2
Yeah. This is night. Oh, yes. I’m sorry. Yes.

00:09:57:04 – 00:09:59:00
Speaker 3
I’m sorry. I was just looking at it.

00:09:59:03 – 00:10:03:26
Speaker 2
Yeah, yeah, yeah, yeah. So this is the daytime. This is day.

00:10:03:28 – 00:10:09:12
Speaker 3
And for those who are unfamiliar with it, the island is at three 75 meter, right? Yeah.

00:10:09:14 – 00:10:30:08
Speaker 2
Yes. And the, day night band, I think it’s 750. Yeah, yeah, but you can still see evidence of here, and and you can almost see. Oh. It’s interesting to see this viewing from the same angle, but there, there’s a little bit of evidence. So a little bit more, slope in the eyewall. This is a little bit weaker, 145 knots.

00:10:30:08 – 00:10:50:08
Speaker 2
And I think most of that was due to the, the upper clouds, warming from, you know, close to -82, more like 175. And when you do your devoir at technique, you get breaks in that, that, that caused you to reduce the intensity over time.

00:10:52:28 – 00:10:59:12
Speaker 4
I’ll just add that the eight was one. There was the full moon. So the lunar eclipse had just ended at 1640 UTC, right?

00:10:59:12 – 00:11:22:03
Speaker 2
So again, these are some of the best images we’ve gotten from, the viewers day night band because of the way the moon is illuminating the storm. Kind of a unique opportunity for us. And I think this is my, let’s see. You know, I have one more at, at, than the next time period, which is well, that is my last one.

00:11:22:27 – 00:11:31:17
Speaker 2
I’m sorry, I’m a little confused here. Yeah. This is the 1644 night, nighttime image. So, if there isn’t anything else, I got.

00:11:31:17 – 00:11:36:11
Speaker 4
A question that should work. So, then I noticed that you’re recording this session.

00:11:36:13 – 00:11:37:27
Speaker 2
Yes. We are.

00:11:38:00 – 00:11:43:29
Speaker 4
Okay, so I want to chat about some things, and I’m not sure which be recorded. Can we wait for that for a second?

00:11:44:18 – 00:11:47:24
Speaker 1
Afterwards. Afterwards? We can do that.

00:11:47:26 – 00:11:52:07
Speaker 4
Okay. Well, I’d like to talk about this case in more detail afterwards.

00:11:52:09 – 00:11:54:01
Speaker 2
Yeah, I think what? Dan, put it out.

00:11:54:01 – 00:11:57:12
Speaker 3
Bill, if you want to.

00:11:57:14 – 00:11:58:03
Speaker 4
Whatever it is.

00:11:58:03 – 00:12:02:18
Speaker 2
Yes. Okay. Thank you.

00:12:02:21 – 00:12:04:20
Speaker 2
Go ahead with your question.

00:12:04:23 – 00:12:09:23
Speaker 4
Okay. So did you pause, the recording?

00:12:09:26 – 00:12:39:29
Speaker 1
Okay. Okay. Well, let’s let’s move on here to, some real time imagery since, we have some, real time imagery to look at here and, here’s, here’s Tropical cyclone, Gonzalo here at the imagery, and you can see some interesting trends. Well, first note that this is, a pretty small storm. So it, intensified quite a bit, yesterday.

00:12:39:29 – 00:13:01:06
Speaker 1
And you see, in the most recent trends here, it’s, not quite as well defined as it was, earlier in the morning. And then if we go to the, invisible loop here, I guess the first interesting thing to note is that observation very close to the eye there, about 40 knots from the northeast.

00:13:01:06 – 00:13:19:11
Speaker 1
But, also in the visible here. Like I said, the eye isn’t quite as well defined as it was, in the early morning hours here. So, any any other observations, thoughts, comments and, the imagery here?

00:13:19:14 – 00:13:49:06
Speaker 2
I do have a comment. Actually, the size of this system is it’s rather small. And, despite I don’t know exactly what got it estimated is intensities probably around 100 knots. But look at the, the debris at that point, you can see how tight the pressure gradient is. The, the system actually has something around at 9/9, 75 or so, pressure, which is rather rather high for a major hurricane.

00:13:49:06 – 00:14:09:06
Speaker 2
And I think that all goes back to, how big the system is. And you can you can definitely, if you were compare this with the with an ensemble of tropical cyclone sizes. This is this is on the small side. So you would expect higher pressures and, tighter gradients and, and smaller features. So that that’s my general comment.

00:14:09:22 – 00:14:13:06
Speaker 2
You also see some

00:14:13:08 – 00:14:14:23
Speaker 3
I was ready to comment on this.

00:14:14:23 – 00:14:25:06
Speaker 2
This. Yeah, that’s that’s been noted, as it’s called Fanning, I think in some of the, the Dvorak type literature and, it’s been noted sometimes.

00:14:25:06 – 00:14:26:19
Speaker 3
Having transverse banding.

00:14:26:23 – 00:14:53:01
Speaker 2
Yeah. Sometimes when you see that fanning, it means the storm is going through a slight period of intensification. But, that usually is associated with, storms that are around on weaker end. And this one, it looks like it’s, it’s doing a little bit of intensification, but it’s not going to go much further because it’s limited by the sea surface temperatures, which are shown by the red, the red, numbers.

00:14:53:01 – 00:15:13:26
Speaker 2
So blue temperatures there that so 82 is about 27 degrees C, so, it’s moving into an area to near 84, moving into an area of 82. So that is going to drop from about 28 degrees C to about 27. So should start the level off or weaken.

00:15:13:28 – 00:15:22:00
Speaker 1
Okay. Any additional thoughts comments about that.

00:15:22:03 – 00:15:31:17
Speaker 1
Okay. Well at this time I’m going to turn it over to Scott Enstrom at Sims. Wisconsin.

00:15:31:19 – 00:15:53:12
Speaker 4
And we will look at a different tropical cyclone. This is a tropical storm and a very strong tropical storm, I believe 70 miles an hour. And this is the semi NPP path from 11 C this morning. And I also have the day night band from the same time. This is from the antenna at, in Honolulu. Okay.

00:15:53:12 – 00:16:11:21
Speaker 4
There we go. So that’s the day night band. So kind of washed out sometimes the day night band doesn’t give you a very good contrast if you have a kind of a flat field, because you don’t see if it’s a move to the wrong place, the shadowing just doesn’t show up very well. So that’s it’s beautiful that you can see these visible images late at night.

00:16:11:29 – 00:16:40:13
Speaker 4
But I’m going to just focus on the, 11.35 micron here. One one of the things that I’ve noticed that the cloud tops with this are really, really cold. There have been, up in the mid 90, -95, 97 Celsius. So extremely cold. I’ve even seen the 91 Celsius below 91 Celsius below zero on goes. So that’s a four kilometer footprint.

00:16:40:24 – 00:17:04:04
Speaker 4
It’s pretty close to the sub satellite point, so it’s probably close to a nominal four kilometer. So just some extremely cold cloud tops with this system. Of course it’s forecast to nick the southern edge right now. The forecast track I think is to nick the southern edge of the Big Island. Then kind of curve toward Oahu. So it’s, it’s it seems like it’s going to have an impact on the entire chain of the Hawaiian Islands.

00:17:04:04 – 00:17:15:23
Speaker 4
So this is going to be a huge impact out there. If the forecast track is correct. So any comments on this particular storm, then I’ll talk about the, that that we had here earlier this week.

00:17:16:03 – 00:17:20:25
Speaker 2
Do you know what the, forecast intensity when it next the southern tip of the.

00:17:20:27 – 00:17:37:27
Speaker 4
I know it’s supposed to be a hurricane. I’m not I don’t remember what. I don’t see my tab open now for the. No, I don’t see. I don’t see it. I don’t have a Central Pacific Hurricane Center tab open right now. And the current. I don’t think it’s supposed to be major. But I really don’t remember.

00:17:38:02 – 00:17:40:23
Speaker 2
In the current intensity. They have it at, what.

00:17:40:25 – 00:17:54:22
Speaker 4
70 miles an hour? Okay, that was from the last. I mean, it’s about time for new updates. That was from the left. So that was me from the Navy. I’m not exactly sure what. Cycling. Yeah. What time the Central Pacific Hurricane Center puts their stuff out.

00:17:54:25 – 00:18:19:21
Speaker 2
One thing you can comment here is that when you see, you usually don’t see really, really cold, cold tops with with hurricanes, with strong hurricanes. But when they’re developing before they form, they’re real strong warm caught and I this is when you see this overshooting, persistent cold cloud. I think, it can be two things. One, it can be, it can be.

00:18:19:21 – 00:18:38:09
Speaker 2
I mean, there’s a lot of shear, but on the other hand, a lot of overshooting tops means that there’s a tremendous amount of, latent heat being, put up. And this one looks like it’s in a pretty low shear environment, or those two. So it looks like it’s going through a slight intensification period.

00:18:38:12 – 00:19:01:23
Speaker 4
And it’s kind of a rare it seems to be a rare place for a storm to form and then move to the Hawaiian Islands. So it’s looking at a goes 15 multi-day animation. And it’s really kind of interesting that there’s a, a westward propagating feature that kind of interacts with an eastward propagating tropical wave, probably down, you know, off to the southeast of this image.

00:19:01:25 – 00:19:06:07
Speaker 4
And this tropical system emerges out of that. And this westward propagating.

00:19:06:07 – 00:19:14:20
Unknown
System is now coming up toward Baja right now. So you can see these two systems kind of interacting, and the tropical system.

00:19:14:22 – 00:19:21:04
Speaker 4
Gets spun off from it. So it’s kind of really interesting genesis of where the system has emerged from. Yeah, I.

00:19:21:04 – 00:19:49:28
Speaker 2
Think it’s been about 20 years since we’ve had, storms form, this late in the season and had such active Eastern Pacific, storms in general. But the, the mid nine, early to mid 90s were the last time periods where we had such activity in the East Pacific. And it goes back to sort of the overall the the sea surface temperatures have been warmer in the whole eastern, tropical cyclone basin this year.

00:19:50:01 – 00:20:06:12
Speaker 2
And if, if history and this has been a very active year out there, if history has it, October should also be, fairly active. And this is good evidence that that’s occurring again. So it’s kind of in the early 90s, sort of climatology again.

00:20:06:15 – 00:20:26:27
Speaker 4
And I want to talk a little bit about, this is a different super typhoon. This is fun, fun. And there are I didn’t I noticed no put out a loop that shows the same thing. But if you track this, this system, the big cyclone that we just had in the middle part of the U.S.

00:20:27:00 – 00:20:50:28
Speaker 4
So here we have looking at from Goes 15 now you can track this all the way across up over the ridge and then down into the central part of the U.S with this big system that has just come through, the central part of the U.S and now is exiting the U.S so when I see something like this would and I just kind of wonder, well, how were you ever going to get?

00:20:51:00 – 00:21:10:29
Speaker 4
I mean, if you think if you want to do a ten day forecast, you had to you have to do a good forecast of what’s going on in the Pacific tropics as well. But when you have this kind of interaction and if you’re wondering, like I was when I did this. So you see Fung Fong is there. So Fong Fung is in the image here, the remains of Fong Fong.

00:21:10:29 – 00:21:33:06
Speaker 4
Now we’re up in the Bering Sea, so I’m kind of curious to see what happens to that with time. So fun. Funny. Or having a say that, some of that energy was associated with the big system that just came to the central part of the U.S with a nice, variant, a really nice example of cross cross Pacific transport of essentially tropical moisture.

00:21:33:06 – 00:22:00:07
Speaker 4
So, I thought that’s kind of a cool little thing to note on that particular system. So I was also looking at the moisture from Hurricane Simon. So from Pacific Hurricane Simon, that came ashore, I think about the 8th of October, and most of that moisture was not involved with this last system that came up to the, which over the eastern part of the US, which, incidentally, dropped a lot of rain.

00:22:00:14 – 00:22:08:16
Speaker 4
If you look at the let me just show you one other thing that I put together here, if I can find them. So we have these, Yeah.

00:22:08:17 – 00:22:13:25
Unknown
That’s not it.

00:22:13:27 – 00:22:16:06
Unknown
So we have this sounder deeper.

00:22:16:10 – 00:22:34:28
Speaker 4
This is available in and was. But I just went back to the archive to show this. So if you look down in, Arizona here, this is before the system that we just came through is organize. You can kind of see the clouds starting to dive to the southeast, but this moisture and is left over from Simon, the actual impulse that Simon has shifted off to the east.

00:22:34:28 – 00:22:59:08
Speaker 4
I think it’s on the on the East coast at this particular time. That’s a step forward in time, that you see the system diving down from the from the coming down the ridge and the moisture is starting to pull, starting to feed it. But if you if you watch the moisture over the southwest from Simon, that really doesn’t seem to get get caught by this picture that’s associated with fun.

00:22:59:08 – 00:23:19:24
Speaker 4
Funny. So it’s only one tropical system here. And then at the very end, you see the surge of moisture coming up out of the Gulf of Mexico. You can see that in the mimic TP, UW, which is a microwaved morphed microwave image. And you can also see it in the, ghost town. So just a tremendous amount of moisture being fed into this particular system.

00:23:19:26 – 00:23:35:11
Speaker 4
And I see it’s 11. So I could talk about other things, but I think I’ll stop in just going to put back a nice image of, what I assume isn’t going to be Hurricane Ana. Any other questions on this?

00:23:35:13 – 00:23:58:18
Speaker 2
You know, I do have a comment, and maybe forecasters should be aware of this, but when these storms, in the West Pacific, recurve, they set up a, downward propagating wave train. And there’s been quite a few studies that have shown that, with that wave train, the, the seven and ten day forecast predictability goes way down.

00:23:58:19 – 00:24:19:22
Speaker 2
Yeah. And, so, you know, I guess that’s something you should be aware of if you’re making a 5 or 7 day forecast. Is that with a couple of these things going down, your ability will be, quite diminished. So great talk. Scott, thanks.

00:24:19:24 – 00:24:25:26
Speaker 1
Okay. Any other questions or comments?

00:24:25:28 – 00:24:35:29
Speaker 1
Okay. Well, thanks, everybody, for attending, today’s satellite chat. And we want to especially thank, John Neff for offering, his expertise. So thanks, everybody. Have a great day. Thanks.