TC Bertha

[Blown Away]

This pass was around four hours ago.

Well that having been four hrs ago clearly shows something about 16.6N 43.3-.5W right in line with Deltadog's position and Matt's from earlier today.Now I ask how right are the coordinates we have now?

Looking at the visible it's hard to find the LLC down near 16.6, I guess it has to be under the convection ball.

http://www.ssd.noaa.gov/goes/flt/t1/loop-vis.html

[storms in NC]

Little or no change from Accuweather.

I have never found that Accuweather has ever been right. It may have and may now. But I don't buy it right now. I sill think it will go on out to sea. It is so close to 20 before the 50. Most of the time 20 before the 50 it out to sea. If it wasn't for the ridge in place it would have turned out to sea already.JMO

[RL3AO]

0900 July 5: 16.3N 34.4W
0900 July 6: 17.3N 43.2W

24 hour movement of 276 @ 21.6kt.

There have been a few who feel the latest position is too far north. If it is, the overall movement is closer to due west.

[gatorcane]

The issue now IMHO is that Bertha is relatively shallow and being steered more by the low-level flow. Unless she can deepen she won't be turning WNW anytime soon.

But -- with warming SSTs in the next 24 hours there is a chance she can deepen and finally move more WNW.

[robbielyn]

MiamiWx yes I was about ready to post a similar observation. I don't understand how the NHC is not showing a cone that is basically due west under 3 days with more of a bend at 3-5 days.

The cone keeps trying to recuve Bertha but she is remaining shallow and showing no signs of moving WNW anytime soon. I can't see how they will not shift the cone left at this advisory or the next advisory in response to a nearly due west movement.

Not only that but she is moving so fast and there must be some lacking data out there where models are underestimating the ridge.

Probably because they are relying heavily on climatology and not just what this wierd storm has decided to do. They are trying to force bertha to do what she should do and not letting her do what she wants to do.

[MiamiensisWx]

It doesn't seem that recurvature will occur east of Bermuda, especially with Bertha's rapid movement and the upper level ridge building west on water vapor imagery. Even if Bertha deepens within the short term, the fact that it is moving rapidly W in tandem with the strengthening ridge to the N relegates any long term WNW movement as unlikely, in my view. It's becoming increasingly plausible that recurvature will occur between the Southeast coastline and Bermuda, as I previously stated yesterday. A CONUS brush/landfall (probably along NC) can't be entirely eliminated or discarded from the equation as well.

http://hadar.cira.colostate.edu/ramsdis/online/trop_ge_wv_ls_0.html

[Blown Away]

MiamiWx yes I was about ready to post a similar observation. I don't understand how the NHC can keep ignoring the nearly due west movement now for over 18 hours.

The cone keeps trying to recuve Bertha but she is remaining shallow and showing no signs of moving WNW anytime soon. I can't see how they will not shift the cone left at this advisory or the next advisory in response to a nearly due west movement.

Not only that but she is moving so fast and there must be some lacking data out there where models are underestimating the ridge.

The ridge to the W obviously is not going to contain Bertha beyond 70W based on all these model runs, the disagreement is whether Bertha turns at 55W or 65W. The more due W Bertha goes the better the chance the turn happens closer to 65W. If the models are underestimating the strength of the ridge once Bertha gets near 20N/60W then we may have a different story.

[gatorcane]

It doesn't seem that recurvature will occur east of Bermuda, especially with Bertha's rapid movement and the upper level ridge building west on water vapor imagery. Even if Bertha deepens within the short term, the fact that it is moving rapidly W in tandem with the strengthening ridge to the N relegates any long term WNW movement as unlikely, in my view. It's becoming increasingly plausible that recurvature will occur between the Southeast coastline and Bermuda, as I previously stated yesterday. A CONUS brush/landfall (probably along NC) can't be entirely eliminated or discarded from the equation as well.

http://hadar.cira.colostate.edu/ramsdis/online/trop_ge_wv_ls_0.html

I do agree with you and think this is a plausible scenario: recurvature between Bermuda and the East Coast of the U.S.

[RL3AO]

Correct me if I'm wrong. The first sign that Bertha may be starting to curve, would be it slowing down correct?

[MiamiensisWx]

Correct me if I'm wrong. The first sign that Bertha may be starting to curve, would be it slowing down correct?

That's correct.

[Javlin]

What I am wondering are the overlays on the loops wrong?or was the graph of the QS overlats wrong?We all see it going W it appears 16.6N->17.3N in 4-6hrs is a quite a stretch maybe it has something to do with the time frames.I have to admit not very good with Zulu stuff.

[MiamiensisWx]

Personally, I believe the NHC's position of the LLC is correct based on observations of visible satellite data. However, it still appears to be moving west, and it may pass south of the next TPC forecast point (again).

http://www.ssd.noaa.gov/goes/flt/t1/loop-vis.html

11 a.m. EDT package should maintain Bertha's fast W movement.

[deltadog03]

Well, on there 5am advisory I think they were close, but it did appear that it was a bit further south then what they had it....but, really not much....

[Blown Away]

Personally, I believe the NHC's position of the LLC is correct based on observations of visible satellite data. However, it still appears to be moving west, and it may pass south of the next TPC forecast point (again).
http://www.ssd.noaa.gov/goes/flt/t1/loop-vis.html
11 a.m. EDT package should maintain Bertha's fast W movement.

I don't see any sign of the LLC near 16.6. I think it's near 17.3 racing due W and south of the next TPC forecast point (again), as MiamiensisWx said, and with no sign of starting any WNW movement.

[Javlin]

Personally, I believe the NHC's position of the LLC is correct based on observations of visible satellite data. However, it still appears to be moving west, and it may pass south of the next TPC forecast point (again).
http://www.ssd.noaa.gov/goes/flt/t1/loop-vis.html
11 a.m. EDT package should maintain Bertha's fast W movement.

I don't see any sign of the LLC near 16.6. I think it's near 17.3 racing due W and south of the next TPC forecast point (again), as MiamiensisWx said, and with no sign of starting any WNW movement.

I don't see an LLC at 16.6 either but that' s what the QS showed??I would say 17.1-.3 myself just asking ??'s

[NDG]

It doesn't seem that recurvature will occur east of Bermuda, especially with Bertha's rapid movement and the upper level ridge building west on water vapor imagery. Even if Bertha deepens within the short term, the fact that it is moving rapidly W in tandem with the strengthening ridge to the N relegates any long term WNW movement as unlikely, in my view. It's becoming increasingly plausible that recurvature will occur between the Southeast coastline and Bermuda, as I previously stated yesterday. A CONUS brush/landfall (probably along NC) can't be entirely eliminated or discarded from the equation as well.

http://hadar.cira.colostate.edu/ramsdis/online/trop_ge_wv_ls_0.html

I do agree with you and think this is a plausible scenario: recurvature between Bermuda and the East Coast of the U.S.

I agree as well, Bertha better start slowing down, no sign of that yet, she reached 44W a good 3 hrs ahead of last night's NHC forecasted position.
My thinking that if she stays moving faster than what most models indicate, she will feel the weakness near the US east coast a lot further west. The only thing that is not making me back up my own theory 100% is that the Euro is not backing me up, in which I have a lot of trust for, thus the last couple of runs have not been that persistent.
But I would say that most of the US east coast this morning look to be in a better position than what they did yesterday morning, but way too early to sound the all clear.

[Blown Away]

Personally, I believe the NHC's position of the LLC is correct based on observations of visible satellite data. However, it still appears to be moving west, and it may pass south of the next TPC forecast point (again).
http://www.ssd.noaa.gov/goes/flt/t1/loop-vis.html
11 a.m. EDT package should maintain Bertha's fast W movement.

I don't see any sign of the LLC near 16.6. I think it's near 17.3 racing due W and south of the next TPC forecast point (again), as MiamiensisWx said, and with no sign of starting any WNW movement.

I don't see an LLC at 16.6 either but that' s what the QS showed??I would say 17.1-.3 myself just asking ??'s

I agree,the QS showed the LLC near 16.6N, like you I was hoping wxman57 would post one of his LLC crosshair maps.

[wxman57]

Lots of debate about where's Bertha going overnight and the cause of the current rapid west movement. Will it continue? Let's take a look at the steering currents as depicted by the latest GFS and see if we can see why Bertha has accelerated westward in the past 24 hours:

First, the mean 700mb-400mb wind flow (about 10,000-20,000 ft) across the Atlantic valid right now (10am CDT Sun). As you can see, it's passing right beneath a high center, resulting in a tight east-west wind gradient. That's the reason for the acceleration. But look just to the west and you'll see that the gradient drops off very rapidly later today as Bertha approaches the weakness in the ridge along the TUTT axis.



Now let's look 96 hours out to 10am CDT Thursday and see what the steering currents look like. I've plotted Bertha's 96hr position on the map. Look at that trof digging down along the East U.S. Coast and the position of the Bermuda high northeast of Bertha. A perfect opportunity to recurve out to sea. And for those of you concerned about Florida, not the big "H" sitting over Florida. So if the GFS is even close to being right, the odds of a Florida landfall are slim and chances are, Bertha will begin making the turn north in about 4 days.

Of course, this all assumes that the GFS forecast is good. It seems to have done a good job with Bertha so far, so I see no reason to totally discount it.

[wxman57]

I agree,the QS showed the LLC near 16.6N, like you I was hoping wxman57 would post one of his LLC crosshair maps.

Your wish is my command! I don't see anything at 16.6 but a clear sky. Unless my grid is way off, I put the center at 17.9N/44.9W as of 1415Z. That's assuming the center is close to the middle of the convection as earlier microwave imagery suggested.

[Derek Ortt]

unless there is a slight decoupling of the low and MLC