Tropical Storm Bertha Model Runs

[Blown Away]

Title is a bit misleading, hour 204 is about 300 miles E of SFL and hour 252 is near NY.

Actually what you are seeing near NY is not Bertha. If you look at the GFS run closely, you can see that the weakening Bertha slowly drifts around the vicinity of the bahamas between hour 204 and hour 252..

hr. 204 - http://www.nco.ncep.noaa.gov/pmb/nwprod ... n_204l.gif
hr. 216 - http://www.nco.ncep.noaa.gov/pmb/nwprod ... n_216l.gif
hr. 228 - http://www.nco.ncep.noaa.gov/pmb/nwprod ... n_228l.gif
hr. 240 - http://www.nco.ncep.noaa.gov/pmb/nwprod ... n_240l.gif
hr. 252 - http://www.nco.ncep.noaa.gov/pmb/nwprod ... n_252l.gif[/quote]


I see, Bertha still remains @300 miles offshore.

[Aric Dunn]

well im sure most of you have seen the 00z euro.. but thats an interesting track.. and it intensifies it...

http://www.meteo.psu.edu/~gadomski/ECMW ... floop.html

[Frank2]

Here's the VIS loop:

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

I still have to argue that the LLC is now at 16N 31W, with most of the weather between 17N and 20N, so, anything that "high" that far east is likely to recurve northward at some point...

Even one hurricane at 20N 50W a few years ago (I forget which one) still recurved, even though it was thought to be a "sure thing", so, at almost half the longitude, it seems almost obvious (as with many models) that Bertha is more likely to remain at sea because of it's early northward position...

Frank

[Aric Dunn]

not only that the ridge stays in place up to 168 hours which would drive it into florida.. im curious to see the 12z from the euro later today

[NDG]

I am glad people are starting to remember how well the euro did last year with sypnotic set ups,

[dixiebreeze]

I'm starting to wonder if this could actually become a N.C. or even Long Island storm?

[gatorcane]

how come I am reading posts about models with Bertha and Florida in the same post?

For a system that many thought would be a sure fish, it certainly seems like trends are drastically changing. Let's see what the new model runs have in store. It's possible they are only temporarily shifting west and then will start showing a recurve again.

Again, the SHIPS was crazy thinking it would bomb out to hurricane status so quickly and why I think the GFS and GFDL were a bit mislead at first.

[Steve]

>>not only that the ridge stays in place up to 168 hours which would drive it into florida.. im curious to see the 12z from the euro later today

Yeah, that's always been my contention against earlier models and them trying to recurve too soon. A couple of scenarios also pump the western Atlantic ridge behind Bertha allowing it to build in stronger.

[cycloneye]

12z GFDL for the first time reaches 60w.

Fri Jul 4 13:49:21 EDT 2008
WHXX04 KWBC 041730

CHGQLM

ATTENTION...NATIONAL HURRICANE CENTER



NCEP COUPLED GFDL HURRICANE MODEL FORECAST MADE FOR



TROPICAL STORM BERTHA 02L



INITIAL TIME 12Z JUL 4



DISCLAIMER ... THIS INFORMATION IS PROVIDED AS GUIDANCE. IT

REQUIRES INTERPRETATION BY HURRICANE SPECIALISTS AND SHOULD

NOT BE CONSIDERED AS A FINAL PRODUCT. PLEASE SEE THE TPC/NHC

OFFICIAL FORECAST.





FORECAST STORM POSITION



HOUR LATITUDE LONGITUDE HEADING/SPEED(KT)



0 14.5 29.1 290./14.0

6 15.4 30.6 303./17.3

12 15.8 32.5 281./19.1

18 16.1 34.4 279./18.3

24 16.5 36.4 280./19.2

30 16.7 38.2 277./17.4

36 16.9 40.0 277./17.2

42 17.5 42.1 285./21.0

48 18.0 44.2 282./20.5

54 18.5 46.3 284./20.3

60 18.9 47.9 284./16.2

66 19.2 49.4 283./14.6

72 19.9 50.8 296./14.4

78 20.3 52.0 288./12.1

84 20.9 52.9 303./10.8

90 21.5 54.0 299./12.0

96 22.3 55.0 311./11.5

102 23.1 56.0 308./12.5

108 23.8 57.0 302./11.5

114 24.4 58.1 301./11.9

120 25.0 59.0 305./10.2

126 25.8 60.0 306./11.4

[gatorcane]

>>not only that the ridge stays in place up to 168 hours which would drive it into florida.. im curious to see the 12z from the euro later today

Yeah, that's always been my contention against earlier models and them trying to recurve too soon. A couple of scenarios also pump the western Atlantic ridge behind Bertha allowing it to build in stronger.

Seeing how we are in July, such strong ridging does not surprise me at all.

[Aric Dunn]

how come I am reading posts about models with Bertha and Florida in the same post?

For a system that many thought would be a sure fish, it certainly seems like trends are drastically changing. Let's see what the new model runs have in store. It's possible they are only temporarily shifting west and then will start showing a recurve again.

Again, the SHIPS was crazy thinking it would bomb out to hurricane status so quickly and why I think the GFS and GFDL were a bit mislead at first.

thats because they are showing bertha getting very close to florida and the coast. like always models change .. but this change started yesterday as the the models have continued to trend westward for more than 24hours now.. allthough it may recurve it wont at 45 west or where the models had it curving yesterday it would likely be farther west.

[Aric Dunn]

12z GFDL for the first time reaches 60w.

Fri Jul 4 13:49:21 EDT 2008
WHXX04 KWBC 041730

CHGQLM

ATTENTION...NATIONAL HURRICANE CENTER



NCEP COUPLED GFDL HURRICANE MODEL FORECAST MADE FOR



TROPICAL STORM BERTHA 02L



INITIAL TIME 12Z JUL 4



DISCLAIMER ... THIS INFORMATION IS PROVIDED AS GUIDANCE. IT

REQUIRES INTERPRETATION BY HURRICANE SPECIALISTS AND SHOULD

NOT BE CONSIDERED AS A FINAL PRODUCT. PLEASE SEE THE TPC/NHC

OFFICIAL FORECAST.





FORECAST STORM POSITION



HOUR LATITUDE LONGITUDE HEADING/SPEED(KT)



0 14.5 29.1 290./14.0

6 15.4 30.6 303./17.3

12 15.8 32.5 281./19.1

18 16.1 34.4 279./18.3

24 16.5 36.4 280./19.2

30 16.7 38.2 277./17.4

36 16.9 40.0 277./17.2

42 17.5 42.1 285./21.0

48 18.0 44.2 282./20.5

54 18.5 46.3 284./20.3

60 18.9 47.9 284./16.2

66 19.2 49.4 283./14.6

72 19.9 50.8 296./14.4

78 20.3 52.0 288./12.1

84 20.9 52.9 303./10.8

90 21.5 54.0 299./12.0

96 22.3 55.0 311./11.5

102 23.1 56.0 308./12.5

108 23.8 57.0 302./11.5

114 24.4 58.1 301./11.9

120 25.0 59.0 305./10.2

126 25.8 60.0 306./11.4

http://www.nco.ncep.noaa.gov/pmb/nwprod ... loop.shtml

no real re-curve a slight one then last couple frames look like a wnw track again ..

[Blown Away]

Is the W trending models an indication that they are backing off intensification and keeping her weak, thus moving more W.

[Aric Dunn]

Is the W trending models an indication that they are backing off intensification and keeping her weak, thus moving more W.

sort of yeah. the weaker bertha now and for the next couple days would miss the weakness in the mid level ridge than some models strengthen bertha afterwards and is at that point under another ridge keeping her on a w to wnw track..

[cycloneye]

The Canadian (For what its worth) has a strong Bertha,and that is why at the end of the run,it goes north.

http://moe.met.fsu.edu/cgi-bin/cmctc2.c ... =Animation

[Aric Dunn]

12z ukmet
http://moe.met.fsu.edu/cgi-bin/ukmtc2.c ... =Animation

look at the ridge build back in towards then of the run ..

[NDG]

Yeah, forget about the Canadian forecast past its 96hrs. We all know it always tries to strengthen storms too much as poleward bias.

[Aric Dunn]

The Canadian (For what its worth) has a strong Bertha,and that is why at the end of the run,it goes north.

http://moe.met.fsu.edu/cgi-bin/cmctc2.c ... =Animation

yeah and no.. if you look the ridge to the north is much much weaker than say the ukmet or the euro and a few other..

[Blown Away]

12z ukmet
http://moe.met.fsu.edu/cgi-bin/ukmtc2.c ... =Animation

look at the ridge build back in towards then of the run ..

I guess Bertha dissipates at the end and heads towards Hispanola.

['CaneFreak]

12z ukmet
http://moe.met.fsu.edu/cgi-bin/ukmtc2.c ... =Animation

look at the ridge build back in towards then of the run ..

I guess Bertha dissipates at the end and heads towards Hispanola.

Don't look at global models for intensity. Global models such as the GFS, UKMET, and some others have a terrible time with predicting intensity. In other words, what a global model shows as an open wave might in all actuality be a hurricane. Why? Global models have poor resolution. GLOBAL MODELS SHOULD ONLY BE USED FOR PATTERN EVOLUTIONS!!!