Tropical Storm Bertha Model Runs

[Steve]

>>Interesting how everyone is giving up on the NW motion so quickly - especially since it's still moving in that direction (now nearing 16N 29W)...

Between this post and the "zomg, we need to take 93L off the front page so we don't confuse anyone", looks like another year of wish-away-casting for Frank2.

Steve

[cycloneye]

Ok.lets not enter into personalistic talk.Lets continue to analize what the models are showing in this thread.

[cycloneye]

12z GFS is already more west than the 00z run albeit a weaker system.We can discuss about that other low at the thread for model runs at Talking tropics.

[KWT]

Yep very similar to the 06z run and also the other major models like the UKMO and the ECM, looks the models are now in broad agreement.

[Extremeweatherguy]

Here is the 12z GFS loop (it will update as new images become available)...

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

Through hour 78 it looks like a steady west-northwest motion with a few periods of a more westerly motion from time to time. Definitely a major change from where the GFS was yesterday!

[Nimbus]

The center of Bertha is starting to become exposed this morning perhaps verifying the models that have a weaker system.

Actually the models have come left about as far as you would expect from a strong atlantic ridge / weak storm scenario.

It is hard to believe that in the next 7 days there won't be a weakness in the ridge to pull Bertha north out to sea, but maybe the models are that good a week or more out?

[cycloneye]

Riding the 18n latitud westward.

[Scorpion]

I wouldn't discount a threat to the Caribbean if Bertha remains weak. Of course, the shear situation isn't very good in that area.

[MiamiensisWx]

Turning north:

http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/carib/gfs/12/images/gfs_ten_084l.gif

Moves back to the WNW:

http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/carib/gfs/12/images/gfs_ten_114l.gif

Continues WNW movement:

http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/carib/gfs/12/images/gfs_ten_126l.gif

Based on analysis of the upper levels, it appears that the run indicates Bertha will remain east of the Bahamas and dissipate over the western North Atlantic.

[Extremeweatherguy]

the 12z GFS brings the system very near the NE islands in this run, but finally lifts Bertha north of the 20N line just before reaching 60W (sparing the islands any kind of direct impacts).. http://www.nco.ncep.noaa.gov/pmb/nwprod ... loop.shtml

Also - - check out the new low the model is trying to show forming off of Africa in a few days. It too looks pretty interesting.

[cycloneye]

Also - - check out the new low the model is trying to show forming off of Africa in a few days. It too looks pretty interesting.

Go to "Long Range Models" thread at Talking tropics to discuss that one.

[KWT]

Will be very interesting to see where the GFS takes Bertha past 120hrs, because the ridge is still strong to the north of the system and its still moving WNW, only just clearing 20N by 60W (which is amazing given the GFS had this at 20N before 45W a few days back!) and therefore could be a risk to the USa afterall, or at least a close call IF this run was to come off.

[Extremeweatherguy]

From hour 108 to hour 132 the GFS pushes the system WNW past the 60W line.

hr. 108 - http://www.nco.ncep.noaa.gov/pmb/nwprod ... n_108s.gif
hr. 132 - http://www.nco.ncep.noaa.gov/pmb/nwprod ... n_132s.gif

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

[MiamiensisWx]

It looks like the system becomes a broad surface trough around ~138 hours. Interestingly, at this time, it is entirely under the influence of the subtropical ridging at H7:

http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/carib/gfs/12/images/gfs_700_138l.gif

If this is taken ad verbatim, it would suggest a possible slim threat to the Southeast. However, it likely won't "make it" beyond 55-60 W.

[NDG]

Like I said earlier the models are going to be trending more and more towards the euro and UKMET,

[Extremeweatherguy]

Position at hour 150 - http://www.nco.ncep.noaa.gov/pmb/nwprod ... n_150s.gif

Much closer to the U.S. than any previous GFS run and still heading generally WNW.

[MiamiensisWx]

Florida/Southeast threat?!

http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/carib/gfs/12/images/gfs_700_150l.gif

It is highly unlikely that a threat will come to fruition. It appears that the system is sheared around this time; note the 1015 mb minimum pressure at the surface as well.

[Extremeweatherguy]

The storm inches closer to the bahamas by hour 162 - http://www.nco.ncep.noaa.gov/pmb/nwprod ... n_162s.gif

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

looking to weaken a bit at hour 174, but still heading WNW - http://www.nco.ncep.noaa.gov/pmb/nwprod ... n_174s.gif

[vacanechaser]

Florida/Southeast threat?!

http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/carib/gfs/12/images/gfs_700_150l.gif

It is highly unlikely that a threat will come to fruition. It appears that the system is sheared around this time.

so you are just going to buy into it now... funny how everyone seems to turn with each model run... before it was out to sea, now it has a weak low and headed for the U.S. .. the model changes with each run... you cant just say that this is it... its over...

not to mention that with each run yesterday the shift westward continued to grow and flatten out.. follow the trend...



Jesse V. Bass III
http://www.vastormphoto.com
Hurricane Intercept Research Team

[MiamiensisWx]

so you are just going to buy into it now... funny how everyone seems to turn with each model run... before it was out to sea, now it has a weak low and headed for the U.S. .. the model changes with each run... you cant just say that this is it... its over...

not to mention that with each run yesterday the shift westward continued to grow and flatten out.. follow the trend...



Jesse V. Bass III
http://www.vastormphoto.com
Hurricane Intercept Research Team

I agree with the westward shift, but I don't agree with the prospects of Bertha "making it" to the CONUS coastline. I don't buy the "threat" implied by some posters, but to each his own.

I will state one thing. If the progged upper pattern and track indicated by the GFS is correct, it would likely favor a stronger system approaching the Southeast coast (ala Bertha '96).