Tropical Storm Bertha Model Runs

[MiamiensisWx]

gatorcane - I wouldn't worry too much about the center line of the cone right now. The line is sure to change many more times in the days ahead, and beyond 24-48 hours out, it is probably best to just view the cone as a whole instead of focusing on the line.

You're only stating it's prudent to focus on the cone "beyond 24-48 hours out"?!

There have been many cases where the track of a TC within 24 hours deviated from the center of the cone. See Katrina '05, Humberto '07, and many others as examples. I would focus more on the cone instead of the line at all times.

[cheezyWXguy]

gatorcane - I wouldn't worry too much about the center line of the cone right now. The line is sure to change many more times in the days ahead, and beyond 24-48 hours out, it is probably best to just view the cone as a whole instead of focusing on the line.

You're only stating it's prudent to focus on the cone "beyond 24-48 hours out"?!

There have been many cases where the track of a TC within 24 hours deviated from the center of the cone. I would focus more on the cone instead of the line at all times.

Its still better than focusing on the middle line...

[Aric Dunn]

anyway... so i know what im posting right now everyone is going to have something to say.. but the NAM ( yes i know its the nam) but im not looking at it for anything but the strength of the ridge .. but it has a strong ridge through its forecast and keeps bertha pretty far south ..

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

[Nimbus]

I'm curious as to the sudden apparent NW-WNW turn Mon afternoon though?

My guess is that the dynamic models are ramping up the system as it hits the warmer SST's (see WXman57 graphic).
That is assuming a strengthening system often moves poleward.

Could just as easily be uncertainty about the ridge at the time.

[boca]

I wonder if Bertha can make it as far west as Florida.Its a big long shot and way to early to tell. Shear will probably rip the guts out of Bertha anyway in this part of the world.

[Aric Dunn]

18z gfs coming in..

[Aric Dunn]

so far gfs is south from its last run... on heading west below 20n

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

[KWT]

Amazing that the models are still shifting westwards, I would be seriously worried if I was anywhere north of south Carolina, lets see what the 18z GFS does this run, but the GFS has once again over-egged the upper lows, over here in the UK I've noted it often overdoes these features.

[lebron23]

How far south are these models going to keep going?!

[MiamiensisWx]

Actually, the operational 18Z GFS' track of Bertha is slightly faster and further north when compared to the 12Z run. The west "trend" may have ended with this model.

18Z at ~66 hours:

http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/carib/gfs/18/images/gfs_ten_066l.gif

12Z at ~66 hours:

http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/carib/gfs/12/images/gfs_ten_066l.gif

[Aric Dunn]

Actually, the operational 18Z GFS' track of Bertha is slightly faster and further north when compared to the 12Z run. The west "trend" may have ended with this model.

lol...

anyway.. look at the ridge.. at 66hrs off the east coast

[lebron23]

Actually, the operational 18Z GFS' track of Bertha is slightly faster and further north when compared to the 12Z run. The west "trend" may have ended with this model.

lol...

anyway.. look at the ridge.. at 66hrs off the east coast

The ridge off the east coast means it has to go further south right?

[KWT]

Hmmm well the models will shift about and the westward shift could only go on for so long, the GFS may well have found roughly where it thinks Bertha will head. If it remains below 24N by 60W then the chances for the east and NE coast of the states for some kind of hit increase a lot IMO.

Hmmm, that upper ridge off the east coast is interesting if it remains till about 144hrs.

[Aric Dunn]

its faster but not farther north at all

[Aric Dunn]

seriously look at the loops.. the gfs on this run is going to keep drving west..
http://www.nco.ncep.noaa.gov/pmb/nwprod ... loop.shtml

look at the ridge.. off the east coast ...

[lebron23]

NAM

very far SOUTH

Also. a tropical storm in mexico?


http://www.nco.ncep.noaa.gov/pmb/nwprod ... _084.shtml

[ekal]

Note that at 12z, nearly all of the guidance members that comprise the GFS ensemble were farther south than the official GFS output.

http://euler.atmos.colostate.edu/~vigh/guidance/northatlantic/track_gfs1.png

I thought ensembles were supposed to be an average of their members. Why the lack of correspondence here?

[Aric Dunn]

check out the zonal flow !! no troughs... the ridge still in place at 90 hrs..

[boca]

check out the zonal flow !! no troughs... the ridge still in place at 90 hrs..

Aric it looks like the ridge extends as far west as the Central Gulf of Mexico.

[jlauderdal]

gatorcane - I wouldn't worry too much about the center line of the cone right now. The line is sure to change many more times in the days ahead, and beyond 24-48 hours out, it is probably best to just view the cone as a whole instead of focusing on the line.

You're only stating it's prudent to focus on the cone "beyond 24-48 hours out"?!

There have been many cases where the track of a TC within 24 hours deviated from the center of the cone. See Katrina '05, Humberto '07, and many others as examples. I would focus more on the cone instead of the line at all times.

5 day error is about 300 miles so i would expect the center of the cone to be off target in 5 days.