Global Model Runs for W.Caribbean Early Season Development

[cpdaman]

HI everyone

the miami trop weather discussion which mentioned that anything forming in the Epac will likely move NE thru central america and then North leads me to believe this needs to be watched closely for atlantic/gulf interest (although i would think this is a rainmaker and not much else given the time of year)

[NDG]

GFS puts the tropical system right over Florida at 240 hours:

This was last night's run

[KWT]

12z GFS out to 72hrs now, shows the EPAC low and the SW Caribbean low both at 1007mbs though the SWC low looks alittle better defined in terms of precip.

[NDG]

I have noticed so far that this run, it keeps the Caribbean low a little further east than previous 00z run, thus a little more organized.

[Aric Dunn]

12z GFS out to 72hrs now, shows the EPAC low and the SW Caribbean low both at 1007mbs though the SWC low looks alittle better defined in terms of precip.

right but the carribean is much larger..

[Aric Dunn]

84 hrs the carribean system is better looking .. .

[NDG]

It pretty much absorbs the EPAC low on this run so far.

[Aric Dunn]

ok now at the 96 hr the carribean system moves over and and the east pac is becoming more defined

[KWT]

Yep by that point the Caribbean system is certainly the more dominant of the two centers that try and develop and the EPAC side weakens somewhat...but still enough of a presence to sugges a WNW type track towards Yucatn until the high to the north retracts even further eastwards and a weakness strengthens.

[gatorcane]

It pretty much absorbs the EPAC low on this run so far.

well that doesn't surprise me. Latest SAT pics to me show the SW Caribbean area starting
to suck in moisture from the EPAC already. There is definitely a battle between two broad areas of low pressure at the moment. I would still think the EPAC has the better shot but model runs seem to be flipping from run to run on which will be the dominant low.

Still you got to hand it to the GFS -- it forecasted this scenario 10+ days ago.

[stormhunter7]

Still pretty broad area... that mid level spin is decaying above panama....

http://hadar.cira.colostate.edu/ramsdis/online/RMTC_COS_2km_vis.html

[x-y-no]

Way too much mid-level ridging for anything to come north.

[KWT]

Interesting 96hrs Aric...to be at this stage where any center could form the models may not be the best device to use beyond 72hrs simply because it depends on what forms.

As for the rigding issue, that will slowly decay I should think to the east and open a weakness up which will eventually send the system more to the north, may mean a very slack moving system though for a good 2-3 days, maybe overland.

[Aric Dunn]

we may end up with a bit of the fujiwawa effect .. not even sure if i spelled that right

Fujiwhara effect

[RL3AO]

we may end up with a bit of the fujiwawa effect .. not even sure if i spelled that right

Close enough. (Fujiwhara)

[HURAKAN]

http://img165.imageshack.us/slideshow/p ... 03hrn.smil

The slideshow above shows what the NHC is thinking. The TW nearing the Caribbean could be a catalyst in about two days.

[x-y-no]

As for the rigding issue, that will slowly decay I should think to the east and open a weakness up which will eventually send the system more to the north, may mean a very slack moving system though for a good 2-3 days, maybe overland.

GFS at 96 hours:

http://www.nco.ncep.noaa.gov/pmb/nwprod ... 0_096m.gif

Solid mid-level ridge across Texas, the Gulf all the way to the Bahamas.

[KWT]

Yep I think thats what the models, esp the GFS has been showing to some extent over the last few runs, it heads WNW inland because of both that and the upper level ridge present, then as the ridge breaks down it detaches from the 'link' and heads north I reckon...bjut as I said that could be a very slow process indeed.

[gatorcane]

Interesting 96hrs Aric...to be at this stage where any center could form the models may not be the best device to use beyond 72hrs simply because it depends on what forms.

As for the rigding issue, that will slowly decay I should think to the east and open a weakness up which will eventually send the system more to the north, may mean a very slack moving system though for a good 2-3 days, maybe overland.

Clearly the worst case for the SE US, especially Florida, is that we get a slack moving system over the open waters of the SW and Western Caribbean for a couple of days allowing this low to deepen and then the low eventually finds a weakness in the ridge to the north which would eventually happen....but its way too uncertain at this time what will happen.

actually the GFS keeps sniffing out a weakness to drive whatever is in the Caribbean north and then eventually NE....I think it is picking up on a new system that will approach the Pacific NW and drive SE possibly eroding the ridge over Texas and the northern GOM.

[Aric Dunn]

http://img165.imageshack.us/slideshow/player.php?id=img165/5158/1211904603hrn.smil

The slideshow above shows what the NHC is thinking. The TW nearing the Caribbean could be a catalyst in about two days.

that wave is the second one to reach the area .. there is one entering later today ..

but yeah that sounds good