Possible development in Western Caribbean - (Is INVEST 93L)

[USTropics]

Looking at the 18z GFS ensemble runs per each member as they roll in, an elongated monsoonal trough that spins up multiple vorticities along the mean axis is a very likely outcome. Seven of the first ten members (70%) have some type of vorticity heading towards the northern GOM (you can check out each member in the collage below).


http://i.imgur.com/YE3J9PB.jpg

[Steve]

It looks like a split with an ejected piece and then some type of weaker development off the MX Pacific coast. CMC is only out to 3.5 days, but it couldn't be more clearer in what it's doing. The low is coming up. It's 998 at around 20.5N/85W at 90 hours. Much stronger earlier but let's see if it pulses and deepens as the rest of the run comes out.

http://www.tropicaltidbits.com/analysis ... s=0&ypos=0

[stormhunter7]

00z CMC goes off in southern gomz (988mb?) and they weakends as it's closes in on Florida Panhandle. Strongest run from this model IMO of this possible low....

[Kingarabian]

00z GFS is spinning up multiple vort's now.

[Steve]

Yeah. It approaches from the south about the MS/AL Line (8ish?) as 993mb at 144 hours. It sort of stutter steps or stalls out for a few hours and then landfalls around 174/180 hours showing 997mb on the low res around the Santa Rosa/Okaloosa County border or maybe 85ish miles west of the 18z.

?

[stormhunter7]

00z GFS-PAR has 1005mb off Florida panhandle this run, where as 18z had 995mb.

[stormhunter7]

00z GFS... turn due west begins in GOM

[stormhunter7]

Yeah. It approaches from the south about the MS/AL Line (8ish?) as 993mb at 144 hours. It sort of stutter steps or stalls out for a few hours and then landfalls around 174/180 hours showing 997mb on the low res around the Santa Rosa/Okaloosa County border or maybe 85ish miles west of the 18z.

?

Yeah that sounds about right?

[bamajammer4eva]

They gave it an Orange!!

A complex area of low pressure is expected to form over the
northwestern Caribbean Sea and the adjacent Yucatan peninsula by the
weekend. Conditions appear to be favorable for some development of
this system while it moves slowly northwestward toward the southern
Gulf of Mexico by early next week.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 5 days...medium...40 percent.

[Hammy]

Quite odd that NHC is upping the numbers, considering anything beyond a disorganized monsoonal gyre seems increasingly less likely with each model run.

[AtlanticWind]

Quite odd that NHC is upping the numbers, considering anything beyond a disorganized monsoonal gyre seems increasingly less likely with each model run.

That's not really an accurate observation. All the models but the gfs show development and the gfs Para even shows
at least a depression. Also convection continues to increase in the western carribean. An argument could be made the NHC
Is being conservative.

[northjaxpro]

Quite odd that NHC is upping the numbers, considering anything beyond a disorganized monsoonal gyre seems increasingly less likely with each model run.

That's not really an accurate observation. All the models but the gfs show development and the gfs Para even shows
at least a depression. Also convection continues to increase in the western carribean. An argument could be made the NHC
Is being conservative.

Agree. The models are in very good agreement that we will see a tropical cyclone in the GOM by the middle of next week at least.

[Kazmit]

Landfall near Fort Walton Beach.

[Hammy]

Quite odd that NHC is upping the numbers, considering anything beyond a disorganized monsoonal gyre seems increasingly less likely with each model run.

That's not really an accurate observation. All the models but the gfs show development and the gfs Para even shows
at least a depression. Also convection continues to increase in the western carribean. An argument could be made the NHC
Is being conservative.

Agree. The models are in very good agreement that we will see a tropical cyclone in the GOM by the middle of next week at least.

Are any semi-reliable models showing development? GFS-Para is somewhat untested tropically (and somebody else pointed out earlier it hasn't done well in general) and the GEM seems to develop just about every cloud that forms over the tropics.

[ronjon]

06z GFS and para GFS now on board with development in the eastern GOM. Add CMC and NAVGEM with Fl Panhandle hit of strong tropical storm or CAT 1 hurricane. ECM out on its own with BOC development now.

[northjaxpro]

Yes that is correct, which I also noticed prior to my previous post. Yeah the models are now picking up on an apparent weakness in the upper ridge to develop by late next week. So, if this comes to fruition, this would put the Eastern GOM in play and that region may be impacted, but still early on in this process. Changes are likely with the models as time progresses.

[Kingarabian]

GFS - showing a weak TS, and doesn't do much with it.
Euro - showing a weak TS, has landfall points from southern Mexico to LA/MS.
Euro Paralell - flipflopping between a moderate TS and a weak TS with landfall points spread out similar to the Euro.

GFS Paralell - consistently showing a strong TS making landfall over a GOM state.
CMC - has a decent hurricane making landfall over a GOM state.
Navgem - same as the CMC.

So we basically have two groups:

GFS, Euro, Euro Paralell - showing minimal to modest development of this gyre.

GFS Paralell, CMC, Navgem - showing robust development of this gyre.

So there's a pretty good agreement across the board that we will see development. Will we get anything more than a weak TS remains to be seen.

[NDG]

That's not really an accurate observation. All the models but the gfs show development and the gfs Para even shows
at least a depression. Also convection continues to increase in the western carribean. An argument could be made the NHC
Is being conservative.

Agree. The models are in very good agreement that we will see a tropical cyclone in the GOM by the middle of next week at least.

Are any semi-reliable models showing development? GFS-Para is somewhat untested tropically (and somebody else pointed out earlier it hasn't done well in general) and the GEM seems to develop just about every cloud that forms over the tropics.

The Euro is still reliable within its 5-7 day range, IMO.

[AtlanticWind]

That's not really an accurate observation. All the models but the gfs show development and the gfs Para even shows
at least a depression. Also convection continues to increase in the western carribean. An argument could be made the NHC
Is being conservative.

Agree. The models are in very good agreement that we will see a tropical cyclone in the GOM by the middle of next week at least.

Are any semi-reliable models showing development? GFS-Para is somewhat untested tropically (and somebody else pointed out earlier it hasn't done well in general) and the GEM seems to develop just about every cloud that forms over the tropics.

Every model shows some degree of development, remember the 40 percent the hurricane center gives is for the system
To reach at least depression status. Their forecast therefore is probably conservative.

[ronjon]

Yes can't discount ECM being on it's own....as it's correctly predicted the outcome in the past being the lone rider. Wait and see time...still 5-6 days out.