2016 Atlantic Hurricane season

[Justin]

That mid level circulation is going to pull the low level center South a bit.  Have a feeling this is going right over Puerto Rico and the North coast of Hispanola.  

[Jim Marusak]

On 8/18/2016 at 8:19 AM, Kmlwx said:

The CMC is not even worth posting for tropical stuff. If you watch it with any regularity it's no stranger to this. 

for trying to pick the right wave for development, yea the CMC does suck and blow. But actually once it does get a hold of the right wave, it doesn't do too bad on its track, but still speeds things up too fast further out.

But one thing the model is pretty good at though, is the later stages of a storm, especially when a tropical system transforms to hybrid, then extra-tropical. It usually does the phase-change timing pretty well.  

[Kmlwx]

20 minutes ago, Jim Marusak said:

for trying to pick the right wave for development, yea the CMC does suck and blow. But actually once it does get a hold of the right wave, it doesn't do too bad on its track, but still speeds things up too fast further out.

But one thing the model is pretty good at though, is the later stages of a storm, especially when a tropical system transforms to hybrid, then extra-tropical. It usually does the phase-change timing pretty well.  

That sounds much more evenly written than what I wrote  

It does seem early on to want to blow up every single storm and do loopy things with them. I don't doubt that once there's a developed storm it probably does a lot better. Thanks!!!

[JC-CT]

4 minutes ago, Kmlwx said:

That sounds much more evenly written than what I wrote  

It does seem early on to want to blow up every single storm and do loopy things with them. I don't doubt that once there's a developed storm it probably does a lot better. Thanks!!!

Nah, it sucks

[hawkeye_wx]

99L does not look like much on satellite.  Despite the increased convection over the last day or two, the surface flow is still lousy.  Recon data is pretty weak.  This morning's GFS shows 99L vanishing by the time it reaches the Bahamas, and now the recently-bullish HWRF is having trouble holding onto the system past Hispaniola.  If the euro backs off it will be a huge letdown from a weathergeek perspective(and a big sigh of relief for Floridians).

[hawkeye_wx]

I was thinking the 12z euro may begin to back off, but nope.  It still begins to develop 99L in about 72 hours, then turns west over south Florida as a high-end storm/low-end cane.  This latest run then takes it farther west than any previous run, striking the Mobile/Pensacola area as a major cane.  To say there is uncertainty is a massive understatement.

[WhiteoutWX]

I have serious doubts this thing fully clears Puerto Rico and Hispanola but it's disorganized nature may help it here. To me the southern end of the wave looks more robust and would be most likely to further develop but it's kind of a crapshoot at this point given how disorganized it is.

[RU848789]

Just curious if there's any chance the large-scale counterclockwise flow around Gaston is helping to drive the dry Saharan Air Layer towards 99L.  I'm guessing one could probably be able to tell by the water vapor loop, but I don't have that at my fingertips and only had a few minutes to post.  

[Superstorm93]

Really not sure if this will be able to clear Hispaniola. System is incredibly strung out and tilted, so any land interaction would pretty much destroy its chances of becoming a tropical cyclone. Really not biting on this one yet, has an Erika vibe to it. 

 

Also, it seems the southern circulation may be winning out, which would guarantee that this crashes in Hispaniola. We'll see what happens. 

 

[DTWXRISK]

12z   TUESDAY EURO  RUN   all last week when  GFS (and others hurricane models)  were developing  99L  ways too fast & early only  the  EURO kept it  weak.   Now the GFS  does nothing  with it but the  Euro  goes  bonkers O

 

 

 

[DTWXRISK]

Having the  big RIDGE / DOME   ( HIGH TO THE NORTH)  always  a   dangerous  thing  and even more so   as
 the TC  crosses  the gulf  stream... see   andrew    Katrina

[Indystorm]

Scary, especially when you consider the ECMWF is still the best medium range model out there for the time period in question.

[wxmx]

Agree with the comments that the southern part of the wave looks to be consolidating into a circulation. That would almost certainly put it in Hispaniola's path. That's also something the models are not that good at forecasting.

[Superstorm93]

Such a confusing system...the 850 mb vort map was just updated and it doesn't appear the southern part of 99L will take over. Definitely tilted, but that could change tonight since the upper level outflow looks excellent and it should have a pretty respectable DMAX

Sent from my XT1585 using Tapatalk

[Windspeed]

Such a confusing system...the 850 mb vort map was just updated and it doesn't appear the southern part of 99L will take over. Definitely tilted, but that could change tonight since the upper level outflow looks excellent and it should have a pretty respectable DMAX

Sent from my XT1585 using Tapatalk

Yes, the radar out of the Guadeloupe shows this very clearly. You can see the sharp NW tilted axis of the wave moving towards the nothern Antilles. Deep convection is currently expanding in an arc around a developing broad surface circulation. The MLC spin to the south appears very weak. More likely that feature will lose out to a new MLC in pattern with that arc of convection tonight and this is represented by the stronger vorticity showing in the ECMWF through 48 hours.

Sent from my LG G4.

[hlcater]

Hasn't the euro always outperformed the GFS when it comes to the tropics? I remember the euro having better forecast credence over the GFS(Sandy and Joaquin come to mind), and given its relative consistency of developing the wave in the Bahamas, I'm siding with the euro at this point, however I can't write off the GFS completely either.

[Scott747]

0z Euro shifts even further W in the Gulf. Cat 4 into Sabine Pass to Cameron.

Global Hawk has a planned mission later today with 86 drops.

[hawkeye_wx]

Despite an impressive blob overnight, it appears 99L's organization is still crap.  The surface flow continues to be elongated and weak.  It also appears to be tracking along the southern edge of the recent guidance.

[midatlanticweather]

1 hour ago, hawkeye_wx said:

Despite an impressive blob overnight, it appears 99L's organization is still crap.  The surface flow continues to be elongated and weak.  It also appears to be tracking along the southern edge of the recent guidance.

 

I think it looks a lot better than yesterday but still not great. It will have to form the circulation under the convection if it can. As much as it is elongated, there is some consolidation to the south.. Still looks like it has a  ways to go and the convection is shrinking or consolidating this AM. I see what looks to be some outflow that is not too bad. It looks alright on visible.. I think it is trying http://www.ssd.noaa.gov/PS/TROP/floaters/99L/html5-vis-long.html

 

[hawkeye_wx]

Thankfully, 99L is now in rapid-scan satellite range.  Just now the loop is showing the surface center, or at least an eddy within the broader elongated center, over Anguilla, the northernmost island.  Now it just needs to blow some convection over that center/eddy and start to tighten up a bit. If this center can continue wnw it shouldn't have any trouble clearing Hispaniola.  Even the ultimately-bullish models don't really get this organized for another couple days, though.

[WhiteoutWX]

This thing is going to go right over Puerto Rico and likely Hispanola as well. It's only hope is to stay weak enough before this period that it can quickly pop a new circulation along the northern coasts of these islands. Really seems to be still focusing convection on the southern end of the wave still which to me doesn't bode well for its chances of that happening. You then have to think it goes right up Cuba as well and wouldn't have much time to organzie in the Gulf. 

[MJO812]

[LakeEffectKing]

1 hour ago, WhiteoutWX said:

This thing is going to go right over Puerto Rico and likely Hispanola as well. It's only hope is to stay weak enough before this period that it can quickly pop a new circulation along the northern coasts of these islands. Really seems to be still focusing convection on the southern end of the wave still which to me doesn't bode well for its chances of that happening. You then have to think it goes right up Cuba as well and wouldn't have much time to organzie in the Gulf. 

Medium chance the center goes over northern PR....little to no chance this goes over Hispaniola...IMO

[Superstorm93]

7 hours ago, Scott747 said:

0z Euro shifts even further W in the Gulf. Cat 4 into Sabine Pass to Cameron.

Global Hawk has a planned mission later today with 86 drops.

That's all for Gaston 

 

(Because it's not like the GFS is struggling or anything) 

[WhiteoutWX]

45 minutes ago, LakeEffectKing said:

Medium chance the center goes over northern PR....little to no chance this goes over Hispaniola...IMO

On second look at vis satellite I think you may be right, there appears to be a low-level center on the northern edge of the convective blob. This center will likely clear Hispanola but to me it looks like it will be very close, especially if the persistent convection on the southern end tugs the center further south which can definitely happen with these weaker systems. 

[Eskimo Joe]

1 minute ago, WhiteoutWX said:

On second look at vis satellite I think you may be right, there appears to be a low-level center on the northern edge of the convective blob. This center will likely clear Hispanola but to me it looks like it will be very close, especially if the persistent convection on the southern end tugs the center further south which can definitely happen with these weaker systems. 

Would be great to get that naked swirl out from under the shear, probably would flare up pretty quickly.

[NJwx85]

I know most people have given up on Gaston because of how far North it will be in 4-5 days, but the models keep increasing the strength of the ridge off the East coast, so it's not completely inconceivable that Gaston could eventually take on a more Westerly track once near 55W. 

[Superstorm93]

HWRF keeps 99L as a naked swirl for three days. 

Doesn't seem that far off since we have a strong vort (or LLC based on what recon finds) ejecting out of the convection. 

 

 

[hawkeye_wx]

The GFS continues to do very little with 99L.  It keeps the center moving through a shear zone for the next three days.  It is also much slower than the Euro.  At 108 hrs the GFS has a weak disturbance over the Bahamas while the Euro has a cane well into the gulf.

[Superstorm93]

Model report cards so everyone can see whats happening here...

 

GFS is ranked fifth behind the CMC and JMA in the tropics, ECM and UKMET dominating at three days out. Its ranked fourth at day 5.