WxWatcher007

Posted in the main forum but pasting here too Just quickly, my areas of interest: 1. BoC low/Invest 91L—80% Looks most likely to break our NS drought. Like I said before, it’s hard to bet against the BoC topography, though I’m not sure we’d have this area as likely to pop without old 90L and the boundary assisting what was an anemic wave. Western Gulf should watch closely. 2. Invest 92L—50% I won’t lie. I’m still nervous that this next iteration of the MT breakdown will fail to immediately produce, but like Windspeed said the tropical Atlantic portion of the MDR is looking substantially better than it did even a week ago. The apparent organization tonight gives me a little more confidence something is developing here. 3. MT Part II—40% This is the eastern end of the trough that will take more time to organize, if at all. A future AEW coming off Africa may help give the area the kick it needs to develop. Models are waffling on which part of the MT develops first, but it looks like 92L is in the lead. This is the easternmost NHC orange. 4. SE Coast—20% There’s still a signal late next week for a low to develop along a stalled boundary, and this may factor in the eventual track of 92L. What has my interest here is 1) the further south potential for development in a more tropical genesis favored zone, and 2) the possibility of a ridge developing over the top, potentially cutting off a quick exit. Two things 99L didn’t have. Long way away so not worth much attention. I’m not going to declare anything until it happens, but I do wonder if the lid is starting to come off…from west to east.

Just quickly, my areas of interest: 1. BoC low/Invest 91L—80% Looks most likely to break our NS drought. Like I said before, it’s hard to bet against the BoC topography, though I’m not sure we’d have this area as likely to pop without old 90L and the boundary assisting what was an anemic wave. Western Gulf should watch closely. 2. Invest 92L—50% I won’t lie. I’m still nervous that this next iteration of the MT breakdown will fail to immediately produce, but like Windspeed said the tropical Atlantic portion of the MDR is looking substantially better than it did even a week ago. The apparent organization tonight gives me a little more confidence something is developing here. 3. MT Part II—40% This is the eastern end of the trough that will take more time to organize, if at all. A future AEW coming off Africa may help give the area the kick it needs to develop. Models are waffling on which part of the MT develops first, but it looks like 92L is in the lead. This is the easternmost NHC orange. 4. SE Coast—20% There’s still a signal late next week for a low to develop along a stalled boundary, and this may factor in the eventual track of 92L. What has my interest here is 1) the further south potential for development in a more tropical genesis favored zone, and 2) the possibility of a ridge developing over the top, potentially cutting off a quick exit. Two things 99L didn’t have. Long way away so not worth much attention. I’m not going to declare anything until it happens, but I do wonder if the lid is starting to come off…from west to east.

happy hour GFS indeed

Sitting currently with .24”.

I do wonder how much room there is for an eastward trend or sharper hook. The track forecast looks like it could be pretty sensitive until we have a well defined system. I’d imagine faster/stronger will get carried more efficiently, which could also make the upper air conditions more favorable as well.

12z Euro is weaker, but finally in line with other guidance. Doesn’t matter as much at this point, but it has intensification through landfall.

Worth watching the SE coast next week as the window for something to form along the persistent troughing remains open. Development could happen as a high builds over the top, pushing it into the coast.

That’s a really good illustration. Thanks for sharing. You can see how the concave nature of the BoC may be assisting with organization as 90L’s residual vorticity shifts south. https://tropic.ssec.wisc.edu/real-time/atlantic/movies/wg8vor5/wg8vor5_loop.html

Verbatim it’s a good environment for intensification on the GFS. Has to stay offshore though. I’m sure the Euro will show nothing.

Now designated as Invest 91L

There’s been a persistent and broad signal for activity for a week or two now for both the Gulf and off the East Coast with all this troughing. They didn’t develop into anything tropical, but the signal eventually produced 99L off the EC (it’s a really nice looking system off the NS coast right now) the newest non-tropical low off the Carolina coast right now, what was 90L in the Gulf and whatever happens in the next few days in the BoC. I think the window is open for more in the next two weeks.

Tropical Weather Outlook NWS National Hurricane Center Miami FL 800 AM EDT Sat Sep 7 2024 For the North Atlantic...Caribbean Sea and the Gulf of Mexico: 1. Southwestern Gulf of Mexico: A tropical wave over the Bay of Campeche is producing disorganized showers and thunderstorms. An area of low pressure is forecast to develop while the wave interacts with a frontal boundary during the next couple of days. Environmental conditions are forecast to be conducive for development, and a tropical depression could form during the early or middle part of next week while the system moves slowly northwestward to northward over the southwestern Gulf of Mexico. * Formation chance through 48 hours...medium...40 percent. * Formation chance through 7 days...medium...60 percent.

Really interesting how that signal evolved. First the models were latched onto the western Caribbean wave (which if you recall came out of that monsoon trough last week) before the wave almost got washed out in the Caribbean. Then the models focused on 90L trying to do something before that got absorbed by a frontal system. Now it looks like the Caribbean wave and residual vorticity from what was 90L coalesce and try to develop as it gets pulled northward. Still not a lock to develop because it could get pushed into Mexico too soon but if it stays offshore it could become something decent. At least break the boredom. SE coast may be ripe for something late next week too.

The 00z op GFS continues the signal that started in large part with the ICON. What was 90L dives down into the Bay of Campeche as our western Caribbean wave (which started as part of the monsoon trough a week ago) reaches the BoC. Vorticity merges and organizes into a weak low. A trough/front pulls the coalesced low NW and then NNE into the northern Gulf next week. This is far from a lock to develop and a higher end system is even less likely at this time, but I think the key at least on recent guidance is that the potential low gets pulled north before running out of time to organize. Anywhere from the Gulf coast of Mexico to Louisiana should watch this one imo.

It couldn’t get there before crossing into cooler waters but this is a pretty nice late summer non-tropical low.

I expect this thread to get more active in a few days. It’ll need a title change though as the NHC will likely designate a new invest (if the merged area becomes invest worthy). Very interesting how the model signal has evolved over the last week—from focusing solely on the western Caribbean wave to focusing solely on 90L to now kind of combining the residual vorticity of the two.

Model signal looking a little more legit at 12z as the energy from 90L merges with the western Caribbean wave we’ve had on our radar forever. The BoC topography may help organize this over the weekend.

A little surprised to see the ensemble signal there but it’s hard to bet against the BoC topography. Hyper inactive…

Pretty wild

Each night the convection has waned significantly but the model signal has increased a touch. Best chance of genesis would be the ICON if this shifted south this weekend before getting pulled north. Clearly it needs space and time.

That’s what I meant by the longer range wave, but it’s hard for me to be bullish on anything in the eastern MDR given the stability issues. The signal for genesis is there though and we’re talking closer to mid month when conditions are progged to be more favorable. https://www.tropicaltidbits.com/analysis/models/gfs/2024090518/gfs_z850_vort_atl_37.png The GFS plays with something spinning out of the MT but very low odds https://www.tropicaltidbits.com/analysis/models/gfs/2024090518/gfs_z850_vort_atl_19.png

Always one model run each season