WxWatcher007

Wow, 94L looks much better than when I made the post 8 hours ago. Convection looks like it’s trying to organize around a more consolidated center. Impressive move toward genesis this morning.

Alright, after about a month, it's time to talk tropics seriously again. First--let's take a look at the basin. In the last month, we've seen quite a bit of warming, which is typical, and with El Nino highly unlikely, the peak of the season has strong signals to see continued reduced shear that favors an active peak, which I personally classify between August 20 and October 20 (note--that's what I base my annual peak season forecast off of). July and early August are times for the basin to simmer, and simmer it did. It's not as warm as last season, which is why I am likely to base the peak as shy of hyperactive, but for another year, conditions thermally look to be most robust near the US coast and in the homebrew region. Below are a few images from the latest CSU hurricane season forecast, which I think are helpful in providing an additional picture of where the basin is with regard to signals for the coming peak. Above average, but short of hyperactive. Note the extreme drop in shear that led to the historic 2020 peak we saw in September and October. As we approach the 2021 peak, the basin is waking up. We're moving into a favorable MJO phase, and enhancement we're seeing that has moved the EPAC into an active period is making its way toward the Atlantic. After a few misfires (Invests 91L, 92L, and I suspect 93L), the Atlantic Basin has produced an area of interest that I believe has a better than even chance of some development. Designated as 94L less than 24 hours ago, I've been watching this little wave at the western edge of a monsoonal trough as guidance had an oscillating signal on whether development could come from it over the last half week or so. An objective assessment would reveal that this invest isn't particularly special. Vorticity is just decent, the convection is disorganized, and the system is small, which makes it prone to disruptions that could kill it before it ever tries to get off the ground. Although the shear looks minimal for the immediate path ahead, big challenges remain. First, you have dry air that is lurking. The image below is a mid level water vapor snapshot which shows all of the invests within the monsoon trough have effectively been starved of convection, which, of course, aids greatly in lowering pressures and creating an organizational feedback loop (for lack of a better term) within a center of low pressure. If that wasn't enough, then you have the Greater Antilles, which the latest GFS envisions a collision course with Haiti/DR and Cuba. So why am I even posting about this little critter then? Well, because TC genesis is neither linear nor static. Like Elsa, a poor environment in one part of the Atlantic doesn't necessarily prevent genesis or development in another. Sometimes you just have to survive. That's just what we've seen in some of the recent guidance. Although there are serious questions about how sheared anything would be as it approaches the US due to PV streamer (upper level low), the guidance while bouncing around seems to be giving 94L a greater chance of some minor development. There's actually not a lot to discuss seriously because there is so much that can change depending on track and potential development location, but for illustrative purposes only let's look at the 18z GFS, which has been fairly consistent with the general evolution of 94L. What do we see? Well, early on you see 94L trying to tighten up, and it looks like it does so in time just to hit PR or one of the other major islands. That causes obvious weakening, and there isn't a lot of development as the system is driven WNW by a strong ridge until a trough creates a weakness that pulls it up the coast. Still a lot to sort out there. It isn't until it is along the SE coast more significant development looks to take place. What does it all mean? At this point my takeaways are the following: 1) 94L looks to be the wave that has the best chance of coming out of the monsoon trough and developing into a weak system because it is in the best shear/moisture/SST environment. Development is not a guarantee, though. 2) Interaction with the Greater Antilles and a possible PV streamer will have a significant impact on the overall evolution of the system. 3) The presence of a strong ridge likely means this is driven WNW, and the timing and strength of an incoming trough will have an impact on whether 94L (should it develop) is able to (re)develop in the Gulf or off the East Coast. The ceiling for this one seems low, but we're tracking again. A lot to watch for as we get an appetizer before the main course arrives.

Posting the GFS is fine, people aren't really talking that much about it because there isn't a lot to really discuss IMO, but trying to attach hidden meaning to what F264 means is just a little much. Again, not trying to be rude, but I think you'll get more robust discussion if you keep your posts focused on the invest, the overall environment, and computer model runs.

Look, I mean this with all due respect...maybe throttle back on the posts a bit here bud. Meaningful discussion can't happen if posts don't make sense.

Dear God yes.

Not that I’m the fountain of knowledge lol but if you ever have questions please just ask.

12z EPS makes a pretty stark reversal as @Weather Will illustrates above, increases the signal for development.

Weenies galore While still obviously disorganized, both invests are holding their own and the signal for development of 94L has increased across guidance. We may finally have something real to track. Will be interesting to see if the overnight period aids in helping either organize a bit.

Hoping to do a 94L/basin overview at some point today.

Tropical Weather Outlook NWS National Hurricane Center Miami FL 200 PM EDT Sun Aug 8 2021 For the North Atlantic...Caribbean Sea and the Gulf of Mexico: An elongated area of low pressure located several hundred miles east of the Windward Islands continues to produce disorganized showers and thunderstorms. Environmental conditions are expected to be favorable to support some gradual development over the next few days, and this system could become a tropical depression while it moves west-northwestward at 10 to 15 mph. The disturbance is forecast to reach portions of the Lesser Antilles late Monday, and then move near the Virgin Islands and Puerto Rico on Tuesday, and near Hispaniola around the middle of this week. Interests in those areas should monitor the progress of this system, as it could bring locally heavy rainfall and gusty winds to portions of that area. * Formation chance through 48 hours...medium...40 percent. * Formation chance through 5 days...medium...50 percent. Showers and thunderstorms associated with an area of low pressure located over the tropical Atlantic about midway between the Cabo Verde Islands and the Lesser Antilles have diminished this morning. Although environmental conditions appear to be only marginally conducive for development, this system could still become a tropical depression later this week while it moves toward the west-southwest or west at around 10 mph. * Formation chance through 48 hours...low...30 percent. * Formation chance through 5 days...medium...40 percent. $$ Forecaster Brown

Tropical Weather Outlook NWS National Hurricane Center Miami FL 200 PM EDT Sun Aug 8 2021 For the North Atlantic...Caribbean Sea and the Gulf of Mexico: 1. An elongated area of low pressure located several hundred miles east of the Windward Islands continues to produce disorganized showers and thunderstorms. Environmental conditions are expected to be favorable to support some gradual development over the next few days, and this system could become a tropical depression while it moves west-northwestward at 10 to 15 mph. The disturbance is forecast to reach portions of the Lesser Antilles late Monday, and then move near the Virgin Islands and Puerto Rico on Tuesday, and near Hispaniola around the middle of this week. Interests in those areas should monitor the progress of this system, as it could bring locally heavy rainfall and gusty winds to portions of that area. * Formation chance through 48 hours...medium...40 percent. * Formation chance through 5 days...medium...50 percent. 2. Showers and thunderstorms associated with an area of low pressure located over the tropical Atlantic about midway between the Cabo Verde Islands and the Lesser Antilles have diminished this morning. Although environmental conditions appear to be only marginally conducive for development, this system could still become a tropical depression later this week while it moves toward the west-southwest or west at around 10 mph. * Formation chance through 48 hours...low...30 percent. * Formation chance through 5 days...medium...40 percent. Forecaster Brown

You went a little wild there but you're a new poster. Enthusiasm is good. Just keep in mind that those model runs will jump all over the place as it tries to sort out a complex environment. Yeah, I think some short term development is looking increasingly likely, but I think we probably will agree it's going to find a hard time hanging on in the western Atlantic if it runs straight into Haiti/DR or Cuba and then encounters the PV streamer that's progged on some of the guidance near Florida. Of course, that can be hit or miss, so certainly something worth watching over the next few days.

That lead wave/western edge of the monsoon trough has been designated Invest 94L. Of all the disturbances we've seen the last few days, I've thought this one had the best chance of development if it could avoid land interaction. It is disorganized and ugly looking right now, but looks better than it did 24 hours ago (same could be said for 93L) as it is more convectively active. Has a lot of work to do and it's far from certain it develops.

what happened in here last night?

Beautiful day here in upstate NY. Not quite PF level scenery lol but this’ll do.

Central Atlantic wave is now designated Invest 93L. NHC jumped the gun with the last two invests so we’ll see if the third time’s the charm.

Some modest support for waves 1 & 2 on the GEFS. Virtually nothing for 92L.

Just an observation—not saying it’ll happen—but that GFS run was close to an impact somewhere. TC comes in as the high builds over the top and blocks a quick recurve. Get that to happen sooner and it’s much closer to a coastal scraper in the SE at least. Edit: that, or removing/weakening the trough that creates the weakness in the ridge.

Yeah—I still think it’s a little wild but some development closer to the Antilles is a legit possibility. Note that the lead part of the monsoon trough tries developing too albeit much weaker due in large part to land interaction.

Something could pop eventually out of that monsoon trough, but that’s a classic GFS gone wild run IMO. MDR still isn’t quite ready for Primetime

All depends on the environment whenever a system got there. Just look at Marco and Laura last year. Both ran into the Gulf and had entirely different outcomes just a few days apart due to the conditions they met.

As I was saying yesterday, I think that lead wave (current NHC lemon) is something to watch as it reaches the Antilles. If it’s able to track north of the larger islands it may run into a more favorable environment, at least with regard to OHC and moisture. Shear TBD. It’s no surprise the guidance is struggling with projecting what, if anything, comes out if this monsoon trough. We’re kind of at the point in the season where MDR environmental conditions are favorable enough for a signal but still hostile enough to preclude a robust one with what we’ve got going on currently. Sure, something could develop, but we’re probably jumping the gun by a week or two in having a truly conducive pattern for TC genesis. Of course, that’s why climo is climo.

Dog days for sure. Glad football is starting to ramp back up.