WxWatcher007

Up the Bay!

Two invests in one day almost feels historic lol

All good. This place should be fun especially during the “down” times.

12z models so far are a little more robust with the Gulf low by keeping the center offshore. Plenty of rain for parts of the coast though.

Congrats Nova Scotia. Newly designated 99L is trying to develop…while getting blasted by 40kt shear lol. The MDR can’t even generate real convection lol let alone have it attempt to organize.

We have 5 lemons in the basin and a new invest, so let's take a quick morning look at each because any of them could have a chance in the short or long term. I attach my own personal odds of development to each. 1. Invest 99L--40% odds of subtropical development The area off the east coast has continued to be interesting on satellite and the models despite being blasted by exceptionally high shear and as a result, we have our first invest in an eternity. What's most of interest to me this morning is that despite the shear, you can clearly see the low level center try to tuck itself under deeper convection, a key element for TC genesis. The model signals continue to suggest that in the next 48 hours or so this has its best chance to further organize and deepen some. I'd prefer to see a tighter low rather than some of the current model depictions to feel that genesis is more likely, but for now this has held its own in a high shear environment. I think the shear ultimately keeps this from becoming fully tropical, but we'll see. WPC analysis still has this attached to a boundary for now. What to watch for: evidence of convection building over the LLC on IR 2. Area of Interest in northern Gulf of Mexico--30% odds Sometimes the door is open, and something just needs to walk through. I'm not sure if the area of interest that folks have been tracking for days now will step forward, but this morning it looks like it's trying. Shout out to @salbers for sticking with this one. On satellite, we see the sun rise over deep convection just off the Texas coast. Radar suggests that there is some level of a low level rotation, though imo the signal is just modest. This is the strongest iteration of what we've been tracking however, and given the SSTs in the area, present area of deep convection, and apparent pocket of low wind shear, it has a chance to develop. However, the big caveat is that there's not a lot of time to do so. The models bring a boundary through the region as early as tomorrow afternoon, meaning that the upper winds become hostile for any organization. If this one is going to steal a name, it needs to do it fast. With more time, I'd say this one has a fairly good chance of development, but with little time it seems much less likely. This is one that'll be interesting to watch through the day though, especially if deep convection can continue to fire over the apparent center. What to watch for: persistent deep convection over the center on IR, and evidence of a tightening LLC, increase in velocities, and banding on radar. 3. Western Caribbean Wave--30% odds We've been tracking this one seemingly forever, and it's entering the put up or shut up stage. Our wave has a little more spin and convection this morning, but probably not enough time to do anything meaningful before hitting land. Its best shot will be in the Bay of Campeche, where there's still a model signal for development, though it's not as robust as it once was. I'm far less bullish than I was the other day, but anytime a wave gets into the BoC it bears watching. 4. Eastern Atlantic Wave & Monsoon Trough--20% This is meh for now, but guidance has shown that something could pop out of the monsoon trough in the central Atlantic at any point in the next 7-10 days, and there is a longer range signal for an African wave to develop. Wake me up when it actually happens given the massive stability issues in the tropical Atlantic. This area gets a 1/5 shot right now out of respect for climo. 5. Central Atlantic Wave--10% This one may be more interesting 5 days from now, but as it travels WNW into the western Atlantic, there is some signal, most notably on the Euro that it'll try to organize some before getting either obliterated or turned OTS by an east coast trough. Nothing interesting at this time.

lol what a year (so far)

Fantastic

I prefer a January 20 plug pull

Which is absolutely bananas. We’ll see if things pick up on the backside of the peak.

Definitely east and not for us. But like I said earlier there is a window with this early season troughing if things align right. Maybe next week with a boundary over the Gulf and SE.

With slim pickin's out there to analyze in the Atlantic, why not spend a few minutes on this newest lemon. I first posted about the potential here on August 29th (yes, with my peak season forecast in mortal danger I will throw up a whoop for identifying this lol) as the guidance was consistent in developing an area of low pressure or series of areas along a stalled frontal boundary. Normally we see these during the early or latter part of the season, but with greater EC troughing recently, a window of opportunity has opened. Yesterday, you could see a robust area of lower level vorticity along the boundary Today that vorticity has wrapped up into an area of low pressure along the boundary. This is not currently tropical for a few reasons. First and foremost, it's attached to a boundary. That means that the low is baroclinic, not tropical. Secondly, despite there being a low and convection nearby, the convection is getting blasted to the east by very strong shear. The result is the following: While the boundary-attached low is clearly able to generate convection, the shear is pushing the convection off in a way that currently prevents this from becoming independent of the boundary and sustaining the necessary convection over the center to begin the tropical genesis process. Over the next few days however, the guidance tries to at least get this low to intensify some, and that could be the window for it to acquire more tropical characteristics. I doubt given the shear that it'll be able to fully become tropical, but there will at the least be a non-tropical low that quickly develops off the East Coast as it moves into Nova Scotia this weekend, and it could acquire enough convection during the intensification phase to be counted as subtropical. For those that truly care about the meteorology of tropical genesis, this will be interesting to watch. I should also note...that with persistent troughing over the next week or so, this is unlikely to be our only area to monitor. The guidance is picking up on a second quick developing low offshore late this weekend and perhaps another further south sometime next week. These boundaries can spur seedlings that become NS, especially if they are further south like the long range Euro hints at today. Just something to be aware of.

If it has a chance, it has to be tagged, irrespective of the type of season its been--at the very least for mariners.

The area off the east coast is now tagged. The models have quick development but it’s an open question of whether it’ll get enough tropical characteristics to be subtropical.

It may not develop lol but I love it when I can tag something before the NHC Subtropical would be the way to go and not fully tropical given how much shear is in the area. 1. Northwestern Atlantic: A non-tropical area of low pressure located a few hundred miles east of North Carolina is producing disorganized showers and thunderstorms. This system could acquire some subtropical characteristics over the next few days as it moves north- northeastward, remaining offshore of the northeastern United States. Additional information on this system can be found in High Seas Forecasts issued by the National Weather Service. * Formation chance through 48 hours...low...10 percent. * Formation chance through 7 days...low...20 percent.

Lemon tagged by the NHC now

Only one option now

The signal for some area of low pressure to develop off the east coast has been across guidance for the better part of a week now…likely non-tropical or perhaps hybrid. I’ll readily admit I’m grasping for straws as the basin remains barren with the following comment, but there may be a window for some September hybrid lows with so many troughs and offshore boundaries showing up on the models in the next 7-10 days.

@weatherwiz Maybe a partial explanation for the quiet in the western portion of the basin too. Too much subsidence in the Gulf/western Atlantic…too much rising air over the African continent, particularly over the Sahara. This kind of early peak bust requires all the dominoes to fall too. Take a look at the thread as it has other years included.

This is a worthwhile read. That massive area of subsidence over the Gulf and western Atlantic may also be why the western half of the basin has been bereft of activity despite several opportunities—as we’re even seeing now with the Gulf disturbance we’ve been casually watching.

People are trying to do them now with 65-70% of the season to go so yes Don’t get me wrong it looks bad—historically bad—but it’s like canceling winter on December 31, which people do every year as we know lol.

I think that’s one of the reasons—seedlings that would otherwise mature are getting smothered by a combination of stable air profiles and cool SSTs to the north of the CV islands before getting anywhere. That said, even stuff that’s come off south and plodded along into the tropical Atlantic east of the Lesser Antilles has struggled mightily. So I don’t think that’s the only explanation. The ITCZ dropping south may be late for tropical Atlantic genesis which should suppress the NS number, but if an active WAM is going to allow the train of vigorous waves to continue into October, once they get to the Caribbean and western Atlantic where TC genesis is climatologically favored things may open up. We’re just so far into uncharted territory (no NS during this period since 1968) that idk if anyone knows what’ll happen. It’s incredibly fascinating to watch.

I’m not sure if it’s just a delayed signal that’ll get washed out on the EPS, but 12z was quite robust in the Gulf with the current Caribbean disturbance. Seems to pull it north or NE eventually too with the eastern U.S. trough next week.

Right. SSTs/OHC can tell you which side of the AN/BN coin to lean, but that only takes you so far. It’s shocking that with shear being low so often across the basin we’re as low as we are. I’ve been factoring in stability/SAL for a few years now and it just seems like every year it gets worse. It’s far from apples to apples but it reminds me of the great setups we get in winter and confluence to the north just grinds up what’d be a KU 95 times out of 100. Everything else is good as it gets from a broader seasonal perspective—but you can’t factor in this one persistent feature that kills potential in the cradle. It’s both maddening and fascinating. Pouring in the Sahara and puffy sand laden clouds in the tropical Atlantic.