2024 Tropical Tracking Thread

[87storms]

Snoozer of a tropical season so far…again. We’re really just in a generally long term boring weather pattern at this point and droughts are a byproduct.

[Weather Will]

WB 0Z EPS... latest TD, TS and Hurricane probs

[ldub23]

[WxWatcher007]

Just now, WxWatcher007 said:

The operational models on balance today have latched onto a TC genesis signal for something near the Antilles/Caribbean via the monsoon trough. This is the NHC designated orange.

The 18z Euro is faster and more robust with development through 90.

Still, I’d caution that monsoon trough TC genesis is very difficult to predict and get right, so there could still be a waffling signal over the next day or two. However, given that I believe the primary reason for a “lid” in the basin so far has been stability/SAL/northern extent of past waves, we have legitimate reasons to believe genesis is possible.

First, shear is relatively low in the zone where genesis is most likely, which has been a characteristic of the season thus far. 

Second, in this area further west, we have additional instability and a highly favorable SST/OHC profile. This is still in sharp contrast to the eastern MDR, which has seen a substantial rise in instability, but is still well below normal climo due to what’s been discussed the last few pages.

I can’t overstate how important I think it is to have the MT south and possible development in the central portion of the MDR. This keeps potential development away from the greatest influence of SAL, as you can see below. Still, it’ll be important to watch convective trends the next 48 hours. No convection, no early development. 

 

You can see the MT easily with the ribbon of convection south of the SAL above, and below you can see how there’s already elongated modest low level vorticity.

What breaks off and where will matter for the future, but for now, we just watch for convective activity and signs of vorticity consolidation. 

 

[WxWatcher007]

 

[PrinceFrederickWx]

On 8/22/2024 at 8:14 AM, PrinceFrederickWx said:

Still no storms anytime soon… I can’t help but get last winter vibes 

[WxWatcher007]

Tropical Update--September 3, 2024

Yikes

Now that we're actually moving through the upswing of the climatological peak of the season, we're entering epic bust territory. 

 

Since Hurricane Ernesto early in August, there has been an intractable lid on the Atlantic. Not just the MDR, but the entire basin. We have held at 5/3/1, and while our ACE number is still above normal for this time of year due to the fast start and high end systems relative to the early part of the season, we've gone from historically active to historically...inactive. 

According to Dr. Phil Klotzbach, this is the first time since 1968 that we haven't had a named storm between August 13 and September 3. That's extraordinary. 

There is a lot of conversation happening in the tropical wx space about reasons for this. I'd argue that despite historically warm SST/OHC and anomalously low wind shear across the MDR most of the season, that a combination of stability, SAL, and in the last month or so, a much further north ITCZ leading to waves leaving Africa too far north to survive getting to even the central Atlantic has been the main culprit. It's possible that too wet a West African Monsoon is bad for TC genesis. 

Stability issues further west into the tropical Atlantic (the area between Africa and the Antilles) has stifled everything that has tried to develop there in essentially the last month. Even now, it's not a good look in the tropical Atlantic. 

 

For my peak season forecast of 15/10/5, we need to get on the board soon. The reason to not completely pull the plug on higher end activity in terms of H and MH is two fold.

1) Despite the iron lid being over the basin, the underlying factors for a quality over quantity season still remain 

Simply put, the lack of instability in the eastern MDR to this extreme once again makes me believe that truly significant activity here is a lost cause.

However, just west, with a combination of lower shear (especially as the trade wind impact diminishes with climo) and historically high OHC and much more normal instability, I do think that a lot can happen through later September and October. 

2) Even though it's September 3, approximately 65-70% of historical activity in a given season still remains. 

The favorable conditions above should be able to take center stage as climatology abandons the tropical Atlantic and the focus for TC genesis becomes the western Atlantic and Caribbean. We'll see if they do. 

Areas of Interest

The basin is still hostile, but the chance of development is there for any one of these. The NHC notes three areas and I add a fourth. 

1. Caribbean Disturbance--60% 

This is the one we've been following for a while, and the signal has continued to waffle on the models. Unlike in the tropical Atlantic, this one has been firing more convection in the Caribbean (speaking to greater instability) but ran into the problem of shear and becoming more strung out as it quickly moved west.

It's just south of the island of Hispaniola right now, and while it barely has visible signs of life I would not count this one out yet. The ensemble signal is still modest, and with a more favorable environment likely as it gets into the western Caribbean or potentially Bay of Campeche, it's worth watching.  

 

2. Eastern Atlantic Wave--40%

All the way near the Cabo Verde Islands we have a strong wave that's a bit tied up in the currently further south ITCZ/monsoon trough. The model signal is modest but I need to see that something can develop this far east to believe it given the profound stability issues. 

3. Central Atlantic Wave--30%

The third area on my list has only really started grabbing attention in the last 24 hours, in large part because it has for now been able to maintain persistent convection. 

If you refer back to the SAL/water vapor image at the beginning of this post, you'll see that there's a lot of dry air lurking. I'm less bullish on this one as well because there's no evidence yet of robust low level vorticity. Yet at least. 

This wave only has a few days before conditions become even more hostile, but if it can keep convection firing that may be enough time for a quick spin up before getting ripped apart. Low odds at this time. 

4. East Coast Hybrid--10%

Finally, the lowest odds of development come from something not even tagged by the NHC. The signal for some type of low pressure to form off of an offshore boundary has been persistent for a week now, and the guidance continues to try to spin something up along the boundary in the coming days. If you look at the vorticity image above, it's easy to see why. 

The question however, is how far south does something develop, and can it attain tropical characteristics. Most indications are that it's more baroclinic than tropical or subtropical, which makes sense given the trough and fact that anything tropical trying to develop would get blasted by shear, but something hybrid may be worth keeping a casual eye on. 

 

[Yeoman]

Have we hit tayshaun yet?

[Terpeast]

If the reason behind quiet activity is that the ITCZ is too far north, I wonder if we’ll see a delayed but active period when the ITCZ starts moving back south. But by then it may be too late for MDR genesis

[WxWatcher007]

3 hours ago, Terpeast said:

If the reason behind quiet activity is that the ITCZ is too far north, I wonder if we’ll see a delayed but active period when the ITCZ starts moving back south. But by then it may be too late for MDR genesis

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. 

[JenkinsJinkies]

So you think we'll be getting a "what went wrong" write up in November?

[WxWatcher007]

1 minute ago, JenkinsJinkies said:

So you think we'll be getting a "what went wrong" write up in November?

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. 

[JenkinsJinkies]

1 minute ago, WxWatcher007 said:

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. 

That's why I said November.

[PrinceFrederickWx]

It's the Chicago White Sux of hurricane seasons lol

[stormy]

Yes, I know it's still early, but it is absolutely amazing how so many truly believed 10 - 20 years ago that Climate Change would be like pouring gasoline on a fire for hurricane frequency and strength. It was so bad that some insurance companies stopped issuing policies.

Now, a record breaking season predicted for this year.

I look forward to being wrong on November 5 when Sara gives me 10 inches of rain and a flood.

 

[JenkinsJinkies]

24 minutes ago, stormy said:

Yes, I know it's still early, but it is absolutely amazing how so many truly believed 10 - 20 years ago that Climate Change would be like pouring gasoline on a fire for hurricane frequency and strength. It was so bad that some insurance companies stopped issuing policies.

Now, a record breaking season predicted for this year.

I look forward to being wrong on November 5 when Sara gives me 10 inches of rain and a flood.

 

Last year and 2020 would like a word.

[stormy]

38 minutes ago, JenkinsJinkies said:

Last year and 2020 would like a word.

Thanks my friend!   I agree, 2020 was remarkable but only 14 hurricanes when 2005 had 15. I was not really impressed with last year as Idalia was the only land-falling hurricane.

[WxWatcher007]

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.

[Yeoman]

21 hours ago, WxWatcher007 said:

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. 

Seems to work out well

[WxWatcher007]

54 minutes ago, Yeoman said:

Seems to work out well

I prefer a January 20 plug pull

[JenkinsJinkies]

56 minutes ago, WxWatcher007 said:

I prefer a January 20 plug pull

We're at the hurricane season equivalent of a perfect track rainstorm on MLK day.

[WxWatcher007]

31 minutes ago, JenkinsJinkies said:

We're at the hurricane season equivalent of a perfect track rainstorm on MLK day.

Fantastic  

[PrinceFrederickWx]

Five lemons on the NHC page now. We’re good at making lemons this year at least 

[IronTy]

When Mets start predicting a sistene chapel pattern foretelling an upcoming spike in tropical development then we'll know it truly is over.  

[WxWatcher007]

Just now, WxWatcher007 said:

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. 

 

[32º]

I know hr 384 of the GFS is totally unreliable.

[ldub23]

2 hours ago, 32º said:

I know hr 384 of the GFS is totally unreliable.

[clskinsfan]

2 hours ago, 32º said:

I know hr 384 of the GFS is totally unreliable.

Nah. I set all of my forecasts off of the 384 GFS. Works out all of the time. 

[WxWatcher007]

Up the Bay!

[scope1]

Beautiful