2024 - tracking the tropics

[WinterWolf]

Talk to us Don….is it really that dead/quiet out there?  

[WxWatcher007]

39 minutes ago, WinterWolf said:

Talk to us Don….is it really that dead/quiet out there?  

It’s not great lol. My own peak season forecast aside, I think the high NS seasonal forecasts are likely cooked, with the H forecasts now in legitimate danger. MH still squarely on the table because I think the environment outside of the eastern MDR is ripe for nukes, but we can’t get anything developed enough to take advantage of historic SST/OHC and anomalously low shear.   

Just throwing a number out but something like a 14/8/4 seasonal total instead of a 25/15/6 seems more likely especially if we can’t get this central Atlantic wave to pop in the next 5-7 days. I think that one is a true toss up. 
 

Edit: and to be clear since I was defending the forecasts/activity two weeks ago lol, 14/8/4 would be a seasonal bust of EPIC proportions. 

[WinterWolf]

Yes sir…so far the forecasts have absolutely flopped.  Good post btw. 

[WxWatcher007]

16 minutes ago, WinterWolf said:

Yes sir…so far the forecasts have absolutely flopped.  Good post btw. 

I still think it’s too early to pull the plug completely. We could easily have a big peak between September 15 and October 30 and that’s probably impactful for the US given climo, but for now…the lid is still on even though it’s showing signs of trying to come off. 

[40/70 Benchmark]

Crazy how the season just tanked after the historic Beryl.

[WxWatcher007]

14 minutes ago, 40/70 Benchmark said:

Crazy how the season just tanked after the historic Beryl.

Going to need to be a lot of study on how pervasive stability and a further north ITCZ stifled the highest end potential. I don’t recall the ITCZ issue in the past, but stability has been a major issue the last decade. 

[CoastalWx]

Pretty epic bust coming up for the tropical forecasts.

[powderfreak]

2 hours ago, CoastalWx said:

Pretty epic bust coming up for the tropical forecasts.

I oddly enjoy big seasonal forecast busts for some reason.  It’s nothing against any seasonal forecaster and it’s awesome we are always trying to figure out and advance our knowledge of the world’s environmental systems… but it’s a nice reminder of how little we know too.

[kdxken]

1 minute ago, powderfreak said:

I oddly enjoy big seasonal forecast busts for some reason.  It’s nothing against any seasonal forecaster and it’s awesome we are always trying to figure out and advance our knowledge of the world’s environmental systems… but it’s a nice reminder of how little we know too.

I thought you liked Ray? Just kidding Ray!!!!

[WxWatcher007]

1 minute ago, kdxken said:

I thought you liked Ray? Just kidding Ray!!!!

Beat me to it  

[Dan76]

46 minutes ago, powderfreak said:

I oddly enjoy big seasonal forecast busts for some reason.  It’s nothing against any seasonal forecaster and it’s awesome we are always trying to figure out and advance our knowledge of the world’s environmental systems… but it’s a nice reminder of how little we know too.

Insurance company's making $$ with the under preforming season (so far).  

[Typhoon Tip]

expanded hc is fuckung things up

kelvin waves are less identifiable and in fact are weaker in weaker hc circulation manifold  … not propagating as efficiently. 

we appear trapped in an “unscheduled” standing wave problem as a result.   we’ve persisted in neg uvm anomaly over our hemisphere for several weeks. without the canonical progression of kelvin wave to then reverse the uvm field this season is likely toast for those original predictions. 
 

 

[40/70 Benchmark]

1 hour ago, kdxken said:

I thought you liked Ray? Just kidding Ray!!!!

Heh...I've hooked him up the past couple of seasons. 

[ineedsnow]

Congrats cape cod

[Hazey]

Changing climate making tropical weather less predictable. Old thoughts and understanding ain’t working so good anymore.

[WinterWolf]

Long range forecasting is always unpredictable lol. 

[weatherwiz]

18 hours ago, CoastalWx said:

Pretty epic bust coming up for the tropical forecasts.

Aren't the official tropical outlooks created by inputting a slew of various parameters with applications of physics, incorporating climatology, and running simulations upon simulations to derive the forecasts? 

The hyper active forecasts seemed to rely on two major factors;

1) Decaying EL Nino and developing La Nina.

2) The record warm waters/OHC going through spring.

We'll see what happens through the next 8 weeks, but let's say even if we tack on another 7-8 storms, maybe 75% of those achieve hurricane status, 1-2 of those become major, and we don't see any significant landfalling impacts and the season ends at this. 

Instead of folks admitting the forecast was off, Beryl will be used to justify because of ridiculously high ACE. That's ridiculous. There is no questioning Beryl was in the historic category, however, you can't use that one storm to define the entire season. I mean you can but the truth of the matter is that one storm was not reflective of the entire story. If you got 52 inches of snow during the winter (and your average is like 49'') but 25'' of that came within one storm, are you going to quantify the winter as "epic" because of that one storm. That one storm was not reflective of the season, it was reflective of short-term processes. 

[WxWatcher007]

2 minutes ago, weatherwiz said:

Aren't the official tropical outlooks created by inputting a slew of various parameters with applications of physics, incorporating climatology, and running simulations upon simulations to derive the forecasts? 

The hyper active forecasts seemed to rely on two major factors;

1) Decaying EL Nino and developing La Nina.

2) The record warm waters/OHC going through spring.

We'll see what happens through the next 8 weeks, but let's say even if we tack on another 7-8 storms, maybe 75% of those achieve hurricane status, 1-2 of those become major, and we don't see any significant landfalling impacts and the season ends at this. 

Instead of folks admitting the forecast was off, Beryl will be used to justify because of ridiculously high ACE. That's ridiculous. There is no questioning Beryl was in the historic category, however, you can't use that one storm to define the entire season. I mean you can but the truth of the matter is that one storm was not reflective of the entire story. If you got 52 inches of snow during the winter (and your average is like 49'') but 25'' of that came within one storm, are you going to quantify the winter as "epic" because of that one storm. That one storm was not reflective of the season, it was reflective of short-term processes. 

I don’t think that’ll be the case.

Everyone not a hypster acknowledges that there was a major miss analyzing the sub-seasonal stability in the basin. 

If we ended up 13/9/3 that’s an epic failure of the consensus seasonal forecast. 

That said—I still caution against calling bust on big H and MH numbers. The NS forecast is gone, but when climo shifts the primary development region to the Caribbean there will be much more instability, and lack of shear, and historically warm SST/OHC. 

Even before all that we could see some activity. 

[WxWatcher007]

Not related to New England, but this one is one of the all time greats. Going 1 to 5 that close to FL is incredible. 

 

 

[weatherwiz]

4 hours ago, WxWatcher007 said:

I don’t think that’ll be the case.

Everyone not a hypster acknowledges that there was a major miss analyzing the sub-seasonal stability in the basin. 

If we ended up 13/9/3 that’s an epic failure of the consensus seasonal forecast. 

That said—I still caution against calling bust on big H and MH numbers. The NS forecast is gone, but when climo shifts the primary development region to the Caribbean there will be much more instability, and lack of shear, and historically warm SST/OHC. 

Even before all that we could see some activity. 

You also know it’s been bad when there haven’t been any naked swirls that get named for like 10 minutes driving up numbers  

but yeah this could end up being an active post-peak season so can’t sleep on it but that just leads into the mind set we get with winter and things not going well…”it looks like we get over the bump in 10 days”. We’re going to have to start seeing these changes occur in the present, not just on guidance 5-6-6+ days out. Granted, we are seeing some changes occur but is it going to be enough? 

[dendrite]

Was looking at old obs from Carol. BOS Had some fun ones.

METAR KBOS 311600Z 14075KT 11/2SM -RA FG BKN/// OVC/// 21/19 A//// RMK SLP776 P0028 T02110194

[40/70 Benchmark]

5 hours ago, weatherwiz said:

Aren't the official tropical outlooks created by inputting a slew of various parameters with applications of physics, incorporating climatology, and running simulations upon simulations to derive the forecasts? 

The hyper active forecasts seemed to rely on two major factors;

1) Decaying EL Nino and developing La Nina.

2) The record warm waters/OHC going through spring.

We'll see what happens through the next 8 weeks, but let's say even if we tack on another 7-8 storms, maybe 75% of those achieve hurricane status, 1-2 of those become major, and we don't see any significant landfalling impacts and the season ends at this. 

Instead of folks admitting the forecast was off, Beryl will be used to justify because of ridiculously high ACE. That's ridiculous. There is no questioning Beryl was in the historic category, however, you can't use that one storm to define the entire season. I mean you can but the truth of the matter is that one storm was not reflective of the entire story. If you got 52 inches of snow during the winter (and your average is like 49'') but 25'' of that came within one storm, are you going to quantify the winter as "epic" because of that one storm. That one storm was not reflective of the season, it was reflective of short-term processes. 

You basically described 1996-1997 winter and no, we don't consider that season epic.

[WinterWolf]

8 hours ago, WxWatcher007 said:

Not related to New England, but this one is one of the all time greats. Going 1 to 5 that close to FL is incredible. 

 

 

892mb central pressure….absolutely insane! Holy shit.  185mph sustained winds…..that’s even hard to imagine.  Could you imagine the gusts?    Now that’s a complete Beast. 

[WxWatcher007]

1 hour ago, WinterWolf said:

892mb central pressure….absolutely insane! Holy shit.  185mph sustained winds…..that’s even hard to imagine.  Could you imagine the gusts?    Now that’s a complete Beast. 

892mb at landfall too, and it was a slow mover. Just insane. 

[Cyclone-68]

Is that tropical wave in the Caribbean attempting to set some record for non development as it passes through the entire Atlantic without becoming anything?

[WxWatcher007]

7 minutes ago, WxWatcher007 said:

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. 

 

 

[weatherwiz]

Great stuff!

[WxWatcher007]

20 minutes ago, weatherwiz said:

Great stuff!

Thanks. I’m dumbing down why it’s been historically quiet, but there are likely a series of factors that has made the season an increasingly epic dud thus far. The real interesting part is whether this continues into later September when we usually see climo shift west and warmth aloft diminish. 

I’m not ready to totally pull the plug. The late season storms we get in the western Atlantic could be absolute nukes with enough runway. 

[weatherwiz]

1 minute ago, WxWatcher007 said:

Thanks. I’m dumbing down why it’s been historically quiet, but there are likely a series of factors that has made the season an increasingly epic dud thus far. The real interesting part is whether this continues into later September when we usually see climo shift west and warmth aloft diminish. 

I’m not ready to totally pull the plug. The late season storms we get in the western Atlantic could be absolute nukes with enough runway. 

I thought your explanations were great and you hit the nail on the head, there more than likely are multiple factors at play. I'm sure the low shear/historically high SST's/OHC going into the season raised alot of concern, however, as you know these two factors don't necessarily dictate whether a season will be active/inactive. These are more fuel...they are energy. Like CAPE and convection, 5000 J of CAPE doesn't mean you will see thunderstorms. You need conditions and factors which favor tropical waves/disturbances and you highlighted very well why they have been absent. 

[WxWatcher007]

19 minutes ago, weatherwiz said:

I thought your explanations were great and you hit the nail on the head, there more than likely are multiple factors at play. I'm sure the low shear/historically high SST's/OHC going into the season raised alot of concern, however, as you know these two factors don't necessarily dictate whether a season will be active/inactive. These are more fuel...they are energy. Like CAPE and convection, 5000 J of CAPE doesn't mean you will see thunderstorms. You need conditions and factors which favor tropical waves/disturbances and you highlighted very well why they have been absent. 

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.