ATL: INVEST 94L - Discussion

[CrazyC83]

An active wave train early seems to lead to busy seasons in the deep tropics. Thinking 2017, 2010 and 1996 among them.

[ScottNAtlanta]

While the MDR might not be as warm as previous years...it will be "warm enough". SSTs are just one piece of the thermodynamic puzzle that includes how the temps are in the atmospheric as you go up and the temperatures in the adjacent waters.

[Stormybajan]

Interestingly, 18z gfs doesnt seem to be as enthusiastic on developing 94L as previous runs did

[cycloneye]

A strong tropical wave located several hundred miles south of the
Cabo Verde Islands is producing a large area of cloudiness and a few
showers and thunderstorms. Some development of this system is
possible during the next few days before a combination of dry air
aloft and strong upper-level winds limit any chance of formation
while the wave is over the central tropical Atlantic Ocean late this
week.
* Formation chance through 48 hours...low...10 percent.
* Formation chance through 5 days...low...20 percent.

[toad strangler]

94L will struggle and ultimately meet it's demise but at the same time it's at LEAST a full month ahead of it's time.

[cycloneye]

AL, 94, 2021061500, , BEST, 0, 81N, 239W, 25, 1010, DB

[cycloneye]

Void of convection.

 https://twitter.com/cyclonicwx/status/1404624134617899009

[MarioProtVI]

94L will probably serve more as a warning sign for the MDR this year, kind of like 2017 with Bret (which came from a similar wave at a similar latitude). Don’t expect Claudette/Danny from this though.

[Hammy]

94L will struggle and ultimately meet it's demise but at the same time it's at LEAST a full month ahead of it's time.

I do recall 1996 having a few fairly strong waves like this in 1996 (and similarly a system form off the Carolinas around this time)--a year that was quite active in the MDR despite none forming quite yet.

[Shell Mound]

94L will probably serve more as a warning sign for the MDR this year, kind of like 2017 with Bret (which came from a similar wave at a similar latitude). Don’t expect Claudette/Danny from this though.

I respectfully disagree. We’ve seen Ana, Bill, and future Claudette (92L) all form in the subtropics vs. the MDR/Caribbean thus far. If anything, this suggests a less active season. Many inactive seasons feature lots of early- and/or preseason storms in the subtropics. If we were seeing tropical storms in the MDR by now, I would be more concerned. But an INVEST designation so far east, at this time of the year, is insufficient cause for alarm, in my view. I can also recall plenty of inactive years that featured at least a few abnormally vigorous, well-organised African easterly waves in June.

[Stormybajan]

94L will probably serve more as a warning sign for the MDR this year, kind of like 2017 with Bret (which came from a similar wave at a similar latitude). Don’t expect Claudette/Danny from this though.

I respectfully disagree. We’ve seen Ana, Bill, and future Claudette (92L) all form in the subtropics vs. the MDR/Caribbean thus far. If anything, this suggests a less active season. Many inactive seasons feature lots of early- and/or preseason storms in the subtropics. If we were seeing tropical storms in the MDR by now, I would be more concerned. But an INVEST designation so far east, at this time of the year, is insufficient cause for alarm, in my view. I can also recall plenty of inactive years that featured at least a few abnormally vigorous, well-organised African easterly waves in June.

I have two arguments against that:
1. AEW based invests in the MDR are rare in June, this tells me the WAM and the strength of the tropical waves are above average and are usually a precursor for an active season (2010,2017)
2. I dont believe having early development in the subtropics hints at a below average season, plenty of our recent seasons in this 5 years active streak (2016-2020) have had develop in the subtropics, it shouldnt be a cause for alarm nor be seen as a sign of a slow season

[Sciencerocks]

[ElectricStorm]

94L will probably serve more as a warning sign for the MDR this year, kind of like 2017 with Bret (which came from a similar wave at a similar latitude). Don’t expect Claudette/Danny from this though.

I respectfully disagree. We’ve seen Ana, Bill, and future Claudette (92L) all form in the subtropics vs. the MDR/Caribbean thus far. If anything, this suggests a less active season. Many inactive seasons feature lots of early- and/or preseason storms in the subtropics. If we were seeing tropical storms in the MDR by now, I would be more concerned. But an INVEST designation so far east, at this time of the year, is insufficient cause for alarm, in my view. I can also recall plenty of inactive years that featured at least a few abnormally vigorous, well-organised African easterly waves in June.

Last year had quite a bit of early activity in the subtropics and look what happened... I don't think early activity in the subtropics leads to an inactive season. But I do get what you're saying though as yes, there have been inactive seasons with early activity. But to me, I think this is more of a signal of an above average season to come, not below average.

[aspen]

94L will probably serve more as a warning sign for the MDR this year, kind of like 2017 with Bret (which came from a similar wave at a similar latitude). Don’t expect Claudette/Danny from this though.

I respectfully disagree. We’ve seen Ana, Bill, and future Claudette (92L) all form in the subtropics vs. the MDR/Caribbean thus far. If anything, this suggests a less active season. Many inactive seasons feature lots of early- and/or preseason storms in the subtropics. If we were seeing tropical storms in the MDR by now, I would be more concerned. But an INVEST designation so far east, at this time of the year, is insufficient cause for alarm, in my view. I can also recall plenty of inactive years that featured at least a few abnormally vigorous, well-organised African easterly waves in June.

All of the last several active seasons had June or July storms in the subtropics. However, if 2021 only has subtropic systems in July, then it’ll be a potential signal of an inactive year (see the seasonal indicators thread).

With a wave like this in mid June during a SAL outbreak, it seems probable that a MDR TC could form in July when conditions have improved.

[cycloneye]

Showers and thunderstorms have decreased and become less organized
during the past several hours in association with a tropical wave
located a few hundred miles south of the Cabo Verde Islands.
Development, if any, should be slow to occur during the next couple
of days while the wave moves westward. Thereafter, a combination of
dry air aloft and strong upper-level winds should limit the chances
of formation when the wave reaches the central tropical Atlantic.
* Formation chance through 48 hours...low...10 percent.
* Formation chance through 5 days...low...10 percent.

[Hypercane_Kyle]

94L will probably serve more as a warning sign for the MDR this year, kind of like 2017 with Bret (which came from a similar wave at a similar latitude). Don’t expect Claudette/Danny from this though.

I respectfully disagree. We’ve seen Ana, Bill, and future Claudette (92L) all form in the subtropics vs. the MDR/Caribbean thus far. If anything, this suggests a less active season. Many inactive seasons feature lots of early- and/or preseason storms in the subtropics. If we were seeing tropical storms in the MDR by now, I would be more concerned. But an INVEST designation so far east, at this time of the year, is insufficient cause for alarm, in my view. I can also recall plenty of inactive years that featured at least a few abnormally vigorous, well-organised African easterly waves in June.

Not really? Most of 2020's early season storms formed in the subtropics and look how that turned out for the Caribbean. And 92L is in the Gulf of Mexico, not the subtropics.

[Shell Mound]

94L will probably serve more as a warning sign for the MDR this year, kind of like 2017 with Bret (which came from a similar wave at a similar latitude). Don’t expect Claudette/Danny from this though.

I respectfully disagree. We’ve seen Ana, Bill, and future Claudette (92L) all form in the subtropics vs. the MDR/Caribbean thus far. If anything, this suggests a less active season. Many inactive seasons feature lots of early- and/or preseason storms in the subtropics. If we were seeing tropical storms in the MDR by now, I would be more concerned. But an INVEST designation so far east, at this time of the year, is insufficient cause for alarm, in my view. I can also recall plenty of inactive years that featured at least a few abnormally vigorous, well-organised African easterly waves in June.

Last year had quite a bit of early activity in the subtropics and look what happened... I don't think early activity in the subtropics leads to an inactive season. But I do get what you're saying though as yes, there have been inactive seasons with early activity. But to me, I think this is more of a signal of an above average season to come, not below average.

Another point of mine is that it is difficult to gauge how “impressive” 94L is without a thorough database of tropical waves going back several decades.

[hurricanehunter69]

Should we be concerned about the relative lack of SAL so far?

[Stormybajan]

Should we be concerned about the relative lack of SAL so far?

Atleast im not the only one who has noticed the SAL plumes so far in June havent been as prevalent as im used to, but im sure in ate June-July they will be right on track im sure

[StPeteMike]

The past week has seen beneficial rain to west Africa. If the weather pattern stays the same into July and August, we will have more to worry about.