Reasons for 2018 Tropical Inconsistency?

[chaser1]

A year with zero named storms in August and then suddenly having 4 at one time in September? The last few days have seen more tropical systems (hurricane, T.S, and invests) within the Atlantic basin then at any point in memory. Having said that, I'd be curious as to whether MJO induced sinking air or simply this being a year with an over abundant amount of mid level dry air as a contributor to greater then normal tropical cyclone decay and/or hampered ability to develop. Contrary to more typical years during the peak of season we have:
- an invest in the Gulf that contrary to forecast and good upper air, may fail to even develop into a T.D. before landfall
- a recent Cat 4 hurricane forecast to maintain intensity up to near landfall, weakening with a degrading CDO over very warm SST's and having great upper divergence
- a hurricane in the MDR that began rapidly becoming disorganized prior to encountering strong upper level westerlies and now moving over the Leewards as an open wave

Can't blame it on El Nino basin induced wind shear or a ripping mid-Atlantic TUTT, not an issue with SST's, and not due to high surface pressures. SAL certainly was very significant over recent months but there's no obvious new surges of Saharan air now spreading throughout the basin. Could recent months SAL outbreaks still be responsible for basin wide particulates still saturating a particular layer of the atmosphere? Sure does seem like some type of Tropical cyclone "UTC" Infection going on......

[CyclonicFury]

I don't think it's anything that unusual that some systems are underperforming intensity forecasts. Intensity forecasting remains a challenge.

The Atlantic is above average in ACE FWIW. Not every storm is going to undergo RI like 2017. It's not anything remotely similar to a year like 2013 as we have five hurricanes and a major.

[TheStormExpert]

The Atlantic basin overall is in a somewhat unfavorable state at the moment. The reason why these storms were able to develop and overcome that was because of the MJO being favorable in our region, correct me if I’m wrong.

Wouldn’t be surprised if the second half of September is much quieter than the first half, unless Isaac surprises us which I have doubts.

If that’s the case then things overall may shutdown much earlier than normal. Still can’t rule out the weak short-lived development in the far north Subtropical Atlantic.

[Hammy]

And I think this year is similar to 2014, being warm neutral (though that year was much warmer) which has been contributing to the Gulf being less favorable, as well as the cooler than normal MDR for much of August, so like 2014 this year is more dependent on the MJO in order for anything to form. But unlike 2014, we're not at a near-Nino and the wave train was much stronger, with more moisture over Africa.

Wouldn’t be surprised if the second half of September is much quieter than the first half, unless Isaac surprises us which I have doubts.

If that’s the case then things overall may shutdown much earlier than normal. Still can’t rule out the weak short-lived development in the far north Subtropical Atlantic.

While I'm on 2014, there was nothing from September 19-Oct 10 but October was quite active. With the pattern setup looking favorable for early to mid October, I'd rule out an early end to the season unless we have a replay of 2002 or 06 with El Nino onset.

I don't think it's anything that unusual that some systems are underperforming intensity forecasts. Intensity forecasting remains a challenge.

The Atlantic is above average in ACE FWIW. Not every storm is going to undergo RI like 2017. It's not anything remotely similar to a year like 2013 as we have five hurricanes and a major.

We're on the low end of near-normal for ACE I believe--the median is 87 and the average is 67-111.

And there were two storms in August.

Edit: the realization that I've technically replied to every post in this thread

[canes92]

Mother Nature does things her own way.

[RL3AO]

The Atlantic has a pretty extreme peak of the season compared to other basins. Even the slowest seasons in August and October usually have an active week or two in September. It's just climatology.

[AnnularCane]

Do you mean zero hurricanes? We had Debby and Ernesto in August.

[TheStormExpert]

The way I see it this season is behaving just about average depending how you look at things. Most forecasters were expecting below average. So far the storm tally is 10/5/1. Wouldn’t surprise me if we manage to reach around 15 named storms, can’t rule out a few more hurricanes, and maybe we can squeeze out another major likely in October over the second half of this month. That could easily put the numbers at for example 15/7-8/2. That’s about average to slightly above average in terms of numbers, ACE totals is yet to be seen so that’ll be another discussion for later on.

[EquusStorm]

The under-performers are weird, as are the August subtropical storms; but on the other end of the Spectrum, Florence's first round of RI to a 4 when we expected a TS, Beryl's unexpected jump to July MDR hurricane, Chris nearly hitting cat 3 in mid July way up north, those significantly overperformed or surprised. So while there have been a lot of storms that weakened when they shouldn't have, and this is worth discussing, hey, at least a few others balanced it out a bit. 10/5/1 isn't that bad a season all things considered.

[Patrick99]

I can't think of the exact seasons, but I feel like this has happened many times, when we have a slow August and then all of a sudden everything boils over in September. I get the sense that some years, we spend much of August still trying to get rid of the typical heavy SAL pattern we see in July.

[tolakram]

I think it's perfectly normal. We tend to remember the extreme seasons where conditions are perfect and not the less perfect ones.

[chaser1]

Do you mean zero hurricanes? We had Debby and Ernesto in August.

Acknowledged; thanks for the correction

[Hurricaneman]

I can't think of the exact seasons, but I feel like this has happened many times, when we have a slow August and then all of a sudden everything boils over in September. I get the sense that some years, we spend much of August still trying to get rid of the typical heavy SAL pattern we see in July.

Not all years are going to be like 2005 or 1983 for that matter, this year waking up the first week of September is not all that uncommon and typically back loaded seasons tend to last until late October early November and sometimes later

[Hammy]

I can't think of the exact seasons, but I feel like this has happened many times, when we have a slow August and then all of a sudden everything boils over in September. I get the sense that some years, we spend much of August still trying to get rid of the typical heavy SAL pattern we see in July.

Not all years are going to be like 2005 or 1983 for that matter, this year waking up the first week of September is not all that uncommon and typically back loaded seasons tend to last until late October early November and sometimes later

Interestingly though, even 2005 had a very quiet August relative to the season's high activity--before Katrina, we had two tropical storms (one very short-lived) and a hurricane that struggled most of it's lifetime.

[Ptarmigan]

September is historically the most active part of the hurricane season. August and October can be active as well.