2021 Indicators: SST's / SAL / MSLP / Shear / Steering / Instability / Sat Images

[AlphaToOmega]

Here is the VP pattern for 2013 ASO. This seems like a VP pattern typical of -AMO years, not +AMO years.

[Category5Kaiju]

Here is the VP pattern for 2013 ASO. This seems like a VP pattern typical of -AMO years, not +AMO years.
https://i.postimg.cc/zG1rnqWM/w6-Mh-Rwj-F.png

2013 is literally like the new boogieman for hurricane season comparisons ! Yes, when compared with 2021, the VP pattern really do not share much in common. It's also interesting to note that in 2013 at around this timeframe the WPAC, EPAC, and Atlantic were struggling to generate quality storms. This year with Surigae and Felicia that is definitely not the case. And the Atlantic has the massive issue of waves simply drying out before they even entered the MDR, and this year we have seen the ITCZ active even during a suppressive phase. So yeah, 2021 and 2013 really share little in common.

[SFLcane]

Buckle up!!

 https://twitter.com/bennollweather/status/1421100770749943813

[Category5Kaiju]

Buckle up!!

https://twitter.com/bennollweather/status/1421100770749943813

By mid-August? Seems like the drill to me as it has been the past recent years. I really think the idea that early August is typically not active in the Atlantic, even during La Nina years, should really be hammered down. I feel like some individuals expect way too much out of the Atlantic sometimes even during times it is not supposed to be that active and take such inactiveness to be a sign that the season overall will be inactive.

[AutoPenalti]

Would you look at that, rising motion expected during peak season.

[aspen]

Buckle up!!

https://twitter.com/bennollweather/status/1421100770749943813

Still some -VP anomalies over the EPac. However, the -VP cell weakens with the Africa cell becoming far more dominant by the 2nd week of August/mid-August.

[NotSparta]

Buckle up!!

https://twitter.com/bennollweather/status/1421100770749943813

Still some -VP anomalies over the EPac. However, the -VP cell weakens with the Africa cell becoming far more dominant by the 2nd week of August/mid-August.

During ASO, the -VP cell in the EPAC has been present every year since 1995, with the exception of 2010 and 2020. As long as Africa becomes very dominant as expected, it probably won't be of much consequence. Even on these plots it seems the EPAC -VP cell won't be that strong even in the second week of August

[cycloneye]

Looks like Mr Noll's twit changed the mood around here.

[tolakram]

The EPS is shifting toward a much stronger -VP cell over the EPAC through early September, so at this point I think the Atlantic season is going to underperform significantly. The entire month of August is basically going to be dead and early September looks to be far from hospitable for “homegrown” systems, given strong, convectively driven VWS emanating from the EPAC and impinging on the Caribbean. This is significant, because most people here have been expecting “homegrown” development to compensate for a potentially inactive MDR, yet the -VP cell over the EPAC would likely shut down the western part of the basin. Anything that forms there would need to occur along the northern Gulf Coast or off the East Coast, and such a system would be much more likely to be relatively weak than something that forms farther south, i.e., over the western Caribbean.

You sound extremely confident based on one single parameter that frankly I had never paid attention too. If we end up with a slow season how will you verify that this -VP is the actual cause?

[Category5Kaiju]

The EPS is shifting toward a much stronger -VP cell over the EPAC through early September, so at this point I think the Atlantic season is going to underperform significantly. The entire month of August is basically going to be dead and early September looks to be far from hospitable for “homegrown” systems, given strong, convectively driven VWS emanating from the EPAC and impinging on the Caribbean. This is significant, because most people here have been expecting “homegrown” development to compensate for a potentially inactive MDR, yet the -VP cell over the EPAC would likely shut down the western part of the basin. Anything that forms there would need to occur along the northern Gulf Coast or off the East Coast, and such a system would be much more likely to be relatively weak than something that forms farther south, i.e., over the western Caribbean.

You sound extremely confident based on one single parameter that frankly I had never paid attention too. If we end up with a slow season how will you verify that this -VP is the actual cause?

Honestly I have never heard of a recent year Atlantic season in which we had a -ENSO but a -VP cell that killed the season. NotSparta does have a point though; for every season since 1995 to have a -VP cell at one point (with the exceptions of 2010 or 2020), I just don't know how significant of a factor that even is in hindering overall Atlantic activity, particularly in the peak months of -ENSO years. If the -VP EPAC cell was so important, then why do forecasting agencies not consider such so highly but rather look at the general ENSO state to determine the level of expected Atlantic activity instead?

[captainbarbossa19]

Buckle up!!

https://twitter.com/bennollweather/status/1421100770749943813

Still some -VP anomalies over the EPac. However, the -VP cell weakens with the Africa cell becoming far more dominant by the 2nd week of August/mid-August.

During ASO, the -VP cell in the EPAC has been present every year since 1995, with the exception of 2010 and 2020. As long as Africa becomes very dominant as expected, it probably won't be of much consequence. Even on these plots it seems the EPAC -VP cell won't be that strong even in the second week of August

-ENSO, along with climatology, are likely going to make the Atlantic the dominant basin in terms of intensity and activity. I also do not like the projected setup of VP anomalies for the peak season. That pattern is very similar to the pattern of ASO 2005. With the MDR warming up now and the possibility of waves forming further south, peak season could be quite dangerous for the CONUS, Central America, and the Islands.

[AlphaToOmega]

Here is what is known for sure: ASO will feature +AMO, +TNA, -ENSO, -PDO, and -VP over Africa. What matters is VP anomalies over the East Pacific. If there is not -VP over the East Pacific, the season will feature a pattern similar to 2020 and 2010. If there -VP over the East Pacific, the season will feature a pattern similar to 2011, 2008, 2007, 2005, 2001, 1999, and 1998. Averaging 2020 and 2010 yields 24.5 storms, 13 hurricanes, 6 major hurricanes, and 172.5 ACE. Averaging 2011, 2008, 2007, 2005, 2001, 1999, and 1998 yields 17 storms, 9 hurricanes, 4.285714 major hurricanes, and 151.571428 ACE. The sample sizes are small, so these might be underestimates or overestimates; or they might be accurate.

[CyclonicFury]

The latest ECMWF has shifted toward the GFS and now shows multiple strong hurricanes over the C/EPAC during the next few weeks. As far as the African monsoonal trough is concerned, the -VP over the IO during ASO should continue to contribute to highly amplified AEWs. These would tend to take their time to consolidate over the MDR, so if a secondary -VP cell is also present over the C/EPAC, it would likely shear any AEW that attempts to develop closer to the Caribbean and/or the islands. Regarding the -AMO, I was referring to the fact that the Canary Current remains cool, despite recent warming of the MDR. One would need to see significant warming over key areas such as the Canaries to be relatively certain that the MDR will continue to warm over time.

The canary current isn’t actually that cool at all. CDAS might be showing that because it’s biased towards cooling with SAL outbreaks making it look cooler then it actually is, thus I would use a different data set such as OISST or Coral Reef

The EPS is shifting toward a much stronger -VP cell over the EPAC through early September, so at this point I think the Atlantic season is going to underperform significantly. The entire month of August is basically going to be dead and early September looks to be far from hospitable for “homegrown” systems, given strong, convectively driven VWS emanating from the EPAC and impinging on the Caribbean. This is significant, because most people here have been expecting “homegrown” development to compensate for a potentially inactive MDR, yet the -VP cell over the EPAC would likely shut down the western part of the basin. Anything that forms there would need to occur along the northern Gulf Coast or off the East Coast, and such a system would be much more likely to be relatively weak than something that forms farther south, i.e., over the western Caribbean.

The composite of all hyperactive-ACE seasons since 1995 has a -VP cell over the EPAC during ASO.

[SFLcane]

The canary current isn’t actually that cool at all. CDAS might be showing that because it’s biased towards cooling with SAL outbreaks making it look cooler then it actually is, thus I would use a different data set such as OISST or Coral Reef

The EPS is shifting toward a much stronger -VP cell over the EPAC through early September, so at this point I think the Atlantic season is going to underperform significantly. The entire month of August is basically going to be dead and early September looks to be far from hospitable for “homegrown” systems, given strong, convectively driven VWS emanating from the EPAC and impinging on the Caribbean. This is significant, because most people here have been expecting “homegrown” development to compensate for a potentially inactive MDR, yet the -VP cell over the EPAC would likely shut down the western part of the basin. Anything that forms there would need to occur along the northern Gulf Coast or off the East Coast, and such a system would be much more likely to be relatively weak than something that forms farther south, i.e., over the western Caribbean.

The composite of all hyperactive-ACE seasons since 1995 has a -VP cell over the EPAC during ASO.

https://i.imgur.com/Ogicc5W_d.webp?maxwidth=640&shape=thumb&fidelity=medium

Honestly, it’s very small. Look at the relative size and magnitude. Try an average of like 2011, 2008, 2001, 1996.

[Steve]

The EPS is shifting toward a much stronger -VP cell over the EPAC through early September, so at this point I think the Atlantic season is going to underperform significantly. The entire month of August is basically going to be dead and early September looks to be far from hospitable for “homegrown” systems, given strong, convectively driven VWS emanating from the EPAC and impinging on the Caribbean. This is significant, because most people here have been expecting “homegrown” development to compensate for a potentially inactive MDR, yet the -VP cell over the EPAC would likely shut down the western part of the basin. Anything that forms there would need to occur along the northern Gulf Coast or off the East Coast, and such a system would be much more likely to be relatively weak than something that forms farther south, i.e., over the western Caribbean.

Literally all other factors point to an above-average season. I don’t know why you’re so confident the Atlantic is going to underperform and your basically suggesting the season might 2013 itself. Come November 30 I am 100% certain that is going to age poorly. Things can change quickly and models are not all the same and can verify poorly like last year.

Well I will say (and this is not a critique of Shell Mound of course and I don’t intend it to be in any way), but I think when it comes down to S2K posters, we all have our own levels of how active and optimistic we are for a certain season (especially if it has not started yet), and Shell Mound is perhaps one of S2K’s most conservative posters when it comes down to this.

Shell isn't always right. But where I'll credit him unlike certain posters from the past who were borderline trolls, is that he does his research and presents what he thinks might happen. He's not egomaniacal about it which is refreshing. He takes some heat and doesn't tend to fire back. I think he's a good poster who presents a lot of information worth considering. JMO.

[toad strangler]

Literally all other factors point to an above-average season. I don’t know why you’re so confident the Atlantic is going to underperform and your basically suggesting the season might 2013 itself. Come November 30 I am 100% certain that is going to age poorly. Things can change quickly and models are not all the same and can verify poorly like last year.

Well I will say (and this is not a critique of Shell Mound of course and I don’t intend it to be in any way), but I think when it comes down to S2K posters, we all have our own levels of how active and optimistic we are for a certain season (especially if it has not started yet), and Shell Mound is perhaps one of S2K’s most conservative posters when it comes down to this.

Shell isn't always right. But where I'll credit him unlike certain posters from the past who were borderline trolls, is that he does his research and presents what he thinks might happen. He's not egomaniacal about it which is refreshing. He takes some heat and doesn't tend to fire back. I think he's a good poster who presents a lot of information worth considering. JMO.

I'll second this but he does tend to swing back and forth depending on which model run just came out

[Shell Mound]

The 00Z EPS is starting to hint at TCG in the MDR by mid August. Perhaps this is related to the fact that it shows only weak storms forming in the EPAC.

[Category5Kaiju]

I'd also have to imagine that if the EPAC storms were to remain weaker then that wouldn't really shear the Atlantic side as much? Doesn't strength and proximity to Mexico/CA matter too?

[Deshaunrob17]

The canary current isn’t actually that cool at all. CDAS might be showing that because it’s biased towards cooling with SAL outbreaks making it look cooler then it actually is, thus I would use a different data set such as OISST or Coral Reef

The EPS is shifting toward a much stronger -VP cell over the EPAC through early September, so at this point I think the Atlantic season is going to underperform significantly. The entire month of August is basically going to be dead and early September looks to be far from hospitable for “homegrown” systems, given strong, convectively driven VWS emanating from the EPAC and impinging on the Caribbean. This is significant, because most people here have been expecting “homegrown” development to compensate for a potentially inactive MDR, yet the -VP cell over the EPAC would likely shut down the western part of the basin. Anything that forms there would need to occur along the northern Gulf Coast or off the East Coast, and such a system would be much more likely to be relatively weak than something that forms farther south, i.e., over the western Caribbean.

The composite of all hyperactive-ACE seasons since 1995 has a -VP cell over the EPAC during ASO.

https://i.imgur.com/Ogicc5W_d.webp?maxwidth=640&shape=thumb&fidelity=medium

Earlier today, I was going to post that I remember some Twitter posts last year talking about the -VP in EPAC potentially could cause some negative effects across the Caribbean. This was based from from forecasts from JMA or Euro.

[USTropics]

One of the major issues with using 2013 as an analog is the complete lack of an Atlantic Nino. In fact, the Atlantic equatorial mode remained anomalously cool throughout the Summer months (JJA) and into SON for 2013:


This promotes a sinking cell in the Atlantic (particularly the SATL) and negates rising motion over Africa, weakening the WAM:


In contrast, we've had a vigorous Atlantic Nino beginning in April that has persisted through MJJ:


If seasonal model SSTA forecasts are accurate for SON, we're likely to have what is classified as a persistent Atlantic Nino mode. The warmer waters in the Atlantic equatorial zone promotes rising motion over Africa, and enhances the WAM. We can see this using the analog years that exhibited a persistent Atlantic Nino: