2023 Indicators (SST, SAL, MSLP, Wind shear, Steering, Instability) and Day 16+ Models

[cycloneye]

One week from today the bell rings and we will begin to see things pop.

Dr William Gray's traditional ringing.

[Ntxw]

If we want to see activity pick up in the Atlantic (theoretically lets say hyperactive) the tropical forcing needs to be pulled back to the maritime continent (120E Indonesia vicinity.) Even at a sub seasonal scale the Atlantic becomes active for periods of time when forcing flares up over the MC. Obviously on a seasonal scale the El Nino isn't going to give in to that since it continuously pulls the forcing out into the Pacific as evident with OLR being a fairly significant one.

For example in 2017 with the 'failed' nino attempt forcing pulled back into the MC.



2018 was a unique case that tropical forcing was split between Pacific and Africa. That's not been happening right now with a stronger ENSO event focusing the Pacific.



In short I wouldn't believe the guidance modeled entities until there is a change in the tropical forcing (maybe passage of MJO) over the IO-MC, even for a short movement would do the trick.

[LarryWx]

I've never believed the hyperactive 2023 forecasts. One can look at my 2023 contest entry to see evidence of that. But that doesn't at all mean I'm expecting a repeat of last August's lack of TCGs either. There is such a thing as in between the extremes for August, which is where I remain. I earlier forecasted 3 TCs this month in the August contest largely based on past El Niños and I'm currently at 2-3, a far cry from the 0 of last August.

[Ianswfl]

I've never believed the hyperactive 2023 forecasts. One can look at my 2023 contest entry to see evidence of that. But that doesn't at all mean I'm expecting a repeat of last August's lack of TCGs either. There is such a thing as in between the extremes for August, which is where I remain. I earlier forecasted 3 TCs this month in the August contest largely based on past El Niños and I'm currently at 2-3, a far cry from the 0 of last August.

This inactive aug isn't due to el nino. Dry air like last year. Waters are hot but less rainfall allowing waters to heat. Joe Bastardi talked about this in a tweet too. When the pressures lower and atmosphere cools down storms will come. Explains why aug are becoming slower. Waiting longer for peak.

[chaser1]

I've never believed the hyperactive 2023 forecasts. One can look at my 2023 contest entry to see evidence of that. But that doesn't at all mean I'm expecting a repeat of last August's lack of TCGs either. There is such a thing as in between the extremes for August, which is where I remain. I earlier forecasted 3 TCs this month in the August contest largely based on past El Niños and I'm currently at 2-3, a far cry from the 0 of last August.

Agreed; if simply ignoring El Nino discussion for the time being, present 300mb-700mb conditions from about 30W to 70W are dry dry dry. I'm sure that we'll see the tropics moisten up in time as the GFS is suggesting however there is little to suggest any rationale that broad scale upper-level conditions or dry air will largely change to an extent that we'll suddenly see a flurry of tropical cyclone development. That could change in the Eastern MDR toward end of month with increasingly potent waves emerging off the African coastline. My guess is that we may eventually see fairly quick development however weak mid-level ridging might have us see a series of fast poleward "recurvers" long before most E. MDR systems pose much threat. The whole idea regarding "hyperactive" however becomes increasingly questionable if one were to assume that even a moderate increase of El Nino induced upper-level winds might begin to impinge on Atlantic development by some point during September. I'm sure there will be pockets of favorability for genesis and high SST's might surely add fuel to quicker intensification, but I think that the window for "hyper" in terms of number of named storms has got to become increasingly smaller as time moves forward.

[ElectricStorm]

I've never believed the hyperactive 2023 forecasts. One can look at my 2023 contest entry to see evidence of that. But that doesn't at all mean I'm expecting a repeat of last August's lack of TCGs either. There is such a thing as in between the extremes for August, which is where I remain. I earlier forecasted 3 TCs this month in the August contest largely based on past El Niños and I'm currently at 2-3, a far cry from the 0 of last August.

Yeah I voted for 3 August NS. Not sure if we'll get that but I would think we'll at least get a couple after 8/20

[LarryWx]

I've never believed the hyperactive 2023 forecasts. One can look at my 2023 contest entry to see evidence of that. But that doesn't at all mean I'm expecting a repeat of last August's lack of TCGs either. There is such a thing as in between the extremes for August, which is where I remain. I earlier forecasted 3 TCs this month in the August contest largely based on past El Niños and I'm currently at 2-3, a far cry from the 0 of last August.

This inactive aug isn't due to el nino. Dry air like last year. Waters are hot but less rainfall allowing waters to heat. Joe Bastardi talked about this in a tweet too. When the pressures lower and atmosphere cools down storms will come. Explains why aug are becoming slower. Waiting longer for peak.

1. This August is only 13 days old with the climo most active part still yet to come. So, we don't yet know whether or not it will end up slow.

2. Here are # of August 16-31 TCGs that became NS when no August 1-15 TCG that became NS since 1995: 5 active, 2 quiet. So, we'll see about how the entire month ends up:

-1996: 4
-1997: 0
-1998: 4
-1999: 4
-2015: 3
-2019: 3
-2022: 0

3. I see no slower trend in August activity as per the following. One year (2022) doesn't make a trend:

# of TCG in August for TC that later became NS:
2022: 0
2021: 7
2020: 5
2019: 3
2018: 3
2017: 4
2016: 4
2015: 3
2014: 2
2013: 2
2012: 8
2011: 7
2010: 4
2009: 4
2008: 4
2007: 3
2006: 3
2005: 5
2004: 7
2003: 3
2002: 3
2001: 3
2000: 4
1999: 4
1998: 4
1997: 0
1996: 4
1995: 7

[Teban54]

Before the season started, I was thinking we’d see something similar to 2018. Now it seems like I was right. I’m getting serious 2018 vibes from this season in both the Atl and EPac so far: a high-quality EPac with a triple basin crosser (Hector ‘18 and Dora ‘23), unusually early and substantial MDR systems (Beryl ‘18 and Bret ‘23), decent levels of subtropics activity (most of early 2018; unnamed and Don ‘23), and a potentially lackluster August except for at the very end (2018 didn’t kick off until Florence formed like on the last day of August). I think many of the latest forecasts will bust high like they did last year, but we could see a rather late switch flip like 2018, and I expect the Caribbean to be as dead as that year with the El Niño and the EPac’s high activity.

2018 had Cat 1 Michael in the Western Caribbean proper.

[aspen]

Before the season started, I was thinking we’d see something similar to 2018. Now it seems like I was right. I’m getting serious 2018 vibes from this season in both the Atl and EPac so far: a high-quality EPac with a triple basin crosser (Hector ‘18 and Dora ‘23), unusually early and substantial MDR systems (Beryl ‘18 and Bret ‘23), decent levels of subtropics activity (most of early 2018; unnamed and Don ‘23), and a potentially lackluster August except for at the very end (2018 didn’t kick off until Florence formed like on the last day of August). I think many of the latest forecasts will bust high like they did last year, but we could see a rather late switch flip like 2018, and I expect the Caribbean to be as dead as that year with the El Niño and the EPac’s high activity.

2018 had Cat 1 Michael in the Western Caribbean proper.

Oh right, I forgot Michael was technically a WCar hurricane. But I’m doubtful we’ll see a significant WCar system this year. Michael shows it’s definitely possible for a +ENSO year, but far from guaranteed.

[cycloneye]

Dr Levi Cowan. Here is his whole tweet.

As we enter the peak weeks of the Atlantic hurricane season, it will be interesting to see where genesis events are produced. Sometimes, El Nino's suppressive influence on the Caribbean leads to a northward shift in the favorable zone.

In a year when the Gulf of Mexico + west Atlantic warm pool is much warmer than normal, patterns such as this one in Week 2 ensemble forecasts can increase risks for genesis close to North America. Strong anticyclonic wave breaking at 200mb can lead to low to mid-level vorticity perturbations (such as from weak frontal boundaries or cutoff lows) being injected south of 30N, where warm water and deep moisture can lead to so-called "homegrown" TC genesis. Sometimes African easterly waves arrive from the east as an additional source of vorticity and moisture.

The plots of 200mb and 850mb zonal wind anomaly from the ECMWF ensemble below show an overlap of anticyclonic wave breaking over anomalous vorticity at the surface across the western Atlantic and Gulf of Mexico, which will be something to keep an eye on in late August.

 https://twitter.com/TropicalTidbits/status/1690795984283127808

[LarryWx]

The 00Z CFS long-range CFS through Sept 14th has just two storms, one last week of this month and a stronger one around Labor Day, both recurve well east of the Lesser Antilles. Nothing in the Gulf or Caribbean:

https://www.pivotalweather.com/model.ph ... -met&m=cfs

The 12Z CFS is similarly quiet through 9/14 with at most 2 NS and not too much threatening the western basin. About the only literal threat is a TD hitting S TX 8/24. But it is an inferior model and it is looking out way beyond the time limit for the semi-reliable timeframe.

[Spacecoast]

Today's weekly extended range: Three possible (~20% prob) TS's for the last week of August:




Week 4 (9/4-9/11) has similar curve patterns.

[Ianswfl]

I've never believed the hyperactive 2023 forecasts. One can look at my 2023 contest entry to see evidence of that. But that doesn't at all mean I'm expecting a repeat of last August's lack of TCGs either. There is such a thing as in between the extremes for August, which is where I remain. I earlier forecasted 3 TCs this month in the August contest largely based on past El Niños and I'm currently at 2-3, a far cry from the 0 of last August.

This inactive aug isn't due to el nino. Dry air like last year. Waters are hot but less rainfall allowing waters to heat. Joe Bastardi talked about this in a tweet too. When the pressures lower and atmosphere cools down storms will come. Explains why aug are becoming slower. Waiting longer for peak.

1. This August is only 13 days old with the climo most active part still yet to come. So, we don't yet know whether or not it will end up slow.

2. Here are # of August 16-31 TCGs that became NS when no August 1-15 TCG that became NS since 1995: 5 active, 2 quiet. So, we'll see about how the entire month ends up:

-1996: 4
-1997: 0
-1998: 4
-1999: 4
-2015: 3
-2019: 3
-2022: 0

3. I see no slower trend in August activity as per the following. One year (2022) doesn't make a trend:

# of TCG in August for TC that later became NS:
2022: 0
2021: 7
2020: 5
2019: 3
2018: 3
2017: 4
2016: 4
2015: 3
2014: 2
2013: 2
2012: 8
2011: 7
2010: 4
2009: 4
2008: 4
2007: 3
2006: 3
2005: 5
2004: 7
2003: 3
2002: 3
2001: 3
2000: 4
1999: 4
1998: 4
1997: 0
1996: 4
1995: 7

This years slow July and August isn't due to El Nino. This is a dry air issue just like last year. The deserts over Africa growing is one of the factors in more dust too. While the Atl gets warmer due to less rainfall the air is drier and warmer waters could be pushing the meat of the season back a couple weeks as Mark Suddith has mentioned.

Heck, the East pacific at this time last year had 2 more storms already and that wasn't a El Nino year. The dry air could explain why the epac maybe slightly less active than last year too. Less robust waves making it into the EPAC to develop.

[Hurricane2022]

In January 2023: Let's wait until March/April to get a sense of what might happen. El Nino may occur in the peak season, leading to a slower 2023 in the atlantic

In April: Let's wait for May/June to see what happens, things still aren't aligned here for an good prediction about the season, since we have an warm atlantic but also warm pacific... But the El Nino conditions will likely win

In June: Let's wait a little longer... There's still an significant uncertainity about what can happen in August/September, since the El Nino still on the way but the Atlantic still warming even more!

August: why we're still trying to predict this?

looks accurate

[Teban54]

 https://twitter.com/AndyHazelton/status/1691191065112461312

[Teban54]

While still drier than EPac, the Atlantic isn't nearly as dry as it was a few days ago:

[cycloneye]

Webb see's a chance for GOM development like a Hanna type.

 https://twitter.com/webberweather/status/1691432661779365888

[jconsor]

I am skeptical of the idea that the main period of favorability for Atlantic TC development will be compressed into a week to 10 day period at the end of Aug/very beginning of Sep like some extended guidance is hinting at. Overall, there are indications of a more active than usual September. I explain why in the thread below:

 https://twitter.com/yconsor/status/1691422330625363969




 https://twitter.com/yconsor/status/1691426597725732864




 https://twitter.com/yconsor/status/1691474694476627968




 https://twitter.com/yconsor/status/1691478531891408896

[SFLcane]

 https://twitter.com/TropicalTidbits/status/1691481185783091201

[Teban54]

Webb see's a chance for GOM development like a Hanna type.

https://twitter.com/webberweather/status/1691432661779365888

Very ominous #Throwback tweet mentioned by Webb:
 https://twitter.com/webberweather/status/1286520353632718849