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

[Category5Kaiju]

Yeah to be honest I don’t intend to point fingers at specific people or go on a disagreement storm, but I think simply seeing the sst profile now and assuming that will be the case in ASO (when recent years have shown otherwise and when all other signs point toward an above average season) is too premature. As I have stated earlier, a pattern like this in ASO is quite unlikely imho, and if it were to actually manifest then I would be quite stunned.

[cycloneye]

Does anyone has a 2020 ssta graphic by this time to compare with 2021 at MDR?

https://i.imgur.com/MtxznyN.png

https://i.imgur.com/sJCh3RH.png

Using high-res data from coral reef watch (NOAA) - ftp://ftp.star.nesdis.noaa.gov/pub/sod/mecb/crw/data/5km/v3.1_op/nc/v1.0/daily/ssta

Thank you for the comparison graphics. A little bit cooler MDR and a much warmer subtropical Atlantic in May 2021.

[toad strangler]

SST's are a significant indicator in general so one can't brush off the current signature BUT it's way too early IMO to attach that to what it means to the meat of the season. This current look isn't overly interesting to me given the date but I know that it is the SST handwringers time of year and on deck are the SAL handwringers

[IsabelaWeather]

Oh also, does anyone know if our first tropical wave has formed yet over Africa?

I know things usually start getting toasty around this time.

I believe so, we just had our first easterly wave roll through the Caribbean the other day. Was pretty weak, but there.

[SFLcane]

Weather channel increases there numbers to 19/8/4 With the expectations of the Atlantic warming some in the coming months as the CFS is calling for. The Euro says nope so we shall see

[Blown Away]

Weather channel increases there numbers to 19/8/4 With the expectations of the Atlantic warming some in the coming months as the CFS is calling for. The Euro says nope so we shall see

Cooler MDR will allow those TW's to move farther W before developing and may increase chances of landfalls in Caribbean/CONUS.

[jasons2k]

I see we're talking about SST anomalies in May as if they mean anything again.

I always start looking at the Gulf in May. The cold front intrusions into the Gulf of Mexico usually cease and if the Gulf is already boiling in May, odds are it will be come peak season.

[aspen]

If the exceptionally above-average mid-latitude pattern persists into peak season, there’ll probably be an increased chance of having an active subtropics like 2018 or having rather strong storms above 20N, like Lee ‘17, Lorenzo ‘19, or Epsilon ‘20. A recurving MDR storm could find some very warm waters in the 15-25N range, and going from a lower to a high OHC/SST pocket could cause a phase of significant intensification. Of course, every storm is different and this speculative scenario might not happen depending on what specific recurving tracks are favored.

Regardless, the MDR will be warm enough. It remains to be seen how warm. I think I recall hearing that a cooler MDR compared to the mid-latitudes could increase unfavorable conditions (sinking air, shear, etc) over the MDR. Can someone correct me on this if I’m wrong?

[SFLcane]

Take with a grain of salt but look out Florida and Carolinas in August.

[AutoPenalti]

Take with a grain of salt but look out Florida and Carolinas in August.

https://i.imgur.com/TOZx22w.png

Azores high looks predominantly weaker.

[SFLcane]

Take with a grain of salt but look out Florida and Carolinas in August.

https://i.imgur.com/TOZx22w.png

Azores high looks predominantly weaker.

September also looks like East Coast.

[Shell Mound]

Much more active look then the Euro for sure because it warms the Atlantic. That’s the question mark I see

Although the UKMET is envisioning a somewhat weaker African monsoon than in 2020, it is actually showing more precipitation over the Sahel and the MDR, along with a much drier EPAC, even though the IOD and ENSO are expected to be closer to neutral than Niña. Furthermore, notably, the latest forecast signifies a stronger +AMO than the previous outlook did in 2020. On the latest run the southern half of the Caribbean looks to be roughly as wet as in 2020. Given the drier conditions over the Greater Antilles, along with a warm Gulf of Guinea, this run is likely implying a more active CV season than in 2020, because the weaker African monsoon allows storms to consolidate earlier over a warmer MDR, rather than wait until farther west. The run also seems to imply a -NAO during peak season, hence many OTS tracks and a reduced risk to FL and/or the Eastern Seaboard, as in 2010. Note the absence of abnormally dry conditions over the Great Plains during ASO, hence less of a “ridge-bridge” and a weaker, more suppressed Bermuda High than in 2020. (Incidentally, 2010 also featured a very active MDR and a strong +AMO despite a warm Gulf of Guinea.)

https://i.postimg.cc/7Pg06KWj/2020-UKMET-1.png
https://i.postimg.cc/Z5qdw45h/2021-UKMET-1.png
https://i.postimg.cc/g2Pswm86/FLprecipitation-1.png
https://i.postimg.cc/GhdYsk0t/2020-UKMET-2.png
https://i.postimg.cc/Qxm7gHsb/2021-UKMET-2.png
https://i.postimg.cc/50TtSQ2X/2010-ASOSST-1.png

It seems like you are always downplaying the risk to Florida. Of course it is possible if not likely South Florida will avoid a big hit again, but NOAA stresses every year in their preseason outlooks that you cannot predict which areas will be affected (or safe) months in advance.

Actually, in this case I am implying a reduced risk to the entire U.S. East Coast as well as peninsular Florida. The fact that the MDR is currently cooler than the subtropics as well as the global tropics implies that more sinking air, a strongly suppressive factor, will be present over the MDR. Sinking air also tends to indicate a stronger and/or more persistent TUTT, resulting in increased VWS as well as more OTS tracks due to the TUTT inducing weaknesses in the subtropical ridge (Bermuda–Azores High). Note that the ECMWF shows a pronounced TUTT over the central Atlantic, with the ridge displaced well to the north, during August and September, which would encourage more OTS tracks as well. Also, the neutral IOD and warmer Gulf of Guinea would support a weaker African monsoon than we have seen in recent seasons. Given current trends I think the forecasts that call for a very/hyperactive season, notably CSU’s, are increasingly unlikely to verify. ≥ 150 ACE and ≥ four majors? Unlikely.

As an aside, the following is quite interesting:

 https://twitter.com/AndyHazelton/status/1392486699830231043

[Category5Kaiju]

 https://twitter.com/philklotzbach/status/1392860160796856325




Btw here's a recent tweet from Klotzbach that I find quite interesting. The chances of El Nino this season is very low, and La Nina (at least according to this prediction chart) could end up resurging in the fall/winter. I personally do not think the ENSO state will disfavor Atlantic activity, although things can change of course.

[DorkyMcDorkface]

 https://twitter.com/webberweather/status/1392876883130216450

[NotSparta]

Although the UKMET is envisioning a somewhat weaker African monsoon than in 2020, it is actually showing more precipitation over the Sahel and the MDR, along with a much drier EPAC, even though the IOD and ENSO are expected to be closer to neutral than Niña. Furthermore, notably, the latest forecast signifies a stronger +AMO than the previous outlook did in 2020. On the latest run the southern half of the Caribbean looks to be roughly as wet as in 2020. Given the drier conditions over the Greater Antilles, along with a warm Gulf of Guinea, this run is likely implying a more active CV season than in 2020, because the weaker African monsoon allows storms to consolidate earlier over a warmer MDR, rather than wait until farther west. The run also seems to imply a -NAO during peak season, hence many OTS tracks and a reduced risk to FL and/or the Eastern Seaboard, as in 2010. Note the absence of abnormally dry conditions over the Great Plains during ASO, hence less of a “ridge-bridge” and a weaker, more suppressed Bermuda High than in 2020. (Incidentally, 2010 also featured a very active MDR and a strong +AMO despite a warm Gulf of Guinea.)

https://i.postimg.cc/7Pg06KWj/2020-UKMET-1.png
https://i.postimg.cc/Z5qdw45h/2021-UKMET-1.png
https://i.postimg.cc/g2Pswm86/FLprecipitation-1.png
https://i.postimg.cc/GhdYsk0t/2020-UKMET-2.png
https://i.postimg.cc/Qxm7gHsb/2021-UKMET-2.png
https://i.postimg.cc/50TtSQ2X/2010-ASOSST-1.png

It seems like you are always downplaying the risk to Florida. Of course it is possible if not likely South Florida will avoid a big hit again, but NOAA stresses every year in their preseason outlooks that you cannot predict which areas will be affected (or safe) months in advance.

Actually, in this case I am implying a reduced risk to the entire U.S. East Coast as well as peninsular Florida. The fact that the MDR is currently cooler than the subtropics as well as the global tropics implies that more sinking air, a strongly suppressive factor, will be present over the MDR. Sinking air also tends to indicate a stronger and/or more persistent TUTT, resulting in increased VWS as well as more OTS tracks due to the TUTT inducing weaknesses in the subtropical ridge (Bermuda–Azores High). Note that the ECMWF shows a pronounced TUTT over the central Atlantic, with the ridge displaced well to the north, during August and September, which would encourage more OTS tracks as well. Also, the neutral IOD and warmer Gulf of Guinea would support a weaker African monsoon than we have seen in recent seasons. Given current trends I think the forecasts that call for a very/hyperactive season, notably CSU’s, are increasingly unlikely to verify. ≥ 150 ACE and ≥ four majors? Unlikely.

As an aside, the following is quite interesting:

https://twitter.com/AndyHazelton/status/1392486699830231043

I mean, when's the last time a cold MDR signature like this has stuck around? I'm expecting some reversal by ASO as has happened for years now, just not sure how much. You very well may be right but I'm not so confident things will stick around where they are

[Category5Kaiju]

https://twitter.com/webberweather/status/1392876883130216450

 https://twitter.com/DylanFedericoWX/status/1392885296417624065




I remember this composite tweet Eric showed last year and...

[SFLcane]

https://twitter.com/webberweather/status/1392876883130216450

KABOOM! That should wake up everyone on this forum. What an active look across the Atlantic.

[Category5Kaiju]

It seems like you are always downplaying the risk to Florida. Of course it is possible if not likely South Florida will avoid a big hit again, but NOAA stresses every year in their preseason outlooks that you cannot predict which areas will be affected (or safe) months in advance.

Actually, in this case I am implying a reduced risk to the entire U.S. East Coast as well as peninsular Florida. The fact that the MDR is currently cooler than the subtropics as well as the global tropics implies that more sinking air, a strongly suppressive factor, will be present over the MDR. Sinking air also tends to indicate a stronger and/or more persistent TUTT, resulting in increased VWS as well as more OTS tracks due to the TUTT inducing weaknesses in the subtropical ridge (Bermuda–Azores High). Note that the ECMWF shows a pronounced TUTT over the central Atlantic, with the ridge displaced well to the north, during August and September, which would encourage more OTS tracks as well. Also, the neutral IOD and warmer Gulf of Guinea would support a weaker African monsoon than we have seen in recent seasons. Given current trends I think the forecasts that call for a very/hyperactive season, notably CSU’s, are increasingly unlikely to verify. ≥ 150 ACE and ≥ four majors? Unlikely.

As an aside, the following is quite interesting:

https://twitter.com/AndyHazelton/status/1392486699830231043

I mean, when's the last time a cold MDR signature like this has stuck around? I'm expecting some reversal by ASO as has happened for years now, just not sure how much. You very well may be right but I'm not so confident things will stick around where they are

I believe 2014? Of course, that was an El Nino year, although I really cannot think of a recent cool neutral or La Nina year that had a cool MDR in the hurricane season's heart. Maybe 2007 is one exception, although beyond that idk entirely

[Iceresistance]

Actually, in this case I am implying a reduced risk to the entire U.S. East Coast as well as peninsular Florida. The fact that the MDR is currently cooler than the subtropics as well as the global tropics implies that more sinking air, a strongly suppressive factor, will be present over the MDR. Sinking air also tends to indicate a stronger and/or more persistent TUTT, resulting in increased VWS as well as more OTS tracks due to the TUTT inducing weaknesses in the subtropical ridge (Bermuda–Azores High). Note that the ECMWF shows a pronounced TUTT over the central Atlantic, with the ridge displaced well to the north, during August and September, which would encourage more OTS tracks as well. Also, the neutral IOD and warmer Gulf of Guinea would support a weaker African monsoon than we have seen in recent seasons. Given current trends I think the forecasts that call for a very/hyperactive season, notably CSU’s, are increasingly unlikely to verify. ≥ 150 ACE and ≥ four majors? Unlikely.

As an aside, the following is quite interesting:

https://twitter.com/AndyHazelton/status/1392486699830231043

I mean, when's the last time a cold MDR signature like this has stuck around? I'm expecting some reversal by ASO as has happened for years now, just not sure how much. You very well may be right but I'm not so confident things will stick around where they are

I believe 2014? Of course, that was an El Nino year, although I really cannot think of a recent cool neutral or La Nina year that had a cool MDR in the hurricane season's heart. Maybe 2007 is one exception, although beyond that idk entirely

2002 was also an El Nino year, but was near average . . .

[Category5Kaiju]

 https://twitter.com/webberweather/status/1392914442677936128




Here's the outlook for wind shear in ASO as posted by Eric Webb. Looks like the Bahamas and Eastern Florida may need to watch out