2020 Indicators: SST's / SAL / MSLP / Steering / Shear / Instability / Sat Images

[ScottNAtlanta]

[url]https://twitter.com/BenNollWeather/status/1262046467658616833url]

Comparing this June setup to past active years, 1995 and 2005 had similar setups with no dominant rising motion over the MC. But in July they did. The July forecast will be important in gauging how active this season will be.

In 2005 we had Emily in July as the earliest Cat 5 in recorded history that formed in the MDR and sailed across the CS (I still say the name should have been retired that year)

[NotSparta]

New imagery from NOAA:

https://i.postimg.cc/qMHSkLP3/ct5km-ssta-v3-1-global-20200516.png

The yellow colorbars are a bit deceptive most of the mdr is basically near average right now.

https://i.imgur.com/AZZiYBi.jpg

Yeah the main difference here is the anomaly period, original is 1985-1993 (not including 1991-1992) which horribly biases it for +AMO conditions, while this one is 1981-2010 climo, which is a lot more neutral

[NDG]

The Caribbean over all has been seeing below average shear and below average surface divergence during the past few weeks, with the monsoonal trough forecasted to move in I would not be surprised to see development in the NW Caribbean/southern GOM in early June.

[USTropics]

Some more of Ben Nolls custom graphics he creates:

 https://twitter.com/BenNollWeather/status/1263122054938845190

[CyclonicFury]

Some more of Ben Nolls custom graphics he creates:

https://twitter.com/BenNollWeather/status/1263122054938845190

That doesn't look like reduced low-level winds over the Atlantic MDR and Caribbean. It appears to be an easterly 850hPa zonal wind anomaly, which means stronger than normal trade winds.

[USTropics]

Some more of Ben Nolls custom graphics he creates:

https://twitter.com/BenNollWeather/status/1263122054938845190

That doesn't look like reduced low-level winds over the Atlantic MDR and Caribbean. It appears to be an easterly 850hPa zonal wind anomaly, which means stronger than normal trade winds.

Agreed, ECMWF/UKMET blend showing slightly enhanced trade winds near peak season. I think he was just referring to the transition from May-July though (where trade winds look to decrease near the end of May/beginning of June). Long term, that type of zonal wind pattern at the low-levels would limit MDR activity (and likely why the ECMWF/UKMET seasonal forecasts are below other models). Interestingly, CFS/CANSIPS/NMME show a more favorable 850mb zonal pattern at peak season:

[USTropics]

For those wondering what they're looking at, here are two composites of what active and nonactive anomalies look like for 850mb zonal wind patterns for JAS:

Top 12 active ACE years


Bottom 12 nonactive ACE years

[Shell Mound]

Some more of Ben Nolls custom graphics he creates:

https://twitter.com/BenNollWeather/status/1263122054938845190

That doesn't look like reduced low-level winds over the Atlantic MDR and Caribbean. It appears to be an easterly 850hPa zonal wind anomaly, which means stronger than normal trade winds.

Agreed, ECMWF/UKMET blend showing slightly enhanced trade winds near peak season. I think he was just referring to the transition from May-July though (where trade winds look to decrease near the end of May/beginning of June). Long term, that type of zonal wind pattern at the low-levels would limit MDR activity (and likely why the ECMWF/UKMET seasonal forecasts are below other models). Interestingly, CFS/CANSIPS/NMME show a more favorable 850mb zonal pattern at peak season:

https://i.imgur.com/X2zek18.png
https://i.imgur.com/YTPQ7xc.png

The CFS/CANSIPS/NMME also seem to be showing a more favourable steering regime for U.S. landfalls than the UKMET/ECMWF. While the former are better at forecasting precipitation in the long range, the latter are more reliable in terms of steering. Even the former show most of the enhanced TC activity remaining east of the Gulf and FL during ASO, while the latter suggest most TC activity will either remain OTS or head toward Central America. So there are some early indicators that the U.S. will see few CV threats during peak season. Maybe October will produce a Caribbean threat.

[TheStormExpert]

That doesn't look like reduced low-level winds over the Atlantic MDR and Caribbean. It appears to be an easterly 850hPa zonal wind anomaly, which means stronger than normal trade winds.

Agreed, ECMWF/UKMET blend showing slightly enhanced trade winds near peak season. I think he was just referring to the transition from May-July though (where trade winds look to decrease near the end of May/beginning of June). Long term, that type of zonal wind pattern at the low-levels would limit MDR activity (and likely why the ECMWF/UKMET seasonal forecasts are below other models). Interestingly, CFS/CANSIPS/NMME show a more favorable 850mb zonal pattern at peak season:

https://i.imgur.com/X2zek18.png
https://i.imgur.com/YTPQ7xc.png

The CFS/CANSIPS/NMME also seem to be showing a more favourable steering regime for U.S. landfalls than the UKMET/ECMWF. While the former are better at forecasting precipitation in the long range, the latter are more reliable in terms of steering. Even the former show most of the enhanced TC activity remaining east of the Gulf and FL during ASO, while the latter suggest most TC activity will either remain OTS or head toward Central America. So there are some early indicators that the U.S. will see few CV threats during peak season. Maybe October will produce a Caribbean threat.

Yeah but if development gets delayed until further west due to the not so favorable state of the SST’s in the Tropical Atlantic then these storms may not be able to turn quickly enough without striking land. Also if the Caribbean, especially the Western Caribbean is favorable then storms can move north or northeast from there towards the Gulf Coast. I’m personally not betting on anything more than a slightly above-above average Atlantic Hurricane Season despite the state of the ENSO.

[SFLcane]

Some more of Ben Nolls custom graphics he creates:

https://twitter.com/BenNollWeather/status/1263122054938845190

That doesn't look like reduced low-level winds over the Atlantic MDR and Caribbean. It appears to be an easterly 850hPa zonal wind anomaly, which means stronger than normal trade winds.

Agreed, ECMWF/UKMET blend showing slightly enhanced trade winds near peak season. I think he was just referring to the transition from May-July though (where trade winds look to decrease near the end of May/beginning of June). Long term, that type of zonal wind pattern at the low-levels would limit MDR activity (and likely why the ECMWF/UKMET seasonal forecasts are below other models). Interestingly, CFS/CANSIPS/NMME show a more favorable 850mb zonal pattern at peak season:

https://i.imgur.com/X2zek18.png
https://i.imgur.com/YTPQ7xc.png

Yeah that's the big difference. ECMWF and UKMET are good models If they agree on something like that it's worth noting.

[jconsor]

 https://twitter.com/yconsor/status/1263203468682178567

[drezee]

https://twitter.com/yconsor/status/1263203468682178567

I think we all need to be really prepared this year. All indications are the possibilities are there and more likely than normal

[TheStormExpert]

What do you guys think of 2007 as a potential analog season? In my opinion just going off the more reliable models ECMWF and UKMET with their seasonal outlooks it wouldn’t be too unrealistic. It too was slightly above average in terms of numbers but below average with ACE.

[aspen]

What do you guys think of 2007 as a potential analog season? In my opinion just going off the more reliable models ECMWF and UKMET with their seasonal outlooks it wouldn’t be too unrealistic. It too was slightly above average in terms of numbers but below average with ACE.

Perhaps we could see something like that, where the season is dominated by a few really strong Caribbean systems and just about everything else is weak. However, given the current setup (cool neutral ENSO + decent MDR + high tropical moisture + chance of enhanced early season activity), I think 2020 is likely to be above-average in terms of both named storms and ACE, either similar to 2018/19 or something closer to 2017.

[SFLcane]

https://twitter.com/yconsor/status/1263203468682178567

Yeah, CFS is all in. UK/EC not so much.

[cycloneye]

https://twitter.com/yconsor/status/1263203468682178567

Yeah, CFS is all in. UK/EC not so much.

The big question is which one(s) are right.

[TheStormExpert]

What do you guys think of 2007 as a potential analog season? In my opinion just going off the more reliable models ECMWF and UKMET with their seasonal outlooks it wouldn’t be too unrealistic. It too was slightly above average in terms of numbers but below average with ACE.

Perhaps we could see something like that, where the season is dominated by a few really strong Caribbean systems and just about everything else is weak. However, given the current setup (cool neutral ENSO + decent MDR + high tropical moisture + chance of enhanced early season activity), I think 2020 is likely to be above-average in terms of both named storms and ACE, either similar to 2018/19 or something closer to 2017.

A year like 2017 seems very unlikely with the state of the Atlantic SST configuration. A year like 2018/2019 seems more likely with somewhat similar ACE, give or take.

[TheStormExpert]

https://twitter.com/yconsor/status/1263203468682178567

Yeah, CFS is all in. UK/EC not so much.

The big question is which one(s) are right.

The CFS is way too bullish in my opinion.

[Kingarabian]

The CFS's solution is more realistic to me. When looking at forecasts, we also have to look at present conditions. Clue's on what's actually occurring. The CFS has done a remarkable job in correctly predicting the ocean transitioning towards a possible La Nina. Much better than the Euro. An atmospheric response is lagging, but there's a large and strong trade burst in the far western Pacific that will likely warm the waters near the IPWP/MC which will likely promote increased convection there and trigger the missing La Nina standing wave. It's a process. Some active years I believe in 1995 and 2017, also had little rising motion near the MC during June, but switched in July.

[aspen]

What do you guys think of 2007 as a potential analog season? In my opinion just going off the more reliable models ECMWF and UKMET with their seasonal outlooks it wouldn’t be too unrealistic. It too was slightly above average in terms of numbers but below average with ACE.

Perhaps we could see something like that, where the season is dominated by a few really strong Caribbean systems and just about everything else is weak. However, given the current setup (cool neutral ENSO + decent MDR + high tropical moisture + chance of enhanced early season activity), I think 2020 is likely to be above-average in terms of both named storms and ACE, either similar to 2018/19 or something closer to 2017.

A year like 2017 seems very unlikely with the state of the Atlantic SST configuration. A year like 2018/2019 seems more likely with somewhat similar ACE, give or take.

I’m thinking it’ll be somewhere between 2018/19 and 2017 — more active than the former, but not reaching the crazy hyperactive levels of the latter, with a total ACE between 130 and 170 units. There are plenty of things going for yet another above-average season, but there are several ways it falls short of being ripe for something with 200+ ACE and six or seven major hurricanes.