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

[JetFuel_SE]

Using the same data and thresholds as my last post compared to major hurricanes, hurricanes, and named storms:

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

Interesting that dead neutral has a lower ACE than warm neutral, but I'd guess that may be a result of a small sample size.

That's exactly the reason, dead neutral (exactly 0) only has a sample size of 3 years whereas warm neutral has a sample of 10 years. Here is the exact breakdown for 1950 - 2019.

Code: Select all

Year   ACE   MH   H   NS   ONI
1959   77.11   2   7   11   Cold Neutral
1961   205.40   7   8   11   Cold Neutral
1962   35.57   1   3   5   Cold Neutral
1967   121.71   1   6   8   Cold Neutral
1981   100.33   3   7   12   Cold Neutral
1983   17.40   1   3   4   Cold Neutral
1984   84.30   1   5   13   Cold Neutral
1989   135.13   2   7   11   Cold Neutral
1996   166.18   6   9   13   Cold Neutral
2001   110.32   4   9   15   Cold Neutral
2005   250.13   7   15   28   Cold Neutral
2008   145.72   5   8   16   Cold Neutral
2017   224.88   6   10   17   Cold Neutral
1951   126.33   5   8   10   Moderate El Nino
1953   98.51   4   6   14   Moderate El Nino
2002   67.99   2   4   12   Moderate El Nino
1954   110.88   2   8   11   Moderate La Nina
1955   158.17   6   9   12   Moderate La Nina
1964   169.77   6   6   12   Moderate La Nina
1970   40.18   2   5   10   Moderate La Nina
1971   96.53   1   6   13   Moderate La Nina
2007   73.89   2   6   15   Moderate La Nina
2011   126.30   4   7   19   Moderate La Nina
1952   69.08   3   6   7   Neutral
1980   148.94   2   9   11   Neutral
2014   66.73   2   6   8   Neutral
1957   78.66   2   3   8   Strong El Nino
1963   117.93   2   7   9   Strong El Nino
1965   84.33   1   4   6   Strong El Nino
1972   35.61   0   3   7   Strong El Nino
1982   31.50   1   2   6   Strong El Nino
1987   34.36   1   3   7   Strong El Nino
1997   40.93   1   3   8   Strong El Nino
2015   62.69   2   4   11   Strong El Nino
1973   47.85   1   4   8   Strong La Nina
1975   76.06   3   6   9   Strong La Nina
1988   102.99   3   5   12   Strong La Nina
1998   181.77   3   10   14   Strong La Nina
1999   176.53   5   8   12   Strong La Nina
2010   165.48   5   12   19   Strong La Nina
1960   72.90   2   4   7   Warm Neutral
1966   145.22   3   7   11   Warm Neutral
1979   92.92   2   5   9   Warm Neutral
1992   76.22   1   4   7   Warm Neutral
1993   38.67   1   4   8   Warm Neutral
2003   176.84   3   7   16   Warm Neutral
2006   78.54   2   5   10   Warm Neutral
2012   132.63   2   10   19   Warm Neutral
2018   132.58   2   8   15   Warm Neutral
2019   132.20   3   6   18   Warm Neutral
1958   109.69   5   7   10   Weak El Nino
1968   45.07   0   4   8   Weak El Nino
1969   165.74   5   12   18   Weak El Nino
1976   84.17   2   6   10   Weak El Nino
1977   25.32   1   5   6   Weak El Nino
1986   35.79   0   4   6   Weak El Nino
1990   96.80   1   8   14   Weak El Nino
1991   35.54   2   4   8   Weak El Nino
1994   32.02   0   3   7   Weak El Nino
2004   226.88   6   9   15   Weak El Nino
2009   52.58   2   3   9   Weak El Nino
1950   211.28   8   11   13   Weak La Nina
1956   56.67   2   4   8   Weak La Nina
1974   68.13   2   4   11   Weak La Nina
1978   63.22   2   5   12   Weak La Nina
1985   87.98   3   7   11   Weak La Nina
1995   227.10   5   11   19   Weak La Nina
2000   119.14   3   8   15   Weak La Nina
2013   36.12   0   2   14   Weak La Nina
2016   141.25   4   7   15   Weak La Nina


That's why I think it's a better idea to have a range for "dead neutral" so something like -0.1 to +0.1

[SFLcane]

Just keeps coming...

 https://twitter.com/MJVentrice/status/1256593223142854662

[SFLcane]

 https://twitter.com/BenNollWeather/status/1256603099906535425

[aspen]

How does enhanced convection/a standing wave in the Indian Ocean help increase activity in the Atlantic? Does it make tropical waves more vigorous or frequent?

Also, does that bit of suppressed convection in CanSIPS data over the Caribbean and Gulf even matter in the long run, or could it help keep somewhat of a lid on activity in those regions?

[USTropics]

How does enhanced convection/a standing wave in the Indian Ocean help increase activity in the Atlantic? Does it make tropical waves more vigorous or frequent?

Also, does that bit of suppressed convection in CanSIPS data over the Caribbean and Gulf even matter in the long run, or could it help keep somewhat of a lid on activity in those regions?

You're on the right track. African easterly waves (AEWs, or tropical waves) originate as mesoscale convective systems (MCSs) in far eastern/central Africa and then traverse westward towards the Atlantic. So when you have enhanced 200mb vorticity potential over this region, you're essentially stating you have enhanced convection. This favors a higher frequency in MCS development. These AEWs also essentially act as pouches to stave off marginal conditions until the entity reaches more favorable conditions (i.e. somewhere in the Atlantic). Enhanced AEWs from favorable 200mb vorticity potential allows for a better chance of survival until optimal conditions can be met.

If this forecast were to verify, the suppressed area over the Caribbean/GOM is negligible if the AEW has already developed into a tropical entity, where localized conditions become more of an influence. In fact, this is seen in composites of hyperactive years. I've created 200mb velocity potential composites for 14 hyperactive seasons (using ACE values) and 14 below normal seasons to compare to.

hyperactive seasons


below normal seasons

[cycloneye]

To followup on how is the MDR doing here is the latest. The cooling continues on May 3 in the Tropical Atlantic as the waters are getting colder and falling like a rock per data. I only post the data and not do analysis about what is going on. I let that to others like members USTropics and DorkyMcDorkface and others that have posted good information.

[aspen]

To followup on how is the MDR doing here is the latest. The cooling continues on May 3 in the Tropical Atlantic as the waters are getting colder and falling like a rock per data. I only post the data and not do analysis about what is going on. I let that to others like members USTropics and DorkyMcDorkface and others that have posted good information.

https://i.imgur.com/PSuB5n0.png

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

The MDR is probably going to still be warm enough by ASO, but if it does end up slightly cooler, could that delay AEWs developing into TCs until they get closer to the Caribbean?

[cycloneye]

To followup on how is the MDR doing here is the latest. The cooling continues on May 3 in the Tropical Atlantic as the waters are getting colder and falling like a rock per data. I only post the data and not do analysis about what is going on. I let that to others like members USTropics and DorkyMcDorkface and others that have posted good information.

https://i.imgur.com/PSuB5n0.png

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

The MDR is probably going to still be warm enough by ASO, but if it does end up slightly cooler, could that delay AEWs developing into TCs until they get closer to the Caribbean?

Yes. After 50W and westward, normally waters are more warm.

[toad strangler]

To followup on how is the MDR doing here is the latest. The cooling continues on May 3 in the Tropical Atlantic as the waters are getting colder and falling like a rock per data. I only post the data and not do analysis about what is going on. I let that to others like members USTropics and DorkyMcDorkface and others that have posted good information.

https://i.imgur.com/PSuB5n0.png

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

The MDR is probably going to still be warm enough by ASO, but if it does end up slightly cooler, could that delay AEWs developing into TCs until they get closer to the Caribbean?

Yes. After 50W and westward, normally waters are more warm.

As previously stated here in one form or another, those cooler SST's in the MDR could be more worrisome than helpful should long range indicators be correct and a larger amount of waves than normal slip into the Atlantic this season. They could cruise through undeveloped until terra firma points further W become targets. With that said, I'm not big on MDR temps being able to influence the basin much on their own.

[JetFuel_SE]

Doesn't CDAS have a weird cold bias?

[SFLcane]

The MDR is probably going to still be warm enough by ASO, but if it does end up slightly cooler, could that delay AEWs developing into TCs until they get closer to the Caribbean?

Yes. After 50W and westward, normally waters are more warm.

As previously stated here in one form or another, those cooler SST's in the MDR could be more worrisome than helpful should long range indicators be correct and a larger amount of waves than normal slip into the Atlantic this season. They could cruise through undeveloped until terra firma points further W become targets. With that said, I'm not big on MDR temps being able to influence the basin much on their own.

They're pretty important for ACE.

[toad strangler]

Yes. After 50W and westward, normally waters are more warm.

As previously stated here in one form or another, those cooler SST's in the MDR could be more worrisome than helpful should long range indicators be correct and a larger amount of waves than normal slip into the Atlantic this season. They could cruise through undeveloped until terra firma points further W become targets. With that said, I'm not big on MDR temps being able to influence the basin much on their own.

They're pretty important for ACE.

Yes sir, I get it. Personally the last thing ever on my mind is ACE. I just don't care about it. But, I get the significance of the measurement for scientific and analysis reasons for the basin on a whole.

[cycloneye]

Other sites have warmer data than Levi's site so I dont know which one may be the right one right now.

[aspen]

Other sites have warmer data than Levi's site so I dont know which one may be the right one right now.

https://i.imgur.com/oN9ulH0.png

https://i.imgur.com/43yD4LJ.gif

The majority is going for a constant above-average MDR, so I’m starting to think there might be an error with Levi’s maps.

[USTropics]

We are seeing cooling in this region, largely due to the processes described in my post last week (viewtopic.php?p=2799864#p2799864). Increased southeasterly winds has promoted upwelling near the coastline, as well as anomalous precipitation near and just off the coast:



Depending on what data set you use, this can cause discrepancies. CDAS SSTAs uses more satellite derived data than NOAAs SSTA data set. So if we had an instance where the satellite data estimates may be off, likely due to the convective mass that has been extended over that region for April, it would cause SSTA readings to potentially be lower than they actually are. Here is a high definition derived map of NOAA SSTA data:

[cycloneye]

We are seeing cooling in this region, largely due to the processes described in my post last week (viewtopic.php?p=2799864#p2799864). Increased southeasterly winds has promoted upwelling near the coastline, as well as anomalous precipitation near and just off the coast:

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

Depending on what data set you use, this can cause discrepancies. CDAS SSTAs uses more satellite derived data than NOAAs SSTA data set. So if we had an instance where the satellite data estimates may be off, likely due to the convective mass that has been extended over that region for April, it would cause SSTA readings to potentially be lower than they actually are. Here is a high definition derived map of NOAA SSTA data:

https://i.imgur.com/56TZq3A.jpg

In other words, MDR is a little bit less warm but warmer than what CDAS data has.

[USTropics]

Don't be shocked if we see some more marginal cooling through part of May. What will ultimately change this? Eventually the ITCZ will establish its peak location. The mean for this time frame is late July/early August, but this can really occur anytime between early July-mid September. June/July are peak months for SAL outbreaks, which will cause subsidence over this area as well. A decrease in convection and strong winds causing upwelling will allow SSTs to rebound June-August.

[Kingarabian]

Other sites have warmer data than Levi's site so I dont know which one may be the right one right now.

https://i.imgur.com/oN9ulH0.png

https://i.imgur.com/43yD4LJ.gif

The majority is going for a constant above-average MDR, so I’m starting to think there might be an error with Levi’s maps.

It comes down to the climo period the maps use. The NOAA maps usually show a warmer ATL compared to OISST and CDAS.

[TheStormExpert]

Well the NAO is forecasted at the moment to go negative next week so let's see if they try to rebound some or not. The trend is both good and bad, the good part is it may suppress development in that region, the bad part is the development of these AEW's will likely be delayed until past 50ºW similar to Dorian from last year for example which if you do not want landfalling tropical cyclones is a bad thing!

[TheStormExpert]

To followup on how is the MDR doing here is the latest. The cooling continues on May 3 in the Tropical Atlantic as the waters are getting colder and falling like a rock per data. I only post the data and not do analysis about what is going on. I let that to others like members USTropics and DorkyMcDorkface and others that have posted good information.

https://i.imgur.com/PSuB5n0.png

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

This has more a -AMO look, definitely not a +AMO like you would expect in an active era.