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

[hurricanes1234]

Earlier in the year, there was a lot of talk about Caribbean hurricanes during August and September based on precipitation anomalies.. Good thing those didn't verify (atleast until now) ... The models weren’t wrong because most the Caribbean have had a wet August and September but it wasn’t from hurricanes (excepting Laura for the Greater Antillies). Airport in Trinidad for example had almost 20” of rain in August and Barbados been seeing rough weather

Point is precipitation anomaly is a bad indicator to show where storms are going to go...

That's true, at the airport in Trinidad, we had almost 500 mm in August in and almost 300 mm in September (although the real September total was probably over 300 mm since the rain gauge didn't record any data on one especially wet, stormy day). August 2020 was the third wettest August on record for Trinidad and the sixth wettest for Tobago, if my memory serves me right. Rainfall was well above-normal and it actually helped bring our reservoirs closer to their usual year-to-date levels after a long stretch of below-normal rainfall between December 2018 and July 2020.

I remember distinctly that models kept showing above-average precipitation for the Caribbean region this hurricane season and they most certainly verified, although most of the rain wasn't as a result of organised storms passing through in large numbers.

[chaser1]

I have lost a link to a site that I use often and wondering if anyone here can help me locate it. I believe Aric originally posted the link several years ago. It is the NESDIS/STAR GOES from NOAA (East Band 13) but with the ability to zoom in and out and move the globe around. I would be grateful to anyone who might have the link and can post it here please.

Perhaps this isn't the exact satellite web site you were referring to, but the NASA site does allow you to click on a region, and then allow you to pinpoint the exact spot you would like a zoomed in loop for. One of the options does include the Band - 13 resolution. Once there, you'll be further able to choose up to 10 special IR enhancements as well. I like this site because it updates fast AND you can easily change the length of the loop as well. NASA Interactive Geo Weather Satellite Images- https://weather.msfc.nasa.gov/GOES/

Hope that helps

[Orlando]

Thank you Chaser1 for the link. I will play around with that one.

Aric sent me the one I was looking for which is here:

https://rammb-slider.cira.colostate.edu ... 448&y=8528

[TheStormExpert]

Quite a lot of shear out in the Atlantic right now. Definitely more El Niño-ish.

[aspen]

Quite a lot of shear out in the Atlantic right now. Definitely more El Niño-ish.

https://i.imgur.com/94uhvWn.gif

https://i.imgur.com/O1u5Tc7.gif

That is quite a lot, but if the forecasts of that upper level ridge verify, shear over a large portion of the Caribbean will become fairly low and favorable. I think the massive cold front is expected to weaken over the next few days.

[ElectricStorm]

Quite a lot of shear out in the Atlantic right now. Definitely more El Niño-ish.

https://i.imgur.com/94uhvWn.gif

https://i.imgur.com/O1u5Tc7.gif

Yeah the atmosphere sure isn't acting like a La Niña right now given all that shear. Plus an active Cat 4 in the EPAC right now.

[TheStormExpert]

Quite a lot of shear out in the Atlantic right now. Definitely more El Niño-ish.

https://i.imgur.com/94uhvWn.gif

https://i.imgur.com/O1u5Tc7.gif

That is quite a lot, but if the forecasts of that upper level ridge verify, shear over a large portion of the Caribbean will become fairly low and favorable. I think the massive cold front is expected to weaken over the next few days.

Shear in the Gulf looks to be increasing not decreasing and that’s where Gamma is headed straight into.

[aspen]

There’s a vigorous low-rider AEW out in the MDR that’s within one of the largest low-shear pockets in the basin. It’s producing a ton of convection and it has a pretty good 850mb vorticity signature. I’m very surprised it hasn’t been mentioned in any TWO yet, and I think there’s a chance it could try to snag the name Delta away from the 10/40 AOI.

[AutoPenalti]

Quite a lot of shear out in the Atlantic right now. Definitely more El Niño-ish.

https://i.imgur.com/94uhvWn.gif

https://i.imgur.com/O1u5Tc7.gif

Yeah the atmosphere sure isn't acting like a La Niña right now given all that shear. Plus an active Cat 4 in the EPAC right now.

That tends to happen when you have the MJO in that part of the region...

[TheStormExpert]

There’s a vigorous low-rider AEW out in the MDR that’s within one of the largest low-shear pockets in the basin. It’s producing a ton of convection and it has a pretty good 850mb vorticity signature. I’m very surprised it hasn’t been mentioned in any TWO yet, and I think there’s a chance it could try to snag the name Delta away from the 10/40 AOI.

Probably because Cape Verde seasons over. But definitely worth monitoring.

[Steve]

With Gamma already past 87W, and with some models developing the wave (00z Icon, 00z CMC, 06z GFS-paralel) with all of them bringing it at least as far west as 85W (some take it past 90), we might easily add 2 NS west of 85W and possibly west of 90W (especially if Gamma can keep its name past the Yucatan and if the next wave slings around the top of Gamma). No doubt we would be in record territory with 10 or 11 storms past 85 by next weekend. I want to say there were 9 in 2005.

[Steve]

There’s a vigorous low-rider AEW out in the MDR that’s within one of the largest low-shear pockets in the basin. It’s producing a ton of convection and it has a pretty good 850mb vorticity signature. I’m very surprised it hasn’t been mentioned in any TWO yet, and I think there’s a chance it could try to snag the name Delta away from the 10/40 AOI.

Probably because Cape Verde seasons over. But definitely worth monitoring.

Is Gamma and the wave behind it not of Cape Verde origins?

[toad strangler]

There’s a vigorous low-rider AEW out in the MDR that’s within one of the largest low-shear pockets in the basin. It’s producing a ton of convection and it has a pretty good 850mb vorticity signature. I’m very surprised it hasn’t been mentioned in any TWO yet, and I think there’s a chance it could try to snag the name Delta away from the 10/40 AOI.

Probably because Cape Verde seasons over. But definitely worth monitoring.

Is Gamma and the wave behind it not of Cape Verde origins?

I was thinking the same thing BUT a Cape Verde system has to be classified in a certain far E region to be considered a true Cape Verde storm. It seems that benign waves that make it far to the W before sparking do not apply. I don't really agree with this but that's the way it is it seems.

[Steve]

Probably because Cape Verde seasons over. But definitely worth monitoring.

Is Gamma and the wave behind it not of Cape Verde origins?

I was thinking the same thing BUT a Cape Verde system has to be classified in a certain far E region to be considered a true Cape Verde storm. It seems that benign waves that make it far to the W before sparking do not apply. I don't really agree with this but that's the way it is it seems.

Yeah, I know that Cape Verde "system" has origin points (which I think I read changed sometime last century) pretty far east. She said Cape Verde Season which I don't think has the same meaning as a Cape Verde System. Maybe it's just how you consider it or semantics, but I want to say that the Cape Verde Season more considers African waves (mid-to-late summer) whereas a Cape Verde System has to form close to the islands.

[Steve]

I also don't think anyone should be surprised that Marie formed or Gamma. We saw the telegraph with the coming upward motion from a couple weeks back. MJO remains in Phase 5 which isn't an indicator of a burst of super intense storms in the Western Atlantic or Gulf, but isn't completely unfavorable.

https://www.cpc.ncep.noaa.gov/products/ ... r_wh.shtml

Upper favorability looks to remain beyond Ventrice's site's 2 week forecast (through 10/17) and possibly well beyond as no suppressive wave is crossing the Pacific at the end of the period. That doesn't mean we'll see a bunch more storms, because again, the MJO isn't favorable and won't likely be in any favorable phases at least through this same 2 week period. But with the big cold highs coming down, you already know to look south for storms. We've seen this with the last 2 deep fronts, and we will likely see it at least a couple more times (e.g. Pattern Storms).

[TheStormExpert]

Probably because Cape Verde seasons over. But definitely worth monitoring.

Is Gamma and the wave behind it not of Cape Verde origins?

I was thinking the same thing BUT a Cape Verde system has to be classified in a certain far E region to be considered a true Cape Verde storm. It seems that benign waves that make it far to the W before sparking do not apply. I don't really agree with this but that's the way it is it seems.

I always thought Cape Verde season was classified as systems that form east of 60°W and south of 20°N in the Tropical Atlantic.

[Steve]

Is Gamma and the wave behind it not of Cape Verde origins?

I was thinking the same thing BUT a Cape Verde system has to be classified in a certain far E region to be considered a true Cape Verde storm. It seems that benign waves that make it far to the W before sparking do not apply. I don't really agree with this but that's the way it is it seems.

I always thought Cape Verde season was classified as systems that form east of 60°W and south of 20°N in the Tropical Atlantic.

The way I understand it is that a Cape Verde System is one that forms somewhere in the vicinity of the islands at a low latitude that stays developed across the Atlantic (e.g. monster storms). And Cape Verde Season is some range of time between July and September where the waves rolling off Africa cross the Atlantic and develop. The two are separate things, but it's not like there are 100% standard definitions.

[chaser1]

I was thinking the same thing BUT a Cape Verde system has to be classified in a certain far E region to be considered a true Cape Verde storm. It seems that benign waves that make it far to the W before sparking do not apply. I don't really agree with this but that's the way it is it seems.

I always thought Cape Verde season was classified as systems that form east of 60°W and south of 20°N in the Tropical Atlantic.

The way I understand it is that a Cape Verde System is one that forms somewhere in the vicinity of the islands at a low latitude that stays developed across the Atlantic (e.g. monster storms). And Cape Verde Season is some range of time between July and September where the waves rolling off Africa cross the Atlantic and develop. The two are separate things, but it's not like there are 100% standard definitions.

That's essentially correct. Of course don't forget those few T.S.'s that form in Sept or even October near or north of the Cape Verde Islands, which track quickly off to the north given the sharper troughing in the E. Atlantic during this time. By definition, one might also call these Cape Verde systems yet those systems don't pose that long track risk to the Caribbean because interseasonal steering changes are in play. For what it's worth though, African origin tropical waves are still tracking westward which has resulted in Gamma, 92L, and probably a couple more to come.

[ElectricStorm]

We definitely need to keep a very close eye on the Caribbean come October or very late September at the earliest. Things could go crazy once the suppressive CCKW moves out. SSTs/OHC are ridiculously high in the Caribbean, as indicated by the MPI map. The entire region could support a sub-900 mbar Cat 5 at the most.
http://wxmaps.org/pix/atlpot.png

I also went back through most of the active seasons, and the majority of above-average to hyperactive Atlantic hurricane seasons had at least one major between September 20th and November 30th: 1893, 1933, 1950, 1954, 1961, 1995, 1996, 1998, 2001, 2003, 2005, 2008, 2011, 2012, 2016, 2017, and 2018. Some below-average/normal years like 2002 and 2015 also had one too. Out of the top 10 ACE producing seasons, only 2004 had no major hurricane form in that time frame, and out of the seasons I listed here, most had a major form in the Caribbean or Gulf (1893, 1933, 1954, 1961, 1995, 1996, 1998,1999, 2000, 2001, 2002, 2008, 2011, 2012, 2016, 2018). A few seasons also had very late season Cape Verde or open Atlantic majors like 1893's Hurricane Nine, Jig '50, Frances '61, Isidore '96, Issac '00, Kate '03, Joaquin '15, Nicole '16, and Ophelia '17. With 2020's ease at forming storms, a favorable Caribbean, and the potential for an active October, at least one major in that region and time frame is highly likely just looking at the frequency of such storms. I won't rule out a major off of the SEUS coast because of that untapped pocket of 29-31C SSTs northeast of the Bahamas.

To add to the first part of your post, here is the current OHC for 2020:
https://i.imgur.com/lKfYkYr.gif
And here is the OHC for this date in 2005, about a month before Wilma:
https://i.imgur.com/fOPXr1s.gif
I know Wilma didn't occur for another month but we are actually very similar to 2005 right now in the Western Caribbean The dark red on the 2005 map represents OHC values at about 150 kJ cm^-2 compared to 2020's map, where the darkest red is about 175 kJ cm^-2. So although at first glance it appears that 2005 had much more OHC than 2020, they are actually relatively similar. I know a few of the models are hinting at something trying to develop over there the first week of October. If something does indeed get going over there and has good enough conditions to fully be able to take advantage of that OHC and MPI, it could certainly explode into a Wilma-like storm. Obviously it would have to have absolutely perfect conditions, but it is something to think about.
EDIT: Here is the current OHC map with the same scale as the 2005 map as a direct comparison:
https://i.imgur.com/KkCH7kO.gif

I posted this OHC comparison a few weeks ago mentioning the possibility of a storm absolutely exploding if it had enough time in the Caribbean with an extremely favorable upper environment. Fast forward a couple weeks and, well... we may have our storm. I know it's a bit early, but if PTC 26 gets going quick enough, it may be a biggie... Before it enters the gulf that is, as conditions should deteriorate once it gets there. Either way, 26 looks to contribute a solid amount of ACE to the season. Praying for everyone in the path of future Delta. Rough week ahead.

[tolakram]

I have lost a link to a site that I use often and wondering if anyone here can help me locate it. I believe Aric originally posted the link several years ago. It is the NESDIS/STAR GOES from NOAA (East Band 13) but with the ability to zoom in and out and move the globe around. I would be grateful to anyone who might have the link and can post it here please.

RealEarth?

https://realearth.ssec.wisc.edu/