2021 Global Model Runs Discussion (Out thru day 16)

[Shell Mound]

So much for those people who said no Cape Verde threats for the rest of the season

Based on climatology/timing, CV threats to the CONUS are likely finished, but this upcoming system could very well impact the Islands, including Bermuda.

The CV threats are not over! There has been October Cape Verde Hurricanes before! (Joan-Miriam 1988)

I was only referring to the CONUS. Most CV landfalls on the CONUS occur on or before 20 September. However, CV systems can still affect the Islands in October.

[Hammy]

https://i.postimg.cc/rsqxGSZW/AD9-BB8-F2-D1-CC-4892-B4-E5-C126-DBE29-D5-D.gif

So much for those people who said no Cape Verde threats for the rest of the season

At the same time it looks like a lot of the waves coming off too far north is still stunting the MDR--we're not seeing the storm train like we've seen in other seasons.

[AlphaToOmega]

https://i.postimg.cc/rsqxGSZW/AD9-BB8-F2-D1-CC-4892-B4-E5-C126-DBE29-D5-D.gif

So much for those people who said no Cape Verde threats for the rest of the season

At the same time it looks like a lot of the waves coming off too far north is still stunting the MDR--we're not seeing the storm train like we've seen in other seasons.

Rene came off at a high latitude

[sma10]

https://i.postimg.cc/rsqxGSZW/AD9-BB8-F2-D1-CC-4892-B4-E5-C126-DBE29-D5-D.gif

So much for those people who said no Cape Verde threats for the rest of the season

Based on climatology/timing, CV threats to the CONUS are likely finished, but this upcoming system could very well impact the Islands, including Bermuda.

This is an absurd take. There are many examples of CV waves that have rolled off the African coast in mid Sept and struck the US

[sma10]

Gloria and Georges would like a word

There are quite a few TUTTs and shortwaves passing through on the 12Z EC guidance, so there is a lot of opportunity for a N turn beyond the Islands.

Wait, according to you This season was going to underperform yet we have had 3 majors already. Enough with the down casting it’s really tiring and getting old frankly,

And let's not forget the famous "given the lack of CV threats, it looks extremely unlikely the CONUS will be threatened by a Major" prediction.

And then Ida struck 5 days later.

[Category5Kaiju]

So much for those people who said no Cape Verde threats for the rest of the season

Based on climatology/timing, CV threats to the CONUS are likely finished, but this upcoming system could very well impact the Islands, including Bermuda.

This is an absurd take. There are many examples of CV waves that have rolled off the African coast in mid Sept and struck the US

Also I know it is not a part of the CONUS, but let’s not forget about the US territory Puerto Rico, right? Storms at this time of the year could very well impact the island (especially as we saw with Maria), and I just don’t think we should focus solely on whether or not the CONUS will be hit. Other land masses, especially the Lesser Antilles and Puerto Rico, have people, and we should still feel concern for them.

[GeneratorPower]

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[crownweather]

So much for those people who said no Cape Verde threats for the rest of the season

Based on climatology/timing, CV threats to the CONUS are likely finished, but this upcoming system could very well impact the Islands, including Bermuda.

This is an absurd take. There are many examples of CV waves that have rolled off the African coast in mid Sept and struck the US

Couldn't agree more. Two that I can think of off the top of my head are the 1938 Long Island, New England hurricane on September 9th and the second one, Hazel I would arg was from an African wave that waited to develop until just east of the Lesser Antilles. Hazel formed on October 5th.

[Spacecoast]

Just out of curiosity, (please don't flame me), using the 360hr 12z Euro ensembles provided by Larrywx, SFLcane,
I plotted all modern era storms <992mb crossing within 340nm of 25N, 65W.
This puts the range box 20-30N, 60-71W (the approx. euro ensemble mean @360rs, perhaps a bit west of mean).

Strictly climatology, I have no idea where this storm is going, and will not try to guess)
For both Sept, and Oct ,out of 88 storms, ~15% strike CONUS. Jeane, Francis, and Hugo are among these:


For only October, out of 31 storms, 2 strike CONUS, (1 if you exclude Judith, which came from the Caribbean)


After last years experience with climatology, I draw absolutely no conclusions from this. None whatsoever.

[toad strangler]

The 12z Euro and 18z GFS are in good agreement on a coastal GOM TX storm in the short term but vastly different way out E in the MDR.

[toad strangler]

Just out of curiosity, (please don't flame me), using the 360hr 12z Euro ensembles provided by Larrywx, SFLcane,
I plotted all modern era storms <992mb crossing within 340nm of 25N, 65W.
This puts the range box 20-30N, 60-71W (the approx. euro ensemble mean @360rs, perhaps a bit west of mean).

Strictly climatology, I have no idea where this storm is going, and will not try to guess)
For both Sept, and Oct ,out of 88 storms, ~15% strike CONUS:


For only October, out of 31 storms, 2 strike CONUS, (1 if you exclude Judith, which came from the Caribbean)


After last years experience with climatology, I draw absolutely no conclusions from this. None whatsoever.

October climo significantly favors storm origins further W in the basin

[Teban54]

Based on climatology/timing, CV threats to the CONUS are likely finished, but this upcoming system could very well impact the Islands, including Bermuda.

This is an absurd take. There are many examples of CV waves that have rolled off the African coast in mid Sept and struck the US

Couldn't agree more. Two that I can think of off the top of my head are the 1938 Long Island, New England hurricane on September 9th and the second one, Hazel I would arg was from an African wave that waited to develop until just east of the Lesser Antilles. Hazel formed on October 5th.

I also believe Maria might have hit the Carolinas if Jose didn't stay offshore the Northeast for so long. IIRC one of the NHC 5-day forecasts was showing a slight west turn at that latitude.

[IcyTundra]

Based on climatology/timing, CV threats to the CONUS are likely finished, but this upcoming system could very well impact the Islands, including Bermuda.

This is an absurd take. There are many examples of CV waves that have rolled off the African coast in mid Sept and struck the US

Couldn't agree more. Two that I can think of off the top of my head are the 1938 Long Island, New England hurricane on September 9th and the second one, Hazel I would arg was from an African wave that waited to develop until just east of the Lesser Antilles. Hazel formed on October 5th.

1898 Georgia hurricane also hit in October. https://coast.noaa.gov/hurricanes/#map= ... UiOnRydWV9

[LarryWx]

https://i.postimg.cc/rsqxGSZW/AD9-BB8-F2-D1-CC-4892-B4-E5-C126-DBE29-D5-D.gif

So much for those people who said no Cape Verde threats for the rest of the season

So are we now certain there will be a Cape Verde threat? Is this based on just one model run?

Of course not...nothing even close to certainty of another CV threat. It is just a possibility, which would always be the case this early. With it being La Nina(ish) ENSO, that possibility is somewhat above the average threat level because a higher % of CV storms make it to the western basin in La Nina vs other ENSO. That doesn't mean it is necessarily likely that there will be another CV threat. After all, it is getting pretty late. If we're talking CONUS, it will be at least another week (say 9/17 and probably 9/20+) before one could possibly threaten. By 9/20, a large majority of CV storms in history have already hit the CONUS. That being said, there are a decent number of notable exceptions of storms forming E of 50W and hitting the CONUS 9/20+ with more in La Nina/cold neutral vs other ENSO phases. So, the area east of 50W still bears watching for sure!

Also, the chance depends on one's definition of a "CV threat" as the meaning of that phrase is subject to interpretation. And remember that "threat" could still mean a close miss or could even turn into a not so close miss.

[Spacecoast]

12Z ECMF Ens.


18z GEFS:

[tolakram]

Based on climatology/timing, CV threats to the CONUS are likely finished, but this upcoming system could very well impact the Islands, including Bermuda.

The CV threats are not over! There has been October Cape Verde Hurricanes before! (Joan-Miriam 1988)

I was only referring to the CONUS. Most CV landfalls on the CONUS occur on or before 20 September. However, CV systems can still affect the Islands in October.

How about Hugo, only one of the most famous CV systems? Not sure where you are getting your stats from? It's flat out rare for ANY CV system to hit the mainland US.



Here's the link: https://coast.noaa.gov/hurricanes/#map=2.59/3.24/-16&search=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

I used the euro forecast point at 144 hours, which is probably way off but more accurate than 240.

[LarryWx]

12Z ECMF Ens.
[url]https://i.ibb.co/pdKMxcJ/ecmp.jpg [/url]

18z GEFS:

[url]https://i.ibb.co/g6TLS0r/Animationf.gif [/url]

[url]https://i.ibb.co/wK26YNc/ecmq.jpg [/url]

18Z EPS just out and is even more active as well as further W at 144 than the 12Z at 150

[eastcoastFL]

https://i.postimg.cc/rsqxGSZW/AD9-BB8-F2-D1-CC-4892-B4-E5-C126-DBE29-D5-D.gif

So much for those people who said no Cape Verde threats for the rest of the season

Based on climatology/timing, CV threats to the CONUS are likely finished, but this upcoming system could very well impact the Islands, including Bermuda.

It’s only sept 10

[LarryWx]

The CV threats are not over! There has been October Cape Verde Hurricanes before! (Joan-Miriam 1988)

I was only referring to the CONUS. Most CV landfalls on the CONUS occur on or before 20 September. However, CV systems can still affect the Islands in October.

How about Hugo, only one of the most famous CV systems? Not sure where you are getting your stats from? It's flat out rare for ANY CV system to hit the mainland US.

https://i.imgur.com/3lGozW1.png

Here's the link: https://coast.noaa.gov/hurricanes/#map=2.59/3.24/-16&search=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

I used the euro forecast point at 144 hours, which is probably way off but more accurate than 240.

He said, “Most CV landfalls on the CONUS occur on or before 20 September.”

Depending on how one interprets the word “most” as well as “CV”, that can be considered an accurate statement if it doesn’t mean “almost all”. If when he says “most” he just means well over 50%, he’s right. I suspect that’s what he means. But if he’s saying it is like 98%+, he’s not right. I think some here think he means like 98% or almost all. If we’re talking about those that became a TD+ E of 50N, I’m roughly guessing that it is more like 80-85% of CV LFs occurred by 9/20. That qualifies as “most” to me. That doesn’t at all mean the Conus can come even close to assuming we’re in the clear because we’re nowhere near that, especially in La Niña! Keep in mind that I had said in late August that I thought the US was pretty safe from a CV in the first half of this month but I also said that that wasn’t the case for the 2nd half, which is clearly up in the air even if it isn’t actually “likely” one will hit then. It is far above a zero chance I’d say.

[tolakram]

He said, “Most CV landfalls on the CONUS occur on or before 20 September.”

Depending on how one interprets the word “most” as well as “CV”, that can be considered an accurate statement if it doesn’t mean “almost all”. If when he says “most” he just means well over 50%, he’s right. I suspect that’s what he means. But if he’s saying it is like 98%+, he’s not right. I think some here think he means like 98% or almost all. If we’re talking about those that became a TD+ E of 50N, I’m roughly guessing that it is more like 80-85% of CV LFs occurred by 9/20. That qualifies as “most” to me. That doesn’t at all mean the Conus can come even close to assuming we’re in the clear because we’re nowhere near that, especially in La Niña! Keep in mind that I had said in late August that I thought the US was pretty safe from a CV in the first half of this month but I also said that that wasn’t the case for the 2nd half, which is clearly up in the air even if it isn’t actually “likely” one will hit then. It is far above a zero chance I’d say.

Based on how many storms? There's very few that have hit the US, so how can one be confident in any metric other than it gets less likely as the season progresses? To slap a date on it, as if we have enough examples to be confident, is flat out wrong IMO.