2017 indicators: SST's / MSLP / SAL / Steering / Instability

[wxmann_91]

I'd probably get downvoted to hell for this but we've been in an inactive phase for Atlantic activity for awhile now and PV streamer activity along with basin-wide subsidence is the culprit. The latest CCKW did perturb this but you have to add on the fact that the global-wide signal is negative for TC activity and this CCKW did nothing in the EPAC (the EPAC!) as well. The fat lady is singing for forecasts of an above-average season but I think we'll see some late-season activity as we have in the past few years.

[Hammy]

Here are the same VP anomalies averages for MJJ posted back in July.



So far for August, convergence has expanded in the EPac and decreased considerably in the Atlantic as shown in the Mike Ventrice tweet.

Given the signals are showing a pretty static atmosphere, and the CFS long term doesn't show anything that jumps out (just a bunch of above normal in the MDR, and troughs in the western Atlantic and western Gulf) I'm thinking 7/5/1 might be what's in store for the rest of the season at this point if conditions do in fact remain the same through the rest of the month. But that being said, there is still plenty of time for things to change especially if we continue the recent trend of back-loaded seasons.

[Ntxw]

If looking at that spatial map here is what I attempt to interpret.

The central Pacific (near dateline) lack of El Ninoish convection probably has some play in that spatial pattern. Many mentioned "modoki" but you can't get a modoki without getting El Nino to bring forcing near the dateline to create the spatial pattern of rising Cpac, sinking EPAC and rising ATL. There is also no La Nina to force sinking motion near Central America and Nino 1+2 region, this is the oddity area of interest.

Lets see if that changes this month

[Kingarabian]

If looking at that spatial map here is what I attempt to interpret.

The central Pacific (near dateline) lack of El Ninoish convection probably has some play in that spatial pattern. Many mentioned "modoki" but you can't get a modoki without getting El Nino to bring forcing near the dateline to create the spatial pattern of rising Cpac, sinking EPAC and rising ATL. There is also no La Nina to force sinking motion near Central America and Nino 1+2 region, this is the oddity area of interest.

Lets see if that changes this month

So more variables in favor of an El Nino atmosphere rather than a La Nina.

I also wanted to point out that the pattern was due to change this month ever since the fall off @ Nino 3.4 but it appears not or it's still lagging.

[TheStormExpert]

Smells like 2013 all over again.

 https://twitter.com/pppapin/status/893915338567450624

[Kingarabian]

Smells like 2013 all over again.

[tweet]https://twitter.com/pppapin/status/893915338567450624[tweet]

It's completely different than 2013. Just look at the SST's configuration between 2017 and 2013. If this season busts (which is still way too early to say considering it's still early August), it'll be because of the mentioned El-Nino-esque atmosphere somehow dominating.

[RL3AO]

Why is the only season people reference is 2013? It was the quietest season in decades and is extremely unlikely to repeat. Find a different quiet season.

[tarheelprogrammer]

Why is the only season people reference is 2013? It was the quietest season in decades and is extremely unlikely to repeat. Find a different quiet season.

I like similar numbers to 1987. Just feel like for the most part since 2006 the Atlantic has struggled with storms west of 70W. In the past 5 years the Atlantic has struggled overall. I am not seeing much change in the basin this season. It only takes one though.

[Hammy]

Smells like 2013 all over again.

[tweet]https://twitter.com/pppapin/status/893915338567450624[tweet]

It's completely different than 2013. Just look at the SST's configuration between 2017 and 2013. If this season busts (which is still way too early to say considering it's still early August), it'll be because of the mentioned El-Nino-esque atmosphere somehow dominating.

The waters off of Mexico still seem quite warm and are probably causing some issues in the Atlantic. Didn't 1983 have similar problems?

And unless there is some indication that the thermohaline circulation underwent some weakening (which is the root cause of 2013's bust) the comparisons don't really hold any water. That year was significantly drier in the tropics than this year (we weren't seeing large convective waves like 99L after mid-July) and shear was almost linear west-east across the entire basin thanks to an almost winter-like pattern (which brought three solid months of below normal temperatures/above normal rainfall to the whole eastern US.)

[Siker]

I'd probably get downvoted to hell for this but we've been in an inactive phase for Atlantic activity for awhile now and PV streamer activity along with basin-wide subsidence is the culprit. The latest CCKW did perturb this but you have to add on the fact that the global-wide signal is negative for TC activity and this CCKW did nothing in the EPAC (the EPAC!) as well. The fat lady is singing for forecasts of an above-average season but I think we'll see some late-season activity as we have in the past few years.

Luckily for you there's no downvote option .

[Ntxw]

Smells like 2013 all over again.

[tweet]https://twitter.com/pppapin/status/893915338567450624[tweet]

It's completely different than 2013. Just look at the SST's configuration between 2017 and 2013. If this season busts (which is still way too early to say considering it's still early August), it'll be because of the mentioned El-Nino-esque atmosphere somehow dominating.

The waters off of Mexico still seem quite warm and are probably causing some issues in the Atlantic. Didn't 1983 have similar problems?

And unless there is some indication that the thermohaline circulation underwent some weakening (which is the root cause of 2013's bust) the comparisons don't really hold any water. That year was significantly drier in the tropics than this year (we weren't seeing large convective waves like 99L after mid-July) and shear was almost linear west-east across the entire basin thanks to an almost winter-like pattern (which brought three solid months of below normal temperatures/above normal rainfall to the whole eastern US.)

1983 held on to extremely warm waters in Nino 3 and 1+2. The atmospheric forcing of the 1982-1983 super event lingered much longer

[Bocadude85]

Why is the only season people reference is 2013? It was the quietest season in decades and is extremely unlikely to repeat. Find a different quiet season.

I like similar numbers to 1987. Just feel like for the most part since 2006 the Atlantic has struggled with storms west of 70W. In the past 5 years the Atlantic has struggled overall. I am not seeing much change in the basin this season. It only takes one though.

So from now until November 30th you only expect two more named storms? I'm fairly certain we will have Franklin from 90L so that would leave only one more named storm to be at 1987 levels.

[Andrew92]

I can only imagine if the year was 1967 right now. We didn't have our first named storm until the tail end of August that year! I personally could see some of the ten depressions there were before that storm upgraded, but the point is, we are still at least on par with that season. I think if you ask anyone from Brownsville if that was a quiet year, it will be meet with a resounding NO because of Beulah a short time later. And we "only" had eight named storms that year.

Oh, and that theory I have that a destructive storm is supposed to hit the US this year? It doesn't have to have happened by now, and it doesn't have to be either 99L or 90L. In fact, it usually doesn't come until later in August or September. (And 1967 was such a year, by the way.) Let's see what the atmosphere is like then, and then if it's still unfavorable overall, we'll talk.

Remember, it only takes one to make the season!

-Andrew92

Edited to fix typo.

[wxmann_91]

Why is the only season people reference is 2013? It was the quietest season in decades and is extremely unlikely to repeat. Find a different quiet season.

Fine, can I use 1993-1994 or 1986-87 or 1983?

[Hammy]

Oh, and that theory I have that a destructive storm is supposed to hit the US this year? It doesn't have to have happened by now, and it doesn't have to be either 99L or 90L. In fact, it usually doesn't come until later in August or September. (And 1967 was such a year, by the way.) Let's see what the atmosphere is like then, and then if it's still unfavorable overall, we'll talk.

Remember, it only takes one to make the season!

-Andrew92

Last year serves as a good example of this--Hermine (the first US hurricane of the season) didn't hit until what, almost a month from now? And Matthew didn't come until October.

[Andrew92]

Oh, and that theory I have that a destructive storm is supposed to hit the US this year? It doesn't have to have happened by now, and it doesn't have to be either 99L or 90L. In fact, it usually doesn't come until later in August or September. (And 1967 was such a year, by the way.) Let's see what the atmosphere is like then, and then if it's still unfavorable overall, we'll talk.

Remember, it only takes one to make the season!

-Andrew92

Last year serves as a good example of this--Hermine (the first US hurricane of the season) didn't hit until what, almost a month from now? And Matthew didn't come until October.

Exactly! Patience is a virtue, especially when tracking hurricanes. We are still not quite in the most active part of the season. 99L and 90L hint that we are getting close perhaps, but with their own struggles, not quite yet.

-Andrew92

[Steve]

Why is the only season people reference is 2013? It was the quietest season in decades and is extremely unlikely to repeat. Find a different quiet season.

Fine, can I use 1993-1994 or 1986-87 or 1983?

Haha. You're better than that 91! I am enjoying the posts though. It's not 2005, 1933 or 1983 or 2013.

[Steve]

Smells like 2013 all over again.

[tweet]https://twitter.com/pppapin/status/893915338567450624[tweet]

It's completely different than 2013. Just look at the SST's configuration between 2017 and 2013. If this season busts (which is still way too early to say considering it's still early August), it'll be because of the mentioned El-Nino-esque atmosphere somehow dominating.

The waters off of Mexico still seem quite warm and are probably causing some issues in the Atlantic. Didn't 1983 have similar problems?

And unless there is some indication that the thermohaline circulation underwent some weakening (which is the root cause of 2013's bust) the comparisons don't really hold any water. That year was significantly drier in the tropics than this year (we weren't seeing large convective waves like 99L after mid-July) and shear was almost linear west-east across the entire basin thanks to an almost winter-like pattern (which brought three solid months of below normal temperatures/above normal rainfall to the whole eastern US.)

And a dry east and southeast isn't this year at all. Florida was even in drought conditions not long ago. Our house has had 2 flooded cars in the last 2 weeks including today. This isn't a normal late July/August for us, it's way wetter. It actually has been reminding me of mid season 2002 and then March/April of 2003 though mostly because of the multiple flooding events.

[Hammy]

Why is the only season people reference is 2013? It was the quietest season in decades and is extremely unlikely to repeat. Find a different quiet season.

Fine, can I use 1993-1994 or 1986-87 or 1983?

Haha. You're better than that 91! I am enjoying the posts though. It's not 2005, 1933 or 1983 or 2013.

While I'm not betting on it at the moment, IF this year does end up being below average, I can see 2002 being the closest similarity to what it would probably end up like after this point.

[WeatherEmperor]

https://twitter.com/cfanclimate/status/ ... 6991520769


Sent from my iPhone 7 using Tapatalk