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

[CyclonicFury]

Almost forgot but here is the 15th update from ECMWF of MSLP for September,October and November and looks like neutral pressures in the Atlantic.

Considering ECMWF usually has a high bias of pressures across the MDR wouldn't that mean lower than normal pressures are likely?

[Hammy]

Almost forgot but here is the 15th update from ECMWF of MSLP for September,October and November and looks like neutral pressures in the Atlantic.

Considering ECMWF usually has a high bias of pressures across the MDR wouldn't that mean lower than normal pressures are likely?

Would that likely translate to less stable air, i.e. another backloaded season?

[beoumont]

Indicator of the coming season: a picture might be worth 1000 words.

[Kingarabian]

Indicator of the coming season: a picture might be worth 1000 words.

[img]http://i.imgur.com/CqrQBMh.jpg[img]

Active wave train, Atlantic becoming more favorable, Windows XP, AND AOL? This definitely gives me an early 2000's vibe!

[CyclonicFury]

I personally believe that it is too early to just assume that the MDR will be unfavorable again this year. Although the MJO is expected to be less favorable in September, there will likely also be less SAL, and that could help the MDR out a little bit if shear is low and we get a strong wave over the coast of Africa. The CFS does seem to keep the MJO over the northwestern Indian Ocean and this could keep the AEWs fairly strong as we head towards the peak season despite sinking air over the Atlantic. I'm interested to see what happens with 91L, 92L and future 93L. I believe future 93L has the best shot at being a hurricane down the road, but we'll have to see what models are showing after splashdown into the Atlantic.

Even if the MDR does not end up favorable, it doesn't mean the season will be quiet as a whole. The past few years have had a secondary peak from late September into October, and with sinking motion likely leaving the Atlantic basin by that time, we'll have to watch out. The East Pacific really has slowed down, so it will be interesting to see if this means that shear could be lower in the Caribbean and Western Atlantic by October. Still think we will see at least 2-4 major hurricanes this year. As we have already had Franklin and Gert, this season can't be any worse than 2013 and if you look back at history, seasons with MDR development and early hurricanes in the Caribbean/GOM almost always end up above average. Only one season since 1995 has had a Gulf of Mexico or Caribbean hurricane before mid-August and ended up below average - 1997, which was a Super El Nino year. It's also worth noting that nearly all Atlantic seasons except 2013 with MDR activity before mid-July ended up above average. Based on our current numbers of 7-2-0, the chances of a below average season are low unless we have one of the quietest peak periods on record. That seems unlikely, despite the unfavorable MJO, considering how we are in ENSO-neutral with an overall favorable Atlantic SST pattern.

Basically what I'm saying is it is WAY too soon to say "season cancel." Just about every season, active or not, has its weak storms and strong storms. Just because one storm struggles in the MDR doesn't mean they all will. There's a reason why TSR, CSU and NOAA all predicted above normal activity, and it will be interesting to see what happens during the next two months!

[Alyono]

I personally believe that it is too early to just assume that the MDR will be unfavorable again this year. Although the MJO is expected to be less favorable in September, there will likely also be less SAL, and that could help the MDR out a little bit if shear is low and we get a strong wave over the coast of Africa. The CFS does seem to keep the MJO over the northwestern Indian Ocean and this could keep the AEWs fairly strong as we head towards the peak season despite sinking air over the Atlantic. I'm interested to see what happens with 91L, 92L and future 93L. I believe future 93L has the best shot at being a hurricane down the road, but we'll have to see what models are showing after splashdown into the Atlantic.

Even if the MDR does not end up favorable, it doesn't mean the season will be quiet as a whole. The past few years have had a secondary peak from late September into October, and with sinking motion likely leaving the Atlantic basin by that time, we'll have to watch out. The East Pacific really has slowed down, so it will be interesting to see if this means that shear could be lower in the Caribbean and Western Atlantic by October. Still think we will see at least 2-4 major hurricanes this year. As we have already had Franklin and Gert, this season can't be any worse than 2013 and if you look back at history, seasons with MDR development and early hurricanes in the Caribbean/GOM almost always end up above average. Only one season since 1995 has had a Gulf of Mexico or Caribbean hurricane before mid-August and ended up below average - 1997, which was a Super El Nino year. It's also worth noting that nearly all Atlantic seasons except 2013 with MDR activity before mid-July ended up above average. Based on our current numbers of 7-2-0, the chances of a below average season are low unless we have one of the quietest peak periods on record. That seems unlikely, despite the unfavorable MJO, considering how we are in ENSO-neutral with an overall favorable Atlantic SST pattern.

Basically what I'm saying is it is WAY too soon to say "season cancel." Just about every season, active or not, has its weak storms and strong storms. Just because one storm struggles in the MDR doesn't mean they all will. There's a reason why TSR, CSU and NOAA all predicted above normal activity, and it will be interesting to see what happens during the next two months!

quick heads up, below average is largely ACE driven these days. That's why 2007 is considered a slightly below average season, despite having 2 cat 5 hurricanes

[Tampa Bay Hurricane]

Question for the pro-mets or anyone that knows- Is the SAL north of the tropical waves coming off Africa due to an anomalously strong flow off of the dry regions of Africa north of the tropical waves, or due to anomalous dry conditions north of the anomalously wet conditions impacting areas like Sierra Leone, for example? Just curious. I've been watching these MCSs roll off Africa and seeing large swaths of SAL to the north. Thank you in advance

[chaser1]

Indicator of the coming season: a picture might be worth 1000 words.

I keep hearing about 'ol Uncle SAL, but that pic of Africa sure looks like someone's cooking up and about to dish out an awful lot of Alyono's "turd-burgers". Sure, they could all just go poof.... just like Franklin & Gert did, right? No, this season has already exhibited what some fail to accept. The ITCZ is healthy, MDR surface pressures are low, the low level trades & cross equatorial flow have aided low latitude genesis, and SST's practically throughout all the deep tropics have remained warm. ....And ALL the SAL, and all the dry air, and even with all of King TuTT's men, could not prevent 7 Turd-Burgers from developing again (and before August 15).

So, all things being equal, and in light of the season racing toward its climatological peak, you might find transitional or regional conditions temporary cap strong waves for a period of time. It's NOT about all the reasons why tropical systems might sputter right here - right now, it is about where they'll be and where will they go, when they suddenly hit "that sweet spot". Maybe 2, 3, or more hurricanes over the next 15 days will finally make that point a bit more clear. So if activity continues to ramp up and storms continue to become stronger, excuse me for taking a pass when the next sinking air band-wagon comes driving by.

[Alyono]

Those strong waves may keep reinforcing the SAL

Often times, SAL outbreaks are caused by the strong waves themselves. Would be better for development if these waves would come off south of 10N, where Matthew did. Those waves will likely not cause a major SAL outbreak. These high amplItude waves coming off as far north as these ones are just keep pumping the SAL

[Tampa Bay Hurricane]

Those strong waves may keep reinforcing the SAL

Often times, SAL outbreaks are caused by the strong waves themselves. Would be better for development if these waves would come off south of 10N, where Matthew did. Those waves will likely not cause a major SAL outbreak. These high amplItude waves coming off as far north as these ones are just keep pumping the SAL

Thank you for the explanation. I have noticed the waves being at a higher latitude this year.

[Hammy]

Those strong waves may keep reinforcing the SAL

Often times, SAL outbreaks are caused by the strong waves themselves. Would be better for development if these waves would come off south of 10N, where Matthew did. Those waves will likely not cause a major SAL outbreak. These high amplItude waves coming off as far north as these ones are just keep pumping the SAL

Are there any other years you can think of where the waves were coming off this far north?

[Alyono]

Those strong waves may keep reinforcing the SAL

Often times, SAL outbreaks are caused by the strong waves themselves. Would be better for development if these waves would come off south of 10N, where Matthew did. Those waves will likely not cause a major SAL outbreak. These high amplItude waves coming off as far north as these ones are just keep pumping the SAL

Are there any other years you can think of where the waves were coming off this far north?

didn't they come off fairly far north in 2013? Think 1985 also had a few coming off north

[SFLcane]

A different tune this morning thought environment was favorable...

 https://twitter.com/MJVentrice/status/897794818159595520

[tolakram]

Indicator of the coming season: a picture might be worth 1000 words.

At least upgrade to Windows 7 while you can still find it on refurbished machines. Wait too long and you'll be stuck with Windows 10. XP, good grief!

And I agree, impressive wave train.

[tolakram]

I can't get enough of GOES16.

http://rammb-slider.cira.colostate.edu/?sat=goes-16&sec=full_disk&x=15652&y=6620&z=2&im=12&ts=1&st=0&et=0&speed=130&motion=loop&map=1&lat=0&p%5B0%5D=1&opacity%5B0%5D=1&hidden%5B0%5D=0&pause=0&slider=-1&hide_controls=0&mouse_draw=0&s=rammb-slider

Using the dust layer and adding band 9, mid level moisture. I've increased band 9 opacity until the dust appears as the darker slightly orange 'fog' around and north of the invests.

http://rammb-slider.cira.colostate.edu/?sat=goes-16&sec=full_disk&x=15652&y=6620&z=2&im=12&ts=1&st=0&et=0&speed=130&motion=loop&map=1&lat=0&p%5B0%5D=19&p%5B1%5D=0&p%5B2%5D=8&opacity%5B0%5D=1&opacity%5B1%5D=0.61&opacity%5B2%5D=0.3&hidden%5B0%5D=0&hidden%5B1%5D=1&hidden%5B2%5D=0&pause=0&slider=-1&hide_controls=0&mouse_draw=0&s=rammb-slider

saved image


Description of the GOES16 bands: http://www.goes-r.gov/education/ABI-bands-quick-info.html

[SoupBone]

Pretty impressive Mark.

[tarheelprogrammer]

Wow the Atlantic must be hostile, as evidence by the fact that this system, as well as 93L are weak even as they pass north of the islands. So much for great conditions. If only they were in the BOC or in the middle of the Atlantic. This could be the story all season. Models seem to be backing off developing this system.

It's the model thread. But has anyone said "Great Conditions" or is that just something you're saying we're not currently experiencing? If so, please direct me to that as I'd love to read whomever would post that the Atlantic's conditions are great just to see for myself. I really don't recall anyone saying that conditions were "great". I mean they are in some places I'm sure.
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I'm not sure about 91L/92L modeling. I kind of agree that 91L is a southern runner and 92L would come up farther north. It usually works that way. But 91l buried into Central America vs. Bay of Campeche could be the difference between a recurve/FL hit or Gulf storm with 92L. I don't have a good feel yet for how north 91L breaks.

Um.... every agency that releases forecasts are calling for above average activity. That would seem to be a hint of great conditions, but what do I know. I am just an average Joe when it comes to this stuff.

[Steve]

I hear you. I was curious if anyone on the site was making that argument or some pros out there on other sites. I haven't seen anyone say that the conditions were great. I think the Bahamas and north of there is pretty solid, and just about everything else is hit or miss depending. I know the MDR wasn't anticipated to be favorable this year, and the Caribbean probably not all that much except the West Caribbean at times. Probably the same with the Gulf of Mexico. There will be times it should be close to optimum and times when it's got walls of shear flying across it. I don't know.

Now the conditions have to be somewhat good to have a higher than average season (or at least conditions would be "better than average").

[RL3AO]

It also doesn't take that much to make the Atlantic above average. I think some think above average = multiple cat 4s in the GOM. 11 named storms. 6 hurricanes. 3 majors. 100 ACE. Those aren't exactly the most difficult goals to beat. We're already at 7/2/0 (maybe 7/2/1...) and ACE is now near average. Why would you think an above average season is a long shot?

[Steve]

Me? I don't. But I still think it's more likely to be close to average except name storms should be +3 or +4. I was asking Tar Heel if anyone had actually said that because he brought it up in his post. But then he said it was an assumption based on the higher than average predictions.

It was similar to me disagreeing with Mike and StormExpert the other day. They were referencing an optimistic side of the season I just haven't seen by calling out people for overhyping. I didn't see that going on so I brought that up too. Sometimes people will have an impression about something opposite of what they are thinking or saying where it's really more of their ideas coming out if that makes sense.