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

[TheAustinMan]

Back in late May 2013 a lot of the attention seemed to be focused on what looked to be an active season; combined with a Bermuda high positioning favorable for storms to track further west. Vertical instability in the tropical Atlantic was right around average and actually went above average for a bit. Near normal instability continued into early June. Early June UKMO modeling indicated above average precip and slightly below average pressures for the main development region. However the Euro and CFS forecasts in June shifted to above average pressures for the Atlantic, with a late summer warm neutral or El Nino to boot, denoting a change from previous forecasts. This caused some rethinking of seasonal activity, though, of course, with skepticism. To quote Levi Cowan at the time, "It's not time to throw in the towel, but either the models or the humans are going to be horribly wrong about this hurricane season." You can follow along on the old 2013 indicators thread.

[Hurricaneman]

One of the main differences between 2013 and this year is that the waters near Europe are warmer and the cooler waters near Europe set up the Azores high farther east than usual which drove a lot of dry and stable air off of Africa and the drought in Brazil also aided in drying out the Atlantic which it seems we don't have this year

[NDG]

 https://twitter.com/JamesBelanger/status/873159645015285760

[Ntxw]

Back in late May 2013 a lot of the attention seemed to be focused on what looked to be an active season; combined with a Bermuda high positioning favorable for storms to track further west. Vertical instability in the tropical Atlantic was right around average and actually went above average for a bit. Near normal instability continued into early June. Early June UKMO modeling indicated above average precip and slightly below average pressures for the main development region. However the Euro and CFS forecasts in June shifted to above average pressures for the Atlantic, with a late summer warm neutral or El Nino to boot, denoting a change from previous forecasts. This caused some rethinking of seasonal activity, though, of course, with skepticism. To quote Levi Cowan at the time, "It's not time to throw in the towel, but either the models or the humans are going to be horribly wrong about this hurricane season." You can follow along on the old 2013 indicators thread.

Thanks for bringing this up! Looking back at old predictions is helpful and one point I'd like to reiterate is to post images! Its helpful looking at them especially ones that are not hotlinked to compare.

[tolakram]

Instability better than past years but not above average yet. Just throwing a wrench in the works here and there.

[RL3AO]

I'm sure most people are picking up on this, but I'll repeat it. The next two weeks look very interesting in the Atlantic (BY JUNE STANDARDS!). There is a good chance we don't even get Bret in the next couple weeks. However, between the monsoon gyre and the models hinting at a fairly active ITCZ (once again by June standards), I'm somewhat excited to see what the next couple weeks can bring.

[tarheelprogrammer]

Here is a comparison of 2013 to now on the same date in the ITCZ:

2013:


Now:

[cycloneye]

Definitly an active ITCZ for "June standards" as RL3AO said.

[Ntxw]

I took a snapshot of 300mb specific humidity just to take a look at mid level air for May and the first week or so of June

Not dry like 2013, MDR seems about normal to slightly moist



Here are some chosen curious years

2013- noticeably dry more than this year across the MDR


2004-MDR is good


2005-MDR is somewhat moist, noticeably moist in the eastern MDR for waves coming off Africa


Last year 2016-noticeably more moist especially the streak that Matthew took from the eastern Carib then northward, that would've foretold the season.

[Hammy]

The Atlantic certainly looks odd at the moment, the western half of the basin resembles mid-to-late May, while the eastern half resembles the first or second week of July.

[tarheelprogrammer]

The Atlantic certainly looks odd at the moment, the western half of the basin resembles mid-to-late May, while the eastern half resembles the first or second week of July.

Personally I think it is a sign that the Atlantic is about to flip the switch on. Just a gut feeling when looking at analog years, and past satellite images from active years.

A few eerie analogs starting to show up on Tropical Tidbits:

[TheStormExpert]

Look for tropical development somewhere in the Atlantic basin within the upcoming week or so.

 https://twitter.com/mjventrice/status/873502361842483200




 https://twitter.com/mjventrice/status/873502778894766080




 https://twitter.com/mjventrice/status/873504571817111552

[Alyono]

early 300mb moisture may not mean much aside from shot term development. The 300mb was dry in 2005 in the Gulf, yet that was the focus of that season with 11 storms in the Gulf

[cycloneye]

What Eric Blake says of 80%? is the probability the calibrated EP had for a MDR (East of Lesser Antilles) developmemt but it was a false alarm per Michael Ventrice.

 https://twitter.com/EricBlake12/status/873509335791538176




 https://twitter.com/MJVentrice/status/873511064415199232

[Kingarabian]

I'm not sure how Ventrice got a calculated 80% possibility from the EPS in regards to MDR development, when not once did the EPS show development there?

[tarheelprogrammer]

Very impressive over Africa right now:

[NDG]

 https://twitter.com/BigJoeBastardi/status/874223792398139393

[SFLcane]

Yikes!

 https://twitter.com/bennollweather/status/874222777036808193

[cycloneye]

Eric Blake says it all.

 https://twitter.com/EricBlake12/status/874274104408510465

[wxman57]

RAMMB/SSD's instability archives haven't been updating past 2013, so I browsed around for instability charts people happened to save on forums, blogs, and etc. and found enough early season material to stitch together a graph of 2013, 2014, 2015, 2016, and 2017's tropical Atlantic instability. Unfortunately the other graphs aren't posted as often so I probably can't stitch together a similar quantity of data for other regions or tropical cyclone formation potential variables like wind shear or cold water vapor areal coverage.
http://i.imgur.com/Ifzyz7d.png

How did you get this graphic? I'd like to keep it updated for 2017.