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

[Shell Mound]

https://twitter.com/webberweather/status/1295443555759140868

This is pretty scary. Hyperactivity highly likely and that phase is suppose to stick for a while. Never seen anything like this.

We could certainly witness three or even four named storms within the next seven days, including 97L, 98L, this area, and a wave currently over Ghana that is expected to emerge from West Africa in about three days. The current setup with the MJO, in conjunction with the global background state, is about as conducive as it gets for two or more tropical cyclones, including one or more (potentially intense) hurricanes, to form and coexist in the Atlantic basin. Vertical wind shear will be below average, PWATs will be high, and the ITCZ will be displaced to the north.

[TheStormExpert]

Please don't attack me for posting this!

This guy used to be on this forum so it's interesting to see what he has to say.

 https://twitter.com/DerekOrtt/status/1295757314616709120




 https://twitter.com/DerekOrtt/status/1295744886361251840

[CyclonicFury]

Please don't attack me for posting this!

This guy used to be on this forum so it's interesting to see what he has to say.

https://twitter.com/DerekOrtt/status/1295757314616709120

https://twitter.com/DerekOrtt/status/1295744886361251840

No offense to Derek, but I remember him comparing 2017 to 2013 when Harvey struggled in the MDR. That obviously wasn't the case.

[TheStormExpert]

Please don't attack me for posting this!

This guy used to be on this forum so it's interesting to see what he has to say.

https://twitter.com/DerekOrtt/status/1295757314616709120

https://twitter.com/DerekOrtt/status/1295744886361251840

No offense to Derek, but I remember him comparing 2017 to 2013 when Harvey struggled in the MDR. That obviously wasn't the case.

I remember him as Alyono and he had some interesting things to say! Was just posting for some giggles.

[Steve]

Please don't attack me for posting this!

This guy used to be on this forum so it's interesting to see what he has to say.

https://twitter.com/DerekOrtt/status/1295757314616709120

https://twitter.com/DerekOrtt/status/1295744886361251840

No offense to Derek, but I remember him comparing 2017 to 2013 when Harvey struggled in the MDR. That obviously wasn't the case.

I love Derek and was a big fan of him as Alyono as well. I think it's important to differentiate that he's saying the GFS continues to forecast a Mark McGuire version of 2013.

[gatorcane]

The GFS has been keeping all of the activity in the EPAC and so far it is verifying.

Eventually we should get some significant storms in the Atlantic per climo as we are getting closer to the peak.

[EquusStorm]

Ok but the GFS has been predicting monsters pretty much all season there and only now does that actually happen, it's more throwing things at the wall until it sticks and claiming victory than accurate modeling

Hopefully that means it's actually getting a handle on things now and getting back to the excellent model it was in previous years; it was objectively not very good in either basin last month

[ClarCari]

Is it normal for tropical waves to speed off of Africa so fast!? This is the first season i’ve tracked storms hour by hour lol but I remember this being a problem with Isaias and I’m curious if steering patterns or something else in the atmosphere are making these things moves so fast that they can’t get their act together. I wanted to ask in the Invest threads but they both are having the same issue that I couldn’t chose which one bahahah.

[TheStormExpert]

Ok but the GFS has been predicting monsters pretty much all season there and only now does that actually happen, it's more throwing things at the wall until it sticks and claiming victory than accurate modeling

Hopefully that means it's actually getting a handle on things now and getting back to the excellent model it was in previous years; it was objectively not very good in either basin last month

We’ve only seen 2 majors in the East Pacific out of how many the GFS has forecasted since May or June?

[captainbarbossa19]

While 97L and 98L are currently struggling to organize, one thing to keep in mind is that it is still only August 18th. Three years ago, Harvey was struggling to organize in the MDR and opened into a wave on the 19th in the Caribbean. Five days later, it reformed in the Gulf of Mexico and then eventually became a major hurricane. While it is impossible to say what is going to happen right now, it is still not quite August 20th. Many times, things seem to change once you reach this date.

[EquusStorm]

Ok but the GFS has been predicting monsters pretty much all season there and only now does that actually happen, it's more throwing things at the wall until it sticks and claiming victory than accurate modeling

Hopefully that means it's actually getting a handle on things now and getting back to the excellent model it was in previous years; it was objectively not very good in either basin last month

We’ve only seen 2 majors in the East Pacific out of how many the GFS has forecasted since May or June?

Yup, essentially forecasted a climo July in both basins, many ghosts that would have probably materialized big time in an El Niño year... I'd like to see a comparison of every storm in both basins from 24 and 48 hours before genesis to see exactly how well it did do at least in the EPac

[Hammy]

The GFS has been keeping all of the activity in the EPAC and so far it is verifying.

Eventually we should get some significant storms in the Atlantic per climo as we are getting closer to the peak.

GFS has actually been doing this since early July and completely missed everything that's formed so far--including two hurricanes.

[toad strangler]

Double Shot Tuesday

[AutoPenalti]

Double Shot Tuesday

http://i.ibb.co/2YB3cGP/boom.png

Great, another AEW that won’t develop.

[toad strangler]

Double Shot Tuesday

http://i.ibb.co/2YB3cGP/boom.png

Great, another AEW that won’t develop.

Looks like a fish even to the islands but you know how that can go!

[Kazmit]

Double Shot Tuesday

http://i.ibb.co/2YB3cGP/boom.png

Great, another AEW that won’t develop.

The models will be all over it in a few days only to drop it shortly thereafter. Only then can it develop.

[Steve]

Is it normal for tropical waves to speed off of Africa so fast!? This is the first season i’ve tracked storms hour by hour lol but I remember this being a problem with Isaias and I’m curious if steering patterns or something else in the atmosphere are making these things moves so fast that they can’t get their act together. I wanted to ask in the Invest threads but they both are having the same issue that I couldn’t chose which one bahahah.

Sometimes yeah. You’ll even see lows moving across faster. Sometimes it’s 10 or 15k. It kind of depends on what all is happening. Right now we have very strong high pressure across much of the Atlantic. It’s a couple of pretty powerful ridges. So you expect storms riding south of it to be booking up to a certain point. And that will be where things like amplification or stuck upper pressure systems can slow things down. Right now that appears to be the western Caribbean so we willl see later this week.

[USTropics]

Is it normal for tropical waves to speed off of Africa so fast!? This is the first season i’ve tracked storms hour by hour lol but I remember this being a problem with Isaias and I’m curious if steering patterns or something else in the atmosphere are making these things moves so fast that they can’t get their act together. I wanted to ask in the Invest threads but they both are having the same issue that I couldn’t chose which one bahahah.

Welcome to the board and great question! Ultimately forward speed is influenced by a few mechanisms. For starters, easterly flow is the biggest factor. Baroclinic/barotropic processes involving the African Easterly Jet (located to the north ~ 600mb) and the Tropical Easterly Jet (located to the south ~ 200mb) are the main components over Africa/eastern Atlantic. Here is visual representation of this for August 1st - 16th:

African Easterly Jet


Tropical Easterly Jet


The African Easterly Jet (AEJ) arises as a result of a reversal of lower tropospheric temperature gradient over western/central Africa. Essentially we have this really warm, dry air over the Sahara Desert (red) to the north (~42 - 46 C) and significantly cooler temperatures to the south (blue) along the coastal countries (~20 - 24 C):


Once we get through Africa/eastern Atlantic, steering currents and speed is largely dictated by the Azores/Bermuda high and location of ridging. Orientation and pressure gradient forcing is the largest influence:


In addition, a more shallow system (i.e. a tropical wave or weak system) will be influenced more by the low-level flow (which typically means a faster forward speed).

[Hammy]

FWIW with the models there may have been some bad or incomplete data ingested into the models last night and this morning--I checked yesterday's CFS run and it pretty much cancelled hurricane season after a few weeks of pretty consistent runs showing almost nonstop activity in September, and today's run is back to that hyperactivity as the global models return to showing development.

[HurricaneEdouard]

The Australian Bureau of Meteorology has now issued a La Nina alert, with a 70% chance of developing in 2020 (compared to NOAA's 60% in July). Every climatological factor is aligning behind 2020; La Nina developed in autumn in 2005, as well.