2020 Atlantic Hurricane Season

[cptcatz]

The GFS backed off the June 17 storm for a few days but is back with it on today's 12z run. This run has it going right into the northern Gulf coast so it's definitely something to keep an eye on.

[Windspeed]

All signs within long range modeling pointing towards a very active synoptic setup for the heart of the Atlantic Hurricane Season:

 

 

[Windspeed]

[Windspeed]

[Windspeed]

Informative chain thread on long-range modeling SSTs and steering pattern for 2020 Atl Hurricane Season:

 

[Windspeed]

Maps of TCHP and depth of 26°C isotherm. I never recall seeing such high-end anomalous kinetic energy stored up this early in the calendar year. These maps look more akin to mid-August. There will be an amplified easterly jet below 700 hpa this week that will hopefully bring down / cool off the MDR somewhat. But with hints in long-range modeling suggestive of a synoptic pattern that would support long-tracking deep Caribbean TCs, the anomalous OHC is a bit troubling, especially given the atmospheric pattern for velocity potential over the Caribbean may be among the most favorable for TCs development during the heart of the season.

[Windspeed]

^ RE: Long-range velocity potential mentioned above into July from GFS and EPS members:

[Windspeed]

Though I have been sharing posts from meteorological and climatological social media, and making comments of my own about the 2020 season, I've yet to make a formal post on any predictions. At this point, it's probably not going to surprise anyone that I am now calling for a "hyperactive" 2020 Atlantic hurricane season. There is no doubt that it will be active, but too many signals are suggesting we will see a big ACE producing year. Possibly even near to something like 2017. Though I do expect more action in the deep Caribbean vs the northern, I also expect MDR development in August-October to be above normal with plenty of cyclogenesis occurring at low latitudes. We may see an Ivan, Dean, Allen or Gilbert type powerful Cape Verde Hurricane reach Central America or the GOM. I expect significant Western Caribbean development as well. Perhaps more than one. The setup looks amped for big numbers and indicators make it difficult to not give into the hype. So really if we see anything not representative of a very active to hyperactive season by October, this would be a huge forecast bust. I am pretty confident in these numbers: An additional 19 tropical cyclones beyond Cristobal for a total of 22, 11 of those hurricanes, 6 being majors, with around 190 accumulated cyclone energy (ACE) for the season.

 

Edit: Already revising total numbers up to 22 as I was thinking ahead and did not account for having had 3 TCs already.

[LansingWeather]

6 hours ago, Windspeed said:

Though I have been sharing posts from meteorological and climatological social media, and making comments of my own about the 2020 season, I've yet to make a formal post on any predictions. At this point, it's probably not going to surprise anyone that I am now calling for a "hyperactive" 2020 Atlantic hurricane season. There is no doubt that it will be active, but too many signals are suggesting we will see a big ACE producing year. Possibly even near to something like 2017. Though I do expect more action in the deep Caribbean vs the northern, I also expect MDR development in August-October to be above normal with plenty of cyclogenesis occurring at low latitudes. We may see an Ivan, Dean, Allen or Gilbert type powerful Cape Verde Hurricane reach Central America or the GOM. I expect significant Western Caribbean development as well. Perhaps more than one. The setup looks amped for big numbers and indicators make it difficult to not give into the hype. So really if we see anything not representative of a very active to hyperactive season by October, this would be a huge forecast bust. I am pretty confident in these numbers: An additional 19 tropical cyclones beyond Cristobal for a total of 22, 11 of those hurricanes, 6 being majors, with around 190 accumulated cyclone energy (ACE) for the season.

 

Edit: Already revising total numbers up to 22 as I was thinking ahead and did not account for having had 3 TCs already.

why do you think the MDR will spawn a lot of low latitude TC's?

[Windspeed]

why do you think the MDR will spawn a lot of low latitude TC's?

Strong +AMO/+NAO with robust Azores ridging may keep the wavetrain and ITCZ slightly displaced at a lower latitude this August-October. Though it should back down somewhat, the pattern could result cyclogenesis at slightly lower latitudes within the MDR and ESE of the Lesser Antilles.

[Windspeed]

I was actually looking at the TCHP a little earlier and I think that may be a bug in the graphic? Just look at the explosion in a few days time. 

 

 
Really odd, no? Wouldn’t we also see a similar explosion of the D26 extent/depth? Either way, quite robust TCHP/SST signal.

Awesome for you to have gone back and checked previous days. Yes, something is amiss.

[Windspeed]

The previous TCHP maps may have been showing old data. This does seem to make sense based on the Gulf Stream data from last week being virtually non-existant for heat content on previous maps. There should be noticeable kinetic energy in the GS off of Florida by this time frame, yet last week's maps were showing zilch there.

[jbenedet]

Would think this is adequate for a 10% lemon, over next day or two.
 

A weak cold front is expected to move off the 
southeastern U.S. coast early next week, then stall over the 
northern Florida offshore waters through Wed. Low pressure may 
form along the front. The front will weaken into a trough from Wed
into Thu. While this takes place, a trough will linger between 
South Florida and the NW Bahamas. Expect unsettled weather 
conditions over the waters in the vicinity of the Bahamas and 
westward to the Florida coast for the next few days.

$$
Ramos

[jaxjagman]

It doesn't have great support right now ,but the KW looks much stronger on today's CFS .It hasn't been showing much of anything past the Eastern Pac but now it does into the 3rd week of June

[jaxjagman]

Seemingly as well if everything teleconnects there should be should be a Upper Level Ridge in the East towards the end of the month, but its still in the long range and could change.but todays Euro shows this in East China into Korea

[Windspeed]

ECMWF + UKMET long-range precipitation forecast courtes of Ben Noll Weather..

 

 

 

 

[yoda]

5 hours ago, Windspeed said:

ECMWF + UKMET long-range precipitation forecast courtes of Ben Noll Weather..

 

 

 

 

 

See a good amount of recurve and Caribbean cruisers if that is to be believed... not much action in GOM or around the islands

[Windspeed]

[LoboLeader1]

This may hinder tropical development for a while.

[etudiant]

2 hours ago, LoboLeader1 said:

This may hinder tropical development for a while.

I'm puzzled, the prior posting by Windspeed shows much above average rainfall in the same area that this unusual amount of dust is coming from. Can someone please help explain?

[Windspeed]

I'm puzzled, the prior posting by Windspeed shows much above average rainfall in the same area that this unusual amount of dust is coming from. Can someone please help explain?

The dust is coming from the Saharan and portions of the sub-Saharan that is not within the above normal precipitation regions discussed earlier. Yes, Morocco and Northern Algeria has seen above normal precipitation due to cutoffs and the previous -NAO pattern, which tracked extra tropical cyclones into the Mediterranean off of the Eastern Atlantic. This had little influence on the main desert regions though. In the image below, the two red Xs have remained normal (dry, low precip) over Saharan and sub-Saharan. The blue X has seen above normal, but that is still mostly an arid region. The point of the original post above was to show the extreme above normal precipitation amounts for already generally moist grasslands and forest regions of the interior and west-central African continent, south of the sub-Saharan region. This suggests increased numbers of multi-convective systems and tropical waves advancing through the West African Monsoon (WAM), which should increase activity out into the Atlantic ITCZ and MDR through the heart of the Cape Verde stretch of the season.

 

As for the dust, the Azores ridge is cranking below the 700 hpa level of the atmosphere seen in purple below. This is inducing strong easterly trades off the Sub-Saharan region pulling desert dust along with it. The low-level easterly jet burst will push all the way across the Atlantic over the next 10 days.

[etudiant]

7 hours ago, Windspeed said:

The dust is coming from the Saharan and portions of the sub-Saharan that is not within the above normal precipitation regions discussed earlier. Yes, Morocco and Northern Algeria has seen above normal precipitation due to cutoffs and the previous -NAO pattern, which tracked extra tropical cyclones into the Mediterranean off of the Eastern Atlantic. This had little influence on the main desert regions though. In the image below, the two red Xs have remained normal (dry, low precip) over Saharan and sub-Saharan. The blue X has seen above normal, but that is still mostly an arid region. The point of the original post above was to show the extreme above normal precipitation amounts for already generally moist grasslands and forest regions of the interior and west-central African continent, south of the sub-Saharan region. This suggests increased numbers of multi-convective systems and tropical waves advancing through the West African Monsoon (WAM), which should increase activity out into the Atlantic ITCZ and MDR through the heart of the Cape Verde stretch of the season.

 

As for the dust, the Azores ridge is cranking below the 700 hpa level of the atmosphere seen in purple below. This is inducing strong easterly trades off the Sub-Saharan region pulling desert dust along with it. The low-level easterly jet burst will push all the way across the Atlantic over the next 10 days.

Thank you, that is very informative. One forgets how big Africa is, lots of room for both wet and dry regions.

[cptcatz]

So is the rain that has already fallen in Africa going to impact peak season?  In other words, if it totally stops raining right now, are the pieces already in place for an active MDR during peak season?

[Windspeed]

So is the rain that has already fallen in Africa going to impact peak season?  In other words, if it totally stops raining right now, are the pieces already in place for an active MDR during peak season?

That precip anomaly map only matters to show that the pattern from the Indian Ocean to West Africa has favored stronger intertropical frontal troughs to support wave formation in the interior of central Africa. This has coincided with an amped West African Monsoon, resulting in a much wetter pattern than normal the past few months. The pattern could, of course, change. At any rate, the N. African anticyclone / SAL typically breaks off aerosol-laden dry airmasses during this stretch of Summer when typical strong Azores ridging below the 700 hpa layer begins cranking the ENE and easterly jet off of NW Africa. But by mid-July to mid-August, the Azores SPHP generally shifts west into a SER/WAR regime, especially during a +AMO/+NAO/-ENSO setup, allowing WAM to expand west of the Cape Verdes and ITCZ to gain latitude. If that occurs, increased numbers of tropical waves and MCSs exiting Africa into the Atlantic MDR would seem to favor the MDR being active this year. I believe it will even be hyperactive based on earlier discussions in this thread, but we shall see.

[Windspeed]

Notice in long-range modeling, the region of above median precipitation shifts from interior western Africa to off of the western coastal region of Africa, just south of the Cape Verdes, into the Atlantic MDR. The ITCZ and WAM becomes focused there. As such, this suggests that easterly intertropical waves that continue forming over deep interior and eastern Africa, if their energy holds together, will move off the African coast, and should reach a favorable environment for tropical development somewhere within the MDR:

[Windspeed]

[Windspeed]

[andyhb]

On 6/15/2020 at 9:19 PM, yoda said:

See a good amount of recurve and Caribbean cruisers if that is to be believed... not much action in GOM or around the islands

The AA precip over almost the entire Gulf suggests a quiet Gulf?

[Windspeed]

[WhiteoutWX]

How will the current SAL outbreak influence this otherwise favorable period? Is it expected to subside soon?