• Hello, please take a minute to check out our awesome content, contributed by the wonderful members of our community. We hope you'll add your own thoughts and opinions by making a free account!

Tropical 2020 Atlantic Hurricane Season Discussion

with the record warm winter in most areas it does make you wonder

but it is very very early
 
I was wondering if the early mild temps we’ve had might lead to any changes in the timing of onset of hurricane season or intensity? I’m sure it’s much more complicated than that but a question none the less.
I would think that with the milder than average sea surface temperatures in the Gulf and off the SE coast, you would want to keep a closer eye out for convection forming along fronts that stall out in those areas come early May.
 
Bertha and Teddy. Big names will be retired one day. The rest are silly names so should be weak folks.
 
With a mild winter and upcoming weather I believe we need to look for a home grown system. Also need to watch the Tennessee area as it is prone to flooding if something goes inland .
 
First storm of the season forming East of NC. Poss. hurricane.
 
This needs a name. I’ve seen way less with a name. 00FCCD51-112C-4E14-9533-5064EE26C9A4.jpeg
 
This needs a name. I’ve seen way less with a name. View attachment 38213

For the moment, this is not anywhere close to becoming a tropical cyclone.


1585765677461.png



Imo, the tell-tale sign of a tropical cyclone is a low-mid level potential vorticity tower superimposed directly onto the strongest portion of the surface circulation, we don't see that here in addition to the strong thermal advection that's occurring around the cyclone.

In fact using a PV cross section, we see exactly the opposite of what we'd expect for a TC, with a cyclone (trough) at the tropopause and depression in tropopause heights (warm shading sags towards the surface) and its displaced westward of the surface cyclone, this is a classic signature of baroclinic instability and an extratropical cyclone w/ colder deep-layer tropopause and maximum cyclonic anomaly at the tropopause.

1585765972732.png


If we step forward about 3-4 days, things have changed. Notice the cyclonic anomaly at the tropopause is weaker &/or non-existent, and it would be at this point, where shallow convection could develop and via PV redistribution, completely erode the upper-level cyclonic PV anomaly and instead create a upper-level PV ridge.

This process of an extratropical cyclone gradually acquiring warm-core characteristics over time is more formally known as tropical transition. It usually takes at a minimum, 3-4 days for convection to have cumulatively generated enough diabatic heating to erode the initial deep-layer tropopause cold anomaly when the cyclone was still cold-core/extratropical, and for subsequent potential vorticity redistribution to have built up & reinforce the "shallow" warm core & thus officially become a subtropical cyclone.

1585766285576.png
 
Back
Top