ATL: DORIAN - Post-Tropical - Discussion

[TheStormExpert]

If Dorian doesn't build convection during DMAX,then it will be toast.

What's DMAX?

[RL3AO]

Ah the evening. Like clockwork the "it looks like garbage" posts come.

[TheStormExpert]

It just seems like we haven't had a decent storm to track in the Atlantic in years! Besides Sandy, and Irene to some extent.

[ozonepete]

Just cant see Dorian doing much from the looks of this water vapor image

Just remember you are looking at the current state of the mid and upper levels of the troposphere as illustrated by a water vapor loop. The water vapor loop (and the actual state of the mid to upper troposphere) can look completely different 3 or 4 days from now. And probably will.

[SFLcane]

Unless things dramatically change i cant see how the NHC maintains a moderate TS through those hostile conditions just ahead.

[summersquall]

If Dorian doesn't build convection during DMAX,then it will be toast.

What's DMAX?

Per wunderground http://www.wunderground.com/blog/future ... ntrynum=39

"Diurnal maximum and minimum. During the day it is diurnal minimum over water because, the surrounding air has less specific heat capacity than the sea,and thus warms faster, but cools down faster during the night. During the night time, the water is typically warmer than the surrounding air. Now the air near the surface which is in contact with the water warms by conduction, and then begin to rise. The during the day, the warming of the air which is above the water creates a quasi-capping inversion, inhibiting convection. Keep in mind that air rises from the surface to the higher levels, so when the air warmer than the sea during the day, it acts as a lid."

Thus, in the evening, convection tends to fire.

[meriland23]

http://www.ssd.noaa.gov/goes/east/catl/flash-wv.html


looks super super weak.. is it dead?

[TheStormExpert]

Unless things dramatically change i cant see how the NHC maintains a moderate TS through those hostile conditions just ahead.

It shocks me they're expecting this storm to become a strong 70mph Tropical Storm in 4-5 days.

[stormhunter7]

bet the mid level winds, along with dry air are beginning to win over the tropical warm air mass being pulled up from the ITCZ. Plus the slightly cooler SST's the system is over now. Its gonna be hard to tell how the storm will do for the next 48hrs.. after that, the warm waters should come back into play. I just have a hard time with a system moving 20mph with that flow to the north... to do much of anything. Time will tell.

[torrea40]

http://www.ssd.noaa.gov/goes/east/catl/flash-wv.html


looks super super weak.. is it dead?

Dry air...

[SFLcane]

Look at those clouds in the WV loop i posted how they are racing towards the east out of the caribbean. Also see a huge upper level low with plenty of dry sinking air across the central atl just waiting for tiny dorian.

[TheStormExpert]

Here is the latest SAL graphic:

[Alyono]

that is a very strong SAL surge that is overtaking the storm

[ozonepete]

If Dorian doesn't build convection during DMAX,then it will be toast.

What's DMAX?

Per wunderground http://www.wunderground.com/blog/future ... ntrynum=39

"Diurnal maximum and minimum. During the day it is diurnal minimum over water because, the surrounding air has less specific heat capacity than the sea,and thus warms faster, but cools down faster during the night. During the night time, the water is typically warmer than the surrounding air. Now the air near the surface which is in contact with the water warms by conduction, and then begin to rise. The during the day, the warming of the air which is above the water creates a quasi-capping inversion, inhibiting convection. Keep in mind that air rises from the surface to the higher levels, so when the air warmer than the sea during the day, it acts as a lid."

Thus, in the evening, convection tends to fire.

You left out the most important part. Start with remembering that the tall thunderstorms that drive these tropical cyclones are tall because there is large difference in temperature between the warm inflowing surface air under the thunderstorm and the very cold cloud tops at the tops of them. During the day incoming solar radiation will heat the cloud tops, causing them to warm and thus reducing the temperature difference between the top and bottom of the thunderstorms - this makes them less intense. At night, with no incoming solar radiation, the cloud tops cool quite a bit and the temperature difference between cloud top and bottom becomes much larger, thus more intense thunderstorms.

[TheStormExpert]

Stable air has been on the list of possible factors for this storm for days now.

[SFLcane]

This thing nearly has 0 model support at the moment.

[tailgater]

Tomorrow morning we'll be hollering it's a cane with eye.

[summersquall]

You left out the most important part. Start with remembering that the tall thunderstorms that drive these tropical cyclones are tall because there is large difference in temperature between the warm inflowing surface air under the thunderstorm and the very cold cloud tops at the tops of them. During the day incoming solar radiation will heat the cloud tops, causing them to warm and thus reducing the temperature difference between the top and bottom of the thunderstorms - this makes them less intense. At night, with no incoming solar radiation, the cloud tops cool quite a bit and the temperature difference between cloud top and bottom becomes much larger, thus more intense thunderstorms.

Thank you ozonepete. I really appreciate learning more from you and the other great contributors here.

[meriland23]

So what is your opinion, is it turning into bones you think? or the 'calm before the storm' so to speak.. you think it will strengthen?

[TheStormExpert]

Tomorrow morning we'll be hollering it's a cane with eye.

I could of sworn last night at this time we were hollering that it kind of looked like it could be trying to make a run for hurricane status.