ATL: DEBBY - Post-Tropical - Discussion

[toad strangler]

12Z models are in very good agreement now. TS passing west of Tampa late Sunday morning and making landfall north of Tampa by mid-afternoon. GFS gave up on the hurricane prediction. Euro and Canadian have landfall as a TD. Only significant disagreement is how close it tracks to the East U.S. Coast early next week. ICON is farthest, GFS farthest west. GFS takes the center over the OB as a possible hurricane next Friday morning before turning it sharply ENE and out to sea.

So no stall like some models were showing? Thanks in advance.

I wouldn't completely rule out a stall. There is still a large amount of uncertainty as a TD hasn't even formed yet.

Levi Cowan talked about this in his newest video. It's not out of the question by any means. He explains that the quick moving short wave trough that creates the flow for 97L to move N will be exiting rather quickly leaving HP filling in from the west. Steering collapses. All depends on where 97L is when that happens.

[Stormlover70]

Stormlover70 no a stall is definitely on the table if not likely at this point because eventually the ridge does trap the system, its whether that occurs in the gulf or off the se US coast remains unclear, its a very complex pattern

thanks. They just cut a huge tree down near my house talk about good timing. I went through Elena so I know the similarities with a fickle system.

[Nimbus]

Stormlover70 no a stall is definitely on the table if not likely at this point because eventually the ridge does trap the system, its whether that occurs in the gulf or off the se US coast remains unclear, its a very complex pattern

The storm would have to move quickly up the west coast of Florida and escape through the weakness to avoid a stall.
Ridge building east would *probably* trap any energy left off Tampa after Sunday.

[IcyTundra]

So no stall like some models were showing? Thanks in advance.

I wouldn't completely rule out a stall. There is still a large amount of uncertainty as a TD hasn't even formed yet.

Levi Cowan talked about this in his newest video. It's not out of the question by any means. He explains that the quick moving short wave trough that creates the flow for 97L to move N will be exiting rather quickly leaving HP filling in from the west. Steering collapses. All depends on where 97L is when that happens.

I saw his video earlier today and he did a good job of explaining the situation as always. He is at the top of my list of meteorologists I pay attention to.

[BobHarlem]

From Tampa AFD 2:55pm

Now lets get into this weekend and early next week. What we know for
sure is a tropical wave current over Haiti will be moving into the
Gulf of Mexico by late Saturday and into our Sunday. Models, at
least for now, have come into better agreement that this wave or low
pressure will be in the Gulf and near Tampa around 18Z Sunday. The
strength of this system at that time is still in question with
models ranging from an open wave to a low end Cat 1 hurricane.
Models still slowly move this system north and northeast on Monday
and pushing into the panhandle and North Florida. At that point
there is still a big spread in speed of the system. The stronger GFS
has the storming moving out of the area by Monday evening while EURO
has the system lingering around north Florida and south Georgia
through early Wednesday. Right now our main concern will be heavy
and persistence rainfall with a slowly moving storms with the
reasonable worst case scenario rainfall totals between 4 to 6
inches.

[fci]

If this does go thru the FL straits and E GOM would SE FL (Keys to WPB) get the "dirty" NE side?

Right the threat is for heavy rainfall as mentioned any loose not developed tc could have the its weather spread out. Follow your local weather office on social media for local info. Or stay here on S2K.

Most likely just a rain maker for us in SE Florida.

[Sciencerocks]

[WaveBreaking]

https://i.imgur.com/W4rdcn4.gif

The convective blowup over Haiti that the GFS has been hinting at might be starting soon.

[canes04]

Possible low on NE tip of Haiti. Convection building.
I believe this one will be a head scratcher.

[Stormlover70]

Possible low on NE tip of Haiti. Convection building.
I believe this one will be a head scratcher.

way too far south

[Hurrilurker]

Maybe I'm crazy but to me it looks like circulation is starting far to the north, over Turks & Caicos. Or are those the wrong level clouds?

[skillz305]

What is with some of these ensembles showing a due east cut across central Florida? Kind of concerning.

[Stratton23]

The Mid level center is still over land, i would expect any sort of “ circulation “ to the north of that would probably get pulled closer to the MLC over lans, im thinking the southern lobe takes over as the wave pretty much goes due west over cuba

[johngaltfla]

If I had a dollar for every spaghetti model for a wave or invest that showed a direct hit on Sarasota-Venice, I would own this place, the NHC, one of those cool USAF stormchaser planes, and at least two Lambos.

[floridasun]

this from miami fl weather office that south fl may get alot rain that their not sure how much affect we will have because we sure were low will form if get cl;ose to south fl we here could get worst weather. ( sw florida need keep eye close in case pass close ) that from me not nws

[underthwx]

My question comes after reading this excerpt from the New Orleans AFD...."Now for the elephant. At the moment, global suites are showing the
very large open tropical wave oriented meridionally over Puerto Rico
this morning possibly cutting off a circulation from its northern
end as it reaches central to western Cuba by Sunday or Monday.
This is common in the summer months and its one of the many
things we look for when something is trying to develop. The
steering is fairly straight forward "no pun intended" at first.
This is because the draw will come from the short wave digging
through the midwest this morning. These two features will be
closest when they are meridonal from each other along the 84th
longitude line by late Sat or early Sun with less than 10 degrees
of seperation. This will be the time of greatest draw northward
toward this trough. And whether this develops into a tropical
system or not, the draw of this mass will still be northward
during this time frame. From model perspective, this tropical
feature gets left behind as the short wave quickly swings through
and the tropical cyclone is just not moving fast enough to engage
the trough. This leaves a frontal boundary over or near the coast
and allows the SW CONUS high to then ridge back into the gulf
south blocking this tropical cyclones movement north by late
Monday. This is where models start to have their strongest
disagreement as they differ on how long the keep this ridging
active over the area and timing of the next short wave digging
into the midwest. Nothing to say after Monday at the moment. But a
simimlar solution is found in each model up to that time frame.
Basically, a circulation develops over the eastern
gulf/Florida/Western Atlantic moves northward Sun into Mon before
stalling somewhere near the lat30 line. Now for the biggest
problem with the extended fcast. Every model is bogusing if, when,
how and where they develop this circulation. And this is where
the problem is with fcasting any tropical system; something needs
to actually form first before it can be further assessed as to
what, where and when things will occur. It is always best to keep
up with the latest fcast and make sure you are always prepared,
especially during this time of year.".......

From what I understand....97L has the possibility of basically stalling/meandering around if it does not get picked up by the shortwave from the midwest?....I know this is a way too early to tell question....if 97L stalls....what are some track scenarios?...

[jlauderdal]

this from miami fl weather office that south fl may get alot rain that their not sure how much affect we will have because we sure were low will form if get cl;ose to south fl we here could get worst weather. ( sw florida need keep eye close in case pass close ) that from me not nws

Stay safe floridasun, looks like just rain for our area but that could change, keep updated.

[MetroMike]

My question comes after reading this excerpt from the New Orleans AFD...

Now for the elephant. At the moment, global suites are showing the
very large open tropical wave oriented meridionally over Puerto Rico
this morning possibly cutting off a circulation from its northern
end as it reaches central to western Cuba by Sunday or Monday.
This is common in the summer months and its one of the many
things we look for when something is trying to develop. The
steering is fairly straight forward "no pun intended" at first.
This is because the draw will come from the short wave digging
through the midwest this morning. These two features will be
closest when they are meridonal from each other along the 84th
longitude line by late Sat or early Sun with less than 10 degrees
of seperation. This will be the time of greatest draw northward
toward this trough. And whether this develops into a tropical
system or not, the draw of this mass will still be northward
during this time frame. From model perspective, this tropical
feature gets left behind as the short wave quickly swings through
and the tropical cyclone is just not moving fast enough to engage
the trough. This leaves a frontal boundary over or near the coast
and allows the SW CONUS high to then ridge back into the gulf
south blocking this tropical cyclones movement north by late
Monday. This is where models start to have their strongest
disagreement as they differ on how long the keep this ridging
active over the area and timing of the next short wave digging
into the midwest. Nothing to say after Monday at the moment. But a
simimlar solution is found in each model up to that time frame.
Basically, a circulation develops over the eastern
gulf/Florida/Western Atlantic moves northward Sun into Mon before
stalling somewhere near the lat30 line. Now for the biggest
problem with the extended fcast. Every model is bogusing if, when,
how and where they develop this circulation. And this is where
the problem is with fcasting any tropical system; something needs
to actually form first before it can be further assessed as to
what, where and when things will occur. It is always best to keep
up with the latest fcast and make sure you are always prepared,
especially during this time of year.

From what I understand....97L has the possibility of basically stalling/meandering around if it does not get picked up by the shortwave from the midwest?....I know this is a way too early to tell question....if 97L stalls....what are some track scenarios?...

Sound like a discussion from this morning. Things area rapidly evolving and solutions are not out there yet.

[Nimbus]

this from miami fl weather office that south fl may get alot rain that their not sure how much affect we will have because we sure were low will form if get cl;ose to south fl we here could get worst weather. ( sw florida need keep eye close in case pass close ) that from me not nws

Keeping my eye on the Windward Passage for thunderstorms.
If there is low level energy it may focus there.

[floridasun]

this from miami fl weather office that south fl may get alot rain that their not sure how much affect we will have because we sure were low will form if get cl;ose to south fl we here could get worst weather. ( sw florida need keep eye close in case pass close ) that from me not nws

Keeping my eye on the Windward Passage for thunderstorms.
If there is low level energy it may focus there.

we need see if low form between Haiti and Cuba move north coast Cuba and pass between south fl and Cuba into gulf that wont good because more time in hot gulf