ATL: ELSA - Post-Tropical - Discussion

[Michele B]

What's up with the annoying blob south Cuba? Does it have any significance on anything?

Very good question…it is a good size blob with ‘activity’. HWRF says she drags it up as a long tail. Think this is what went ‘under’ Jamaica and then never quite merged back.

It seems like lots of storms the past few years have had “blobs” that kind of trail behind them.

Like some new kind of storm...a “twin” of sorts!

[JaxGator]

Elsa had to hit Cuba to get back into shape lmao

Elsa was more than likely assisted by the flat swamp land upon making landfall.

[ConvergenceZone]

Let's see what Elsa does when she fully emerges in SE GOM. Circulation looks robust on radar. Mets at the weather channel are hinting at possible CAT 1 according to models (Euro) and SW shear actually enhancing outflow. Both GFS and Euro showing Cedar Key landfall in their 18z runs early Wednesday morning.

I think the shear is too much for this to make a run at a Cat1. Plus, before it even thinks about that it would have to rebuild much of its convection all over again. It's just not going to have much time, especially with the shear. If there was no shear, I'd give it a shot at a Cat 1....But it would have to get its act together at lightning speed for that to happen...

[artist]

[ColdMiser123]

This is a tough forecast for Elsa while it is over the SE Gulf, the amount of shear being forecast doesn't appear to be overwhelming, while at the same time isn't overly favorable (~15 kt). It really can go either way, which is why you are seeing such dramatic run to run variations in intensity currently with both the globals and hurricane models.

[ColdMiser123]

11 pm: 50 kt/1007 mb, back over water.

[eastcoastFL]

On IR and Radar it looks like convection died down as she started to hit water again….


https://www.weathernerds.org/satellite/sessions/91626943.gif?0.36606712384134354

The convection died due to extended land interaction. If you notice there's convection blowing up around the LLC, that occurred once it hit water.

I haven’t noticed much new convection but I’m also not very sure where the LLC is.

[eastcoastFL]

What's up with the annoying blob south Cuba? Does it have any significance on anything?

Very good question…it is a good size blob with ‘activity’. HWRF says she drags it up as a long tail. Think this is what went ‘under’ Jamaica and then never quite merged back.

It seems like lots of storms the past few years have had “blobs” that kind of trail behind them.

Like some new kind of storm...a “twin” of sorts!

I’ve noticed that. Must be a new TC fashion trend

[StAuggy]

This is a tough forecast for Elsa while it is over the SE Gulf, the amount of shear being forecast doesn't appear to be overwhelming, while at the same time isn't overly favorable (~15 kt). It really can go either way, which is why you are seeing such dramatic run to run variations in intensity currently with both the globals and hurricane models.

That’s kind of the worst outcome really for considering prepping because of the wait and see and now it’s too late… that happened with Michael (not making intensity comparisons) and it left people scrambling at the very end and some no longer had a choice to leave. You never want to hear last minute it’s going to be worse because when they are saying it’s not going to be very bad to begin with there’s even less prepping.


Hypothetically what would happen to Elsa if the shear were to virtually disappear with 12+ hours to go before final landfall and it was already a borderline ts/hurricane at that point?

[eastcoastFL]

11pm Disco

Tropical Storm Elsa Discussion Number 23
NWS National Hurricane Center Miami FL AL052021
1100 PM EDT Mon Jul 05 2021

Radar data from Cuba and Key West, Florida, along with surface
observations, indicate that the center of Elsa is back over water,
having emerged off the northern coast of of Cuba around 0200 UTC.
Doppler velocity data from the NOAA WSR-88D at Key West indicate
values of around 55 t at 10,000 ft, which supports equivalent
surface winds of 49 kt. An Air Force reconnaissance aircraft flying
just offshore the north coast of Cuba over deep water measured
reliable SFMR surface winds of at least 50 kt. Based on these data,
the intensity has been increased to 50 kt.

The initial motion estimate is 330/10 kt. Just like over the past
three days, no significant changes have been made to the previous
track forecast or synoptic reasoning. Elsa is now moving
north-northwestward around the southwestern periphery of a
deep-layer ridge whose axis extends westward across the Atlantic to
central Florida. The cyclone should gradually move around the ridge
over the next 36 hours, turning northward on Tuesday and then
north-northeastward Tuesday night and Wednesday morning. By late
Wednesday, Elsa should accelerate northeastward ahead of a
mid-latitude trough and frontal system, moving across the eastern
United States to near Atlantic Canada. The new NHC track forecast is
very similar to the previous advisory track, but was nudged slightly
eastward due to the more eastward initial position, and lies a tad
east of of the various tightly clustered track consensus models.

Some additional strengthening is expected over the next 36 hours,
with some of the SHIPS and global models showing Elsa possibly
reaching 60 kt just before landfall along the northwestern Florida
peninsula. This would typically require a Hurricane Watch for a
small portion of northwest Florida. However, given that Elsa has
been hugging a very tight mid-level moisture gradient -- a
condition that is expected to continue until landfall occurs in
about 36 hours -- the new official intensity forecast remains
similar to the previous advisory and holds the peak intensity at 55
kt due to expected intermittent dry-air intrusions. Subsequent NHC
forecasts can assess the new reconnaissance and model data that will
be coming in later tonight, and determine if an increase in the
intensity forecast and the issuance of a hurricane watch or warning
is required. By 96 hours, the global models suggest that the
cyclone will merge with a frontal zone, so the new intensity
forecast continues to shows extratropical transition at that time.


Key Messages:

1. Heavy rain will impact the Cayman Islands and Cuba tonight
resulting in significant flooding and mudslides over Cuba. As Elsa
approaches the Florida Keys, Florida Peninsula, and southeast
Georgia through Wednesday, heavy rainfall may result in isolated
flash, urban, and minor river flooding, with considerable flooding
possible in southwest and western portions of Florida. Mid to late
week, heavy rains across coastal South Carolina, North Carolina, and
southeastern Virginia may result in isolated flash and urban
flooding.

2. There is a danger of life-threatening storm surge along
portions of the west coast of Florida Tuesday night and Wednesday,
and a Storm Surge Warning has been issued for that area.

3. Tropical storm conditions are expected to continue across
portions of central and western Cuba tonight, and spread northward
across portions of the Florida Keys and the Florida west coast
through Wednesday, where a Tropical Storm Warning is in effect.

4. There is a risk of tropical storm conditions along portions of
the coasts of Georgia and the Carolinas Wednesday and Thursday.


FORECAST POSITIONS AND MAX WINDS

INIT 06/0300Z 23.5N 82.3W 50 KT 60 MPH
12H 06/1200Z 24.9N 82.9W 55 KT 65 MPH
24H 07/0000Z 26.9N 83.3W 55 KT 65 MPH
36H 07/1200Z 29.2N 83.1W 55 KT 65 MPH
48H 08/0000Z 31.6N 82.0W 30 KT 35 MPH...INLAND
60H 08/1200Z 34.0N 79.8W 30 KT 35 MPH...INLAND
72H 09/0000Z 36.9N 76.1W 30 KT 35 MPH...INLAND
96H 10/0000Z 43.3N 66.0W 40 KT 45 MPH...POST-TROP/EXTRATROP
120H 11/0000Z 50.5N 52.4W 40 KT 45 MPH...POST-TROP/EXTRATROP

[eastcoastFL]

[ronjon]

This is a tough forecast for Elsa while it is over the SE Gulf, the amount of shear being forecast doesn't appear to be overwhelming, while at the same time isn't overly favorable (~15 kt). It really can go either way, which is why you are seeing such dramatic run to run variations in intensity currently with both the globals and hurricane models.

Yes and its still possible a hurricane watch may be posted tomorrow am.

Some additional strengthening is expected over the next 36 hours,
with some of the SHIPS and global models showing Elsa possibly
reaching 60 kt just before landfall along the northwestern Florida
peninsula. This would typically require a Hurricane Watch for a
small portion of northwest Florida. However, given that Elsa has
been hugging a very tight mid-level moisture gradient -- a
condition that is expected to continue until landfall occurs in
about 36 hours -- the new official intensity forecast remains
similar to the previous advisory and holds the peak intensity at 55
kt due to expected intermittent dry-air intrusions. Subsequent NHC
forecasts can assess the new reconnaissance and model data that will
be coming in later tonight, and determine if an increase in the
intensity forecast and the issuance of a hurricane watch or warning
is required.

[SconnieCane]

Let's see what Elsa does when she fully emerges in SE GOM. Circulation looks robust on radar. Mets at the weather channel are hinting at possible CAT 1 according to models (Euro) and SW shear actually enhancing outflow. Both GFS and Euro showing Cedar Key landfall in their 18z runs early Wednesday morning.

I think the shear is too much for this to make a run at a Cat1. Plus, before it even thinks about that it would have to rebuild much of its convection all over again. It's just not going to have much time, especially with the shear. If there was no shear, I'd give it a shot at a Cat 1....But it would have to get its act together at lightning speed for that to happen...

Storms that were supposed to weaken (or at least not be able to continue to strengthen) due to shear while approaching the Gulf Coast since 2018:

Michael
Laura
Sally
Delta
Zeta

[AveryTheComrade]

18Z HWRF is much stronger, taking it essentially to hurricane, Euro also takes it to hurricane. GFS is conservative, keeping it basically where it is the whole way, and the Canadian is the lowest as it has been for a while, barely keeping it a TS up the coast.

[eastcoastFL]

This is a tough forecast for Elsa while it is over the SE Gulf, the amount of shear being forecast doesn't appear to be overwhelming, while at the same time isn't overly favorable (~15 kt). It really can go either way, which is why you are seeing such dramatic run to run variations in intensity currently with both the globals and hurricane models.

Yes and its still possible a hurricane watch may be posted tomorrow am.

Some additional strengthening is expected over the next 36 hours,
with some of the SHIPS and global models showing Elsa possibly
reaching 60 kt just before landfall along the northwestern Florida
peninsula. This would typically require a Hurricane Watch for a
small portion of northwest Florida. However, given that Elsa has
been hugging a very tight mid-level moisture gradient -- a
condition that is expected to continue until landfall occurs in
about 36 hours -- the new official intensity forecast remains
similar to the previous advisory and holds the peak intensity at 55
kt due to expected intermittent dry-air intrusions. Subsequent NHC
forecasts can assess the new reconnaissance and model data that will
be coming in later tonight, and determine if an increase in the
intensity forecast and the issuance of a hurricane watch or warning
is required.

So if things start to pop off over night they could issue a watch or warning at 5am. Any later than that would likely go straight to a warning. But even with a 65mph storm you could get squalls that have 85moh gusts so people should be prepared for Cat 1 conditions no matter what.

[eastcoastFL]

Let's see what Elsa does when she fully emerges in SE GOM. Circulation looks robust on radar. Mets at the weather channel are hinting at possible CAT 1 according to models (Euro) and SW shear actually enhancing outflow. Both GFS and Euro showing Cedar Key landfall in their 18z runs early Wednesday morning.

I think the shear is too much for this to make a run at a Cat1. Plus, before it even thinks about that it would have to rebuild much of its convection all over again. It's just not going to have much time, especially with the shear. If there was no shear, I'd give it a shot at a Cat 1....But it would have to get its act together at lightning speed for that to happen...

Storms that were supposed to weaken (or at least not be able to continue to strengthen) due to shear while approaching the Gulf Coast since 2018:

Michael
Laura
Sally
Delta
Zeta

Michael really threw them for a loop. The shear seemed to be more ventilation than anything. I believe he was forecast to be a TS at landfall and they just had to keep increasing with each advisory.

[Aric Dunn]

I think part of the LLC is stuck on the mountains along the coast.. HI res satellite you can see the LLC moving nearly due west just west of the convection..

[SconnieCane]

I think the shear is too much for this to make a run at a Cat1. Plus, before it even thinks about that it would have to rebuild much of its convection all over again. It's just not going to have much time, especially with the shear. If there was no shear, I'd give it a shot at a Cat 1....But it would have to get its act together at lightning speed for that to happen...

Storms that were supposed to weaken (or at least not be able to continue to strengthen) due to shear while approaching the Gulf Coast since 2018:

Michael
Laura
Sally
Delta
Zeta

Michael really threw them for a loop. The shear seemed to be more ventilation than anything. I believe he was forecast to be a TS at landfall and they just had to keep increasing with each advisory.

Exactly. Not saying I expect a similar outcome in this case, but it wouldn't be unprecedented for a cyclone to strengthen in the face of what was expected to be prohibitive shear in this area.

[InfernoFlameCat]

This is a tough forecast for Elsa while it is over the SE Gulf, the amount of shear being forecast doesn't appear to be overwhelming, while at the same time isn't overly favorable (~15 kt). It really can go either way, which is why you are seeing such dramatic run to run variations in intensity currently with both the globals and hurricane models.

That’s kind of the worst outcome really for considering prepping because of the wait and see and now it’s too late… that happened with Michael (not making intensity comparisons) and it left people scrambling at the very end and some no longer had a choice to leave. You never want to hear last minute it’s going to be worse because when they are saying it’s not going to be very bad to begin with there’s even less prepping.


Hypothetically what would happen to Elsa if the shear were to virtually disappear with 12+ hours to go before final landfall and it was already a borderline ts/hurricane at that point?

Most likely explosive development if the system is stacked. Probably reach cat 3

[eastcoastFL]

They shifted the cone a few miles east again at 11pm