ATL: IDA - Remnants - Discussion

[Hypercane_Kyle]

The fate of Ida becoming a top tier major hurricane in the Gulf is determined by the passage of Cuba. There will certainly be some degree of structural disruption since the system has already developed an inner core.

How good is western Cuba at disrupting a hurricane core? Even at the widest point, it's 45 miles across with elevations maxing out around 1,600 feet (as far as I can tell from terrain maps).

Depends on various factors including the system's forward speed and intensity at the time of landfall. Gustav crossed the western tip of Cuba and never recovered but many storms crossing at high-end TS to low-end hurricane strength recovered pretty quickly without issues. My guess is that it won't cause that much of a disruption to Ida but it's hard to tell with the current inner core being relatively small.

There were a few other factors that prevented Gustav from redeveloping an inner core, such as shear and dry air. Even though Ida has a decent inner core right now, it won't get disrupted nearly as bad as Cat 4 Gustav was.

[aspen]

https://i.postimg.cc/cJsJqSz3/089-DEAE3-41-BC-40-CB-85-B7-8861-DB6-F816-D.jpg

That’s gonna be a big eye once it’s in the Gulf of Mexico.

Ida seems to be nearing landfall, and will probably be over land before the next recon plane is able to get to it.

[FormerNewtotex]

It looks to me like it's not so much the Isle of Youth that's disrupting it, but the inflow over the mountains to the north on the Cuba mainland. In any case, I expect it to reorganize very quickly after it comes off the coast.

Will the interaction with land over mainland Cuba have any effect on the track?

If the center reforms then yes

With the way things are currently with Ida does it seem like it will happen?
Or, does it appear to stick to the NHC track? It doesn't look like Cuba is mountainous enough to completely disrupt the center like Hispaniola or something would, I'm I reading that right?

[Shell Mound]

One possible bit of good news: Ida’s wind field currently appears to be much more compact than modelled previously, given that earlier model runs showed a much larger radius of ≥ 34-kt (tropical-storm-/gale-force) MSW by this time. This might indicate higher background pressures that could persist until landfall on Louisiana. A smaller system would tend to produce significant surge over a narrower swath of the coastline, so in that sense Ida’s structural evolution may prove fortuitous. However, even a small but intense Ida would produce substantial surge near its eye, and the projected angle of approach still favours severe surge, in addition to heavy rainfall and potentially catastrophic winds.

[skyline385]

One possible bit of good news: Ida’s wind field currently appears to be much more compact than modelled previously, given that earlier model runs showed a much larger radius of ≥ 34-kt (tropical-storm-/gale-force) MSW by this time. This might indicate higher background pressures that could persist until landfall on Louisiana. A smaller system would tend to produce significant surge over a narrower swath of the coastline, so in that sense Ida’s structural evolution may prove fortuitous. However, even a small but intense Ida would produce substantial surge near its eye, and the projected angle of approach still favours severe surge, in addition to heavy rainfall and potentially catastrophic winds.

Both hurricane models are suggesting an EWRC before landfall though

[CrazyC83]

Hurricanes often have a way of "stair stepping". That seems to be likely what is happening, not a hard turn to the west. The land interaction may have adjusted its course too.

[cheezyWXguy]

How good is western Cuba at disrupting a hurricane core? Even at the widest point, it's 45 miles across with elevations maxing out around 1,600 feet (as far as I can tell from terrain maps).

Depends on various factors including the system's forward speed and intensity at the time of landfall. Gustav crossed the western tip of Cuba and never recovered but many storms crossing at high-end TS to low-end hurricane strength recovered pretty quickly without issues. My guess is that it won't cause that much of a disruption to Ida but it's hard to tell with the current inner core being relatively small.

There were a few other factors that prevented Gustav from redeveloping an inner core, such as shear and dry air. Even though Ida has a decent inner core right now, it won't get disrupted nearly as bad as Cat 4 Gustav was.

Yeah, Gustav had a structure south of Cuba that allowed it to manage 155mph winds in the face of 20kt of shear, but landfall on Cuba opened the door for that shear and dry air to reach the core. Ida is strong, but nowhere near as well developed as gustav was in this location, and the environment is a lot less hostile this time around. This is probably more akin to charley’s crossing.

[Highteeld]

Immediately seeing new Hot Towers now the center of the storm is back over water. This bodes very poorly for the United States.

[FLpanhandle91]

Ida appears to have made landfall in Cuba near Playa Dayaniguas.

Don’t you mean La Demajagua on the Isle of Youth? Radar indicates that the eye is still over the northern edge of the Isle of Youth.

You are correct. I mistook a banding feature on IR for the eyewall. Apologies.

[tomatkins]

How good is western Cuba at disrupting a hurricane core? Even at the widest point, it's 45 miles across with elevations maxing out around 1,600 feet (as far as I can tell from terrain maps).

Depends on various factors including the system's forward speed and intensity at the time of landfall. Gustav crossed the western tip of Cuba and never recovered but many storms crossing at high-end TS to low-end hurricane strength recovered pretty quickly without issues. My guess is that it won't cause that much of a disruption to Ida but it's hard to tell with the current inner core being relatively small.

There were a few other factors that prevented Gustav from redeveloping an inner core, such as shear and dry air. Even though Ida has a decent inner core right now, it won't get disrupted nearly as bad as Cat 4 Gustav was.

I feel like low end storms just dont have as much to disrupt. A Cat 4 is a well oiled machine and throwing a wrench in the works by crossing over land messes that machine up. But a Cat 1 is not all that well organized - they seem to recover quicker because their simply isnt as big of a drop from their base state to the disrupted state.

[Shell Mound]

 https://twitter.com/newsgirlalison/status/1431350561794834436

[FLpanhandle91]

Kermit in the air.

[grapealcoholic]

One possible bit of good news: Ida’s wind field currently appears to be much more compact than modelled previously, given that earlier model runs showed a much larger radius of ≥ 34-kt (tropical-storm-/gale-force) MSW by this time. This might indicate higher background pressures that could persist until landfall on Louisiana. A smaller system would tend to produce significant surge over a narrower swath of the coastline, so in that sense Ida’s structural evolution may prove fortuitous. However, even a small but intense Ida would produce substantial surge near its eye, and the projected angle of approach still favours severe surge, in addition to heavy rainfall and potentially catastrophic winds.

Just wait till it gets into the gulf and wraps that feeder band

[ConvergenceZone]

One possible bit of good news: Ida’s wind field currently appears to be much more compact than modelled previously, given that earlier model runs showed a much larger radius of ≥ 34-kt (tropical-storm-/gale-force) MSW by this time. This might indicate higher background pressures that could persist until landfall on Louisiana. A smaller system would tend to produce significant surge over a narrower swath of the coastline, so in that sense Ida’s structural evolution may prove fortuitous. However, even a small but intense Ida would produce substantial surge near its eye, and the projected angle of approach still favours severe surge, in addition to heavy rainfall and potentially catastrophic winds.

While it won't have time for 2 Eyewall Replacement Cycles, it should have time for 1, and that alone will expand the windfield.... So how it looks now has no bearing on how it's going to look once it hits land.....

[ChrisH-UK]

A view of IDA from GOES-16 combining Visible Green Band and CIRA Optical Depth ona 1 hour loop. The view helps to show the structure inside IDA by looking at the density of the clouds.

Source - https://col.st/FR6Jt

[grapealcoholic]

The eye is west of the southwest tip of the Isle of Youth. Look at cloud movement on IR

[ChrisH-UK]

Just looked at the image again and theres a spot clearing out in the middle of where it is bundling up. may be the eye.

[Chris_in_Tampa]

Maybe this has been posted before, but in case it hasn't:

 https://twitter.com/splillo/status/1431340060260159499




SHIPS intensity text output can be found here:

From: https://ftp.nhc.noaa.gov/atcf/stext/?C=M;O=D

Look for the latest data with the storm number you want.

If you want to see 6 hour difference:

18Z Friday:
https://ftp.nhc.noaa.gov/atcf/stext/210 ... _ships.txt

12Z Friday:
https://ftp.nhc.noaa.gov/atcf/stext/210 ... _ships.txt

To see graphically on a model site look for these identifier:

"SHIP" is "V (KT) NO LAND"
"DSHP" is "V (KT) LAND"
"LGEM" is "V (KT) LGEM"

SHIP assumes there is no land, so between SHIP and DSHP, DSHP is better usually unless something could miss a land area instead.

[Shell Mound]

Just looked at the image again and theres a spot clearing out in the middle of where it is bundling up. may be the eye.

https://i.imgur.com/f4ODfBy.png

Ida is currently exhibiting a classical “nautilus”-type banding and expanding “feathery” outflow to the west that typically presage rapid intensification.

[MississippiWx]

The eye is west of the southwest tip of the Isle of Youth. Look at cloud movement on IR

The microwave pass just posted does not support this statement.