ATL: MARIA - Post-Tropical - Discussion

[Hugo1989]

I'm skeptical for now. There's a pretty big difference between the eyewall radii, so the outer would probably have to contract quite a bit, which takes time. I've been surprised before though.

Irma never weakened at all during its first big ERC as a cat 5 - all it did was knock the pressure back some and enlarge it. Doing the same here brings it down to 890 or so.

the outer eye is pretty much closed now.. lets see if it begins to contract soon.. HArvey's happened in about 4 to 6 hours. IRMA's were even faster.

Is this a better or worst scenario for PR right now?

[wxmann_91]

Irma never weakened at all during its first big ERC as a cat 5 - all it did was knock the pressure back some and enlarge it. Doing the same here brings it down to 890 or so.

the outer eye is pretty much closed now.. lets see if it begins to contract soon.. HArvey's happened in about 4 to 6 hours. IRMA's were even faster.

Is this a better or worst scenario for PR right now?

No matter what happens, it's going to suck.

[USTropics]

These short term movements of the inner eyewall bouncing around the outer are referred to as trochoidal oscillations (or trochoidal wobbles). Small wobbles in a tropical cyclone's track can occur when the convection is distributed unevenly within its circulation. This can be due to changes in vertical wind shear or inner core structure. Because of this effect, forecasters use a longer term (6 to 24 hours) motion to help forecast tropical cyclones, which acts to smooth out such wobbles.

Essentially think of a hurricane as a spin top moving across the surface of a table. If someone blows on it, the top changes motion for a split moment, but will resume its overall course. The same occurs in intense hurricanes, where the inner eye will zig and zag within the dynamic frame of the outer eyewall.

Here is a really in-depth research that explains trochoidal wobbles and shows some examples of how this can impact track as it approaches landfall (e.g. Ivan, Carla to name a few) - http://rammb.cira.colostate.edu/resources/docs/Wavenumber_Nolan.pdf

[Alyono]

eye may only miss St. Croix by 5-10 miles. May be "game over" for them

[aperson]

The band of warmer tops in the CDO is expanding CCW around the system and appears to be affecting the NW quad of the storm as well now. Recent frames are showing very intense banding near the eye wall, though. I'm really unsure how to interpret this, it seems very strange. I assume there is a huge battle between tangent and normal forces near the eye wall occurring right now.

[Aric Dunn]

the inner eye is really starting to wobble around.. those loops should get bigger.

[TheStormExpert]

 https://twitter.com/TropicalTidbits/status/910298622612434945

[Ken711]

eye may only miss St. Croix by 5-10 miles. May be "game over" for them

How wide is Maria's eye with the strongest winds?

[tolakram]

A cat 5 with that small an eye is very unstable IMO, the only question is how long the ERC takes OR if it's a classic ERC or one of these 2017 specials.

IMO the smaller the eye the better it is for PR, if one can say better. Smaller windfields are always better IMO.

[M_0331]

Yes it is. A very intelligent professor at MIT by the name of Dr. Kerry Emanuel came up with a formula to calculate it. It is based on a lot of very intense thermodynamic equations but basically what he did was calculate what a perfectly efficient engine (hurricane) could potentially produce with no hindrances from shear, mid-level dry air, etc. That map that was posted is the result of crunching all of those equations. It is approaching it now.

It's getting very close to its max potential intensity so this may be why it has stabilized.

Today is the first time I have ever heard of this term. Is "max potential intensity" legit?

Everything=energy & entropy! Per the studies of Carnot in ~1803-1815, many learn that a hurricane is a perfect Energy Conversion Device(ECD) in getting a B. S. in Thermodynamics as I did plus I also got a B. S. in Mechanical Engineering. I spent many years designing HVAC from massive industrial buildings & office complexs. Learn psychometric chart(lol) before computer programs. Finally, 'Basic' was published & I can write code to do a week's work in an hour.

[supercane4867]

Notable dry slot developing between the two eyewalls indicates that EWRC is really get going now.

[Alyono]

eye may only miss St. Croix by 5-10 miles. May be "game over" for them

How wide is Maria's eye with the strongest winds?

close enough that I told a co worker with family there, expect the worst

[txwatcher91]

From what I’ve observed over the years, storms with big eyes have trouble completing an ERC quickly while smaller ones usually don’t take long. It also seems as we’ve seen this year that strong storms like Irma can do them incredibly fast... a completed ERC before landfall would be worst case for PR as the windfield of 140+ winds would cover a much larger area.

[gatorcane]

eye may only miss St. Croix by 5-10 miles. May be "game over" for them

How wide is Maria's eye with the strongest winds?

Looks like "game over" for St Croix I agree. Any chance Maria goes just east of Puerto Rico?

[SunnyThoughts]

[sikkar]

I wonder if the winds in the big outer wall are similar to those in the small inner one?

[Aric Dunn]

josh ( icyclone) might have to move more to the ne part of island to get the right front quad.. on current course.

[PandaCitrus]

The eye might go right over San Juan metro area now. Also hitting more on the east means less time to weaken over land and mountains before hitting san Juan.

[Ken711]

eye may only miss St. Croix by 5-10 miles. May be "game over" for them

How wide is Maria's eye with the strongest winds?

close enough that I told a co worker with family there, expect the worst

I'm praying for all those in Maria's path.

[tolakram]

Cloud tops warming significantly.

http://weather.cod.edu/satrad/exper/?parms=meso2-13-48-1-100

Eye is still very warm.

http://weather.cod.edu/satrad/exper/?parms=meso2-10-48-1-100