ATL: DELTA - Post-Tropical - Discussion

[1900hurricane]

 https://twitter.com/1900hurricane/status/1313174653309980673

[Hypercane_Kyle]

2:00 PM EDT Mon Oct 5
Location: 16.1°N 79.2°W
Moving: W at 7 mph
Min pressure: 998 mb
Max sustained: 60 mph

Upped it to 50 knots and the recon is enroute.

My guess is it'll be a hurricane by 5pm easy.

[supercane4867]

First round of RI may very well already have started.

[CrazyC83]

This definitely is reminiscent of Hurricane Lili in 2002, albeit with less favorable conditions downstream and MUCH more favorable short-term conditions.

[edu2703]

2:00 PM EDT Mon Oct 5
Location: 16.1°N 79.2°W
Moving: W at 7 mph
Min pressure: 998 mb
Max sustained: 60 mph

Upped it to 50 knots and the recon is enroute.

My guess is it'll be a hurricane by 5pm easy.

Yeah. I wouldn't be surprised if the recon finds hurricane-force winds.

[aspen]

Recon is already at 23N and starting to cross over Cuba. It should be arriving at Delta by 3:00-3:30pm EST.

[Hypercane_Kyle]

Worth noting that practically ALL the models, including the HWRF, are lagging on Delta's current intensity.

[tomatkins]

Wilma is THE storm in the Atlantic. Unlikely this storm approaches that level just because the odds mathematically are against it. We could get an absolute beast though and the way it sounds Cat 5 might not be out of range for Delta. With an very outside chance of Wilma level beast.

While reaching Wilma level does seem unlikely, as you say, because any storm becoming the record breaker is unlikely, it does seem like this might be a real test of the "we wont retire Greek letters" stance from the NHC. If this gets up to Cat 4 or 5 in the southern gulf, it could still have plenty of steam when it hits land.

[ConvergenceZone]

This definitely is reminiscent of Hurricane Lili in 2002, albeit with less favorable conditions downstream and MUCH more favorable short-term conditions.

I agreed. Although the conditions aren't favorable for development in the northern Gulf, I think it can hit Cat 3 or even Cat 4 in the southern Gulf before it levels off and begins weakening, as the NHC suggests may happen... I guess how much weakening will be determined by just how much shear there is. It can make landfall as a 100 mph storm or a 75 mph storm. It's really difficult to say how much weakening will take place...

[Hypercane_Kyle]

The only reason I don't see Delta making a run for Cat 4/5 is simply due to time left in the Caribbean. Wilma was a very slow moving hurricane that had ample time to really get a core going. Delta does not.

My guess is a 105 knot peak.

[MississippiWx]

The only reason I don't see Delta making a run for Cat 4/5 is simply due to time left in the Caribbean. Wilma was a very slow moving hurricane that had ample time to really get a core going. Delta does not.

My guess is a 105 knot peak.

Wilma went from Tropical Storm to Cat 5 in 24 hours. Time isn't really the issue here. As always, it will be structure issues or pesky mid-level shear.

[aspen]

The only reason I don't see Delta making a run for Cat 4/5 is simply due to time left in the Caribbean. Wilma was a very slow moving hurricane that had ample time to really get a core going. Delta does not.

My guess is a 105 knot peak.

That’s awfully conservative. While Delta isn’t stalling in the Caribbean like Wilma, it seems very hesitant to start moving NW, and will have roughly another 36 hours in this exceptionally favorable environment. A phase of ERI could easily get this to at least 130 kt by tomorrow night.

[Hypercane_Kyle]

The only reason I don't see Delta making a run for Cat 4/5 is simply due to time left in the Caribbean. Wilma was a very slow moving hurricane that had ample time to really get a core going. Delta does not.

My guess is a 105 knot peak.

Wilma went from Tropical Storm to Cat 5 in 24 hours. Time isn't really the issue here. As always, it will be structure issues or pesky mid-level shear.

True, but you're also forgetting Wilma spent days in the Caribbean before that trying to develop an inner core before IR occurred.

[p1nheadlarry]

Absolutely

Does this also help Delta's outflow from a WISHE perspective? As you pointed out, PVS mixes in low theta-e air in the storm's environment; if that is gone, parcels conserving theta-e likely have a trajectory further out from the storm center.

Outflow is high up in the troposphere.
WISHE is heat exchange of the water to the air induced by high-speed winds.
This occurs at the ocean surface and the troposphere boundary layer.
The parcel trajectory comes from the cold pool over the CoC creating buoyancy.
The warm-core above the cold pool then slings the parcels away from the CoC as they move higher into the troposphere which creates the outflow.

Right but the trajectory is also dependent on it's theta-e in the WISHE model. The enthalpy exchange is isothermal, the ascent is pseudoadiabatic. Figured having low-entropy air mixed out would increase the buoyancy and this secondary circulation is enhanced which exacerbates stronger radial flow, increased enthalpy fluxes, etc, but could be thinking about it wrong.

[cycloneye]

NOAA plane crossed Cuba that gave the ok to fly thru the country.

[p1nheadlarry]

Worth noting that practically ALL the models, including the HWRF, are lagging on Delta's current intensity.

That's fairly common, the most current data is fed in along with previous output as a 'first-guess' in the assimilation process. That + interpolating to grid is why sometimes tc 'initialization' isn't always on point. I'm sure people know this including you, but I like to point it out when there's fuss over model initialization; sometimes it's not all their fault.

[GCANE]

Wilma hit the Yucatan, this one will very likely run the Yucatan Channel.

[tailgater]

Sure wish we had that 1 minute floater over it before nightfall. I’d like to see the RI if it does happen. These 10min intervals seem so 2010. Spoiled
It’s starting to look more likely Delta could clip the NE tip of the Yucatán

[PNG81NDN]

Just scanning the posts for the word "Texas" Praying for family and friends in Southern Louisiana!

[Ken711]

 https://twitter.com/RyanMaue/status/1313148396925001740