ATL: GRACE - Remnants - Discussion

[Astromanía]

Once again the Yucatan demonstrates it is an ideal landmass for a TC to transit intact.

Due to it's flat and low terrain

[beoumont]

About half the time a good hurricane crosses Yucatan, a big, big eye develops as it crosses the Bay of Canned Peaches. We will see on this one. I am not sure this qualifies as a "good" hurricane, though, due to its minimal hurricane landfall status.

[aspen]

Grace should be back over water around the time of the 5pm advisory, maybe within an hour later. Convection near the LLC is looking a little deeper. It doesn’t seem like it’ll emerge into the BoC nearly as ragged and anemic as the HWRF has been forecasting, so the model might be slightly underestimating how strong it could get before landfall.

Is there recon scheduled to catch the storm as it moves back over water?

[abajan]

[youtube]https://youtu.be/_UDBNscDglI[/youtube]

[cycloneye]

Grace should be back over water around the time of the 5pm advisory, maybe within an hour later. Convection near the LLC is looking a little deeper. It doesn’t seem like it’ll emerge into the BoC nearly as ragged and anemic as the HWRF has been forecasting, so the model might be slightly underestimating how strong it could get before landfall.

Is there recon scheduled to catch the storm as it moves back over water?

Yes, Both NOAA and Air Force at 4 PM and 5 PM.

[ElectricStorm]

Looks like the center is starting to reach the coast now

[ThetaE]

As a benchmark, today's 12z HWRF has Grace emerging from the Yucatan around 994-995 mb and not beginning to deepen for almost 12 hours. The HWRF then intensifies Grace to a 959mb, 90kt storm in 24 hrs. I don't spy any PV streamers in Grace's path, but there could be some sneaky mid-level shear. The current decoupled-looking structure suggests that there may be some northerly shear present, but we'll see if that's real or not soon enough (is it possible for land to mimic a sheared appearance like that?).

Otherwise, that sort of rate of intensification seems entirely plausible. And if Josh Morgerman's 978mb reading was accurate, Grace could feasibly emerge with a stronger starting point than the HWRF initialized.

[Sciencerocks]

[Ubuntwo]

Looks like the NHC was a little overzealous with the decay-SHIPS. Current partial recon data good for at least 50kt.

[aspen]

Wow, this is much stronger than I thought. 50-55kt FL and SFMR winds with an extrapolated pressure of 997.8mb so far.

Update: 55 kt SFMR and 992mb…this fared very well over the Yucatán.

[kevin]

Grace and Henri intensifying at the same time. This evening and especially tomorrow will be busy times on the forum. Everyone in the path of these storms, stay safe.

[cycloneye]

First pass by NOAA plane down to 992 mbs

[IcyTundra]

Grace will take several more hours to get its act together and will only have a little more than 24 hours until it makes landfall again, but I think that will be plently of time for Grace to restrengthen. I'm thinking a moderate to a high end cat 2 but I wouldn't be surprised by a cat 3. Grace will also likely be strengthening on approach to the Mexican coastline which will only make things worse.

[aspen]

Seems like the MLC and LLC are a bit misaligned, because the drops in winds and pressure don’t exactly align. It shouldn’t take much for them to restack.

[ElectricStorm]

Grace has a look like it's about to bomb. It has that western band that many intense TC's have had. I've been thinking the entire time if it could get in the Gulf it could get nasty. Well we're finally at that point now. Hopefully everyone in the path of this thing stays safe. I think the only thing that will prevent it from becoming a monster is time.

Personal prediction: 100kt landfall.
I know that's pretty bullish but storms in the Gulf in recent years don't mess around

[CrazyC83]

The center is still onshore too. That suggests the pressure may be even lower.

[aspen]

Another limiting factor for Grace is that its wind field looks to be quite large still. The AF plane is finding 55kt FL winds quite far NNW of the center. This large wind field could give Grace difficulty trying to consolidate and intensify, similar to what happened in the WCar.

[toad strangler]

haha Morgerman goes Hollywood and like a true marketing pro, ... look at the dude strolling by at the end hahaha

 http://twitter.com/iCyclone/status/1428422971085971460

[ElectricStorm]

Drop from the NOAA plane supported 994mb. AF extrap is 996mb. We'll see what the AF drop has

[ThetaE]

Second NOAA pass was cleaner since Grace is further offshore. Got a dropsonde with 995mb and 11kt winds. Also, there is a noticable offset between flight-level wind and extrapolated MSLP minimum, indicating a tilted structure like aspen mentioned. Next few recon passes should give a good sense on whether Grace can recover quickly or not. I suspect it'll take a bit.