wxmx

Looks like a well defined LLC

El Niño & +AMO ... but the lack of significant below normal areas is quite something.

Source

Looking at the models/ensembles, the stronger/earlier development, the farther right it goes, looks like a good example of beta drift.

Officially a cat 2 - 85 kts hurricane, with 967mb central pressure.

968mb extrapolated, 85 kts SFMR. It will probably be upgraded to cat 2

1 hour ago, Prospero said:

Is anybody there to take photos in Mexico? Or are you talking about visible sats?

Visible imagery. Sunset are the beer googles of hurricanes.

3 minutes ago, Amped said:

50/50 on whether the eye forms prior to landfall

Hopefully before sunset. Would be a very photogenic image of Grace

Shear has abated some, to around 10-15 kts. Looks like it gained a bit of latitude during the convective explosion, but not much. Now looks like Tecolutla may be ground zero. If trends continue we can speculate on a major at landfall.

Diana 1990 and Gert 1993 are possible analogs to strength and landfall location. They both caused record flooding in the area.

7 minutes ago, Scott747 said:

That's what it's going to look like too after landfall once it hits those mountains. The disintegration of Karl was pretty amazing.

Yeah, no cyclone is match to the Sierra Madre. The bigger and meaner, the more dramatic the fall. Only thing is all it's juice is squeezed out, causing mudslides and extensive flooding.

2 hours ago, Amped said:

Looking at the IR, it appears the QPF bomb is detonating

21 minutes ago, BooneWX said:

Holy moly that last frame on the IR. 

Yes, now I have this image in my mind

18 minutes ago, hawkeye_wx said:

Grace is beginning to encircle the center with convection.

And right on cue. The last 12 hours up to landfall were the ones that we expected Grace would intensify more aggressively and we are near that threshold. We needed a hurricane that looked like one, and it's taking that look now.

7 minutes ago, Prospero said:

Sorry for not paying attention, having to do day job work catching up. Fred screwed up my schedule.

But did Grace ever get a real visible eye?? (I'd look now and then on sats.)

Will try to back track over posts later tonight...

Briefly yesterday

Quote

A ragged eye appeared for a while on visible satellite imagery, but 
it has recently been obscured by cumulonimbus tops. 

https://www.nhc.noaa.gov/archive/2021/al07/al072021.discus.022.shtml?

Three hours old, but that's a pretty good structure. If it can get steady < -70C cloud tops in the eyewall, it can RI.

13 minutes ago, MJO812 said:

I'm seeing 995

Where are you seeing 989 ?

990mb from dropsonde and 10kts wind. Slowly but steadily intensifying.

989mb extrapolated

Recon supports an upgrade to at least 60 kts, with FL around 74kts and several SFMR obs 60-67 kts.

13 minutes ago, hlcater said:

1004 on the extrap. So mild strengthening occurred while grace transited Jamaica.

 

1002 according to dropsonde

Yes, it has evolved from a classic "9" low, to a more symmetric cyclone, with good outflow in the western semicircle. Most of the core is still over land, and although Jamaica is a bit rugged, the highest peaks are in the eastern portion of the island. It probably still has around 6 hours over land before exiting fully over water. Shear is low, less than 15 knots, and since structure seems to be improving, at least steady strengthening should be expected until landfall in the Yucatan. I don't discard RI, but we will have more info this evening.

Especially in the middle of August

3 hours ago, Floydbuster said:

When in doubt...take the southern route.

Just now, Amped said:

It's been making more progress west the past few hours.   It stalled just long enough to bust my prediction that the new eyewall would not have a chance to takeover. 

It's even gaining some latitude in the short term, that enhances the probability of Puerto Cabezas/Bilwi being in the northern eyewall, plus the highest surge.

885mb 165 kts

That's because that awesome outflow channel is evacuating the upper levels of the cyclone nicely, forcing strong connection to popup over Gamma. The next 24 hours it'll see the strongest shear, relaxing a bit gradually afterwards