ATL: GRACE - Remnants - Discussion

[cycloneye]

A. 07L (GRACE)

B. 18/2330Z

C. 19.9N

D. 84.8W

E. ONE/GOES-E

F. T4.5/4.5

G. IR/EIR/VIS

H. REMARKS...OW EYE SURROUNDED BY MG AND EMBEDDED IN DG RESULTS IN A
DT OF 4.5. THE MET AGREES WITH 4.5 BASED ON A DEVELOPING TREND OVER THE
PAST 24 HOURS. THE PT IS ALSO 4.5. FT IS BASED ON DT.

I. ADDL POSITIONS

NIL


...COVERDALE

[aspen]

Such a tiny core with such a prominent outer band. If this system had multiple days over open water, this would probably lead to an EWRC, but crossing over the Yucatán should pretty much reset Grace’s structure.

The newest eyewall dropsonde of 988mb/3kt supports a central pressure of 988 or 987 mb. Peak SFMR winds remain at 70 kt.

[Iceresistance]

Such a tiny core with such a prominent outer band. If this system had multiple days over open water, this would probably lead to an EWRC, but crossing over the Yucatán should pretty much reset Grace’s structure.

The newest eyewall dropsonde of 988mb/3kt supports a central pressure of 988 or 987 mb. Peak SFMR winds remain at 70 kt.

You beat me to it . . .

[tolakram]

Grace is still lopsided, with very low winds in the SE side. While it appears to be slowly strengthening I don't think it will get much stronger unless something significant changes.

[tolakram]

saved loop

[aspen]

Based on what we’ve seen today, Grace will likely peak as a Cat 1 before landfall in the Yucatán, but that could result in a better structure once it reaches the Gulf. The terrain Grace will be going over isn’t very high, and it’ll only be for 12 hours. That might be enough to “reset” its structure without completely tearing it apart. If Grace ends up with a better structure in the 12 hours after entering the BoC, the higher intensity forecasts are on the table. If Grace ends up with a worse structure, the lower intensities will likely verify instead.

[TallyTracker]

That dry air is really keeping a lid on Grace! Doubt the storm will exceed 90 mph with this structure and continued dry air intrusions. The last few frames show it trying to mix out the dry air, but I don’t think it’s going to have time to intensify significantly.

Also, with such a small core, I wonder if the Yucatán will cause greater disruption and result in Grace struggling to strengthen in the BOC.

[Teban54]

The next system that tracks into Western Caribbean will likely have a better chance at RIing and avoiding dry air intrusions than Grace did, as conditions continue to improve into peak season. Unfortunately it seems that there will be a next system given the ridge forecasts.

Reminds me of Nana last year followed by all the infamous late season Caribbean storms, even though Grace is more organized than Nana.

[Yellow Evan]

[hipshot]

That dry air is really keeping a lid on Grace! Doubt the storm will exceed 90 mph with this structure and continued dry air intrusions. The last few frames show it trying to mix out the dry air, but I don’t think it’s going to have time to intensify significantly.

Also, with such a small core, I wonder if the Yucatán will cause greater disruption and result in Grace struggling to strengthen in the BOC.

From what I have read here, a smaller, compact storm will be less impacted by land intervention, especially if it is the far eastern corner of the
Yucatan which I have heard is pretty flat.

[Iceresistance]

AF304 records 75 knot FL winds in the SW Quadrant, remember that it was only between 30-40 knots only this morning!

[Hammy]

Eyewall broken to the south after being more closed earlier.

[cycloneye]

VDM says eye open to the south and is 20 miles large. What is this?

CTR DROPSONDE LST WND REPORTED 04005KT AT 33 METERS

[GCANE]

IR showing the eyewall hot tower obscuring the eye.
Continues to strengthen from this perspective.
Should see this reflected in measured pressure and wind speeds a bit later.

[GCANE]

Latest recon fix has it south of the forecast track

[MarioProtVI]

Based on what we’ve seen today, Grace will likely peak as a Cat 1 before landfall in the Yucatán, but that could result in a better structure once it reaches the Gulf. The terrain Grace will be going over isn’t very high, and it’ll only be for 12 hours. That might be enough to “reset” its structure without completely tearing it apart. If Grace ends up with a better structure in the 12 hours after entering the BoC, the higher intensity forecasts are on the table. If Grace ends up with a worse structure, the lower intensities will likely verify instead.

I think it could be similar to how Karl 2010 played out. When it first formed it was a large and sprawling system, but then shrunk and compacted itself into a small storm ~65 mph before making landfall in the flat area of the Yucatan, then once it got to the BoC it exploded into a high-end C3 (or low-end C4 if you ask me IMO it got really close and was forecasted to at one point).

So far and what worries me is Grace is following this type of trend, with the central core tightening up into a small area while shedding the larger outer bands. If Grace’s structure here remains intact and doesn’t get mangled, all bets could be off once it’s in the BoC and it very easily shoot up towards C2-3 before making landfall in mainland Mexico.

[ElectricStorm]

Personally I see her peaking in the gulf but we'll have to see how it looks when it emerges back over water. Looks like my 90kt Yucatan landfall will bust but that's a good thing.

[GCANE]

Eye is ingesting higher values of CAPE now.
Latest drop shows air saturated from water to 850mb

[GCANE]

Looks like this will have more time over the Yucatan.

[GCANE]

Looks like this will sit in a high Theta-E ridge until landfall.