ATL: ELSA - Post-Tropical - Discussion

[tolakram]

It's very hard to tell with IR, but the sudden drop south of the convection seems telling.

https://weather.cod.edu/satrad/?parms=meso-meso1-13-96-1-25-1&checked=map&colorbar=undefined

[NDG]

One thing that is obvious is that Elsa seems to have slowed down significantly.

Yep, in the past 5 hours I calculated it to be around 17 mph, but a cyclonic loop to realign the itself closer to the MLC could be real reason why for the slow down at this time.

My calculations were spot on:

11:00 PM EDT Sat Jul 3
Location: 17.9°N 75.3°W
Moving: WNW at 17 mph
Min pressure: 1004 mb
Max sustained: 65 mph

[InfernoFlameCat]

I believe the tower is beginning to rotate on IR

[Hammy]

Is the convection too intense to make a center pass? Looks like they went a bit to the west of it.

[GCANE]

If they have the balls to do so, they need to get into the tower and sample the rain rate.

[InfernoFlameCat]

If they have the balls to do so, they need to get into the tower and sample the rain rate.

It might not be safe. Those updrafts might be exceeding 100mph.

[Hypercane_Kyle]

Stewart is penning this discussion. Usually some really insightful stuff in there. The other forecasters, for some reason, don't provide nearly the depth of insight that Stewart provides.

[toad strangler]

One thing that is obvious is that Elsa seems to have slowed down significantly.

Yep, in the past 5 hours I calculated it to be around 17 mph, but a cyclonic loop to realign the itself closer to the MLC could be real reason why for the slow down at this time.

My calculations were spot on:

11:00 PM EDT Sat Jul 3
Location: 17.9°N 75.3°W
Moving: WNW at 17 mph
Min pressure: 1004 mb
Max sustained: 65 mph

Ya, hard bump on the breaks .... turn coming soon

[eastcoastFL]

that is not the center. lol just throwing it out there ..

Where is it hiding?

[Jr0d]

There is something going on...my guess is structural changes are going...likely getting more aligned. Recon just found an old vort....just my amateur guess. No way the minimal pressure is that high...

[GCANE]

I believe the tower is beginning to rotate on IR

Its been rotating, its just going faster now.
LLC is rotating into it.
Convection is really intensifying.

[Hypercane_Kyle]

I am not seeing any sort of closed LLC near the position that the NHC has Elsa at present.

[tolakram]

saved loop

[Ken711]

The initial motion estimate is now 295/15 kt. Elsa is forecast to
gradually move around the western periphery of a deep-layer
subtropical ridge over the next 96 hours, accompanied by an
additional decrease in forward speed. The latest model guidance has
continued to converge along the previous advisory track, with the
corrected-consensus models HCCA and FSSE nearly on top of each
other. The TCVA simple consensus model is also similar to the HCCA
and FSSE models. However, out of respect for the slightly more
westward GFS and GFS-ensemble models, which have performed
admirably thus far with Elsa, the new official forecast lies a tad
west of the aforementioned consensus models and lies nearly on top
of the previous advisory track.

After interacting with the mountainous terrain of southwestern
Haiti, which could have caused some disruption in the low-level
field despite the center remaining offshore, little change in
intensity is expected tonight. However, some slight restrengthening
could occur by Sunday afternoon as Elsa approaches the south-central
coast of Cuba where the sea-surface temperatures are quite warm at
more than 30 deg C and the water is deep. Weakening is expected
after the cyclone moves across west-central Cuba, followed again by
some slight restrengthening after Elsa emerges over the warm Gulf
Stream in the Straits of Florida. Westerly vertical wind shear
increasing to near 20 kt by 96 hours should prevent any significant
strengthening from occurring. Elsa should become a very
asymmetrical tropical cyclone late on day 3 and on day 4 with most
of the heavy rain and strongest winds displaced along and to the
east of the forecast track. The initial intensity is similar to the
previous advisory and closely follows the simple and corrected
consensus models.

Given the remaining uncertainty in the track forecast and the degree
of land interaction with Hispaniola and Cuba, users are urged to
factor in some of this uncertainty. For reference, average NHC
track errors at days 3 and 4 are 125 miles and 150 miles,
respectively. The average NHC intensity errors are around 15 mph
for both days 3 and 4.

[eastcoastFL]

Yep, in the past 5 hours I calculated it to be around 17 mph, but a cyclonic loop to realign the itself closer to the MLC could be real reason why for the slow down at this time.

My calculations were spot on:

11:00 PM EDT Sat Jul 3
Location: 17.9°N 75.3°W
Moving: WNW at 17 mph
Min pressure: 1004 mb
Max sustained: 65 mph

Ya, hard bump on the breaks .... turn coming soon

Yup. Probably more like central Cuba than western

[NDG]

Is the convection too intense to make a center pass? Looks like they went a bit to the west of it.

Probably way too turbulent for them to take a risk, the continues lightning a good indication of a lot of updrafts and downdrafts going on.

[aspen]

I’m not sure if the storm is actually behaving really weirdly, or I’m just hallucinating from being really tired and having stared at this thing all day long.

[GCANE]

There is something going on...my guess is structural changes are going...likely getting more aligned. Recon just found an old vort....just my amateur guess. No way the minimal pressure is that high...

Pressure will drop quickly once the LLC stacks with the warm core.
Surface air will make a giant sucking sound once the warm core pulls it up.

[Ken711]

FORECAST POSITIONS AND MAX WINDS

INIT 04/0300Z 17.9N 75.3W 55 KT 65 MPH
12H 04/1200Z 19.2N 77.3W 55 KT 65 MPH
24H 05/0000Z 20.9N 79.4W 60 KT 70 MPH
36H 05/1200Z 22.5N 81.0W 50 KT 60 MPH...INLAND
48H 06/0000Z 24.1N 82.2W 45 KT 50 MPH...OVER WATER
60H 06/1200Z 26.0N 82.8W 50 KT 60 MPH
72H 07/0000Z 28.0N 83.0W 50 KT 60 MPH
96H 08/0000Z 32.7N 81.0W 45 KT 50 MPH...INLAND
120H 09/0000Z 37.7N 74.9W 35 KT 40 MPH...OVER WATER

$$
Forecaster Stewart/Papin

[Ken711]