ATL: PHILIPPE - Post Tropical/Extratropical - Discussion

[MarioProtVI]

NHC is having a difficult time with the future forecast.

Afterwards, models are in quite
poor agreement on if the shear continues to rise to strong levels,
which causes dissipation like the ECMWF, or if it becomes more
manageable to allow for further intensification, similar to the
GFS's hurricane forecast at day 5. There are no obvious clues to
the correct solution, and this is probably a very difficult forecast
due to the feedback of Philippe's track affecting intensity, in
addition to the inherent challenges of moderate shear cases

Reminds me a lot of Karl 2016.

[SapphireSea]

Suppressive forces do make forecasting intensity very difficult. I think the best that can be assumed is whether the force is going to occur long term, or abate in a near-term window. (6-10) hours. While very different in mechanism, it's maybe not unlike temperature inversions suppressing convection in which it can create "hot-spots" of suppressed energy that can break through the cap and create isolated severe convection. I believe the same idea could apply here, in where if the storm develops "hot spots" of shear-induced (enhanced) convection and then approaches a better environment (or the more favorable environment moves in) during that time, it could jump start rapid intensification. However, if the shear or the unfavorable environment remains or deteriorates, then suppression can be complete and cause forecast to fail too intense. From the looks of it I would bet Phil would likely under perform until the mid-term if it's still around, and perhaps slightly over-perform late as it recurves, creating a better environment.

[aspen]

It’s actually looking pretty solid right now, despite clearly dealing with shear. It’s trying its best to get the LLC under a proto-CDO of sorts. I’d go with 50, maybe 55 kt at 11pm.

[cycloneye]

AL, 17, 2023092500, , BEST, 0, 169N, 427W, 45, 1000, TS

[Sciencerocks]

[cycloneye]

The center is exposed.

[Sciencerocks]

[REDHurricane]

Yeah I think I'm going with the Euro over GFS on this one, Philippe might not be able to survive too much longer

[MarioProtVI]

Yeah I think I'm going with the Euro over GFS on this one, Philippe might not be able to survive too much longer

I doubt it’ll just kill itself like that. Also Euro seems to have a little bit of bias for dissipating things too quickly. Fiona last year was initially expected to be weak and models indicated dissipation, we know how that turned out.

[aspen]

Phillipe is giving me Peter ‘21 vibes, in how it was modeled to be a MDR-born major but looks to end up as a struggling TS that got its life cut short. Maybe 91L/Rina will have somewhat better luck.

[ElectricStorm]

Phillipe is giving me Peter ‘21 vibes, in how it was modeled to be a MDR-born major but looks to end up as a struggling TS that got its life cut short. Maybe 91L/Rina will have somewhat better luck.

I think Phillippe still has a chance at some intensification if it can survive long enough to get further north. Until then though it should struggle quite a bit

[Teban54]

[Nimbus]

May revert to a sharp wave for a bit but eventually when the shear lets up there should still be enough of a pressure gradient to refocus the center. In the mean time track is more weak and west.

[cycloneye]

It begins to weaken.

17L PHILIPPE 230925 1800 17.1N 46.4W ATL 40 1002

[TallyTracker]

Well the center is definitely closed!

The center is shooting due west currently maybe even slightly south of west. I would expect the near term track to shift to the left for now.

[Sciencerocks]

[Sciencerocks]

[Teban54]

Remember when models were showing a major before it formed?

INIT 26/0300Z 17.6N 47.8W 45 KT 50 MPH
12H 26/1200Z 18.0N 49.4W 45 KT 50 MPH
24H 27/0000Z 18.8N 51.4W 40 KT 45 MPH
36H 27/1200Z 19.8N 53.1W 40 KT 45 MPH
48H 28/0000Z 20.8N 54.6W 35 KT 40 MPH
60H 28/1200Z 21.5N 56.0W 35 KT 40 MPH
72H 29/0000Z 22.0N 57.4W 35 KT 40 MPH
96H 30/0000Z 22.0N 59.4W 30 KT 35 MPH
120H 01/0000Z 22.0N 61.4W 30 KT 35 MPH...POST-TROP/REMNT LOW

[ElectricStorm]

Looks like models have shifted towards 91L becoming dominant instead. Not even expected to recurve now, should just move more west and dissipate.

[aspen]

Remember when models were showing a major before it formed?

INIT 26/0300Z 17.6N 47.8W 45 KT 50 MPH
12H 26/1200Z 18.0N 49.4W 45 KT 50 MPH
24H 27/0000Z 18.8N 51.4W 40 KT 45 MPH
36H 27/1200Z 19.8N 53.1W 40 KT 45 MPH
48H 28/0000Z 20.8N 54.6W 35 KT 40 MPH
60H 28/1200Z 21.5N 56.0W 35 KT 40 MPH
72H 29/0000Z 22.0N 57.4W 35 KT 40 MPH
96H 30/0000Z 22.0N 59.4W 30 KT 35 MPH
120H 01/0000Z 22.0N 61.4W 30 KT 35 MPH...POST-TROP/REMNT LOW

Literally just Peter 2.0.