ATL: DANIELLE - Post-Tropical - Discussion

[Landy]

Looks like it's a TD IMO.

[CrazyC83]

I agree it looks like a TD. I believe it would go down as a September storm though if genesis was 00Z even if it was August 31 in the US.

[CrazyC83]

Unfortunately ASCAT-B missed 93L and ASCAT-C only captured the right side, although it was definitely closed on that side with 30 knot winds.

[Sciencerocks]

[Europa non è lontana]

AL, 93, 2022090106, , BEST, 0, 381N, 452W, 30, 1013, TD, 0, , 0, 0, 0, 0, 1017, 110, 40, 0, 0, L, 0, , 0, 0, INVEST, S, 0, , 0, 0, 0, 0, genesis-num, 023,

[Sciencerocks]

[DorkyMcDorkface]

RAMMB has 05L. Looks like we're getting TD5 momentarily.

[Jelmergraaff]

It is now tropical depression Five. According to the NHC it should become a tropical storm later today and strengthen into a hurricane in about 2 days. Peak intensity forecast at 80 kt/90 mph at +96h.

Satellite imagery indicates that the low pressure area over the North Atlantic west of the Azores has developed a well-defined circulation and convective banding in the eastern semicircle. Based on this structure, advisories are being initiated on Tropical Depression Five with an initial intensity of 30 kt.

Despite the high latitude, the cyclone is in an area of light steering currents on the southeast and south side of an anomalously strong mid-level anticyclone. This should result in a slow motion for the next three days or so, with the guidance showing an eastward drift followed by a westward drift. After three days, the anticyclone is forecast to move eastward and weaken as the mid-latitude westerlies start encroaching on the system. The large-scale models are not in good agreement with how this will steer the cyclone, with the GFS and Canadian showing a general motion toward the east while the UKMET and ECMWF forecast a more northward motion. The track forecast is close to all of the guidance for the first three days, and then calls for a northeastward motion between the HFIP Corrected Consensus and the other consensus models at days 4 and 5.

The sea surface temperatures in the area are warmer than normal - near 27C. This warm water, combined with a forecast environment of light- to moderate westerly shear for the next three days or so, should allow steady strengthening. The intensity forecast calls for the system to become a tropical storm later today, a hurricane in about two days, and reach a peak intensity of 80 kt in about 4 days. It should be noted that this forecast is close to the intensity consensus, and there are models forecasting more intensification. After four days, motion over cooler water and increasing shear should cause the cyclone to weaken.

[MHC Tracking]

HAFS, HWRF, HMON, GFS, ICON all take this to cat 2+. Wonder if it'll be able to get to ~90-95 kt considering the very favorable upper-level conditions modeled + significantly above average SSTs.

[aspen]

Why is this called TD5 instead of TD4? Is it because PTC-4 existed, or they’re planning to upgrade something in July or August in post-season?

[MHC Tracking]

Why is this called TD5 instead of TD4? Is it because PTC-4 existed, or they’re planning to upgrade something in July or August in post-season?

PTC was officially 04L, even though it never became a tropical cyclone.

[MHC Tracking]

Looks like a TS now. Closed LL eyewall "cyan ring". Maybe some significant intensification coming in the near future?

[Category5Kaiju]

Looks like a TS now. Closed LL eyewall "cyan ring". Maybe some significant intensification coming in the near future?
https://cdn.discordapp.com/attachments/733552978572869632/1014852120597495808/image0.jpg
https://cdn.discordapp.com/attachments/733552978572869632/1014851674097074246/20220901.1027.gpm.37hbt.05L.INVEST.30kts.1013mb.38.1N.45.2W.055pc.jpg

I gotta say, it genuinely wouldn't surprise me to see this thing pull a Epsilon or Alex 2004, where it becomes a Cat 3 but at an unusually high latitude. I think that insane subtropical warmth could really help out here; in fact, I'd find it even more comical if this this meanders and adds a ton of ACE to what we have now lol

[Hammy]

It's as if the Atlantic was intentionally holding off until after August

This thing's rapidly organizing by the looks of it, even on satellite you can see the low level spin accelerating in almost real time

[cycloneye]

AL, 05, 2022090112, , BEST, 0, 381N, 448W, 30, 1013, TD

[aspen]

AL, 05, 2022090112, , BEST, 0, 381N, 448W, 30, 1013, TD

I sure hope they revise that. Sure these subtropics systems tend to form banding eyes pretty quickly and before they become hurricanes, but there’s no way a system with a fully formed eyewall is still a TD.

[al78]

Even if it doesn’t get named operationally today this could be a case where cyclogenesis gets backed up in post season. August may not quite make it after all.

This system will be around for a while. I'm becoming confident it will be the first hurricane of the season. Could reach Portugal or France at hurricane strength. Question is, will it still be tropical then?

I mean it is an interesting thought, but bona fide hurricanes threatening Europe are rare but not unheard of. Vince 2005 and Ophelia 2017 come to mind.

Vince made landfall near the Spain-Portugal border as a weakening depression and Ophelia was extra-tropical when it came ashore in Ireland (https://en.wikipedia.org/wiki/2017%E2%8 ... ne_Ophelia), so neither of those were bona fide European hurricanes. It is impossible for a true hurricane to hit Europe outside of the Azores because the sea temperatures and atmospheric winds are always extremely hostile. What we get are former hurricanes that have interacted with the polar jet stream and transitioned into extra-tropical storms.

[kevin]

This system will be around for a while. I'm becoming confident it will be the first hurricane of the season. Could reach Portugal or France at hurricane strength. Question is, will it still be tropical then?

I mean it is an interesting thought, but bona fide hurricanes threatening Europe are rare but not unheard of. Vince 2005 and Ophelia 2017 come to mind.

Vince made landfall near the Spain-Portugal border as a weakening depression and Ophelia was extra-tropical when it came ashore in Ireland (https://en.wikipedia.org/wiki/2017%E2%8 ... ne_Ophelia), so neither of those were bona fide European hurricanes. It is impossible for a true hurricane to hit Europe outside of the Azores because the sea temperatures and atmospheric winds are always extremely hostile. What we get are former hurricanes that have interacted with the polar jet stream and transitioned into extra-tropical storms.

Indeed, subtropical storm Alpha back in 2020 is as far as I know the only (sub)tropical storm to make landfall in Portugal since observations officially started. Note that London is roughly at the same latitude as Calgary, Canada. And even Madrid is 'only' at the latitude of NYC. All Europe can get are transitioning systems that are either extremely resiliant (= Alpha) or very strong and thus still quite damaging even in their weakend state (= Ophelia). I mean never say never (especially with rising sea temperatures due to global warming), but even then I think any tropical system threatening Europe will remain a rarity. Hopefully I won't have to adjust this statement in a week or so. If you really want some tropical action in Europe, I'd recommend to look to the Mediterranean Sea. Only 2 years ago cyclone Ianos reached cat 2 intensity (according to Wikipedia) before landfall in Greece. Bit off-topic, but there really should be an official agency in charge of naming and tracking those storms.

[kevin]

Back on topic, TD05 is looking very good right now. Will probably be Danielle very soon.

[tolakram]

That's no TD, that's a TS rapidly strengthening in my opinion, might already be a hurricane.