ATL: ERIN - Tropical Storm - Discussion

[zzzh]

[Category5Kaiju]

Either this goes fully OTS and doesn't harm anybody, or in future years we're going to have to contend with "you can't say this storm will go OTS, don't you remember Erin?!"

[cycloneye]

Tuesday will be a important day to see how far down in latitude, the circulation goes.

[LarryWx]

Tuesday will be a important day to see how far down in latitude, the circulation goes.

The good news in the short-term for the US is that Erin climbed slightly from 17.4N to 17.6N (275 degree heading) since the previous advisory vs a prog to stay at 17.4N (270 degree heading). Could be a good sign regarding keeping the latitude instead of losing much. We’ll see!

[emeraldislenc]

That is such a small deviation but I guess ever nudge north can make a difference. I agree with the previous post that Tuesday and even Wed will be important days to watch the models. I am heading to Fort Lauderdale on Tuesday to take care of some personal business. I will be watching the models very closely.

[LarryWx]

That is such a small deviation but I guess ever nudge north can make a difference. I agree with the previous post that Tuesday and even Wed will be important days to watch the models. I am heading to Fort Lauderdale on Tuesday to take care of some personal business. I will be watching the models very closely.

It can’t hurt. But the NHC is still progging the low point of 17.1N on Wednesday morning. That will be one key benchmark to compare the actual track to.

[Hurricaneman]

Seems as though the center is racing out of the convection, and also seems to be heading WSW but could be my eyes playing tricks on me

[chaser1]

Not a forecast but more of a rationale should an exaggerated Southwesterly motion occur as some models indicated. Still within a somewhat dry environment (and until increasingly warmer SST's aid in instability), I believe that should a southwest motion ensue it would increase the threat of the MLC and LLC to possibly decouple. That possibility is only exasperated by it having a relatively small inner core. At a minimum this could delay the intensification process. The flip side could also result in a range of differing outcomes as well.

[chaser1]

Seems as though the center is racing out of the convection, and also seems to be heading WSW but could be my eyes playing tricks on me

Yep, that LLC is really booking it to the west with the convection just clinging on. I think i'm seeing a pretty due west motion but like you, I can't be fully sure.

[Woofde]

Seems as though the center is racing out of the convection, and also seems to be heading WSW but could be my eyes playing tricks on me

There's definitely a degree of seperation occurring at the moment. I would not be surprised to see a continued south shift of the models until this reaches warmer waters. The current setup has significantly warmer SSTs to the south and dry air to the north. This leads to convection primarily focusing on the south side of the storm and tugging the center southward.

In theory, the Hurricane models should be able to better depict this than the globals. This matches what we are seeing. The HAFS-A and B at hour 126 are both under 21N, while the GFS and Euro are around 22N.

[kevin]

LLC racing west with the convection making a clear WSW motion. Depending on which element of the storm becomes dominant (and whether or not it'll decouple), this could pull the LLC south as well.

[weeniepatrol]

LLC racing west with the convection making a clear WSW motion. Depending on which element of the storm becomes dominant (and whether or not it'll decouple), this could pull the LLC south as well.

[kevin]

Automated ADT fixes show an average heading of 266 deg over the last 4 hours so ever so slightly WSW, but also well within the margin of error.

[jconsor]

As others have mentioned, Erin has begun to track south of due West in the last 12 hours. Short-term track and intensity intrigue will play a large role in Erin's longer term track.

What insights can historical analogs and ML models bring in terms of Erin's potential impacts to the NE Caribbean and US? Check out my full post here:

https://hurricanehacker.substack.com/p/tropical-storm-erin-forms-in-eastern

[cycloneye]

From the 5 AM discussion:

The official forecast track is a little left, or
south, of the previous one in 3-5 days, and very close to the
latest dynamical model consensus. This also very similar to the
mean of the GFS and ECMWF solutions.