Still looks tropical at 144h on the ECM. Insane.

Lorenzo now cat 4; just missed the record for furthest east cat $ formation which belongs to Julia in 2010. It's forecast to weaken before reaching the Azores, and the eye to pass just north of the islands, but close enough to do a lot of damage. ECM has its central pressure around 945-950mb 200 miles west of Ireland on Thursday.

Sadly the latest NHC has the centre of the warning cone passing directly over Flores in the Azores. It's sparsely populated but a beautiful place. For anyone who's not been to the Azores theh are well worth a visit.

The NW Azores now look as if they will take a bad hit, probably of a record-breaking character for these islands.

For records of a combination of  size/late date/furthest east see

https://www.wunderground.com/cat6/Category-4-Lorenzo-Setting-Records-Karen-Weakening-Tropical-Depression?cm_ven=cat6-widget

then still  a hurricane in the latitude of Biscay on Wednesday, after which I've put notes in the model output thread.

Rare fax hurricane

Might have to start thinking about the first ever UK/Eire TC landfall and the 2nd ever Europe TC landfall.

I think the risk is probably around 25% at this stage.

Note, whether or not the storm is technically a TC does not necessarily matter that much with regards to intensity. The interest with regards to its TC status is meterological. It would break alot of records.

With regards to lowering SSTs I've always maintained it doesn't matter. TCs are less sensitive to SSTS than most people think. Lower upper tropospheric air will compensate for lower SSTS. The big killer of high latitude TCs is shear.

So the question is, will Lorenzo be torn apart very quickly like Helene or use the shear, instead, to ventilate itself like Ophelia?

Lorenzo can be seen near the Azores. This is an example of how wind shear can be used to ventilate a storm by providing a upper level outflow channel to the north.

Lorenzo as it nears the end of its transition. Embedded in a larger scale mid latitude depression but still the core of thunderstorms remaining.

A few humdingers in the GEFS

This might solve the Irish backstop dilemma

ARPEGE has Lorenzo at the latitude of S france with almost no loss of tropical characturistics at all.

Lorenzo may be beggining a second period of RI. I suspect we will see it recover its cat4 status.

The MPI is actually high enough now for it to obtain cat5 but that would require the shear to drop.

OK calling this.

Its catogary 4 and will be upgraded to that.

Dropsonde showing 114kt.

Definitely cat4

NOAA update coming out soon (21Z)
I'm gonna go for 120kt.

NOAA update coming out soon (21Z)
I'm gonna go for 120kt.

 

Confirmed. NOAA have upgraded to 115kt.

I was 5kt out, but it is a Catogary 4.

Extremely deep convection in the last hour or so.

Seems to be still intensifying, if it wasn't for the shear I suspect it might already be cat5.

Lorenzo seems to have symmetrized its eyewall now. Dvorak has it at T6.8

Bottom level cat5 is T7.0

The instantaneous dvorak tends to be the upper limit of what the storms intensity actually is.

Nevertheless I'd expect the SLP to be around 935mb and the wind around 125kt or around 10kt short of Cat5.

Lionell won't be happy to see Ireland 'in the cone'

And there we have it. It finally suceeds in symmetrizising its eyewall. Beautiful storm. Can it get to cat5?

Lionell won't be happy to see Ireland 'in the cone'

I'm watching it very nervously, Q. At least, on that trajectory, it doesn't look like giving its worst to my part of Ireland but there's plenty time for that to change. It really would be incredible to be hit by two almost still hurricanes in three years. Given that this one is arriving that bit earlier in the season, the impact will be worse if it scores a direct hit - more leaves on the trees mean that any storm will cause more damage. The only comfort I can find is that the winter following Ophelia brought us our heaviest snow since the early 80's. So it is does hit Ireland, I can only hope that we get a repeat of winter 2017/18!