Hurricane Helene

[pip22 2,393]

Helene just formed off the coast of Africa.

National Hurricane Center‏Verified account @NHC_Atlantic

Tropical Storm #Helene Advisory 4: Helene Forecast to Become a Hurricane On Sunday. http://go.usa.gov/W3H 

 

Edited September 10, 2018 by Nick L

[pip22 2,393]

BBC Weather‏Verified account @bbcweather

An easterly wave that dumped 170mm of rain in parts of Ghana, has now become #TropicalStormHelene with torrential rain for Cape Verde. CF

[Iceberg 2,288]

Helene is a very large envelope ts. 

Due to this the tightening is taking a while. Currently though raw t numbers indicate quite a strong tropical storm. When she gets it together she should be very pretty. 

 

[summer blizzard 6,942]

Now a hurricane. Gfs and Euro are consistent in having it hang around west of the Azores between days 5-10.

[Had Worse 2,226]

Just looked at the meandering path projected and its not inconceivable that the Azores could get some very wet and windy weather subject to the strength of Helene

[BrickFielder 1,369]

Helene is pretty big with a ragged but quite well defined large eye at the moment. I would not be surprised if it is not close to a CAT 2. Bearing in mind that Isaac is dragging a band of very warm moist air across the North of Helene it is a bit surprising that models have Helene fading away in the mid Atlantic. It would not be the first time that modelling has a hurricane fading away when in reality it manages to survive quite far into the North Atlantic especially since this is forecast to start moving North quite quickly in a few days. If I was in the Azores or Madeira I would be watching this one closely.

[Man With Beard 21,447]

ECM 12Z has the remnants of Hurricane Helene reaching the UK by next Wednesday with winds still at around F10.

Edited September 10, 2018 by Man With Beard

[Lakigigar 23]

[BrickFielder 1,369]

Extract from NHC Forecast discussion 16.

Quote

Interestingly enough, the global models show Helene either maintaining tropical storm strength or even intensifying by the end of the period, possibly due to some mid-latitude dynamic forcing influences. It's also worth noting that the Florida State Cyclone Phase Evolution analysis and forecast product shows the system retaining a relatively symmetric warm core through the entire forecast.

I think discussion 15 suggested the baroclinic transition could see the storm increasing in size and becoming a significant autumn storm moving north eastwards. Modelling today might suggest that it will hold on to its warm core structure for longer than you might expect.  I still think the Azores should be watching this one closely.

 

[Polar Bear 884]

So she’s weakening then https://www.nhc.noaa.gov/text/refresh/MIATCPAT3+shtml/120232.shtml

[Man With Beard 21,447]

Latest ECM has Helene turning into an mini Orphelia for Ireland by next Tuesday (not as bad), with winds gusting over 100 mph. Sustained winds about 60mph by then at worst, and that restricted to the SW coast. A bad autumn storm but not a huge one.

[The PIT 8,792]

Looking like Helena will bring a hot hair driver with strong winds up the Irish sea and wales before moving across northern England with gusts up to 60 mph. Very warm to Hot in the east and south east but dry. Very wet over Ireland and later Scotland and Northern England.

Worth keeping an eye on this at the moment could go anywhere and the strength could vary a bit as well.

[Paul 20,390]

 

[Nick F 20,550]

12z ECMWF blows the cobwebs away early next week, as a deep low formed of the remnants of ex-Helene barrels across the UK.

12z GFS and UKMO also track an ex-Helene low NE over the UK but not as deep

 

[matty40s 2,530]

and there could be a 2nd tropical depression in swiftly following it too...

[The PIT 8,792]

Morning GFS shifts it further west.

[BrickFielder 1,369]

No real evidence of an eye now as far as I can tell but there is deep convention in the south, which may lead to some re-organization. Many models taking just to the west of Ireland as a strong autumn storm. With no clear warm core most tropical characteristics will be lost although this could change (good chance of a little re-organization in my opinion) , but it will still be a significant storm for the Azores.  There are a few outlier model solutions that take Helene over Cornwall as an Autumn Storm, but I think this is unlikely at the moment.

The westward movement could be a little bit of a Fujiwarra effect from tropical storm Joyce. Some models show Joyce developing and following in behind Helene with a more eastwards movement heading eventually towards Portugal before dissipating. Looking at EUMetsat Satellite shots show Joyce not really developing in warm air and I don't really see it having a warm core. NHC seems to think Joyce can move into warmer air left from Helene and take on tropical characteristics. It is possible and it is even possible that Joyce could circulate back to off the coast of North Africa to reform. So I am not totally convinced by the westward movement suggested by the models and would not be surprised to see a little strengthening again of Helene based on convection in the southern quadrant.

To summarize ,I have low confidence in the modelling , but don't expect hurricane like conditions for the UK. The prime risk is likely to be very heavy rainfall if at all based on current low confidence modelling.

[The PIT 8,792]

THis evenings GFS puts it back further east close to last nights track noaa has it slight west but still a long way away. This time though we may get the heat which we didn't with the last visit due to air pollution from Portugal fires.

[The PIT 8,792]

Overnight GFS moves it back westward weakens it and removes the heat. 

[pip22 2,393]

Daily Mirror‏Verified account @DailyMirror 11m11 minutes ago

"Danger to life" warning as Hurricane Helene bears down on UK with 80mph winds https://www.mirror.co.uk/news/uk-news/breaking-hurricane-helene-wind-warning-13242957 …

[The Eagle 1,924]

ICON is pick of the bunch so far. Still some uncertainty on the track and depth.

 

Edited September 14, 2018 by The Eagle

[Fiona Robertson 427]

Hey guys, I'm currently in San Francisco. I fly into Heathrow on Wednesday 19th and then on to Edinburgh. Been following Helene since she formed. Any thoughts on wind speeds Wednesday morning?

[The PIT 8,792]

26 minutes ago, pip22 said:

Daily Mirror‏Verified account @DailyMirror 11m11 minutes ago

"Danger to life" warning as Hurricane Helene bears down on UK with 80mph winds https://www.mirror.co.uk/news/uk-news/breaking-hurricane-helene-wind-warning-13242957 …

UKMO and GFS have much different idea how this is going is going to play out. So any forecast must have a very low confidence value attached to it. A case keep watching and hope that the met office can update warnings quickly enough to reflect the changes closer to the time. Something they haven't been very good at in the past.

[The PIT 8,792]

16 minutes ago, Fiona Robertson said:

Hey guys, I'm currently in San Francisco. I fly into Heathrow on Wednesday 19th and then on to Edinburgh. Been following Helene since she formed. Any thoughts on wind speeds Wednesday morning?

Too early to say keep an eye on the models for the next few days it may yet miss the UK altogether or plough straight up the middle. The fax chart is completely different to the latest ukmo on http://www.meteociel.fr/modeles/ukmo2.php?ech=6&carte=1021 same source as well.

Edited September 14, 2018 by The PIT

[Fiona Robertson 427]

Just now, The PIT said:

Too early to say keep an eye on the models for the next few days it may yet miss the UK altogether or plough straight up the middle. 

Given my flight path, I'm coming in from the north down across Scotland to get to Heathrow, then all the way back up to Edinburgh so if the worst comes to the worst, I get to fly through it twice, with two landings and one takeoff. Oh joy...