Strong winds / Heavy Rain Tues 27 and Storm Diana Weds 28 Nov. 2018

The ECM seems to have lost the plot, much weaker solution at least near Ireland, other models have not changed much from their earlier depictions, so not sure whether ECM has spotted something or suffering from bad data, storm meanwhile chugs along and is near 34N 52W at last hour.

ICON 7km develops a secondary that approaches the south coast Thursday with violent winds depicted for the southeast.

This feature is either muted or absent on other guidance.

Almost all guidance takes a final swipe from the northwest in a last show of strength around Friday morning at latest.

We are going to have our hands full with this mess. And I didn't even mention Tuesday.

Note that, despite the name, very official-looking logo and flashy graphics, the Joint Cyclone Center is nothing more than one private individual in Miami and has no links to any official forecasting service.

Diana is already showing signs of a stingjet in the past few hours, still well out west of the Azores. See the narrowing and fading cloud signature just south of the centre on the satellite loop. This means it's probably reaching its peak and will start to fill and shift a little west of the model tracks over the next 24-36 hours. I'd expect to see that showing up in the 12Z runs.

http://oiswww.eumetsat.org/IPPS/html/MSG/RGB/AIRMASS/WESTATLANTIC/

GLaDOS wrote: »

I have my driving test in Dublin tomorrow . Is it likely to be bad around 11am-12pm?

And so it begins :rolleyes:

The UK Met Office have issued warnings

A very unsettled spell of weather is expected, with strong winds, combined
with widespread and in places heavy rain. Winds are expected to increase from
the far southwest early on Wednesday, spreading northeast, with areas adjacent
to the Irish Sea most exposed to the south to southeasterly wind. Wind gusts of
60 mph are expected, with a few, more exposed, locations seeing 70 mph gusts.
Winds will also turn northwesterly across Northern Ireland later, transferring
the main focus to northern areas here. The strong winds will also bring some
rough seas and large waves, with some coastal impacts possible.

https://twitter.com/JointCyclone/status/1067066456796479489

The 12z GEM (which has had the most straightforward modelling throughout) continues to show Diana on a track that would sweep very strong southwest winds into western counties on Wednesday. It seems to be pulling in the weaker low to its northwest according to CMC analysis, and this may provide a second intensity cycle although I agree with GL on his comments about current energy for the storm out west of the Azores. This has a long way to go to lift north of 50N and is not supposed to get there until 18W. The 12z GFS, UKMO and Arpege seem to have a similar take on it. The ICON is a bit different on extending a trough from Diana, which would probably cause stronger winds to hit south and east. But ICON has lost about half the intensity of the following wave although still developing it more than any other model. I also checked the HIRLAM output and it seems generally in line although not overly intense looking.

So I am waiting for the ECM to confirm that there actually is a Wednesday wind event then probably upgrade from watch to alert status.

Tomorrow may be the stronger rainfall pulse so that already needs an alert, and an update will therefore definitely be posted in the forecast thread for that alone.

Verbatim that would be only 80-100 km/hr range, gradient is not extreme and it's a meso-scale low.

Not to say that something different might not actually happen though.

ECM looks rather like the ICON for Wednesday now, close enough to justify an alert now I think.

Gradient not to be sniffed at with the low off the west coast in the AM, but yes current run holds gusts in excess of 110kph largely offshore...has a core of 80kph meanspeeds around it.

Also interesting secondary centre in the Irish Sea

Very squally along this front on Tuesday morning. AROME signalling some very intense cells with streaks of intense winds accompanying them.

this is from meteociel 3d http://www.meteociel.fr/modeles/gfse_3d.php?arpege=1&mode=6&lat=57.7&lon=-9.84&ech=21&zoom=2.6


The 6am one looks more in line with the spots of low wind speed