TECHNICAL DISCUSSION - Storm Eunice 18th February

Proper postings? Do enlighten...

Cork Airport TAF forecasting gusts up to 65 knots from the south /south west between 2am - 6am. Wild enough!

TEMPO 1802/1806 21040G65KT 

BECMG 1804/1806 27032G54KT 

BECMG 1806/1808 30035G60KT TEMPO 1806/1812 SHRA SCT020CB 

BECMG 1810/1812 29023G40KT 

Yet you just did similar....

I like to watch the mountain forecast site.

Croagh Patrick Weather Forecast (764m) (mountain-forecast.com)

Croagh Patrick forecasted to get 10cm of snow on Thursday evening. At the peak (764m).

Galtymore (917m) only gets 2cm which is in line for this being a W/NW snow event.

Yeah ICON definitely looking weaker. I wonder will GFS follow

The South is the place for the snow tomorrow afternoon as a trough line moves across!

Also, as JS has alluded too, is there possibly more of a widespread snow risk then expected on the 12z GFS? In particular at 9am it has -7 uppers over most of the country. Was that expected? Its the GFS I know...

Arpege and GFS 12z looks a lot weaker have to say

agreed... just saw that there too.. thankfully.

The most significant change in the 12z model suite seems to be the dual-low emphasis with the northern weaker centre tending to pull in just mild enough air to limit the snowfall potential during the early phases to northwest Connacht and Donegal. Parts of Connacht, midlands and Ulster have been removed from the accumulating snow zone as a result. GEM remains a bit less robust with the northern feature so its guidance might retain more snow in those areas mentioned.

The southern part of the structure is still fairly similar to the 06z depiction with the strongest winds following in behind the low centre, it's not until the low reaches about Wexford that there is much of a trend towards more evenly distributed wind speeds and by then the strong winds are heading into southwest England and south Wales.

For the south coast in general, would expect about 2-3 hours of very windy conditions setting in just after the low has passed by, mostly from the W to NW so you might assess your local exposure to that direction as one factor in play. A more general strong blast of WNW winds will then develop over most of the country by later morning. The increased area of the strong wind circulation will drop the intensity somewhat.

Emphasis will be on fast-changing and fast-moving conditions through the morning hours, and the cold, windy period to follow, probably just cold enough for mixed wintry showers rather than widespread snow showers, but minor accumulations on hills.

The Saturday following wave looks interesting and somewhat different versions of it given on different models, potential for an interval of 3-5 cm snow accumulations before milder air arrives, but at this point, can't be too specific about locations.

Will be updating the forecast soon. It's probably a situation of technical local validations of red but more widespread orange for the counties involved in red warnings, and likely the same could be said (orange-yellow) for the orange. I suppose we're always going to have this sort of result and most Boards weather people know that there will be a range of outcomes per county.

A disastrous update from MT in terms of snow laying at lower levels, but I had a feeling too much milder air would be drawn into the circulation. Still , in saying that if we get heavy snow that leads to blizzard like conditions for a time I will be happy with that

Latest UKMO model also has that feature except it crosses the bottom two thirds of the island, not just areas more southerly than that.

Latest from 18Z, showing the Shapiro-Keyser structure (detached cold front) typical of deep lows coming up from the southwest. Pressure has dropped 16 hPa in the 6 hours since 12Z.