*** Heavy Rain and High Winds for many as Storm approaches(Mon 24th - Tues 25th Sept)

The latest national forecast doesn't sound too bad?

Today

A few clear spells in the far southwest, but generally cloudy or overcast with outbreaks of rain.

srmambo wrote: »

The rain has started to become heavier here.

I was half expecting Estofex to issue a warning for excessive precipitation for Ireland :P

Were's here srmambo

DOCARCH wrote: »

Bloody hell!

Has just reached 50.0mm here now. I declare an.....

......event.

It's a bit like a damp day in Valentia!!!

Railway line closed south of dun laoighre

diceyd wrote: »

is that the end of the heavy rain or is there more to come?

thinking the same keep looking out the window, seems very light soft rain if that at times..

The current position of the low appears to be an elongated trough from near Manchester to the central North Sea west of Holland. Within that there are probably two main centres, one in south Yorkshire and one over the North Sea.

The models in so far (basically all but ECM) continue the previous theme of the GFS, while there is some variation, the main idea is a gradual retrograde (westward) drift overnight to bring the centre out into the Irish Sea close to the Isle of Man then southwest pretty much halfway from Dublin to Anglesey by about mid-day Tuesday and then to a point between Wexford and southwest Wales by Tuesday night. The lowest central pressures indicated are either late tonight or mid-day tomorrow depending on model, and some of these reach values below 975 mbs (currently around 983 mbs).

This evolution will probably maintain the moderate to heavy rainfalls across most of Leinster and east Ulster with a very slow southward drift of the rainfall shield although not changing the location of heaviest rain which appears likely to stay just inland from Armagh/Down south to north Wicklow. Severe flood potential must be considered given the rainfall rates already achieved with most of the "event" yet to come. This is speculative but you could see local (total storm event 2-3-day) rainfalls of 150 mm in this situation. There could be widespread totals in the 50-100 mm range in the region. These totals will drop off quite sharply west of the Wicklow-Dublin mountains, and into the north-central counties, although some totals of 20-40 mm are possible over the period.

As for wind potential, this is very tricky in the developing situation. With the expected pressure falls and track, it seems likely that very strong NE winds would develop across the northern part of the Irish Sea and impact the coast north of Dublin, whether they reach the capital or not remains to be seen but would be more likely from about Balbriggan north. These winds would be about NNE (020-030 deg) at their max late tonight and so the very strong winds could come inland across portions of Dublin and Kildare counties, but Meath, Louth, Armagh, Down and Antrim are likely to see a longer period of strong winds. Peak gusts likely around 55-60 mph but some potential for higher gusts, will be keeping a very close eye on developments overnight. I should stress that there could be a very sharp cutoff in strong winds as this storm will develop a 30-40 mile wide "eye" feature and eyewall-like rainfall bands that will produce a much weaker wind field near the centre. The M2 buoy could be reporting almost calm winds at the height of this storm at some point. Also, the winds will be much weaker south of the east-west trough in which the low centre will develop, at least until the circulation responds by becoming more circular. This trough is currently oriented from about Drogheda ESE and will now start to pivot around the low centre in northern England, it won't drift much further north on the Irish side of the Sea and by tonight will be drifting south again.

This will become an overnight close watch situation especially for those with impoirtant weather concerns (emergency managers for example) and if you're in a flood-prone area from rivers overflowing in north Leinster you should be aware that continued heavy rain might lead to emergency situations developing late tonight into Tuesday morning. I don't live in your region so not really the best source of guidance on what rivers could overflow but simple logic would say that any river in the region is at risk of overflowing if rainfalls exceed 100 mms. The heavy rain would be mostly over the Liffey and Boyne drainage regions, plus any small streams further north.

The track of the low will be very critical for highest impacts of strong winds, not so much for rainfall. If the low comes out south of the Isle of Man and heads closer to Anglesey, this would mean stronger winds for Dublin. If it came out into the Irish Sea north of the Isle of Man and came closer than I would currently expect to the east coast, this will cut off potential for the strong winds there and shift them into less populated regions further west where the terrain will result in them being weaker for most locations. The track from Isle of Man to central Irish Sea results in the more complex situation described above where there is a sharp cut-off near Skerries (this time I have been looking at maps), but this cut-off point would also tend to drift south with the track of the low.

Let's put it this way, it won't stay almost calm as reported by many in the region, this is a phenomenon of the development process and as soon as the low turns and deepens, much stronger winds will be pulled into the circulation.

The latest Met O fax charts make for scary viewing - they keep this "event" going will into Wednesday over much the same areas!!:eek:


PS: The latest radar loop has some very heavy stuff moving into North Wexfod/South Wicklow - not sure if that was forecast

Some heavy stuff building in the Irish Sea now just off the coast.

Rainfall is looking a bit weaker than expected for this time. It may well get stronger again overnight, but if it doesn't then this won't turn out to be anything too severe really.

Very calm & quiet up on the hill here in Greystones this evening.
It pelted down all day in Dun Laoghaire but once I came home from work it was like being in a different weather region.

A 2129 Met Eireann update. Summary: Further spells of heavy rain tonight and daytime Tuesday with flooding in places. Tonight

Cloudy tonight with spells of heavy rain.
Lowest temperatures 6 to 9 degrees. Very windy in the north and northwest with gales.

Tomorrow

Overcast Tuesday morning with scattered outbreaks of rain, heavy in places especially in the east.
Some sunny spells will develop during the day but there will be heavy showers also.
Cold and very windy; highest temperatures only 11 to 13 degrees with northerly gales developing.