Heavy Rain South/South East. Possible Flooding Sunday 25 November

ninebeanrows · 21-11-2012 8:52pm #1

Maybe using % risk type threads will lower the chance of upset from some of our members.

I highlight a potential for a damaging wind storm Sunday as a wave feature currently near the Azores tracks northeastwards towards Ireland & the UK.

The feature is forecast to track near a very strong jet streak and some forecast models are highlighting the prospect of it intensifying quite markedly as it approaches Ireland/UK and moves northeastwards through the region.

Some models such as GFS prefer moving a less developed low through the region.

ECM 72hrs

ECM 96hrs

A few GFS Ensembles highlight the severe risk that this could bring to the country.

ninebeanrows · 21-11-2012 9:00pm

ECM Freebie today are the Ensembles timestamps.

Let's hope they are still free this evening.

This mornings run of the EPS show the potential positions of the storm.

http://www.ecmwf.int/samples/d/inspect/catalog/samplers/banner/mean_sea_level_pressure_and_temperature_at_850hpa!96!pop!od!enfo!enplot!2012112100!!/

Nabber · 21-11-2012 11:41pm

Some models are playing with the idea of a low pressure system tracking up from the Iberian coast. Don't see anything as strong as the GFS EN you have there. The lowest I see is 993.

Plus I'd prefer if this Sunday wasn't wet and windy. So please be wrong Weathercheck

ninebeanrows · 22-11-2012 12:02am

Yea, 18z GFS having none of it. But ECM was quite intense in the 84hr frame..

Sponge Bob · 22-11-2012 10:20am

0z ECM SENDS this 'system' to England mainly...around Sunday.

[img][/img]http://www.meteociel.fr/modeles/ecmwf/runs/2012112200/ECM1-72.GIF

Deep Easterly · 22-11-2012 12:02pm

Latest EMHI chart for Saturday 12z; pretty much in line with the ECM 00z. Has a narrow region sustained gale 8 - 9 on its southwestern flank and throwing up the potential for some heavy rain into the south and more especially southeastern corner of the country. GFS keeping the low more to our SE but worth keeping an eye on regardless.

ninebeanrows · 22-11-2012 12:04pm

~5 GFS Ensembles have the system impacting us.

Certainly a very difficult one to call for forecasters.

25% risk this could come off, and it has moved into the Day 3 forecast

Once the system travels over the Azores, hopefully the increase in data coverage will increase forecast accuracy.

maquiladora · 22-11-2012 12:16pm

Could be some strong winds in the English Channel if the ECM is right.

Deep Easterly · 22-11-2012 3:15pm

Nice WV image (at 12z) of the developing wave feature. Going to be an interesting one to watch develop over the next couple of days.

ninebeanrows · 22-11-2012 4:48pm

NAE has storm sub 988mb at T48rhrs while GFS has it ~1000mb

munsterlegend · 22-11-2012 4:54pm

Weathercheck wrote: »

NAE has storm sub 988mb at T48rhrs while GFS has it ~1000mb

is it further west to affect Ireland or still on for a UK track?

ninebeanrows · 22-11-2012 5:01pm

munsterlegend wrote: »

Weathercheck wrote: »

NAE has storm sub 988mb at T48rhrs while GFS has it ~1000mb

is it further west to affect Ireland or still on for a UK track?

In that sequence probably the UK but some parts of Ireland particularly east at risk.

Cantona's Collars · 22-11-2012 6:15pm

BBC forecast today had 2 systems heading our way,one on Saturday & another on Sunday with the latter being the more severe which they tracked to hit SW England while the system on Saturday is to come closer to Ireland.

All subject to change of course,but they concur with what's being forecast here.

munsterlegend · 22-11-2012 7:04pm

http://www.dmi.dk/dmi/index/danmark/vejrkort.htm

A lot of rain for Southern parts Saturday evening per the Nedbor link on this.

ninebeanrows · 22-11-2012 7:16pm

ECM throws system north through England, poss storm force winds.

Sponge Bob · 22-11-2012 7:42pm

Weathercheck wrote: »

ECM throws system north through England, poss storm force winds.

As it was this morning so.

Deep Easterly · 22-11-2012 11:57pm

Looking stormy come Saturday evening for NW France/SW UK

Sponge Bob · 23-11-2012 12:39am

The storm will be a non event in the west both in terms of rain and wind ...thankfully. Can we reduce the % to 15% please.

munsterlegend · 23-11-2012 10:03am

Looks like a lot of rain for the South and South East tomorrow afternoon and evening with Met Eireann having a risk of localised flooding. I know previous systems have a habit of veering north west - is there any possibility of this happening here?

Sponge Bob · 23-11-2012 10:13am

There is but I think the models have a handle on it now so I'd accept the forecast.

It won't be much of a storm, more of a rain event.

Lest anyone start the rainfall totals in the south and east, to date, are no more than 60% of the November average and will still be well under 100% AFTER this event. UKMO forecast chart for midday Sunday.

Rikand · 23-11-2012 1:36pm

late night rte met eireann forecast last night went into a bit of detail about the Global Model and showed the position of all active systems around the world before showing a 12 hour * 12 hour position of this system.

They have it Saturday evening off the south east coast and then into the UK by Sunday morning.

Not too bad - might get a bit of golf in both days

DOCARCH · 23-11-2012 3:27pm

According to ME forecast today, it's still on (well at least the rain bit - maybe not the wind):

SUMMARY: Wet and windy spells over southern and eastern parts at first, followed by colder and drier weather next week as northerly winds set in.

SATURDAY NIGHT: Rain over the east and south will turn heavy with a chance of localised flooding. Colder and clearer in the northwest with frost, will possibly extend to other parts of the country towards morning as the rain clears away to the east, with a danger of ice forming on roads. Windy for a time in the east and southeast, but winds will ease towards morning.

SUNDAY: Any remaining rain in parts of the northeast or east will clear on Sunday morning and the rest of the day will be cold but dry in most areas. However, rain is likely to affect southern parts later and the rain will probably spread across much of Munster and Leinster in the evening. The rain looks like to continue over many parts of Leinster and Munster on Sunday night, together with strengthening winds, while the northwest and north should stay mainly dry with frost returning. The rain might turn to sleet on higher ground later in the night.

MONDAY: The rain and possible sleet should clear the east later on Monday, followed by sunny spells and scattered showers, and cold northerly winds will set in.

Big Daddy Cool · 23-11-2012 5:19pm

Lads any idea how much can be expected from this system for north leinster, after wednesday nights rain, i dont think the pond and field next door will take much more water.

Cantona's Collars · 23-11-2012 9:23pm

Some pictures here of the flooding in England,a weekend of heavy rain is really gonna compound the issue.

http://www.dailymail.co.uk/news/article-2237242/UK-floods-Britain-water-days-rain-deluge-50mph-gales-set-continue.html

A question- how much rain should we expect here in the South East? The Slaney is running high as it is so more heavy rain could end up with it breaking it's banks.

maquiladora · 23-11-2012 10:47pm

zerks wrote: »

A question- how much rain should we expect here in the South East? The Slaney is running high as it is so more heavy rain could end up with it breaking it's banks.

The latest NAE model shows about 15-20mm in the southeast over the next 48 hours. It will be England & Wales getting all the heavy rain though.

downwiththatsor · 23-11-2012 10:51pm

The Nae does not show that much
http://www.weatheronline.co.uk/cgi-bin/expertcharts?LANG=en&MENU=0000000000&CONT=ukuk&MODELL=nae&MODELLTYP=1&BASE=-&VAR=rsum&HH=30&ZOOM=1&ARCHIV=0&RES=0&WMO=&PERIOD=

Hirlam (nedbor) shows more though
http://www.dmi.dk/dmi/index/danmark/vejrkort.htm

However Hirlam here does not show much either
http://www.emhi.ee/index.php?ide=19,394,416,418

Take your pick i guess, maquiladora is more experienced with models though

maquiladora · 23-11-2012 10:57pm

downwiththatsor wrote: »

The Nae does not show that much
http://www.weatheronline.co.uk/cgi-bin/expertcharts?LANG=en&MENU=0000000000&CONT=ukuk&MODELL=nae&MODELLTYP=1&BASE=-&VAR=rsum&HH=30&ZOOM=1&ARCHIV=0&RES=0&WMO=&PERIOD=

...

Take your pick i guess, maquiladora is more experienced with models though

Thats at 30 hours though, if you look at 48 hours you see higher totals in the southeast from another area of low pressure off the south coast Sunday/Monday.

Either way though, all the heavy stuff is headed for the UK and will miss us.

munsterlegend · 24-11-2012 12:07pm

maquiladora wrote: »

Thats at 30 hours though, if you look at 48 hours you see higher totals in the southeast from another area of low pressure off the south coast Sunday/Monday.

Either way though, all the heavy stuff is headed for the UK and will miss us.

Looks fairly wet tomorrow over a lot of the country per this (nedbor): not sure how accurate this is statistically.

http://www.dmi.dk/dmi/index/danmark/vejrkort.htm

Sponge Bob · 24-11-2012 12:08pm

While the thread title has long outlived its usefulness for us in Ireland ( bar perhaps the Slaney catchment) the same cannot be said for Wales and SW England where warnings are in place as heavy rain is predicted to fall on already saturated and flooded ground.

http://www.metoffice.gov.uk/public/weather/warnings/

Redsunset · 24-11-2012 12:51pm

Heavy rain at times in south, south east may cause some local flooding here.

mean while in Wales.

Su Campu · 24-11-2012 12:54pm

This is the TAF for Wateford Airport today. Moderate rain from 3 pm.

TAF EIWF 241100Z 2412/2421 05008KT 9999 SCT012 BKN020 BECMG 2412/2415 03016KT SCT007 BKN010 TEMPO 2415/2421 4000 RA BKN005 BECMG 2418/2421 35015KT=

ninebeanrows · 24-11-2012 12:54pm

This looks like it is going to slam into England with storm winds, really nice structure on latest imagery.

maquiladora · 24-11-2012 4:03pm

12Z NAE showing up to 60mm in Wexford over the next 48 hours.

And you can see from that why there are 153 flood alerts & 42 flood warnings in the UK now.

http://www.shoothill.com/floodmap/

Redsunset · 24-11-2012 7:43pm

Rainfall totals to 6am Monday

Cantona's Collars · 24-11-2012 8:33pm

Non stop rain since before lunchtime today here in Wexford. 60mm by Monday seems very possible.

maquiladora · 24-11-2012 9:11pm

Met Eireann advisory.

Issued at 24 November 2012 - 19:39

Weather Advisory

Heavy rain will affect southern counties of Leinster and Munster from Sunday morning through to Monday morning. Between 30 and 50 mm are likely with some intense downpours. This will lead to localised flooding.

Meanwhile over in the UK, more flood advisories and warnings and the first severe flood warning.

http://www.shoothill.com/floodmap/

M.T. Cranium · 24-11-2012 11:45pm

Can't see this doing much in Ireland, the next system is already pushing it off to the east, about 5-10 mm more could fall mainly in east Ulster and northeast Leinster now ... tomorrow's system could give 10-20 mm falls in the south.

Over in Britain, the low will probably intensify when it reaches the North Sea and the strongest wind gusts will be around East Anglia and just north of London with some westerly gusts to 120 km/hr there, 90-110 km/hr around the Channel coasts also. About 20-40 mm rainfalls in total for parts of England, but largely in places that did not flood earlier except for southwest.

maquiladora · 25-11-2012 12:16am

97 flood warnings and 3 severe flood warnings in the UK now. Some river levels in the southwest of England are at record highs with more rain due Sunday/Monday. I'm glad we are mostly missing out on this.

looksee · 25-11-2012 12:19am

Tramore, County Waterford, there has been some heavy rain during the day but not exceptional, not raining at the moment.

Su Campu · 25-11-2012 12:23am

looksee wrote: »

Tramore, County Waterford, there has been some heavy rain during the day but not exceptional, not raining at the moment.

A very nice night indeed

METAR EIWF 242300Z AUTO 32009KT 280V020 CAVOK 04/02 Q1002=

DOCARCH · 25-11-2012 10:10am

Some very strong winds this morning over the SE UK and English Channel from that storm system.

Grenwich Light Vessel reporting 67mph wind atm or Violent Storm 11.

Rebelbrowser · 25-11-2012 10:42am

Lashing it down in Cork city now....

Clonmel1000 · 25-11-2012 12:04pm

Lashing rain in Clonmel now. Not very cold just a rotten grey dismal November day

Big Daddy Cool · 25-11-2012 12:27pm

anybody any idea how much rain will fall in north leinster, taught this would miss us but doesnt seem likely now, field beside the house is saturated so it will flow into our site, if its anything heavy at all, we could be in trouble.

weisses · 25-11-2012 1:19pm

Very quit here for the last couple of days ... Nice day yesterday with no rain and wind .... had enough for the month

Su Campu · 25-11-2012 1:46pm

J6 Helipad in the North Sea is reporting winds of 62 gust 74 kts this morning. It is at 34 m amsl, so that would mean it gets around 14% stronger winds than at standard 10 m height.

METAR EHJA 251125Z AUTO 23062G74KT 3500 DZ FEW008/// BKN010///
OVC012/// 08/06 Q0988=

Hoorn-s Helipad, just off the Dutch coast, reported slightly weaker

METAR EHQE 251055Z AUTO 23053G65KT 9000 FEW009/// SCT019///
BKN023/// 10/05 Q0996=

On land, the nearest station to that would be Vlieland, which is still pretty windy!

SPECI EHVL 251142Z AUTO 23047G57KT 4900 -RADZ FEW017/// SCT020///
BKN027/// 08/07 Q0997 GRN=

This is how I calculate the difference in windspeed v height. For standard 10 m, the factor is 1.0.

m **Factor
1 **0.74
3 **0.86
5 **0.92
10 **1
15 **1.05
20 **1.08
25 **1.1
30 **1.13
35 **1.14
40 **1.15
45 **1.17
50 **1.18
55 **1.2
60 **1.21

snaps · 25-11-2012 2:36pm

this system seems to be heading more north than north east? Looks like it might miss the UK now, or will it take a turn east soon?

Deep Easterly · 25-11-2012 2:51pm

snaps wrote: »

this system seems to be heading more north than north east? Looks like it might miss the UK now, or will it take a turn east soon?

The wider system is moving ENE but rain band itself is being being pushed very briefly northwards as it pivots around the low pressure center to our south. Should swing away back SE'wards later tonight.

waterways · 25-11-2012 3:12pm

Su Campu wrote: »

This is how I calculate the difference in windspeed v height. For standard 10 m, the factor is 1.0.

m **Factor
1 **0.74
3 **0.86
5 **0.92
10 **1
15 **1.05
20 **1.08
25 **1.1
30 **1.13
35 **1.14
40 **1.15
45 **1.17
50 **1.18
55 **1.2
60 **1.21

Helgoland oberland with 53 m had at 1400 gusts of 107 km and Helgoland Duene with 8 m 86 km (at 1500 97 km)

bassy · 25-11-2012 4:06pm

Raining here in north Kilkenny since about 10.30 this morning,just stopped now.
It was,nt heavy rain.

DOCARCH · 25-11-2012 6:02pm

Moderate (sometimes heavy) rain here since 3pm. 10.0mm so far.

Heavy Rain South/South East. Possible Flooding Sunday 25 November

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