Ireland Regional Discussions 17th January 2013 onwards

[norn iron]

Precepitation seems to be stalling near Fermanagh border. Hitting the block?

[Downburst]

I was yesterday more optimistic about tomorrow's prospects, but in reality it's not looking good unless you're in the far NE of Ulster or on a hill. We're just on the wrong side of the boundary.

Strong southerly airflow today and tonight is introducing a very mean boundary layer. The uppers tomorrow will just not be cold enough to overcome this boundary layer.

Theta-e shows a warm sector developing over most of the island tomorrow evening. We'd need around 10 °C or less for snow to low levels. We're nowhere near it.

no real pull of cold air in from GB.

Dewpoints just too high

GFS sounding for near Dublin summarises it all. Thicknesses 531 dm and 1299 m. A saturated boundary layer eliminating evaporative cooling. Southwesterly winds in the lowest layers, not southeasterly or easterly. Zero isotherm at 400 m, wet-bulb zero around 320 m.

Yes, snow on hills, and at lower levels in NE and eastern Ulster, but I'm afraid for the Republic, a bit more of a mix at low levels.

Dublin TAF was amended at 2121Z. Rain, with only PROB40 of sleet tomorrow afternoon.

TAF AMD EIDW 172121Z 1721/1818 13022G33KT 8000 -DZ SCT004 BKN010 TEMPO 1722/1817 4000 RA BKN004 PROB40 TEMPO 1805/1817 RASN BECMG 1816/1818 9999 BKN020=

Belfast Aldergrove sleet with just a PROB40 of snow.

TAF EGAA 171704Z 1718/1818 14015KT 8000 BKN007 TEMPO 1718/1803 14018G28KT 3000 -RADZ BR PROB30 TEMPO 1718/1724 9999 BECMG 1803/1806 14020G30KT TEMPO 1806/1818 3000 RASN BKN004 PROB40 TEMPO 1812/1818 1000 SN BKN001=

All from 12z though? Compelling though at the time, let's hope it changes, recent info does look better

[The Eagle]

So all the models, all the forecasters and all the warnings are just complete crap?

GFS has no short term support among the hi res models (within 18 hrs). Better chance than not it's not right on this occasion. Even WRF which is real hi res has the same profile as NAE. Temps and DP's falling off a cliff after midnight. None have low level snow by 6 am. But from 9 am it's a different story.

[Su Campu]

So all the models, all the forecasters and all the warnings are just complete crap?

Warnings are in NI as there is a lot of high terrain. The Glenshane Pass is around 300 m, so it will be treacherous. I'm talking about low levels, where the vast majority live. Some snow at low levels in Ulster, like I said.

How exactly are the models complete crap? Because they're not showing snow for more people?

[Cavehill Snow]

I was yesterday more optimistic about tomorrow's prospects, but in reality it's not looking good unless you're in the far NE of Ulster or on a hill. We're just on the wrong side of the boundary.

Strong southerly airflow today and tonight is introducing a very mean boundary layer. The uppers tomorrow will just not be cold enough to overcome this boundary layer.

Theta-e shows a warm sector developing over most of the island tomorrow evening. We'd need around 10 °C or less for snow to low levels. We're nowhere near it.

no real pull of cold air in from GB.

Dewpoints just too high

GFS sounding for near Dublin summarises it all. Thicknesses 531 dm and 1299 m. A saturated boundary layer eliminating evaporative cooling. Southwesterly winds in the lowest layers, not southeasterly or easterly. Zero isotherm at 400 m, wet-bulb zero around 320 m.

Yes, snow on hills, and at lower levels in NE and eastern Ulster, but I'm afraid for the Republic, a bit more of a mix at low levels.

Dublin TAF was amended at 2121Z. Rain, with only PROB40 of sleet tomorrow afternoon.

TAF AMD EIDW 172121Z 1721/1818 13022G33KT 8000 -DZ SCT004 BKN010 TEMPO 1722/1817 4000 RA BKN004 PROB40 TEMPO 1805/1817 RASN BECMG 1816/1818 9999 BKN020=

Belfast Aldergrove sleet with just a PROB40 of snow.

TAF EGAA 171704Z 1718/1818 14015KT 8000 BKN007 TEMPO 1718/1803 14018G28KT 3000 -RADZ BR PROB30 TEMPO 1718/1724 9999 BECMG 1803/1806 14020G30KT TEMPO 1806/1818 3000 RASN BKN004 PROB40 TEMPO 1812/1818 1000 SN BKN001=

Very good technical post though I can't pretend to understand all of it.

Has the theta-e only begun to forecast this warm sector this evening and is why the local tv forecasts have not updated their forecasts tonight and are quitevague on detail?

[Cavehill Snow]

Hi, its a premium feature, its £2.99 per month

here is a screen shot for you. Red is snow, grey is sleet,

Thanks again

[ronan]

Warnings are in NI as there is a lot of high terrain. The Glenshane Pass is around 300 m, so it will be treacherous. I'm talking about low levels, where the vast majority live. Some snow at low levels in Ulster, like I said.

How exactly are the models complete crap? Because they're not showing snow for more people?

Wasn't getting at you was just curious as it seemed to be going against the forecast. A very detailed post. Something this thread lacks and we only get some posts like this from a few users.

I think Pomeroy and Watch may have passed out with the whiskey tonight!!

[markok]

temp down to 5c now in Dub

[Su Campu]

The NAE is showing a colder scenario, and would extend that snow to most of Ulster, but still marginal further south. T850 around -6 °C away from Ulster.

Theta-e shows 10 °C along the north coast.

Theta-w above zero

850-1000 thickness around 1285-1290 m south of Ulster. 1280 m would be roughly required for sea level snow.

T950 hPa -2 °C from 350-400 m. Boundary layer saturated so again, no evaporative cooling. Dewpoints do fall slightly below zero though.

The NAE does shift the snowline south alright so we'll have to see what turns out to be right. For what it's worth, the 18Z GFS snowline charts aren't wonderful except for Ulster.

[ronan]

Just to pick up on a few points made tonight about a breakdown next week! Lately things have been a complete nightmare for forecasters and what the outcome of the current SSW will be is extremely hard to forecast and only educated forecasts can be made based on model output. There is so much changing on a daily basis and i think the 18z could just be playing around with possibilities tonight. More that likely things will change. I really like John Hammond as a forecaster, his article on the BBC website is a good read and explains things in a way that people like myself and many others on the Ireland thread can understand. Hes certainly sticking his neck out and saying that the cold will last for longer than the current model output suggests. Time will tell but i don't really think that we should be looking past 120hrs as so much can change.

http://www.bbc.co.uk/weather/features/21066768

[Neiller22]

God! Met eirann update forecast is nothing like the meto are indicating for ulster! Bizarre !

[Su Campu]

Belfast Aldergrove's 2300Z TAF gives light snow from mid afternoon, with PROB40 of blowing snow.

TAF EGAA 172305Z 1800/1824 14020G30KT 9999 SCT008 BKN015 PROB40 1800/1804 4000 RADZ BKN007 BECMG 1804/1808 7000 -RASN BKN008 PROB40 1807/1812 2000 RASN BKN004 BECMG 1812/1815 2000 -SN PROB40 1812/1824 0300 BLSN VV/// BECMG 1815/1818 11020G30KT=

Dublin still mentions only PROB40 sleet.

TAF EIDW 172300Z 1800/1824 14021KT 7000 -RADZ SCT004 BKN010 TEMPO 1800/1817 14022G33KT 4000 RA BKN004 PROB40 TEMPO 1805/1817 RASN BECMG 1816/1818 9999 BKN020=

Knock (200 m) only rain

TAF EIKN 172300Z 1800/1824 14018G33KT 6000 BKN003 TEMPO 1800/1810 0500 FG RA BKN001 BECMG 1802/1805 12010KT TEMPO 1810/1818 4000 SHRA BKN008 SCT020CB BECMG 1812/1815 06008KT=

[stormforce 10]

very heavy rain here tonight, been pouring down for the last few hours now.

[ronan]

That is strange! Just updated at 23.20 to!! Are they on to something?

[jello]

:o What. niw removed warning on the facebook page????

[bobbarley]

Excellent post Su Campu, from what I can gather greatest risk is for south west ulster, very little precipitation in the far north east

[Neiller22]

Yep! I saw that. Is it all about to go Pete tong or are they updating it!! Is this the mother of all backtracks! Maybe su campo is right!!!

[ronan]

It couldn't all go wrong now?? Could it?

[markok]

haha met eireann. there gas. don't have a clue what's going to happen, why don't they just put that on the forecast and be honest

[somofagun]

Look how quick it changed last nite.

[sundog]

A very windy night out here the heavy rain not far off from my location looking at the latest radar. Max temp today 8.2c,current temp 5.1c

[Neiller22]

Just seen updated weather on bbc news 24!! Not good news I'm afraid!! rain all over Ireland with wintry mix in the north!! Possible snow later ! Unreal. That's it I'm away to bed. Downgrade at last hrs! Said it all with irish met update and northern ireland weather removing warning on facebook ! Shocking. Hope there wrong

[jello]

Oops, never mind, warning back up again was getting updated.

[ronan]

Northern Ireland Weather

WARNING AMENDED/UPGRADED

Yellow, Amber and Red warnings for HEAVY SNOW/ICE, LOW TEMPERATURES & HIGH WINDS have been issued for Northern Ireland. These cover Friday and into Saturday

Heavy Snow, Ice & Low Temperatures & High Winds (Yellow Warning)

Rain is now starting to affect some areas this will turn quickly to sleet and then snow after midnight firstly across Co Antrim and Down. Snow is expected at all levels across the Country during Friday and overnight into Saturday, 5 – 10 cm is possible within the Yellow warning area. Blizzard conditions may occur in some areas especially high ground due to high winds of up to 40 - 50 mph

Heavy Snow, Ice & Low Temperatures & High Winds (Amber Warning, this has been extended to include more parts of the country)

Again heavy & Disruptive snow will affect the areas highlighted Amber, it is here that we can expect up to 15 cm of snow, with drifting and blizzard conditions also possible

Heavy Snow & High Winds (Red Warning)

A RED warning has been issued for some areas within the areas highlighted RED accumulations of snow could be up to 20cm or more locally and possibility up to 30cm/1 foot over high ground

We cannot stress this enough – Please take extreme care and you are advised to avoid travel if possible

TRAVEL DISRUPTION IS LIKELY

Disruption on Roads is expected especially over high level routes were the highest amounts of snow is likely.

Disruption to Air travel is possible please check with your Airline and Airports for information.

We are expecting some Schools to be closed, please contact schools directly for information.

If you must drive

• Don’t attempt to overtake

• slow down – it can take 10 times longer to stop

• allow extra room

• Use the highest gear possible to avoid wheel spin

• Avoid harsh braking and acceleration

• If you skid, ease off accelerator and avoid braking

Other Advice

• Check up on friends, relatives and neighbours who may be more vulnerable to cold weather. Cold weather is especially dangerous for older people or people with serious illnesses, so check up on them if you can. Read how to spot and treat hypothermia.

• People with heart or respiratory (breathing) problems may have worse symptoms during a cold spell and for several days after temperatures return to normal.

• You can find more information and advice on staying healthy in periods of cold weather in Winter health.

PLEASE NOTE: We will be unable to respond to comments at the present time.

Here's their map!! Nice!!

[Neiller22]

Christ I nearly had heart failure!! Bbc forecast I watched was yesterday on sky plus ! I'm an idiot ! Latest bbc news still amber for Northern Ireland. Think I will stay of the wine ! Sorry guys. All passed myself