Snow Ice Warning for Ireland 29 Jan to 03 Feb 2019 *See Mod Note in OP *

Just back from tobogganing up by Cruagh wood, brilliant fun. That's my snow fix gotten for the year Snowman made, snowball fights, kids (including a big one!) had a blast, happy out.

Snow Garden wrote: »

Magical day on Croagh Patrick yesterday. Thanks for Sryanbruen for helping me upload the pictures.

Damn it doesn't seem to be working.

You've given the link to the page of the photo. Make sure you open each photo in a new tab and take that URL.

Snow Garden wrote: »

When I use the photo link in a new tab, it doesn't seem to show. Maybe they are too large in size. I have to use the link start "i." to see anything...

Is this on mobile or PC? Mobile sometimes acts a little weird. I never have problems on PC though.

And yeah, it's advised to reduce your pics' size on here so posters don't have to scroll down through unnecessarily. I use http://picresize.com/ all the time to reduce the size of my pics and it works like a charm always. I use the 75% smaller function every time.

Snow Garden wrote: »

Its on the PC, I will try and reduce the size later. Direct links there for now.
Thanks for your patience!

Nice pics by the way, love the one taken at the top. Reminds me a lot of this one from January 2010:

Snow Garden wrote: »

Magical day on Croagh Patrick yesterday. Thanks for Sryanbruen for helping me upload the pictures.









Here are the actual links;
https://imgur.com/TT31uEM
https://imgur.com/0bEGcco
https://imgur.com/ZglCwM6
https://imgur.com/XDBm5G0
https://imgur.com/4NK7YBJ
https://imgur.com/Wllw3l6
https://imgur.com/KsipL20

Absolutely breathtaking photos well done you. You’ve a great eye for fab shots.

The -5.1c in Athenry seemed to be the lowest temp from this wee spell, at least with regards the reporting stations.
Gurteen managed -4.9c while Mullingar bottomed out at -4.8c.

sryanbruen wrote: »

Dublin Airport recorded -5.8c on 31st January.

Ah right, the Dublin Airport Igloo effect.

Oh lord fix the quotes!

All I can say is THANK F***K its gone.

Rebelbrowser wrote: »

Thought there was a theory it was in a frost hollow or some such? I remember somebody using local temps before to the show it might tend to overdo cold?

If it is in a frost hollow, then so be it, as long as it is naturally formed and not caused by human interaction.

The village I live in is in a frost hollow. On a calm winters night, the temperature can be a several degrees colder than surrounding areas. Would anyone suggest that my temperature readings are not representative or are inaccurate....of course not.

If people think that Dublin Airport station should be moved because the temperatures that are recorded at it are sometimes lower than other nearby areas, then we may as well move the one at Knock because it's too high up @ approx 200m which often gives it lower temperatures (and quite often fog as it's on a hill) and is not representative of the weather conditions in the general area where most people live.

While we're at it, we should move the one at Valentia as well because that one is too near the Atlantic and the temperature readings are way too mild, often being the mildest in the country.

Obviously I am being sarcastic about the two examples above but the weather varies and it can vary quite a lot over short distances. As long as the measurement equipment at Dublin Airport is correctly calibrated, then the temperatures that it records are the correct temperatures at that particular geographical location.

So ..... Is that the end of winter?

Any more cold snaps expected?

Oneiric 3 wrote: »

It is generally seen as good practice not to locate an official station in a 'frost hollow'.

Try as I might, I just can't take min data from D.A seriously, and most certainly not from a climatological perspective. If anything, minima there often deviates more from very nearby station data, and God knows there is plenty in the region, than Shannon's maxima does during hot weather from other stations in the greater region (Athenry, Gurteen, Moorpark etc) And as I showed last Summer, max temps during very hot weather often came in higher in nearby Adare Manor (SW of Shannon), than Shannon itself, and which would be in more open location than the airport.

It would seem that while Shannon's data is always up for debate, Dublin Aps is seen as sacrosanct. I don't subscribe to such selectivity. Having said that, D.A's mins are very probably 'correct' for that one particular spot, but I question its anomalous min figures as being 'representative' for the greater region, especially when other nearby data shows this not to be the case.


Edit: Wind direction at the time Dublin Apt was reporting a -5.0c figure:




While light, it was still straight in off the sea (of which it is only a hop, skip and jump away), while at the same time, Casement Aerodrome, which I believe would be more sheltered from the moderating effects of such a wind direction, was reporting just -1.1c at the time and Johnstown Castle, which would be located in a roughly similar distance from the sea (open to correction) than D.A, was reporting just 0.6c. Stations well inland at the time in the north Midlands and the North, were reporting temps of between -1.0c and -4.0c at the time, which would make more sense.

Sorry, not this Dublin v The Rest of the Country shíte again.

There is nothing wrong with DUB's readings. As I've said before, it's probably the best sited station in the country. It's the only truly rural enclosure, on flat open ground, without trees, with the nearest building being half a kilometre away. Being from the general area and knowing it intimately, to me it has always at least seemed colder as I was growing up. I note car temperature dropping a few degrees as I head up the Ashbourne road off the M50. It all relatively flat, rural landscape with little in the way of large trees, forested areas, etc.).

Dublin Airport's enclosure is 11-12 km from the nearest sea. Johnstown Castle's is actually just 4 km (to its NE, 11 km to its south). Wind there was NE that night.

Casement's enclosure is 16 km and a whole city from the sea and just 25 metres from a building to its west, 60 metres from the apron and hangars to its north and east. The wind at Casement was stronger and coming from the northeast (from the city) at the time of the coldest temperatures there (a couple of hours later than you showed).

Phoenix Park.. well, let's not even talk about that. It's just 15 metres from a large building to its southeast and 30 metres from a whole heap of others to its northeast. That while being totally enclosed by mature trees 50 metres to the west. It's so poorly located they didn't bother putting in an anemometer (by their own admission).

Dunsany's enclosure is 26 km from Dublin Airport's, so not in the same area. While is it relatively open too it does have a large cluster of buildings 150 metres to its northeast.

At the time you showed, Oak Park was at -3.7 °C, only just over a degree warmer than Dublin Airport. Mullingar had already gotten down to -4.8 °C at 9 pm before the cloud piled in. How do you explain that, given its more built-up location? At 9 pm Dublin Airport was only -0.8 °C.

I've been keeping a daily watch on Dublin's minima over the past several years and have absolutely no concerns over the data. The station is a very accurate representation of a large area of north Co. Dublin. I don't know why anything mentioning Dublin becomes almost part of some conspiracy theory by those from the west. Listen to the UKMO forecasts and you'll hear them always say "these are city temperatures; rural locations will be several degrees colder". Well, they're right.

Oneiric 3 wrote: »

Before I address your typically well made points. I am more intrigued for now at how you framed your post in answer to mine, and how you came to these conclusions from my post? I mentioned my scepticism in D.A's anomalous min readings, which, as you know, is not the first time I have done this, and I stated my reasons why. So forgive me if I find these above comments of yours just the tiniest bit perplexing.

It was this...

It would seem that while Shannon's data is always up for debate, Dublin Aps is seen as sacrosanct. I don't subscribe to such selectivity. 

If I took you up wrong then apologies. It seemed to be along the same lines as one or two other posters, but it now seems that it's not what you meant.

Oneiric 3 wrote: »

Obviously a crossed wire, and you have no need to apologise to me.

I take on board all of your points, but I am still not fully convinced. Somebody mentioned 'frost hollow'. If indeed D. A is located within one, then 1. its readings would not representative of even that smaller, north Dublin area. If every other station in the midlands and north were located within known frost hollows, then it stands to reason that at the time of the map posted above, and given the general synoptic pattern at the time, that their temperatures would have read even lower than that of the Airport.

As I have said, I don't doubt the reading itself, but more its representative value. It deviates too much away from other nearby local readings, of which the closest was the -3.9c min (I think) on the same night at P Park.

For what is worth, here is the 'total column water' chart (based on 6hr forecast from 18z analysis) for around the time of the contested reading.



I use these charts (perhaps wrongly) to judge how 'wet' an airmass would be, and going from this, it looks as if the Dub region would have a lower reading compared to all other regions bar the far NE, so perhaps this might have something to do with that odd reading in the region? I honestly wouldn't have clue.

It's not located in a frost hollow. It's pretty flat ground all around. As I said, Mullingar had already gotten down to near -5 by just 9 pm, so it's not restricted to just the D.A. area.

On cold mornings I see a similar phenomenon as I drive from Celbridge to Casement. Driving a few kms through the very flat, open rural area from Celbridge to Hazlehatch and across to Newcastle the temperature is at its lowest and many times the frost is hardest here. Then suddenly it starts to rise at Newcastle as the elevation rises ever so slightly. By Casement the temperature will have risen by 3-4 degrees, all in the space of about 2 kms. The total rise in elevation between Celbridge and Casement is only around 30 metres. That's another reason why Casement sometimes reads higher than other areas. The ground slopes slightly away southwards from the station enclosure, which was aided by the light northeasterly the other night. Which area is correct? Both are. The colder area extends for a large area of east Kildare, across Lyons Estate to Ardclough and towards Clane. I would say if a station were located there it would read similar to D.A. Casement's area extends several km towards Tallaght and the city.

Have a look at the D.A. station on Google maps and see if you can spot any reason why it's in a bad spot. My guess is you'll agree it looks legit.

https://maps.app.goo.gl/Njeyk

By the way, the station enclosure at Johnstown Castle is the same distance from the sea as the D.A. enclosure is from the Terminal building (4 km)! The enclosure is at the very furthest (western) end of the airfield.

Monkeynut wrote: »

Off-Topic
But if you search within the parameters of the airport using google maps. You can see that the airport fire service are following the Google car around for security.

https://www.google.com/maps/@53.4214212,-6.2971662,2a,75y,250.18h,82.48t/data=!3m9!1e1!3m7!1sdmnHVaRGLQqFffXEWYpyVg!2e0!7i13312!8i6656!9m2!1b1!2i39

Airside, everyone is escorted by a credentialed member of staff. No exceptions unless you're a contractor that will be there for some time in which case you go through the vetting process.
Had to escort journalists around the place (as a side duty to pushing trolleys) years ago.