Storm Ciara - Strong Winds & Potential Snow **TECHNICAL DISCUSSION**

Mortelaro

Heavy snow in Arklow now
Its actually dinner plating it
Breeze is northwest

Cw85

Snow has turned more to sleet in Carlow town now flakes are a lot smaller than earlier

Mortelaro

Its actually heavier since I tweeted this and starting to stick

https://twitter.com/Arklowweather/status/1226820731872391168?s=19

Mortelaro

Settling and heavy

Mortelaro

Settling and heavy
Whole place is white now

1.3c

Dp -2

Rebelbrowser

Just on a imby basis for those of us down south, temps and dew points should drop a good bit by late afternoon and we should be good for snow (wet at least) from then on. A few models seem to have decent precipitation around Cork at ca. 3/4pm. Outside chance that might fall as white gold....

Cw85

Back snowing heavy in Carlow town, sleet for five mins and now back to big flakes

sjb25

Heavy snow between Bunclody and Enniscorthy in Wexford not sticking but heavy

Cantona's Collars

sjb25 wrote: »

Heavy snow between Bunclody and Enniscorthy in Wexford not sticking but heavy

Well it's heavy,sleety rain in Enniscorthy. Utterly miserable.

ronnie3585

We've just had a brief flurry of snow in Galway City.

q85dw7osi4lebg

Light dusting of snow in Collon Co Louth this morning.

sjb25

Cantona's Collars wrote: »

Well it's heavy,sleety rain in Enniscorthy. Utterly miserable.

Starting to change to sleet now was nice for 15min

Mortelaro

Very heavy in Arklow and settling
Big flakes
Currently 0.9c
Dewpoint-2c

Place is very white now

Nqp15hhu

Well... what a slushy, marginal mess. Despite temps remaining around 2c we have struggled to remain as snow here.

The snow line is about 200m and rising. Above 300m there is a proper covering.

Tonight may bring snow but I’m not confident! It’s surprising how marginal it is. I guess the Atlantic saturated that lower layer, despite the cold temperatures.

Nqp15hhu

Oscar Bravo wrote: »

Knock gusting 41 knots with a dew point of -4 and a temperature of 5 degrees. Windchill!

That’s odd. Dew points are close to 0c here and it is very marginal!

Nqp15hhu

Donegal Storm wrote: »

Letterkenny is built on two sides of a valley, lower parts of the town are pretty much at sea level, higher parts around 200m. I'm at around 90m I think.

Snow mostly melted again now though some nice heavy hail squalls keeping the place white

Thanks. It’s turned very marginal with sleety snow at 2c.

Tonight will probably be when it turns wintry proper.

JanuarySnowstor

Am hearing there's heavy snow on Cork to Dublin motorway near Thurles see corksafetyalerts

Nqp15hhu

The cold spell we had about two weeks ago was much better than this despite the warmer air? Bit odd.

We managed an inch or two at sea level.

Is the marginality down to the strong winds?

lucy2010

JanuarySnowstor wrote: »

Am hearing there's heavy snow on Cork to Dublin motorway near Thurles see corksafetyalerts

I really hope your saying told ya so 🤣🤣🤣

US2

Nqp15hhu wrote: »

The cold spell we had about two weeks ago was much better than this despite the warmer air? Bit odd.

We managed an inch or two at sea level.

Its early yet.

brettmirl

Bad snow in Kilkenny apparently. Heard from my brother that they are sending the kids home from school

Nqp15hhu

US2 wrote: »

Its early yet.

It is, but I expected the showers to be of snow given that it is only 2c. It looks to me that there has been a lot of mixing/saturation and modification in this air mass.

Rebelbrowser

brettmirl wrote: »

Bad snow....

No such thing!:)

Graces7

THUNDER!!!!! And gone very very dark..... West Mayo offshore.. had a little hail a while back....HUGE hailstones now..... OH MY!

More thunder and the power on and off..

Rebelbrowser

Nqp15hhu wrote: »

It is, but I expected the showers to be of snow given that it is only 2c. It looks to me that there has been a lot of mixing and modification in this air mass.

Hi, I think you are in the North West. If so dew points are actually higher there than in a swathe below you from the mid west to the east coast.

Nqp15hhu

Rebelbrowser wrote: »

Hi, I think you are in the North West. If so dew points are actually higher there than in a swathe below you from the mid west to the east coast.

I have looked at the radar and it’s a real mix everywhere. I don’t think the cold air has fully embedded.

Nqp15hhu

Looks to be marginal in Scotland too.

Dew points falling as showers clear here but rising within the showers. 🀔

Forecast does show heavy snow for me from 3am tonight but heavy rain before that. So maybe a warm sector?

Gaoth Laidir

Oscar Bravo wrote: »

Knock gusting 41 knots with a dew point of -4 and a temperature of 5 degrees. Windchill!

Nqp15hhu wrote: »

That’s odd. Dew points are close to 0c here and it is very marginal!

It's wet-bulb temperature that's important, not dewpoint. A dewpoint of -4 with a temperature of +5 means a wbt of around +1.4. WBT above about 0.5 °C is usually the cut-off, except for heavy showers.

Here are the current wbts. Knock's is currently +1.3 °C.

https://weather.us/observations/ireland/wet-bulb-temperature/20200210-1100z.html

Nqp15hhu

Gaoth Laidir wrote: »

It's wet-bulb temperature that's important, not dewpoint. A dewpoint of -4 with a temperature of +5 means a wbt of around +1.4. WBT above about 0.5 °C is usually the cut-off, except for heavy showers.

Here are the current wbts. Knock's is currently +1.3 °C.

https://weather.us/observations/ireland/wet-bulb-temperature/20200210-1100z.html

Yup, it’s incredibly marginal. What do you think of our chances tonight?

Gaoth Laidir

Nqp15hhu wrote: »

Yup, it’s incredibly marginal. What do you think of our chances tonight?

Better

Nqp15hhu

In these sorts of air masses, no matter the situation, the cut off always seems to be 200/300m... why always that level exactly?

SleetAndSnow

Highly unlikely there will be much snow in cork city today , maybe a passing shower. Latest TAF features hail or rain showers. Temp at current is also about 6/7 degrees with a few point of around 3 degrees. North cork however has a chance along with the west of the county.

We live in hope

Timistry

A few thunderstorms popping up in the west at the moment.

Storm 10

Timistry wrote: »

A few thunderstorms popping up in the west at the moment.

Lots of Thunder in Galway now

jackrussel

wheres all the technical stuff gone?

m17

Durrow

Gaoth Laidir

The GFS is still slightly undergoing the thickness values this morning. The 12Z Valentia sounding gave thickness there of 526 dam but the 06Z GFS forecast had it at 524 dam. This cold bias will likely only get larger when the cold air arrives later. The ECM has it more in line with observations for now.

HighLine

A few photos and videos of the conditions up at the Sally Gap in Wicklow on this twitter thread. (Click on the tweet to see other pics & videos)

https://twitter.com/IrelandSkycam/status/1226859370732040194?s=20

Gonzo

it's been dry here in Meath since yesterday evening, but looks to be a shower approaching at last.

raining now with bits of sleet mixed in with it.

Nqp15hhu

The net weather radar shows rain and sleet over Southern Ireland.

DOCARCH

Mace Head gusting 122 km/h in 1300 reports. Malin Head gusting 107 km/h and Sherkin gusting 104 km/h.

JanuarySnowstor

Much colder from around 3pm....All snow by this evening!!

Nqp15hhu

The warm sector is approaching Donegal.

Gaoth Laidir

The GFS has the 516 dam line making it as far as the east coast tomorrow. The ECM doesn't get it further east than 20W, about 800 km of a difference. One is more right than the other. Which is it?

GFS


ECM

Gaoth Laidir

JanuarySnowstor wrote: »

Didn't you say yesterday that we were going to be the wrong side of marginal? Yet much of the Midlands is seeing heavy and indeed lying snow in parts

No I didn't, I highlighted how close to marginal it was for lowest levels. I said higher up would do well.

davidsr20

Gaoth Laidir wrote: »

No I didn't, I highlighted how close to marginal it was for lowest levels. I said higher up would do well.

What’s your thoughts on the west for tonight and tomorrow u only mentioned East?

highdef

JanuarySnowstor wrote: »

Didn't you say yesterday that we were going to be the wrong side of marginal? Yet much of the Midlands is seeing heavy and indeed lying snow in parts

Just about on the wrong side of marginal in North Kildare. Recent moderate to heavy snow shower combined with strong winds but too warm to stick. Can see it stuck to the grass on the hill bedside me, less than 30 metres higher up. I'd say snow line is above 150m to 200m.

Oneiric 3

Rougies wrote: »

UKV, part of the "Unified model" (UKMO model suite) which Euro4 is also a part of.


https://en.wikipedia.org/wiki/Unified_Model

Thanks for that. Great info! That UKV model, of which they seem to also use in their video forecasts, seems to be much more accurate than the Euro based 'Harmonie', and most certainly with regards wind and rainfall. I think the Harmonie's strength lies more with temperature.

Gaoth Laidir

davidsr20 wrote: »

What’s your thoughts on the west for tonight and tomorrow u only mentioned East?

Almost everywhere should see at least some snow falling, sticking inland above about 100 m. That trough coming into the north tonight does have a slight warm core to it, so hard to know which way that will go. Certainly above 200 m should see a lot.

Nqp15hhu

Gaoth Laidir wrote: »

Almost everywhere should see at least some snow falling, sticking inland above about 100 m. That trough coming into the north tonight does have a slight warm core to it, so hard to know which way that will go. Certainly above 200 m should see a lot.

The trough will raise the freezing levels. It has already started to warm up so the next snow should be in the early hours.

This always seems to happen with westerlies.