Risk Of Heavy Snow Showers As It Turns Extremely Cold Sunday Night/Monday

Wicklow Weather

If you read through the posts over the past few days you can see how we are all waiting in anticipation. In the hours prior to MT's forecasts or updates we are very positive. After MT's forecasts or updates we are shaking ourselves off in disbelief and then you see posters downgrading the chances of MT being correct, I think most of us are looking for a reality check after reading MT's interesting solutions and we naturally are playing it down even though he is probably in the zone. I think its a sense of "jazus he couldnt be right sure thats unbelievable" but I think he has nailed the streamer activity and we await further runs to see where the low positions itself as we get nearer nowcasting time on Sunday......just sayin!

Tom Cruises Left Nut

JanuarySnowstor wrote: »

The 06z is bone dry after Monday though very cold with very severe frosts. It looks like it's all down to Monday

Was never to be any different

We may see ninja snow !

patneve2

Such good charts can't believe it. 30 hr window for some serious convection in strong E to NE winds. Can't get better than that. Also I sense we will have some night-time nowcasting situations further on next week

Deank

t|nt|n wrote: »

Was never to be any different

We may see ninja snow !

You just can't beat a Ninja snowfall:pac:, at this stage I'll take any type of snowfall.

Super hoop

IF this turns into an event.What parts of the east coast are most likely to see snow??

Deank

Super hoop wrote: »

IF this turns into an event.What parts of the east coast are most likely to see snow??

Most of the east coast if these charts deliver.

Elmer Blooker

Anything can happen, we don't know what will happen on Monday let alone Tuesday, I think Irish Sea convection is possible on Monday and Tuesday.

Redsunset

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JanuarySnowstor

It's impossible to say really what will happen on Monday
We could see a lot of snow or just coastal snow showers.
I do think the 06z has started to trend this low further South so stremers may be our best chance.
What looks clear though is that it's a 24hour event and the rest of the week looks cold but not cold enough.
Still not bad for March and what others have said is correct, these type of cold uppers do not come around that often and it's a one in every 3 years type event

Redsunset

Seriously JS I think we are well aware of the time frame of this No one is saying otherwise.

lucernarian

To be confirmed wrote:

The problem I see right now is the nature of those snow streamers. The forecasted lifted index values for Monday are often over 10 degrees. It can be hard to see *any* convection with that but for all the other circumstances like the difference in surface and 850 hPa temperature. CAPE values are not awful but they don't inspire much confidence. Have you any thoughts on this? Because I don't see significant vertical wind shear occurring as the cold air crosses the Irish or Celtic sea. In other words, it may take a longer fetch of sea water to generate the decent showers that we would have seen in 2010.

Actually I'll backtrack on the above bit about lifted index. Lifted Index is practically irrelevant in a setup like this. CAPE is somewhat reasonable all things considered, though the capacity of such cold air to generate showers is limited. We will need some dry/bright weather over Monday to get proper convection going over the sea, especially for those places where the wind will cross Wales before reaching the sea.

Rooy

I would really like to see Met Eireann on board too ! , nothing too exciting on their latest forecast on the website

Nabber

If we do get streamers I'll need some nice offshore breezes. Which for me is as important as the dew points.

Trying to relate weather to historic weather can sometime impair judgement.

So lets forget 2010, lets live up 2013.

I've bought into to this now. Don't make a fool of me again weather charts.

lucernarian

Nabber wrote: »

If we do get streamers I'll need some nice offshore breezes. Which for me is as important as the dew points.

Trying to relate weather to historic weather can sometime impair judgement.

So lets forget 2010, lets live up 2013.

I've bought into to this now. Don't make a fool of me again weather charts.

Why would you want a strong breeze? As it stands there's a chance the wind will carry across cold air before showers have even a chance to form!

mickger844posts

Rooy wrote: »

I would really like to see Met Eireann on board too ! , nothing too exciting on their latest forecast on the website

With their latest update they are still being over cautious i feel but they do mention Extremely cold for Monday. We may see them upgrade things as the day progresses but this probably depends on who is writing the forecasts.

dopolahpec

It is very interesting to read all the conflicting opinion on what the next few days will hold. There is no clear consensus amongst anyone on here, which should underline the appropriately cautious forecast from Met Eireann. There is no secret regarding a snow machine in the Irish Sea that Met Eireann don't know about!!

Wicklow Weather

British Met office just released a level 2 cold warning.
There is an 80% probability of severe cold weather/icy conditions/heavy snow between 1200 on Saturday and 0800 on Tuesday in parts of England. This weather could increase the health risks to vulnerable patients and disrupt the delivery of services. Please refer to the national Cold Weather Plan and your Trust's emergency plan for appropriate preventive action

Iancar29

To_be_confirmed wrote: »

The problem I see right now is the nature of those snow streamers. The forecasted lifted index values for Monday are often over 10 degrees. It can be hard to see *any* convection with that but for all the other circumstances like the difference in surface and 850 hPa temperature. CAPE values are not awful but they don't inspire much confidence. Have you any thoughts on this? Because I don't see significant vertical wind shear occurring as the cold air crosses the Irish or Celtic sea. In other words, it may take a longer fetch of sea water to generate the decent showers that we would have seen in 2010.

Cape and lifted index arent as important for snow streamers to form. Once the temp difference is large enough and with a long fetch decent breeze behind it then they will form. Ye it would be better for some cape to be present , especially for thundersnow but its not essential. Uplift of the mountains could also give some more heavier bursts in the Dublin/Wicklow and Wexford mountains. Im not expecting LOads ... but a decent dusting will be expected imo on the current charts.
:cool:

average_runner

Have a bad feeling about this, think it could be another miss instead of hit

dopolahpec

average_runner wrote: »

Have a bad feeling about this, think it could be another miss instead of hit

It's not going to be a miss in the sense that the other progged cold spells were. I would say cold is NAILED ON. The logistics of precipitation are the issue.

doccy

mickger844posts wrote: »

With their latest update they are still being over cautious i feel but they do mention Extremely cold for Monday. We may see them upgrade things as the day progresses but this probably depends on who is writing the forecasts.

Despite them not telling me what I want to hear (all winter), I think they have called this winter right. That said they do have a big tendency to constantly update their forecasts on the website, something several times a day. Maybe that was the models seesawing this winter, but I'll still wait until their onboard.

lucernarian

Iancar29 wrote: »

Cape and lifted index arent as important for snow streamers to form. Once the temp difference is large enough and with a long fetch decent breeze behind it then they will form. Ye it would be better for some cape to be present , especially for thundersnow but its not essential. Uplift of the mountains could also give some more heavier bursts in the Dublin/Wicklow and Wexford mountains. Im not expecting LOads ... but a decent dusting will be expected imo on the current charts.
:cool:

Indeed they're not, although the lifted index value is very very high and that does have an impact on how far relatively warm air from the sea will be advected upwards. The main consequence of both SSTs and upper air temps being colder than Dec 2010 would be (IMO) that we need a longer sea fetch for the cold breeze to get the moisture necessary to generate showers, ignoring any inherent instability in the air flow. So the Isle of Mann shadow could make a big difference this time around.

Slashermcguirk

people who say Met Eireann have been right all winter are wrong. It just does not count when they say it is going to snow heavily the next day as they often have and then change the forecast that morning. Numerous times they mentioned very cold day in store with heavy snow showers and then changed it later that evening. That to me is not correct forecasting. Anybody can change their mind every 12 - 24 hours and then give a correct forecast !!

Anyway, that aside this does look pretty promising. Ramp ramp ramp

Redsunset

In my opinion the snow machine will be working just fine as the stronger flow of Arctic airmass is advected towards us creating friction across the open water and thus plenty of lift.


Ramp:D

doccy

Slashermcguirk wrote: »

people who say Met Eireann have been right all winter are wrong. It just does not count when they say it is going to snow heavily the next day as they often have and then change the forecast that morning. Numerous times they mentioned very cold day in store with heavy snow showers and then changed it later that evening. That to me is not correct forecasting. Anybody can change their mind every 12 - 24 hours and then give a correct forecast !!

Anyway, that aside this does look pretty promising. Ramp ramp ramp

I kind of agree, but put it this way- if I never came here or NW, I wouldn't have had all the disappointment and false snowmageddons ... I would have got the weather as happened. People slagged off Gerry and his shleet .. but actually he was right.

Rebelbrowser

doccy wrote: »

Despite them not telling me what I want to hear (all winter), I think they have called this winter right. That said they do have a big tendency to constantly update their forecasts on the website, something several times a day. Maybe that was the models seesawing this winter, but I'll still wait until their onboard.

Subject to correction, but whilst they constantly update their short term forecasts, I think the forecast outlook (ie. 48 hrs plus) remains constant all day once written up at 5am or whatever. In fact they tend to be written up before the 0z ecm is out in my experience so they are out of date to some extent all day.

Tom Cruises Left Nut

Redsunset wrote: »

In my opinion the snow machine will be working just fine as the stronger flow of Arctic airmass is advected towards us creating friction across the open water and thus plenty of lift.


Ramp:D

Ha, good ramp there !

Im pretty confident here too, may be misplaced but im on the rollercoaster

Redsunset

Discuss the evolution. Do not turn thread into a Met bash.

JanuarySnowstor

The ECM ppn charts are also very dry.
We basically have the UK MET and Met Eireann and all model ppn charts showing it to be a coastal showery setup with nothing widespread.
For now I think I'll side with the Met until the 12's say different

Irish Steve

M.T. Cranium wrote: »

GEM very similar to GFS, major snowstorm potential all of southern Britain also, Cornwall-Devon could be isolated from world, or world isolated from them, for days (ESE 60-90 mph gradient there, more like 40-60 mph south coast Ireland).

OK, that is thought provoking .

Early ferry Wednesday Dublin to Holyhead, then rail to the South West, via Birmingham, arriving Exeter early evening.

Family wedding Saturday.

Are we likely to see significant travel disruption from this, or is it likely to be short lived? The January Snow didn't cause rail problems, I did same trip then, but this seems to be capable of more significant problems if I am reading it right.