Wintry spell forecasting discussion - 23/11/2010 onwards

Deep Easterly

Su Campu wrote: »

But it's on such a fine balance at the moment that the Norwegian low could scupper this and pull out the plug. It'll be a nowcasting weekend I think....

How the EMHI's 06z HIRLAM run is handling this little feature:

Friday morning 0600z chart: (Wind Speed)




Forecast by the current ECM run to bring gale force winds down along the west coast by Friday evening/night. How it works out in reality remains to be seen.

darkman2

Ok where are we today? Basically for those who wan't snow, ice and frost it does not get any better at this time of year.


The ECM is probrably the best model to stick to so I will just quickly run through the 00z run

Let's start with Saturday




A very cold day with temperatures really struggling to just above freezing and sleet and snow showers at all levels in the East in particular. Frost slow to clear in land and icy streatches on roads.



Saturday night and into Sunday sees further snow showers in the East, might be a bit sleety on coasts at times but should mostly be snow. Accumulations of snow likely esspecially on high ground but not exclusively.




Monday sees a continuation of Sunday really. Temperatures really struggling - I would imagine not rising above freezing in some areas. So an ice day for some. Further snow penetrating further inland - and wind chill will make it feel well below freezing esspecially on East facing coasts.

The cold weather continues then for the forseeable future. Remember the bitterly cold and frosty night aswell. Below -7C to be recorded?

munsterlegend

looks great in theory darkman2 but have my doubts that it will materialise this early in the winter!

Su Campu

I think we're not going to see many sub-zero night time temperatures until Friday night, after the passage of the cold front. Up to then we'll just have to many cloud layers.

And when it does get cold, I would say -5°C will be the lowest, maybe on Saturday night. Sunday winds will be stronger again, so may keep temperatures from falling too far.

darkman2

munsterlegend wrote: »

looks great in theory darkman2 but have my doubts that it will materialise this early in the winter!

I know other have different opinions but im pretty confident that is what can be expected.

The ECM ensembles back up what I am saying aswell. Im talking about Friday night on. I disagree with Su Campu there won't be sub zero nights till then. Temperatures should be down generally between -1 an -3C away from windward coasts between now and Friday at night so severe frost I think.

maquiladora

06Z GFS beyond 96 hours can go in the bin according to the National Weather Service

LATEST 06Z GFS COMPLETELY DISREGARDED FROM DAY 4 ONWARD...

lucy2010

I cant really see MET eirinn saying anything other than rain after January's fiasco. Remember they annouced snowmageddon... Was stuck in Tesco's for 2 hours, not a pizza or loaf of bread left on the shelves & hundreds of people buying like the world was coming to an end.

oil arrived yesterday - not getting caught out the like big thick I was the last 2 years cold spells .... beans in the press..... NTL all paid up to date...Brayweather.com on bookmark - so if it comes it comes & ill be cosy & fed & entertained.

If not theres always the 154 page budget rubbish to complainabout.
Right............... What are the charts all saying today > No point me trying to understand them - 2 years on of this & i still think they are all just colurs & lines:D

TheMilkyPirate

maquiladora wrote: »

06Z GFS beyond 96 hours can go in the bin according to the National Weather Service

LATEST 06Z GFS COMPLETELY DISREGARDED FROM DAY 4 ONWARD...

Why?

nacho libre

i think it's because the pressure reading for the low to the south would be very unusual with a blocking high to the northeast. the low will likely be much weaker. also if it moves further north then milder south westerly air will be drawn into the circulation

maquiladora

baraca wrote: »

Why?

They say that all other models and means end up with an opposite pattern at day 7 so they are not confident the 06Z GFS has a good handle on things beyond a few days.

Speak Now

maquiladora wrote: »

06Z GFS beyond 96 hours can go in the bin according to the National Weather Service

LATEST 06Z GFS COMPLETELY DISREGARDED FROM DAY 4 ONWARD...

I was thinking it looked a bit progressive alright with the mild air pushing north.

TheFairy

Just in the middle of a sleet shower at the moment here in Fermanagh. Can clearly see little bits of ice on the window. Totally unscientific car thermometer showing 7 C.

WolfeIRE

severe weather warning for london and english SE
http://www.metoffice.gov.uk/weather/uk/se/se_forecast_warnings.html?from=rss&sn=2387

Su Campu

darkman2 wrote: »

I know other have different opinions but im pretty confident that is what can be expected.

The ECM ensembles back up what I am saying aswell. Im talking about Friday night on. I disagree with Su Campu there won't be sub zero nights till then. Temperatures should be down generally between -1 an -3C away from windward coasts between now and Friday at night so severe frost I think.

Eh darkman, I said there won't be Many sub-zeroes...I didn't say der won't be Any! Of course where there are prolonged clear skies it will sink lower, but I think tonight and tomorrow night we'll have enough mid-high cloud to keep many places around zero or above, especially so tomorrow night.

ffarrell7

The East of the country is destined it seems to bear the brunt of the severs weather over the weekend and into next week. Probably significant snowfall as usual for Dublin/Wicklow mountains and showers of snow and hail for inland areas of Dublin/Wicklow/Louth.:D:D:D:D

Deep Easterly

I was just looking at our IMT stats (Irish mean temperature based on 5 inland met eireann stations dotted around the country) since January 2009 and found it interesting that we seem to be in a wider phase of cooling after a warmer than average period during the mid 2010 period.


Adding a polynomial trend line to the monthly deviations since Jan 2009, and interesting pattern emerges:




in that the warmer and cooler periods over the last couple of years seem to come in a defined wave. Currently, we seem to be dipping down to cooler conditions again but will it be a dip as deep or as wide as the last such one during the winter 2009/2010 period?? Or will just be a smaller blip in the greater scheme of things? We'll see!




All stats c/o
Met Eireann.

darkman2

12z GFS upping the chances of snow in the Midlands and East early on Friday morning. Don't be supprised to wake up to a few flakes.

ninebeanrows

GFS 12z shows poss of some suprise snow Friday morning

The front throughs slightly milder uppers ahead of its track south, upto -4c in Dublin.

However a harsh frost forms Thursday night in slack winds in the Midlands and East with temperatures dipping to -4c in places.

The front then pushes south above this frost with according to the 12z decent precip levels.

Potential for a decent slab of snow, but more likely sleet/rain. However it very much is possible it will fall as snow. 50/50.

darkman2

GFS showing colder conditions for Saturday and really potential for heavy snow showers in the East. Possibly even a longer period of sleet and snow.

Deep Easterly

Weathercheck wrote: »

Potential for a decent slab of snow, but more likely sleet/rain. However it very much is possible it will fall as snow. 50/50.

Eggs in many baskets there WC

Su Campu

We've a warm front moving southwards Thursday night, so with the increased cloudiness I wouldn't expect a harsh frost to set in.

darkman2

510 DAM not far away on Sunday night...

egan2020

H2UMrsRobinson wrote: »

It's all a waiting game now.

Daily routine for next few days

• Get up, have a peek out the window, grab a coffee and check MT's daily forecast
• Get to work, grab another coffee and check the discussion thread on boards
• More coffee and an f5 every half hour or so
• loo break - all that coffee is starting to take it's toll
• no checking of Boards in the afternoon as I'll have nothing to read when i get home
• Get home and have a cup of tea, wouldn't like to become predictable now would I.
• Snuggle down on Sofa with laptop and f5 the evening away.

Ahhh bliss - I love winter:cool:

This pretty much sums my daily routine during the last cold spell. The only thing missing this time round are posts from Owenc

ninebeanrows

12z to 84hrs is virtual snow-fest for Eastern Ireland, there would be some serious disruption in Dublin, Obviously areas withing 1 mile of the coast would be under question but even with this locations included a fantastic run with varies disturbances developing piling snow into the east.

ninebeanrows

Su Campu wrote: »

We've a warm front moving southwards Thursday night, so with the increased cloudiness I wouldn't expect a harsh frost to set in.

I was thinking the frost would lock in before the high level cloud pushes south, seen this happen last year, GFS for what it's worth progs these temps, not my imagination.

ninebeanrows

Warning: There might be knives out on UK forums over the run, while it might be great for them it's amazing for us. But just one run.

Deep Easterly

Friday evening's disturbance in the form of that small low Su Campu mentioned earlier on still heading for Ireland on the latest HIRLAM 12z run:



extreme NW and western headlands continue to be at risk of some strong winds is it bears down but I think the exact track may not be nailed on just yet.

Defcol

Weathercheck wrote: »

12z to 84hrs is virtual snow-fest for Eastern Ireland, there would be some serious disruption in Dublin, Obviously areas withing 1 mile of the coast would be under question but even with this locations included a fantastic run with varies disturbances developing piling snow into the east.

Is it likely to push into Meath?

ninebeanrows

Sunday would surely be one of the coldest November days in Ireland ever if were to arrive, Baltic winds, 850hpas nearing -10c, 2M temps below 0c for many and minima crashing to -8c inland. The upper air setup is going to be extremely cold for the time of year.

Su Campu

Weathercheck wrote: »

I was thinking the frost would lock in before the high level cloud pushes south, seen this happen last year, GFS for what it's worth progs these temps, not my imagination.

Look what's happened the last two nights with just some scattered mid-high cloud. Although uppers may be a bit colder tomorrow night, there should be a more organised high-level overcast approaching from the north, so maybe all but the extreme south can be excluded from harsh frost.

Maybe I'm wrong with my timings - I'm going from memory of the last time I saw the charts as I'm using my phone this afternoon! But at least i ddnt use txt spk eh!