Cold Snap, T0-180Hours Only

derekon

Weathercheck wrote: »

Well ECM is probably the most optimistic and probably will be the furthest west of its suite.

However we would only need a 100/150 mile shift west of the cold pool @ 72hrs to create a snowy scenario for the east coast during Saturday.

So chances have decreased since yesterday but certainly increased from this morning to around 10-15%

Mmmm....brings to mind the words "flogging" and "dead horse"

Lads, its time to call a day on this (and any chances of snow in Ireland this winter). I hear its snowing in Naples and Bologna, Italy. Oh the injustice of it all :mad:

D

ninebeanrows

derekon wrote: »

Mmmm....brings to mind the words "flogging" and "dead horse"

Lads, its time to call a day on this (and any chances of snow in Ireland this winter). I hear its snowing in Naples and Bologna, Italy. Oh the injustice of it all :mad:

D

Yes we probably are.

But only now is the Atlantic beginning to interact with the block, test it out, so we can see what happens in reality rather than in the programs and this might cause knock on effect.s

a 150 mile move west isn't out of the question.

ninebeanrows

Latest ECM Ensembles are interesting, i expect some cold ramping on some English weather boards

Eastcoastryan

Weathercheck wrote: »

Latest ECM Ensembles are interesting, i expect some cold ramping on some English weather boards

I've been sucked back in again, although its highly unlikely.. it's not out of the question that things will push west and the low temps on the east coast might hang around a bit longer!!

goat2

i have just been out, feeling cold,
but this big circle looking like a halo round the moon with one star within the halo,
is this an indicator of weather to come

darkman2

Ensemble mean ECM 168





Looks like we may get another shot at an Easterly. The ECM in general remains cold for Ireland with very cold nights and cold days and frost most nights.


I also would not rule out snow on Saturday particularly in the East and Northeast.

M.T. Cranium

Lunar and solar halos (haloes?) are caused by diffraction of light from ice crystals suspended high in the atmosphere.

There is a correlation with precipitation within 24-48 hours because warm fronts normally have this sort of regime as an early stage, followed by thicker high cloud and then various other layers of cloud.

However, since cloud formations can be moving in all kinds of directions and with varying amounts of precip, not all of these halos will lead to precipitation and not all precip will have halos as their forerunner.

In this case the front is stalled off to the west of Ireland while the cold air circulates around high pressure over Norway, the situation remains fairly static for 24 hours and then the front begins to edge in from the west. It seems at the moment that precip will begin as rain or sleet in western Ireland with some patchy freezing rain, but could (stress could) begin as snow in parts of the east and north before turning to sleet then rain (amounts may be light in all cases too, the air masses are dry and the front is weak by Atlantic standards).

derekon

The ECM for tomorrow Thursday shows -8 upper level temperatures stopping in the Irish Sea just off the east coast (while the rest of Europe is under brutal cold)

You could not write this stuff!! Is there some human involvement with these models ? Is someone taunting Ireland ?

D

Musicman2000

CFS charts look extremely interesting for the rest of February.
http://www.meteociel.fr/modeles/cfse_cartes.php?ech=6&code=0&mode=0&carte=1&run=10

mcriot29

Musicman2000 wrote: »

CFS charts look extremely interesting for the rest of February.
http://www.meteociel.fr/modeles/cfse_cartes.php?ech=6&code=0&mode=0&carte=1&run=10

Cfs chop and change too much

Musicman2000

mcriot29 wrote: »

Cfs chop and change too much

Like every other model the last few weeks, I have to say it has being fairly bang on this winter so far.

BEASTERLY

Weathercheck wrote: »

Latest ECM Ensembles are interesting, i expect some cold ramping on some English weather boards

Well if last weekend thought us anything it's that no matter how certain the operational runs are even with multi-model agreement, whatever the majority of the ensembles are going for will win out. Even last Friday evening i knew from the ensembles it was only a matter of time before the op run switched to milder outlook with the high sinking.

EDIT: just forgot to mention ivwass refering to the GFS. Hopefully now the ECM is liable to the same behaviour.

ninebeanrows

Never seen such a general swing west at T48 before. Not going to have much benefit here (YET unless it moves macro amounts!).

Stuff gets shunted 100 miles west across eastern England at T48

ninebeanrows

Lets just show differenes at T48 between 12z and 18z.

The significance is it is a 100 mile shift at a forecast just 48 hours away.

At T96 or later that is common place but not so early.

18z at T48



12z at T54

darkman2

18z is a snow fest for Britain. Good news is it is much more amplified more toward the ECM.

Eastcoastryan

darkman2 wrote: »

18z is a snow fest for Britain. Good news is it is much more amplified more toward the ECM.

Any chance that models may have been underestimating the Cold to our east or overplaying the Atlantic? Clutching at straws I know but would this make any difference to how the breakdown takes place here? I'd settle for even a few hours snow at this stage!!

Su Campu

Nothing's changed with me. I still see an Atlantic influence winning out up to around mid month at least. The large scale upper pattern shows no signs of anything else, with large seasonal troughs off the eastern edges of both continents, North America and eastern Siberia. The latter does cause some poleward geopotential through Alaska, but in general we see a mostly zonal setup win out over Canada, causing the NW Atlantic trough to keep the Azores high firmly in place and keeping the NAO's head above water.

Not a good chance of streamers tomorrow either. Low dewpoints, the strong inversion, as well as cold air advection at low-mid levels will continue to surpress cloud activity, yielding just some cumulus humilis or stratocumulus. I'd say less than a 20% chance of anywhere seeing flurries.

Iancar29

darkman2 wrote: »

18z is a snow fest for Britain. Good news is it is much more amplified more toward the ECM.

AND Here that is!... Fecking bro is going to london for the weekend! Grrrr!!

darkman2

Su Campu wrote: »

Nothing's changed with me. I still see an Atlantic influence winning out up to around mid month at least. The large scale upper pattern shows no signs of anything else, with large seasonal troughs off the eastern edges of both continents, North America and eastern Siberia. The latter does cause some poleward geopotential through Alaska, but in general we see a mostly zonal setup win out over Canada, causing the NW Atlantic trough to keep the Azores high firmly in place and keeping the NAO's head above water.

Not a good chance of streamers tomorrow either. Low dewpoints, the strong inversion, as well as cold air advection at low-mid levels will continue to surpress cloud activity, yielding just some cumulus humilis or stratocumulus. I'd say less than a 20% chance of anywhere seeing flurries.

Myself I would not call an Atlantic win yet. If anything we are moving toward a mid latitude block and continued generally cold and frosty weather. It could be the Azores high exerts too much influence. However if the Jet stream plays ball upstream and puts more energy into the Southern arm in the Atlantic it's easy to see where we could end up with this.

Su Campu

darkman2 wrote: »

Myself I would not call an Atlantic win yet. If anything we are moving toward a mid latitude block and continued generally cold and frosty weather. It could be the Azores high exerts too much influence. However if the Jet stream plays ball upstream and puts more energy into the Southern arm in the Atlantic it's easy to see where we could end up with this.

That chart shows a setup that will strenthen the Azores high. The NW trough retreats into Labrador and keeps the core of theAzores high to the south of us, keeping us in (south)westerlies and cutting off the supply to the Scandi high. Interesting to see how it will go but I can't see any other outcome than mildish for the next week to 10 days

ninebeanrows

Su Campu wrote: »

Nothing's changed with me. I still see an Atlantic influence winning out up to around mid month at least. The large scale upper pattern shows no signs of anything else, with large seasonal troughs off the eastern edges of both continents, North America and eastern Siberia. The latter does cause some poleward geopotential through Alaska, but in general we see a mostly zonal setup win out over Canada, causing the NW Atlantic trough to keep the Azores high firmly in place and keeping the NAO's head above water.

Not a good chance of streamers tomorrow either. Low dewpoints, the strong inversion, as well as cold air advection at low-mid levels will continue to surpress cloud activity, yielding just some cumulus humilis or stratocumulus. I'd say less than a 20% chance of anywhere seeing flurries.

I don't see how you could make such wide sweeping comments considering a quick view of the ECM postage stamps at 144hrs see's a wide range of solutions, with a decent cluster including a cold easterly flow over Ireland and the UK.

I do agree however about the very small chance of snow showers tomorrow. The only glimmer of hope (or less than a glimmer) is that we may see some breakdown snow if things backtrack another distance.

ECM postage stamps @ 144hr

Showing wide array of solutions.

Su Campu

Weathercheck wrote: »

I don't see how you could make such wide sweeping comments considering a quick view of the ECM postage stamps at 144hrs see's a wide range of solutions, with a decent cluster including a cold easterly flow over Ireland and the UK.

I'm not really basing my thoughts on the models as they are fairly useless at the moment. A general look at the evolution to date and the current setup can tell a lot about what will come down the road. It's served me well so far but of course that could be tempting fate!! :rolleyes:

ninebeanrows

Some very interesting GFS Ensembles.

Is the retreat on?

Potential cold return of sorts to return by T96hrs..

The rollercoaster turns back on.

till the morning

Sponge Bob

Weathercheck wrote: »

I expect some cold ramping on some English weather boards

I agree, we should always blame them pesky English Boards for gratuitous ramping outbreaks. It would never happen here.

I therefore expect that the Duly Modelled inability of the Atlantic to absolutely prevail between Monday and Thursday bodes well for an Epic fightback by the Deep Cold from that sturdy pocket of crispy coolness in the South East corner of England....no matter what them rampers say. :cool:



AND

ninebeanrows

Well it will be interesting to see what happens in the morning. Another 100 mile shunt in the morning combined with some mini ones thereafter and who knows what might happen.

However again it must be highlighted we are talking about a low chance forecast, so people reading this should not get disappointed if there is not a flake out of it as we are talking about a 10% situation!

Sponge Bob

Weathercheck wrote: »

Some very interesting GFS Ensembles.
Is the retreat on? Potential cold return of sorts to return by T96hrs..

The rollercoaster turns back on.

@23:13

Weathercheck wrote: »

However again it must be highlighted we are talking about a low chance forecast, so people reading this should not get disappointed if there is not a flake out of it as we are talking about a 10% situation!

@23.38

I take it that your Moderation Hat was dusted off in the past hour for fear that some of the pesky 'English Board Disease' could start to creep in here were the eternal vigilance relaxed in any way.

Redsunset

Been trawling for hours trying to find something similar to now and Feb 56 still rates the best plausible outcome. Below is its sequence (while not perfect) looks like what's going to happen to us.

We lose our easterly and winds become south westerly.






Link back up with high



Then breaks away into a mid Atlantic block


Before eventually edging toward Greenland



Still all very uncertain but just to recap I think after this current easterly flow breaks down to become a south west flow, the Azores injection creates new heights and reignites another easterly. This then separates and falls back into the mid Atlantic and creates a block and allowing northerlies and an attack from north east. The mid Atlantic block to then extend somewhat toward Greenland.

This might be complete crap but hey it's possible.

darkman2

DWD good for snow particularly in the East

TheMilkyPirate

Why is the DWD also known as the GME?

mickger844posts

darkman2 wrote: »

DWD good for snow particularly in the East

Are you saying Eastern Ireland or East of us in the UK because the DWD has -4 uppers for Eastern Ireland for that time frame? Surely not cold enough for snow