Southeast England and East Anglia - Weather Chat

[Jax]

Morning

 

 

Cold and frosty start to the day here, dull and calm with it. 0.9oC a short while ago outside from the sensor in the shed.

[Daniel*]

Good morning from the EURO4

0z (Friday)

18z (Thursday)

I'd say an upgrade snow wise with accumulations even possible to North London, I've been following the EURO4 and every run has caused the LP to sink ever so further south so interesting times.

[snowking]

FYI from model thread:

 

 

Quick update with regards to today's snow potential

 

Still a very tricky cool with temperature profiles proving very marginal indeed. I would say above 200m, and indeed North of the M4, it looks a fairly dead cert. For the remaining 95% of the landmass affected by today's precipitation, a lot may come down to evaporative cooling, and hoping the precipitation stays intense enough all the way through in to this evening. 

 

GFS, and hence NMM, remains the furthest North solution:

 

 

As outlined by Mucka, Euro4 keeps the precipitation much further South:

 

 

And at present the best time for the widest cross section of England and Wales, at least according to the Euro4, is around 3am in terms of dew points:

 

 

Though as you can see, still marginal (though at that resolution it is tough to decipher just how much of an area might be above/below 0c).

 

Two things to note here. Firstly, no model is really able to accurately calculate the effects of evaporative cooling (quick FYI for those newer members - as precipitation falls from the clouds, it carries down parcels of air. These parcels of air, having come from much higher up in the atmosphere, are much cooler than the air temperature closer to the surface, and so there is a cooling effect. The heavier the precipitation, the more air parcels get carried down, and so the cooling effect is even greater. This can see rain turning to snow as the temperature profile from cloud to surface cools sufficiently enough to support snow), and so we should be wary of this. Secondly, I have also seen some suggestions that the Euro4 tends to underplay snowfall potential. I personally can find no scientific evidence of this, but something perhaps to consider.

 

The 0z ECMWF paints a halfway house between the two, and tends to follow the track of the updated Met Office yellow warnings - I would suggest that represents the best guess that I could make in terms of a potentially affected area at this juncture. That is not to say it will be the correct track, but based upon model consensus that is the best estimate.

 

We can do some quick checking on this right now. Euro4 projection for 9am:

 

 

Radar imagery from 9am:

 

 Screen Shot 2014-12-26 at 09.56.52.png

 

Observations - The intensity projection of the precipitation is pretty accurate. The system itself looks a tad further North, but that may be down to the fact that it is simply more expansive than projected, covering a larger area from North to South. It has advanced further Eastwards more quickly than projected too so far, though may slow down a little later. 

 

So it looks to me as though in terms of track, the halfway house solution of the ECMWF may be the closest to the truth.

 

From here on in we can monitor the models as much as we like, but the more useful time will be spent looking at obs and radars.

 

Good luck to all.

 

SK

 

Still so much uncertainty for our region, especially when you look at the updated met office warnings, I can only assume these are slightly UKV based, because even the Euro4 signal is a little more muted, for example, in to North Kent.

 

ECMWF tends to make it an East-Anglia type event (perhaps snow falling but not accumulating South of this), and GFS takes all but Northamptonshire and Norfolk out of it altogether.

 

Most recent Stansted Airport TAF suggest Rain/Sleet until midnight, then 40% chance of light snow from midnight until 9am - so far from certain just yet.

 

SK

 

 

 

[JennyJane1]

Just been sitting in the garden drinking my morning coffee, and watched circa 200 large birds flying west at a real pace. They weren't geese and it was too dark to see if they were pigeons or seagulls, but they were that size. '

I don't know about flocks of pigeons, but definately all the seagulls left to go south a few weeks ago.

[Daniel*]

Buckinghamshire, Milton Keynes, Oxfordshire, Greater London, Medway

Have been issued a yellow snow warning â„ï¸

see more here: http://www.metoffice.gov.uk/public/weather/warnings/#?tab=map&map=Warnings&zoom=7&lon=-0.75&lat=52.24&fcTime=1419552000

I urge caution.

[JennyJane1]

i woke up with a bit of a headache ths mornng -not alcohol related i hasten to add - so i haven't looked at the weather outside yet, but i just spoke to southernman who is working out at Reedham today, he left home at around seven thirty and said it was frosty then and now its a bit cold but not bad.

[TROY]

:smiliz19:  Merry christmas. Perfect frosty weather this morning wot tally ho

[Jax]

I don't know about flocks of pigeons, but definately all the seagulls left to go south a few weeks ago.

Had loads of them here last week, quite a sight to see them in such large numbers.

[Hammer]

Looking at 00z chart from METO on iPhone app and comparing to 12z from yesterday, the low is shown I'd say 50 miles further south for midnight tonight. So probably brings a little more of our region in to a chance of snow if that pans out.

In these situations there can often be fairly significant differences in short distances. So it will be interesting to see that later on.

Edited December 26, 2014 by Hammer

[lassie23]

Settling snow will be restricted to the North of London I suspect.

Lassie... There's more emoticons than actual words in your posts! Haha.

I like the Christmas ones :smiliz19: lol !Woke up with 'turkey belly' and boy it was cold out this morning! There are still patches of frost on the ground, even though the temp has risen to 3.5c. It has started to cloud over :smiliz23: looks like snow for the evening! :w00t:

Edited December 26, 2014 by lassie23

[Jax]

Frost appears to have gone here now.

Appears to have gone? what was I thinking when I typed that rubbish up?

[ITSY]

Just a word of warning that whilst the Meto and the BBC are showing the possibility of some snow for our region, both are indicating a transient mix of rain, sleet and snow whilst the models have this morning tended to confine the bulk of the snow to the Midlands - who could see a substantial amount of snow if the GFS is correct. Expect nothing more than a dusting for the bulk of our region and you may be surprised - anyone expecting inches upon inches is likely to be disappointed I fear. Still, 1 day after Christmas and already more snow potential than Autumn, Winter and Spring last year. Could see first snow of any description since March 2013

[Jax]

I like the Christmas ones :smiliz19: lol !Woke up with 'turkey belly' and boy it was cold out this morning! There are still patches of frost on the ground, even though the temp has risen to 3.5c. It has started to cloud over :smiliz23: looks like snow for the evening! :w00t:

:smiliz19:

You get an error if you try to use too many it seems.

[Ǝssex Ǝasterly]

2.4C here

 

With all the rain, then 'sleet', then more rain. I'm expecting to have to stay up till the early hours to see anything, but not wake up to a dusting. I'm only at 40m and near the coast! Don't think I'll see much with the street lights always off now either lol

 

With all that said, my expectations for my area are firmly on the floor!

 

BBC are predicting a heavy hail shower here for 11pm 

[snowking]

Latest Euro4 keeps folk in the North of the region happy - perhaps further South less so:

 

 

This does not preclude snow falling of course, but accumulation wise it's no surprise to see those are the areas underneath the projected tailing occlusion:

 

 

Model projections would suggest Northamptonshire and Norfolk may be the places to be for this one in our region, though as noted in the model thread the radar returns across Ireland at present are far more intense than suggested by the 6z Euro4. The heavier this precipitation becomes the better the chances for snow.

 

SK

[JennyJane1]

Had loads of them here last week, quite a sight to see them in such large numbers.

clearly they all went west, then stopped a while to do some christmas shopping, before continuing south.

[Hotspur62]

Its at times like this that I wish I lived at higher elevation as it makes all the difference. Will just be a rain/sleet event for me in Locksbottom but those in Halstead,Knockholt and areas like Biggin Hill may well have a dusting by tomorrow morning. Good luck to everyone in the Region and hope the Low tracks another 50 miles further South which will give a lot more a white morning tomorrow.

[John Snow]

Think I am a little too far south to get much out of this but got elevation so never know

[John Snow]

Need Yamkin to pop up, know there is going to be snow in the region when he gets excited

[john mac]

I have to say the sky is looking like its full of white to me. I think we might get a nice surprise!!

[Stuie]

Latest Euro4 keeps folk in the North of the region happy - perhaps further South less so:

 

 

This does not preclude snow falling of course, but accumulation wise it's no surprise to see those are the areas underneath the projected tailing occlusion:

 

 

Model projections would suggest Northamptonshire and Norfolk may be the places to be for this one in our region, though as noted in the model thread the radar returns across Ireland at present are far more intense than suggested by the 6z Euro4. The heavier this precipitation becomes the better the chances for snow.

 

SK

We are sitting in a real cusp zone in NW Essex huh.

[Downpour]

I have to say the sky is looking like its full of white to me. I think we might get a nice surprise!!

Yes, still as a leaf in a vacuum around here John – very eerie. Epping Forest for a bit of the white stuff due to cold trapping?

[Daniel*]

Need Yamkin to pop up, know there is going to be snow in the region when he gets excited

Oh boy we do wonder if Croydon council have been alerted by the METO. Once the mix of rain/sleet/snow band has moved through there is a increased probability of sleet/snow showers during overnight period,.

[john mac]

We are sitting in a real cusp zone in NW Essex huh.

I'm in south west Essex 40 mile shift south please!!

Yes, still as a leaf in a vacuum around here John – very eerie. Epping Forest for a bit of the white stuff due to cold trapping?

Yeah we get pretty cold here but we are at low level however a mile or 2 up the road high beech is at 100m so might have a chance there.

[snowrye]

am not expecting any snow down here,but plenty of time,good luck to others in the north of the region,who may get lucky