[Southwest & Central Southern England Regional Discussion 3rd January 2013>]

I wouldnt get to caught up in this weekend although th further east and north you are the higher chance of wintry conditions. For our region we need prolonged cold to build over us so when a break down does try to happen the result will be heavy persistant snow.

My thoughts looking at the current output is that cold will build over us but no break down in site as of yet, cross model agreement support this, what this does show are Low Pressures under cutting which again will produce snow mid next week.

Im 70% of the above scenario. As I said dont rely on snow for our region this weekend let the cold establish itself first.

[Southwest & Central Southern England Regional Discussion 3rd January 2013>]

This is purely down to the positioning of the low pressure and the orientation. If the low slips just a bit further south then theres an opportunity but I dont hold much for snow in the south.....at this stage

[Southwest & Central Southern England Regional Discussion 3rd January 2013>]

PS latest UKMO analysis just received doesn't - on face value - look very wintry at all for most of southern England through weekend - exception being E districts /E Anglia / SE on Sunday and potential for some leading and back edge falls later Sat and again Sun, but UKMO v uncertain on N'ward extent to this. Monday mostly dry in their prog with exception of snow in far SE. Their modified GM fields looks nowhere near as snow-bound as the raw GFS indicated, for example, but take with suitable salt pinch.... will probably see MOGREPS and other snow probs etc later this eve.

My thoughts exactly, temps 3-4c higher for the M4 south. I would expect snow/freezing rain on the back edge....the biggest concern will be icy conditions for the south later in the night looks very dangerous indeed!

[Winter Model Discussion 18Z 8/1/13. The hunt for cold (is closer).]

And this ties in with Ian F's latest comments in the SW & South thread in last 30 mins.

Havent seen that yet....I will have a look thanks for the heads up!

[Winter Model Discussion 18Z 8/1/13. The hunt for cold (is closer).]

The snowfest for parts of the S still on for Saturday

Not for oxford south its not. Temps are actually 4c higher for that region than the 12z compared to the 18z so rain here im afraid......on this run

[Winter Model Discussion - Cold Hunting 08/01/13 00z Onwards]

We've also seen time and time again where the ensembles play catch up and join the Op.

The fact the UKMO has trended the same way gives me a little more hope, the ensembles are excellent in the short term but then scatter into the medium term, as you'd generally expect.

Exactly, the UKMO is coming on board the GEM is looking positive. With the differences in the ensembles suite it would be near impossible to produce a scenario so looking across the models and seeing agreement is where I would pick up a trend. The ensembles of course will be all over the place depending on how it places the PV and with the displaced PV at the moment the output of blocking and colder condtions is where we will be heading in the med term..

[Winter Model Discussion - Cold Hunting 08/01/13 00z Onwards]

BOOM UKMO joins the Greenland High Atlantic Block party

Will be interesting to look at the Fax charts

[Winter Model Discussion - Cold Hunting 08/01/13 00z Onwards]

The precip charts show snow south of the M4 as well actually.

I would expect sleet at best. Dont get confused with later in the run im just talking about Sarturday at this stage

[Winter Model Discussion - Cold Hunting 08/01/13 00z Onwards]

Are you sure about that?

Upgrade in snow potential, but still too far out to have any confidence with. Its what happens after the weekend thats important

From what the models are showing I would say 80% sure, I would say maybe the far south east would get light snow at that point. The uppers are close to 0c.south and west of that area

[Winter Model Discussion - Cold Hunting 08/01/13 00z Onwards]

GFS 12z paints a much snowier picture for saturday morning across england.

It must be said....from the M4 north. The south of that would be just rain/sleet

[Winter Model Discussion - Cold Hunting -12Z 06/01/13]

Shannon entropy is presently at extreme values heading into 4-5d period and this index of v low confidence expected to remain so for a few days. Latest UKMO-GM brings WBFL down to circa 200-300m widely Sat night into Sunday (by latter right across UK) but ppn detail remains problematic and this whole period presents some major forecast headaches at current juncture.

In terms of temp and conditions for sleet and snow the mets confidence is creeping. Just the PPN is the major uncertainty at this stage......of course the conditions are quite likely to differ in the next 24 hours. But confidence seems to be slowly creeping up

[Winter Model Discussion - Cold Hunting -12Z 06/01/13]

I see a few people on the S coast have moaned about this run.

Although futile talking about this but for those in the S it would only take a slight shift S and they would join in the fun and games. Besides this for the S coast and especially SW England it is only this kind of set up being shown that can bring widespread blizzards for them. When you look at some of the classic winters you would sometimes see milder temps reaching the far S/SW but thats to be expected when you live in this location.

I understand your point......My comment was regarding the output being shown now and not what I want it to do (being push 90 miles south) of course we would expect milder conditions down south but with such small surface area in the UK and sea temps not to different from the North we miss out constantly....this isnt a moan its a fact

Im not fussed either way mild or cold just not freezing rain lol

[Winter Model Discussion - Cold Hunting -12Z 06/01/13]

And if the 18z does not include any SSW info just image what it could be like if it did. Now where is my snow shovel.....

Just remeber SSW will only allow heights to build and will not promise a feed of cold air. If we fall on the wrong side of a block then game over!

[Winter Model Discussion - Cold Hunting -12Z 06/01/13]

For any newcomers here or members who don't understand the models then what the 18Z is showing is really the holy grail of cold winter synoptics and to be honest it cannot get any better.

http://www.wetterzen...s/Rtavn2881.png

for oxford north, selfishly I would just see sleety rain. So although im happy for the folks up north not to pleased for us down south.

[Winter Model Discussion - Cold Hunting -12Z 06/01/13]

Chances are always going to be slim here on the south coast. Added factor of the purbecks and the IOW don't help either!.

Indeed they dont, I think there maybe a few more twists. There needs to be caution with models dealing with this set up as proven in Dec.

[Winter Model Discussion - Cold Hunting -12Z 06/01/13]

The higher ground of Scotland and northern England could see some snow on Saturday morning

By Saturday evening lower parts could see snow with wintry showers heading further south

By Saturday night you can see all the cold air waiting to move in

Snow risk moves further south

During Sunday eastern coastal ares from the humber south could see frequent snow showers

The first story in the media regarding the cold spell has appeared this afternoon more will follow thats for sure - http://forum.netweat...80#entry2468212

Suprise suprise, no snow shown for the south..........Again! Great looking charts for cold and there seems to be more upgrades then down. Also all models begining to fall in to line with each other.

[Winter Model Discussion - Cold Hunting -12Z 06/01/13]

'Uncertainty', 'Knife Edge', we hear it every year!

It never seems to be straight forward.

I detect the beginning of a back track in the expectations and excitement of the BBC weather presenters compared to yesterdays forecasts?

Not at all, they are being carefull. They have some confidence or they would not of mentioned it. They are far to wise to be saying get sledges out for next weekend that would be crazy. cross model agreement by Wednesday about cold/snow then start to be specific.

[Winter Model Discussion - Cold Hunting -12Z 06/01/13]

I very rarely post in here because I refused to get sucked in to all the false ramping or doom mungering but I do follow to try and learn from more experienced users, But there seems to be very little acknowledgement to the fact our whole weather system has dramatically changed over the last 20 years & this is why the computers are finding it nearly impossible to read anything past 48hrs so my point is why do so many people get in to arguments over something that is so inaccurate that you may as well toss a coin as to when or if? cold weather will get here or not.

havent models been updated since 1993? if so they would have been updated by scientists with knowledge of our changing environment so Im not sure I agree. I think what has occured are more extreme events and they are becoming more frequent and that is where on occasions we are left in the dark......alittle

[Stratosphere Temperature Watch 2012/2013]

so we have shutter saying it will start to regroup in the next few weeks and snowm4n saying its going to take some time to recover? sometimes this thread can be useful other times confusing.

[Winter Model Discussion - Cold Hunting -12Z 30/12/12]

The models look very boring nothing to suggest cold at the moment. Although a SSW has been predicted there is nothing to suggest a cold spell at this stage. The high pressure we have to our SW at the moment will be crucial in its positioning to how our weather will pan out. Once the SSW has occured I would expect a change to show up very quickly on the output and an evolution to cool/colder conditions as the Atlantic weakens.

[Winter Model Discussion - Cold Hunting -12Z 30/12/12]

They were going by what the models were suggesting at the time? I'm sure most here would agree placing hopes on a LRF is pretty dodgy. It's a shame the media will go for it though and blast it out in the headlines as if its certain to happen. No wonder the text forecasts now are more vague and broad - its to cover their backsides from criticism for somehow saying "they got it all wrong".

The only one to blame in my view is the that sneaky mistress Mother Nature.

Id have to disagree with "No wonder the text forecasts now are more vague and broad - its to cover their backsides from criticism for somehow saying "they got it all wrong"

They have been so broad because the models have been so inconsistant with medium to long range forecasts recently they have actually just been forecasting what signals they have been observing..

[Winter Model Discussion - Cold Hunting -23/12/12]

Hi Damp

Take at look at the BOM run as this illustrates what I was getting at. It's unlikely, but you never know.

Jason

My apologies, i thought you were referring to the GFS 06z. I can now see what you mean.

[Winter Model Discussion - Cold Hunting -23/12/12]

On the 186 chart of the current GFS run that big low is an awfully long way south compared to recent runs. Could we be looking at the bid daddy of undercuts?

Low res will no doubt sent it North again, but something similar is shown on the BOM run.

Jason

There is nothing to undercut. My understanding is to be an undercut the LP system cuts under a HP system to the north and that isnt the case here.

[Winter Model Discussion - Cold Hunting -23/12/12]

ECMWF and JMA @ 192hrs are almost identical in the positioning of the high pressure two well regarded models.........a trend ..........possibly!

[Winter Model Discussion - Cold Hunting -23/12/12]

Sorry im just so disappointed with todays overall output. I find the GEFS means especially depressing because when you compare +300 with previous runs its a case of spot the difference.

Im not even convinced a SSW will come to our rescue. When it comes to N blocking it isn't just what occurs in the Stratosphere that dictates the frequency of blocking because their are many other factors. For example if members revisit the 2009/2010 Strat thread we only had minor warmings and yet look at the exceptional blocking that developed over Greenland and the incredibly negative AO.

As I said a few days ago some other factor is causing this dreadful pattern and the resulting positive NAO which only the ECM seasonal picked up on. The question is can this SSW override this other unknown signal that is causing the positive NAO???

its not by chance we get northern blocking there are numerous factors along with presicion timing along side them. Im far from convinced about the SSW. No doubt globally yes it plays a significant part but for us with a powerful ocean at our doorstep we need a little more help then a SSW.