Glimmer of hope model discussion

[Harsh Climate]

Out of interest, if all went to plan, what kind of accumulations could i be looking at above 200 metres?????

Difficult to say but If everything went perfectly Id say 10-15". But with the way things are going id say probably 1"-3" of temporary snowcover at some stage.

It just depends on

. how much cold air we can get trapped in the ridge of high pressure to start with.

.how quickly the fronts push in from the west

.wether or not we can get any easterly type feed filtering into the mild air trying to push in from the west, which would help keep things cold.

.how the precipitation falling brings down the temperature.

Lets not forget, once there is snow cover and the clouds dissipate (into night time), very low minima would be achieved leading to a very cold morning.... which if there was more precipitation moveing in, a replay of more precipitation moveing into very cold stationary air turning into snow could commend..

[January Snowstorm]

We heard you the first time. When does it ever get snowy in southern ireland anyway????

At least we get Summers

Looks to me like wind and floods will be the main topic in a few days time

[Kentish Man]

There is quite a difference between the latest 12Z Fax for Thursday and GFS 06z for the same time. The fax chart shows the weakish HP to the N and east with a depression over the UK. Could be some potential from the MetO chart. If the MetO is right (and thats not certain) then maybe the JMA should get some plaudits for being the first model to pick up the general synoptics for this date as regards the weak high although the detail is of course a bit different as regards the positioning of the LP over the UK.

[Matty M]

very violent southerly tracking LP's!???

Yes

http://91.121.0.76/modeles/gens/run/gens-0-1-168.png?6

http://91.121.0.76/modeles/gens/run/gens-4-1-168.png?6

http://91.121.0.76/modeles/gens/run/gens-5-1-168.png?6

http://91.121.0.76/modeles/gens/run/gens-14-1-168.png?6

Some more southerly tracking than others!!

Very unsettled outlook.

[KTtom]

A little surprised no-one has commented on the latest Fax: Here it is without having to crick your neck!

http://www.wetterzentrale.de/pics/brack4a.gif

Looks like temps will not fall away much, sub 528 dam following on?

Matty, I remember that well, SW Wales was cut off for over a week after 48hrs of constant blizzards. Probably the last time we had more than an inch here!

KT

[Harsh Climate]

I want snow for everyone not just my or anyones particular area , i think we have all suffered this winter ,i think sounding a little smug can just annoy folk

lol, I think its because I knew people from another board (dont ask which one) from the south east.. they were very arrogant and seemd to boast about all the snow and thundertorms they got, and moaned when they werent getting any.. I think thats why there may seem to be a little anomocity.

Il try and be nicer to the southeast lol as people on here from there seem allright...

[nick sussex]

The general theme from the ensembles is for a train of lows heading in from the atlantic on a more southerly track than we've become used to over the winter so far. This is all high risk though as we would need to see pressure remain strong to the north and ne to keep us close to the cold air and allow for some snow and a general colder theme.

The nirvana for us in the uk is for the right set up that allows for enough colder air to get into the mix whilst still seeing the lows close enough to deliver significant snow, however if pressure falls to the north and ne we will end up on the milder side of all the fun.

Today is the first time we've seen two operational runs go for more significant pressure rises to the ne these being the ecm and gfs, its from now that we need to look at the trend, will pressure continue to build and take the lows even further south and bring us a decent cold spell or will the models keep us in a halfway house or conversely blow the block away.

Actually I should also add the ukmo here judging by the fax chart for 132hrs.

http://85.214.49.20/wz/pics/brack4a.gif

This is an interesting chart in that if pressure continues to rise to the ne then we may see the low split from the PV to the sw of greenland and that bump of high pressure to our sw ridge north and basically force the low back sewards with ridging from the east backing west over the low centred over the uk.

Edited February 3, 2007 by nick sussex

[johnholmes]

Yes

http://91.121.0.76/modeles/gens/run/gens-0-1-168.png?6

http://91.121.0.76/modeles/gens/run/gens-4-1-168.png?6

http://91.121.0.76/modeles/gens/run/gens-5-1-168.png?6

http://91.121.0.76/modeles/gens/run/gens-14-1-168.png?6

Some more southerly tracking than others!!

Very unsettled outlook.

my attempt was to query them tracking SOUTH, they are not tracking south. They are taking a more southerly track than the past few weeks but NOT moving south. Pedantic perhaps but correct, as the charts you quote above show.

[grab my graupel]

I want snow for everyone not just my or anyones particular area , i think we have all suffered this winter ,i think sounding a little smug can just annoy folk

Yes that is what I would like to see.

I must admit I did rather well from the last cold snap, but it took the gloss off it for me

when I learned that some on here didn't get a single flake.

I felt Kind of guilty in a way.

I don't think the 06z will be a downgrade, as we have seen this kind of chopping and

changing all week.

Brian.

[Troubleatmill]

The general theme from the ensembles is for a train of lows heading in from the atlantic on a more southerly track than we've become used to over the winter so far. This is all high risk though as we would need to see pressure remain strong to the north and ne to keep us close to the cold air and allow for some snow and a general colder theme.

The nirvana for us in the uk is for the right set up that allows for enough colder air to get into the mix whilst still seeing the lows close enough to deliver significant snow, however if pressure falls to the north and ne we will end up on the milder side of all the fun.

Today is the first time we've seen two operational runs go for more significant pressure rises to the ne these being the ecm and gfs, its from now that we need to look at the trend, will pressure continue to build and take the lows even further south and bring us a decent cold spell or will the models keep us in a halfway house or conversely blow the block away.

Actually I should also add the ukmo here judging by the fax chart for 132hrs.

http://85.214.49.20/wz/pics/brack4a.gif

This is an interesting chart in that if pressure continues to rise to the ne then we may see the low split from the PV to the sw of greenland and that bump of high pressure to our sw ridge north and basically force the low back sewards with ridging from the east backing west over the low centred over the uk.

Perhaps the JMA model the other day was not so crazy after all hey Nick ?

[tom_f123]

was it around this time last year we had a similar event when parts of yorkshire had about a foot of snow?

[nick sussex]

Perhaps the JMA model the other day was not so crazy after all hey Nick ?

Well the JMA normally sits in my cannon fodder model section! and regardless that it did show a pressure rise its now jumped ship here. The actual mechanics behind its easterly was different though to what is being progged by the possibilites shown in the ecm and gfs, though I'd take any easterly how ever it appears!

[snowray]

Out of interest, if all went to plan, what kind of accumulations could i be looking at above 200 metres?????

Very hard to say but best case scenario I suspect would give you a good 30cm or so, this run does look about right to me I have to say, none the less, still very much hit and miss, we will need nerves of steel over the next couple of days, I aint joking!

As expected we are seeing differences of a hundred miles or so in the projected set up, I suspect that we are no where near to what will actually happen though, as wiser members have comented already, we may have to wait until under T24 to know what realy will happen. Most importantly I would want to see the -5hpa line remain well established over most of the country in successive runs and the high to our east/scandi high to hold strong/build somewhat. Any downgrades though in the next couple of runs and this 100 miles(ish) magin of error could quickly disapear, bringing the Atlantic in far more quickly and great anguish to many on here. As things stand I remain reasonably confident that at the very least northern areas with some elevation are going to get some of the white stuff next week, the rest of us anything could happen. Lets just enjoy a few days of more seasonal temps and night frosts for now .

Edited February 3, 2007 by snowray

[gobbyash]

was it around this time last year we had a similar event when parts of yorkshire had about a foot of snow?

We had this just before New Year

http://news.bbc.co.uk/1/hi/england/humber/4568580.stm

gobbyash

[Snow Queen one]

sorry to ask this as i am still a novice. The charts posted showing the lows coming in also show that there is a lot of cold air (the purple) mixed in. Is it not possable that these lows could hit us with some snow even in the SE as they come over? Maybe i am grasping at straws.

[Troubleatmill]

Well the JMA normally sits in my cannon fodder model section! and regardless that it did show a pressure rise its now jumped ship here. The actual mechanics behind its easterly was different though to what is being progged by the possibilites shown in the ecm and gfs, though I'd take any easterly how ever it appears!

Fully concur with that Nick , i was just trying to point out that two days ago there was not even a hint from the big players that pressure might rise to the east & all we were hoping for was a southerly tracking low pressure to bring in a period of snow before the atlantic came charging back in , but as things stand now we have two possible bites at the cherry , one from the initial depression coming in & then what will happen to the height rises to the east ? , its enjoyable watching the different possibilties unfold

Edited February 3, 2007 by arron123

[johnholmes]

The first part of the cold spell seems fairly certain with the models being in quite close agreement.

Little snow seems in prospect for the main bulk of the UK. The exception to this, as I see it, mid day Saturday, is for the northern half of Scotland, and especially the N Isles. Here, as the trough/low swings south then into the N Sea during Monday into Tuesday then a spell of snow is likely in the far ne. A scattering of sleet, soft hail and snow showers will occur in much the same areas before this.

Frost for almost all from now on each overnight period, and some quite low values seem probable as time goes on.

As to Wednesday onwards then the models are not in major agreement here on either timing or the situation into Saturday. As time goes on the cold spell appears to be lengthening not shortening. Just how much snow will come out of the attempts by the Atlantic to push in remains to be seen? As I keep stressing its pointless expecting to know much more than 48 hours ahead of the expected event as to what will really happen.

At the moment there is the POSSIBILITY for considerable snowfall from about the Peak District northwards for all high ground, say about 1,000ft in the south of this area, and about 3-500ft over the north of Scotland, as this event develops.

The models are generally suggesting that an air frost is possible even into the Midlands on Friday morning and on Saturday morning for parts of the border counties and further north along with parts of N Ireland.

So lots to watch for over the next few days. Certainly a colder spell than most have seen all this winter in prospect.

Posting this in this thread, the techie one and into blog 4.

I will do another blog sometime this afternoon with charts from the 12z run if I have time.

John

[stratty]

sorry to ask this as i am still a novice. The charts posted showing the lows coming in also show that there is a lot of cold air (the purple) mixed in. Is it not possable that these lows could hit us with some snow even in the SE as they come over? Maybe i am grasping at straws.

i think you are looking at the pressure charts, not the temps?

[andy_leics22]

Hmmm 06z not as good as last nights 00z, I hope the 12z picks up the 00z's trend again though otherwise it is game over.

[nick sussex]

The ensembles look strange, given the pattern you would expect to see a bigger scatter. GP mentioned this type of ensemble pattern the other day in the gfs as something it does before we see a big scatter in the following run as currently it really doesnt no where to go later in the week, I would say that we may see some big changes over the next few runs.

Look how flat the mean line is in the ensembles for aberdeen, it may seem strange looking at those ensembles to suggest huge uncertainty but this pattern correlates often with a switch in model output over the following runs.

Edited February 3, 2007 by nick sussex

[Snow Queen one]

i think you are looking at the pressure charts, not the temps?

thanks for the reply i see where i have been going wrong now.

[snowray]

The ensembles look strange, given the pattern you would expect to see a bigger scatter. GP mentioned this type of ensemble pattern the other day in the gfs as something it does before we see a big scatter in the following run as currently it really doesnt no where to go later in the week, I would say that we may see some big changes over the next few runs.

Agreed Nick, I think that the next few runs will be very interesting, they could also be make or break runs, I must say though that over all I remain cautiously positive.

[johnholmes]

for anyone interested I've done blog 4. Sorry its a big file so be patient if you have not got broadband for it to download.

regards

John

[Frosty.]

At least we get Summers

Looks to me like wind and floods will be the main topic in a few days time

LOL you are welcome to your hot sticky summers, we get hot sunshine but always a refreshing breeze which is much nicer. Back on topic, the latest info suggests a change to much colder conditions nationwide next week with an increasing snow threat later in the week although northern and eastern exposed locations will see snow showers from sunday night onwards through to midweek.

Edited February 3, 2007 by Frosty039

[johnholmes]

LOL you are welcome to your hot sticky summers, we get hot sunshine but always a refreshing breeze which is much nicer. Back on topic, the latest info suggests a change to much colder conditions nationwide next week with an increasing snow threat later in the week although northern exposed locations will see snow showers from sunday night onwards through to midweek.

see my blog for your likely weather frosty

Edited February 3, 2007 by johnholmes