192 replies to this topic

[Frosty039]

Iceberg, on 15 January 2012 - 13:01 , said:

GFS 06Z is certainly not hinting at more of the same that we have had this winter.

If that was aimed at my earlier post, I was basing it on what that particular 6z run was showing for the uk in the next few weeks, ie. no snow for the south as that run was trending mild before the euro high arrives on the scene with increasing frost and fog risk, I know there are better solutions but the model output thread is also about commenting on the run we have seen as well as what the potential might be.

[weathermaster]

Review on the weather models this morning,

GFS

At 96 hours we are seeing good agreement from all the models and finally the GFS agrees. At 96 hours we have low pressure just about to enter the Atlantic and high pressure just to the South of the UK. At 120 hours all the weather models still show something similar with the ridge in the Atlantic making its way to Greenland so basically we have high pressure building up there. Looking at the positioning of the ridge all models seem to have it slightly more East than the GFS so from here the GFS has already been left on its own with no support. It's long range outlook for the rest of the month doesn't look too great for snow lovers showing just a few very short periods of cold weather but mostly mild and settled.

ECM

It has good support up to 144 hours from GEM and NOGAPS. However sadly the ECM has downgraded the blocking for next weekend but the UK would see a very short cold spell. Its long range doesn't look too bad similar to yesterday. Today its showing low pressure over the UK bringing cold and unsettled weather with it perhaps wintry as well.

GEM

It agreed with the GFS yesterday afternoon but has backed off from this and seems to support part of the ECM and UKMO its like something in the middle of them. It shows a better chance of cold weather for next weekend and its longer term shows plenty of chances for an easterly set up.

NOGAPS

Not bad this morning it shows a blocking occur next weekend while the UK is seeing good cold weather sadly it doesn't really seem to have much support this morning.

UKMO

Despite the GFS not showing anything too great and even the ECM has downgraded the chances of cold weather the UKMO still seems confident. At the end of the week it builds up high pressure in the Atlantic allowing us to see a blocking occur. We don't know how long the blocking would last because it doesn't go past 144 hours. If it were to agree with any model it would agree with NOGAPS. The UKMO this morning is probably our last hope all we can hope for now is that it sticks to this and shows a stronger blocking and the others follow.

One interesting thing about the UKMO is in 96 hours time I'm not sure if anyone has noticed this but I'll show you below,

72 hours the low out in Atlantic, the UKMO wants to do something different with it.



As shown above most of the models show the low getting 'crushed' by high pressure moving in but the UKMO lets it come out and head towards the UK as shown below,



As you can see in the above the UKMO sends it over the UK meanwhile other models show it in the Atlantic which can change things around a lot from run to run but the UKMO has never done this which is why its being more consistent lately. Also because this low is now gone it lets high pressure build up much more in the Atlantic allowing us to get a better chance of a blocking. Is the UKMO on to something we don't know yet but we will soon find out.

Rest of the weekend to Thursday: Staying settled and cold for most but windy over Western parts today. Monday and Tuesday will carry on this theme. Wednesday will be unsettled for most with wet and windy weather and severe gales over Northern Scotland. Thursday another unsettled day for most and getting colder in the North.

Friday to Sunday: Friday will be unsettled again with cold wintry weather in the far North. Saturday looks more settled mainly for Western and Southern parts meanwhile Eastern parts could see some windy weather. Sunday unsettled across the UK but mainly in the North.

Sunday and Beyond: Unsure at the moment some weather models suggest short cold periods until the end of the month mixed in with mild weather and high pressure. Others suggest colder and unsettled weather.

[stewfox]

Iceberg, on 15 January 2012 - 13:01 , said:

Before anybody says that these are out in FI land, yes they are, but they general themes tend to stay the same.
A pattern change is coming into Feb.

But for who ? We are seeing Global pattern changes for NH now are we not.

Posting a T340 chart does what ?

[Iceberg]

The 30hpa can be pretty accurately modelled out to 15 days as it isn't very fluid in the same way that ssts can be also the forecasts have been very consistent

(null)

[phil n.warks.]

robthefool, on 15 January 2012 - 13:55 , said:

More of the same, it looks like. Mild looks like winning out and temps into the double figures returning. So it's a pretty good run for those of us who like mild weather

Your post would be much better if you could elaborate Rob.
I mean when is this mild spell and how long do you think it will last?Will it ever get cold again?
How about some links or charts to show us,Thanks.

[Iceberg]

I would add the differences to early in the winter seem to be no more dartboard lows for the uk instead slack filling lps, no great temp differences in the cold and warm sectors etc as well the mixing of the pf jet and pm jjet is not happening
Sorry done on phone

(null)

[SP1986]

The move away (by the models) from an easterly source was fairly well engrained in the oscillation, long before this morning. The NAO/AO both moved to neutral (if not slightly above).. I think the Atlantic/Arctic oscillations are a very valuable broad signal tool to have. In terms of the oscillations, NAO is largely forecast positive for the forecastable future, and for the AO well there are more negative AO ensemble members but the majority are in very close agreement on a neutral-positive solution currently.

I think this sums up the models very well, and judging by the AO, it's wise to know that the modelling of a continental regime, isn't necessarily yet over.

[Frosty039]

phil n.warks., on 15 January 2012 - 13:58 , said:

Your post would be much better if you could elaborate Rob. I mean when is this mild spell and how long do you think it will last?Will it ever get cold again? How about some links or charts to show us,Thanks.

Since we have a lull before the 12z rolls out, here is the milder midweek interlude, temps thereafter drop slightly but then recover to 8-9c in the south next satuday, hopefully that won't happen and we will get a colder spell starting on thursday and then intensifying.

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[keithlucky]

Frosty039, on 15 January 2012 - 14:28 , said:

Since we have a lull before the 12z rolls out, here is the milder midweek interlude, temps thereafter drop slightly but then recover to 8-9c in the south next satuday, hopefully that won't happen and we will get a colder spell starting on thursday and then intensifying.

Look how do you forecast 8-9 c in the south when snow is forecast for west UK you are not looking at what the met are saying?

[Frosty039]

keithlucky, on 15 January 2012 - 14:34 , said:

Look how do you forecast 8-9 c in the south when snow is forecast for west UK you are not looking at what the met are saying?

If you had read what I posted properly, you would have noticed I was talking about what the 6z shows next saturday for southern britain.

[i'm dreaming of...]

phil n.warks., on 15 January 2012 - 13:58 , said:

Your post would be much better if you could elaborate Rob.
I mean when is this mild spell and how long do you think it will last?Will it ever get cold again?
How about some links or charts to show us,Thanks.

I will post something for Rob. These are the 2m temps in Somerset:

http://cdn.nwstatic....t2mSomerset.png

As you can see they go out to the end of the month. They rarely drop below zero and despite the Op run being a cool outlier for the last half of the run the mean is consistent around 4-6c. Not the extreme end of mild but slightly above average. No graphs for Feb yet but the latest Met 30 day forecast suggests average to above average during early Feb (upto 13th); the latter isn't scientific but it makes the point. Around 33% of the max 2m temp's days were double figures according to the 0z run on GFS.

So although not mild throughout; as you would expect some cooler interludes, but we get the jist of the perfunctory statement by Rob, that there is very little cold weather for the majority of the UK and it is hard to say when it will end as models don't go out any further than where the mildish weather still predominates.

[dixonoid]

Frosty039, on 15 January 2012 - 14:28 , said:

Since we have a lull before the 12z rolls out, here is the milder midweek interlude, temps thereafter drop slightly but then recover to 8-9c in the south next satuday, hopefully that won't happen and we will get a colder spell starting on thursday and then intensifying.

Going by the GFS, the above may be right.

But looking at the ECM and UKMO, maybe, not so mild, struggling to maybe 2-3c during the day on saturday.

[kold weather]

New thread here:

http://forum.netweat...hread-15th-jan/

This will be closed very soon.