Model output discussion 8th Feb - Cold for now, but then what?

[jvenge]

2 hours ago, A Frayed Knot said:

And ? Explain for us Newbies what this show ' why a post with a dubious face and a Chart not explaining at all what it means ... Confuses me and many others in here . all i see is temprature dropping ? am i right

It shows the temperature anomalies, as compared to what normal is, for the time of year. The day range tells you for when it is applicable to. The temperature gradient tells you by how much.

Showing slightly milder than normal. Means over multiple days don't always tell the story, though.

Can't comment on his emoticon, but Knocker doesn't chase cold run to run, so may be more suspect about what others see at the range on offer.

[geordiekev]

3 hours ago, A Frayed Knot said:

And ? Explain for us Newbies what this show ' why a post with a dubious face and a Chart not explaining at all what it means ... Confuses me and many others in here . all i see is temprature dropping ? am i right

I think it's the mean of average possible anomalies based against Decades of weather taken over nearly a week's worth of possible outcome In 12 days time.  Basically it will blank out any days of interest. Very diffuse if you ask me

Edited March 2, 2017 by geordiekev

[jvenge]

Good Morning to all :-) Earlier than usual start for me. So, the GFS 0Z.

An area of interest for those on the east/north east coast on Tuesday to Wednesday. Nothing special showing, but slight upgrades in the nearer term could make it something of interest to coldies. 

After that, though, near normal temps, if not slightly above, for the next 10 days or so.

Slightly wetter than usual period coming up for parts of the UK over the next 10 days. Nothing special, of course, although those on the north west coast of Scotland might be feeling a little soggy.

Any meaningful shift to cold is still well out into FI.

 

Edited March 2, 2017 by jvenge

[knocker]

The next depression will join the party tomorrow and a complex area of low pressure will remain in situ over the UK for the weekend so continuing unsettled for all albeit not particularly cold. By Tuesday 00z the upper low has moved away SE allowing the Azores to ridge NE which is the start of a power play between the latter and energy in the Atlantic pushing east. This is well illustrated later in the day as fronts, associated with the deep low south of Iceland, traverse the UK but mainly effecting the north.

From here to T240 the high pressure tends to win the battle with only occasional forays from the Atlantic breaking through and then once again mainly effecting the north, So in a nutshell the unsettled weather giving way to more settled in the south with temps trending above average.

Apparently my posting a single temp anomaly chart last night caused confusion for some. For this I apologies as it's not normally a habit I indulge in but it was merely an attempt to once again highlight that it's very unwise to get carried away over the output, especially in the nether regions, from one run, if support isn't forthcoming from elsewhere. Particularly in the current quite fluent pattern which the anomalies are having trouble pinning down. So what I have posted above equally has to treated with some caution as the run progresses.

Ans just a final snippet. The GEFS mean anomaly this morning is showing no great inclination to rush to cold although it is still playing lip service to the Atlantic ridge/trough to the east scenario by day 15. The would still appear the percentage taking last nights EPS into consideration as well.

Edited March 2, 2017 by knocker

[jvenge]

The control run shows quite well what coldies will be wanting to see from day 10 onwards. Of course, it isn't yet a majority solution and one should be taking account the uppers and time of year into account when looking, as even if it comes off it may well just be cold for the time of year, but not a snow fest, but it will be of interest and to some newbies out there it shows quite well why some more experienced members are excited. It also shows they like to be repeatedly disappointed as well ;-) It's a long shot.

[Frosty.]

36 minutes ago, knocker said:

The next depression will join the party tomorrow and a complex area of low pressure will remain in situ over the UK for the weekend so continuing unsettled for all albeit not particularly cold. By Tuesday 00z the upper low has moved away SE allowing the Azores to ridge NE which is the start of a power play between the latter and energy in the Atlantic pushing east. This is well illustrated later in the day as fronts, associated with the deep low south of Iceland, traverse the UK but mainly effecting the north.

From here to T240 the high pressure tends to win the battle with only occasional forays from the Atlantic breaking through and then once again mainly effecting the north, So in a nutshell the unsettled weather giving way to more settled in the south with temps trending above average.

Apparently my posting a single temp anomaly chart last night caused confusion for some. For this I apologies as it's not normally a habit I indulge in but it was merely an attempt to once again highlight that it's very unwise to get carried away over the output, especially in the nether regions, from one run, if support isn't forthcoming from elsewhere. Particularly in the current quite fluent pattern which the anomalies are having trouble pinning down. So what I have posted above equally has to treated with some caution as the run progresses.

Ans just a final snippet. The GEFS mean anomaly this morning is showing no great inclination to rush to cold although it is still playing lip service to the Atlantic ridge/trough to the east scenario by day 15. The would still appear the percentage taking last nights EPS into consideration as well.

Great post knocker, thanks for clearing up that confusion. :- )

[mb018538]

Runs are a bit 'meh' this morning, with no really clear signal about whether high or low pressure will win out.

http://www.theweatheroutlook.com/twodata/chart.aspx?chart=/charts/gefs/gefsens850London0.png

Even at day 7 there is a big ensemble spread between pretty mild and pretty chilly, and thereafter all sorts of outcomes. The ensembles do look a teeny bit wetter than they did a couple of days ago, so perhaps a few more runs have low pressure driven weather, but this is far from certain. Potential still there for a mild couple of days towards the mid/latter half of next week.

[knocker]

Up to around T156 the ecm is very similar to the gfs but from there on quite a significant difference. Or at least an attempt. It once again attempts some blocking via Greenland, and thus introduce some very cold air around the top and then south east over the UK. It did this yesterday evening and initiated severe palpitations with many. This morning the blocking is not quite so effective and the very cold air slides away to the north before it's back in gfs mode by T240.

.....

 

Edited March 2, 2017 by knocker

[knocker]

The EPS is sticking with the Azores becoming more influential theme. Can't stop, off to update Sidney whilst we have a weather window.

 

Edited March 2, 2017 by knocker

[Summer Sun]

ECM and it's ENS try to bring in some milder air by mid next week

UKMO says no

[Frosty.]

2 minutes ago, knocker said:

The EPS is sticking with the Azores becoming more influential theme. Can't stop, off to update Sidney whilst we have a weather window.

 

I don't mind the azores high coming more into play now as it would bring some early spring warmth..bring it on!

 

[knocker]

1 minute ago, Frosty. said:

I don't mind the Azores high coming more into play now as it would bring some early spring warmth..bring it on!

 

I meant to add in the later period the EPS is still looking at ridging to the west and the trough to the east and thus temps below average

[Frosty.]

3 minutes ago, knocker said:

I meant to add in the later period the EPS is still looking at ridging to the west and the trough to the east and thus temps below average

At least the milder phase (Tm air mass) has more chance of verifying as its closer so some pleasant early spring conditions could be on the way, at least for a time.

Edited March 2, 2017 by Frosty.

[Singularity]

 

12z versus 00z for midnight on Tuesday. This does not inspire much confidence in the model output. The trough configuration has changed substantially and so has the HP over Scandinavia by way of response. Some kudos to ECM for sniffing at this idea over the last few days, but it's still been very inconsistent so not many marks gained.

 

Longer-term there is uncertainty over how the stratospheric vortex behaves - how displaced it will be and to what location?

It is noteworthy how resilient it looks to be in the face of so many waves of warming. These are wave-1 attacks which only manage to push the vortex around - so we're not at all on a par with 2016 or 2013 in terms of an early destruction or severe disruption of the stratospheric polar vortex.

While the seasonal relaxation of westerlies should encourage an increasingly extensive blocking response as March progresses, the lack of consistent signals for where the stratospheric ridge and vortex will locate means the UK looks equally likely to find itself on either the warm or cold side of blocking features, or stuck under slow moving lows with variable temperatures.

Another factor to consider is the more ocean-like state of the Arctic than usual this year, with the climatological inversion struggling to establish for very long at a time, allow for frequent bouts of rising motion fueling intense storm systems which have been tending to shove blocking features more toward the mid-latitudes than would otherwise be the case. The optimist in me sees this as increasing the chances of scoring a mid-lat block near or over the UK... but you just know that would position such as to bring a cloudy flow off the N. Sea 

[Frosty.]

As I said yesterday, now it's spring I'm looking for very mild spring-like as well as cold and snow so it's win win for me and judging by the latest models there is mild weather on the way but possibly followed by something colder. 

[mb018538]

I agree Frosty, there aren't really any massive signals pointing to anything very cold developing - which is what we would now need, as it is now going to be at least mid month before anything (if anything) materialises at all.

Let's just forget about winter, and get on our other big model binge - heat and thunderstorms! At least these tend to deliver way more than cold and snow, so we've got a much better chance of being happy!

[weirpig]

Im Going to whisper it  but snow potential on the Aperge for Friday across midlands north,  However other models say no.

Edited March 2, 2017 by weirpig

[karyo]

15 minutes ago, mb018538 said:

I agree Frosty, there aren't really any massive signals pointing to anything very cold developing - which is what we would now need, as it is now going to be at least mid month before anything (if anything) materialises at all.

Let's just forget about winter, and get on our other big model binge - heat and thunderstorms! At least these tend to deliver way more than cold and snow, so we've got a much better chance of being happy!

I had heavy snow twice this week (more than the entire winter) and this happened with no particularly cold uppers. So for me the chase for snow is still fruitful in March and besides I hate heat!

The charts seem to be offering a variety of weather types through March so a bit for everybody 

[mb018538]

Yes, we may well still get some PM shots delivering some bands of snow and snow showers at times....but anything above average is looking hard to get. It does appear some rough agreement is emerging on things staying cool and unsettled, before a few drier and warmer days towards the end of next week, followed by some more colder unsettled weather returns.

[jvenge]

Where did everyone run off to? :-) If the 06z was showing what it is now, say a month ago, this place would be rather lively now.

Showing cold in the Day 10 to Day 15 range, so of course completely unreliable, but for some it can deliver the white stuff. It's just disappointing with the time of year, as we really work against the clock now. Still, you can't ask for much better.

Edited March 2, 2017 by jvenge

[Frosty.]

The Gfs 6z shows the azores high ridging in later next week with tropical maritime air feeding in around it into the uk with temps into the low to mid teens celsius for a time, perhaps low 60's F for favoured spots with some warm sunshine. 

Edited March 2, 2017 by Frosty.

[snowray]

And then from D10, as is usual, a general agreement to things cooling down a fair bit.

 

London and Manchester there.

[Frosty.]

3 minutes ago, snowray said:

And then from D10, as is usual, a general agreement to things cooling down a fair bit.

 

London and Manchester there.

Subject to the usual downgrades nearer the time

[Frosty.]

The GEFS 6z mean shows mild air gradually feeding around the top of the azores ridge later next week so some pleasantly mild days and feeling warm in any sunshine but relatively cooler and generally more unsettled across the n / nw of the uk.

Edited March 2, 2017 by Frosty.

[jvenge]

I counted 3 GEFS showing -12 uppers for the UK out into FI. Quite a few more showing -8 (which I suspect isn't good enough).

It's a good suite, if you are still on the hunt for cold. Luckily, it is also very attractive for us Spring hunters in other parts of the World.