Spring Model Discussion 18Z 9/3/13 onwards....

[nick sussex]

The GFS 06 hrs run looks more like the UKMO with the low further north but even here you can see that its not clear cut because the block is still likely to cause some disruption to the low.

In terms of any undercut this won't happen until that parcel of energy has cleared west and the models still don't agree on that part of the set up.

[Derecho]

06Z unsurprisingly goes back towards something milder, the 06z always seems to be the most bullish to do that though...

I'm not sure whether to dismiss the 00z though as although it was a cold outlier 1 or 2 other runs supported it. The GFS was the first to pick up on the blast of cold at the start of the week because it modelled the placement of the arctic high correctly (i.e further south something which the 00z showed).

Such fine margins with this as the arctic high is difficult to model, I wouldn't be surprised to see the same synoptics occur on the 12z although it's the less likely option at this stage. If the 00z came off we could even beat 1962 in terms of cold.

Even the 06z run looks at risk of bringing in cold in it's latter stages as the trough gets disrupted, it cant really go anywhere...

While I would also like to see some warmth I am more inclined to sit back for a while. Even though we basked in warmth during the second half of last March last year the months that followed provided some of the most miserable weather going here. If we are going to have a delayed start to Spring but the Northern blocking eases when it really counts (mid Spring onwards) then I will be more then happy.

Edited March 16, 2013 by Quicksilver1989

[Matty M]

ECM EPS back away from the prolonged cold scenarios on last nights EPS, disappointing we didnt get further south with that momentum.

[mcweather]

The 850 mean is average, i should have mentioned what average i was talking about.

The op run has very little support.

I wouldn't be that worried about the op run not having much support.

The recent spell of sub minus ten uppers was actually first picked up by a lone GFS operational outlier.

[UV-RAY]

Equally the cold could be pushed further north on subsequent runs, which I and many others are hoping for, it's still not completely clear at this stage.

Plenty of time for warmth, we don't want any warmth showing it's hand early, one only needs to look back at the last few years where early spring warmth was followed by one abysmal summer after another. Cracking output for those of us in the North next week, someone, somewhere will see some significant falls of snow during the course of next week. Thereafter I expect too see less cold but unsettled weather for the foreseeable.

[reef]

06Z unsurprisingly goes back towards something milder, the 06z always seems to be the most bullish to do that though...

I'm not sure whether to dismiss the 00z though as although it was a cold outlier 1 or 2 other runs supported it. The GFS was the first to pick up on the blast of cold at the start of the week because it modelled the placement of the arctic high correctly (i.e further south something which the 00z showed).

Such fine margins with this as the arctic high is difficult to model, I wouldn't be surprised to see the same synoptics occur on the 12z although it's the less likely option at this stage. If the 00z came off we could even beat 1962 in terms of cold.

Even the 06z run looks at risk of bringing in cold in it's latter stages as the trough gets disrupted, it cant really go anywhere...

While I would also like to see some warmth I am more inclined to sit back for a while. Even though we basked in warmth during the second half of last March last year the months that followed provided some of the most miserable weather going here. If we are going to have a delayed start to Spring but the Northern blocking eases when it really counts (mid Spring onwards) then I will be more then happy.

This run actually looks like FI is going to be pretty cold again with 2-3C Maximum temperatures across the majority of the UK:

http://www.wetterzentrale.de/pics/Rtavn18017.png

sub -10C 850hPa making inroads from the east again as the trough flattens:

http://www.wetterzentrale.de/pics/Rtavn1922.png

I honestly wouldnt look beyond Thursday though, theres considerable disagreement between models and indeed individual runs on what the mid-Atlantic low will do. If it remains firm we'll get a milder shot from the south, if it flattens as the GFS has shown on the 00z and 06z then we'll get another significant cold spell. Ironically though the weather on the ground might be sunnier and drier with the latter option though.

[mushymanrob]

Nearly spat my tea all over my computer screen as I saw those charts this morning!

Seems ECM has led the charge with this output, with other models now falling into line. Still plenty of time for it to go horribly wrong (margin for error with regards to the north/south position of the low) of course, but plenty to be optimistic about when looking at the output today

actuall the ecm is now alone as the gfs 06z has reverted to its miler option in the near future. only now in fi is it cold, and yesterday it was very warm! lol. the ukmo, ensembles and gfs are suggesting mild later in the week. of course things are very finely balanced and nothing is certain.]

[mcweather]

It is worth noting from the ecm and and UKMO that the real milder push suggested for next week is beyond 144 at present and is therefore in FI by no means set in stone. Even the meto in their further outlook only say that milder weather will probably push northwards. A little trough disruption and we could be looking at a very different scenario especially with so much bitterly cold air not far from our shores.

To my mind the outlook is from done and dusted.

Interesting that my hunch from thursday evening seems to be coming to fruition.

Indeed although it is beyond 144 and just for fun the GFS 06 is even toying with a Feb 78 scenario around 170hrs

There is no doubting that the trend in the models over the last couple of days has been to firstly delay any milder push and keep pushing it back and also to bring the possible snow line back southwards across the UK. Any further correction in that direction and even I might be in line for a late dose of the white stuff!!

Things are very finely balanced at the moment and the models are struggling to choose a winner between the very cold pool and blocking to our northeast and the westerly influence with a relatively week jet.

Edited March 16, 2013 by mcweather

[legritter]

Iv just lost a whole post so will keep this short ,brilliant charts bring it on ,lets enjoy .looks like there will be some very interesting modell times coming up .ECM looking especially tasty ,i think GFS will have very big swings over coming days ,lets hope the battle ground if we get one is nice and wide ,and for those who think its getting too late ,get the right synoptics and it can be game on even for lowland UK ,catch up later gang

[Methuselah]

actuall the ecm is now alone as the gfs 06z has reverted to its miler option in the near future. only now in fi is it cold, and yesterday it was very warm! lol. the ukmo, ensembles and gfs are suggesting mild later in the week. of course things are very finely balanced and nothing is certain.]

And, as we all ought to know by now (after all the recent 'near misses'), none of the more extreme solutions is ever likely to verify...Whilst we'll almost certainly not be basking in a sunny 22C, for a while yet, neither can we expect a 15-day-long stretch of unremitting snowy ice-days...

Whether it be hot or cold, dry or wet, FI is still FI...

[TEITS]

If the temp is 6c and the average for mid march is 10± then that's 4c or more below average. Depending on where you live as this will affect the average. That is significant and I've known it snow at 6c during heavy showers in march and April.

Funny you say this because I was just about to comment on this.

Looking at some of the GFS charts that suggest a sunshine and snow showers scenario I wouldn't read too much into the predicted max temps. The temps predicted of 6C would only be reached under spells of sunshine but would drop several degrees during a heavy snow shower. Once the shower has cleared the temps would rise back to 6C. This is very typical of the time of year and can think of this occurring many times in the past.

Back to the output and it looks as though I was wrong yesterday because the models are suggesting it will turn colder even for S areas. I still believe however that timing could be a factor and wouldn't rule out snowfalls for S areas during the overnight period. However its very difficult working out where any precip will be at the moment for next week. Could become even more exciting next weekend though!

Just echo what others have said that this winter has been fasinating and draining at the same time. Apart from Xmas the models have always hinted at some interesting cold weather synoptics. I feel absolutely worn out!

[mcweather]

Just for fun this mornings GEM for next sunday. There are still plenty of options on the table in the current set-up.

Don't forget that the northern blocking is not competing with a roaring jet at the moment.

[Frosty.]

The gfs 6z shows a battle, the mild seems to win and then it loses big time with the cold air flooding back within a few days, and the far north continues very cold and wintry throughout. This type of run should have been expected after such a huge cold outlier before it, I still think the ecm 00z will be closer to the truth but with lots of time for north/south adjustment. Some parts of the uk will have blizzards next week, I think that is pretty clear but others will have torrential rain, it's judging where the boundary of the airmasses which will cause the headaches with a steep temperature gradient somewhere across southern britain, northern britain should become locked in the very cold air for much if not all of next week.

[Frosty.]

Equally the cold could be pushed further north on subsequent runs, which I and many others are hoping for, it's still not completely clear at this stage.

and it did on the 6z before the arctic ice gates blew wide open, the 6z was a crazy run but these are crazy times with eye candy charts within the reliable timeframe, really stunning weather for weather fans to wallow in.

Edited March 16, 2013 by Frosty039

[BLAST FROM THE PAST]

Just to put some reality in here this morning the GFS ensembles remain bullish about a warm up from the 22nd with GFS a cold outlier in FI

Just to put some reality back in Gav, you've been hankering for the warm up and HP building from the south for months [it will come hang in there!!], the reality is it hasn't happened despite ensembles showing that on many occasions?

JMA, that could get interesting. The slider follows but will the LP make more inroads?

BFTP

[Frosty.]

And, as we all ought to know by now (after all the recent 'near misses'), none of the more extreme solutions is ever likely to verify...Whilst we'll almost certainly not be basking in a sunny 22C, for a while yet, neither can we expect a 15-day-long stretch of unremitting snowy ice-days...

Whether it be hot or cold, dry or wet, FI is still FI...

Around this time last year the weather was very warm and very dry and some of us were thinking this would mean a long hot summer, how wrong we were, but this year is chalk and cheese with incredible northern blocking and wintry synoptics galore even in mid to late march, it's EPIC, we have a colder arctic than normal, the north sea is a few degrees colder than average, cold fans really need to lap this up and the payoff could be a warmer and drier summer compared to last year.

[The PIT]

No sign of Spring as yet GFS twitches but doesn't deliver so it looks like the below average spell will continue. Complete contrast to last year one thing that I'm watching is the constantly sotherly tracks of low pressure. Hopefully this will change for summe rif it doesn't another wash out.

[Iceni]

Around this time last year the weather was very warm and very dry and some of us were thinking this would mean a long hot summer, how wrong we were, but this year is chalk and cheese with incredible northern blocking and wintry synoptics galore even in mid to late march, it's EPIC, we have a colder arctic than normal, the north sea is a few degrees colder than average, cold fans really need to lap this up and the payoff could be a warmer and drier summer compared to last year.

I'm just glad this cold and wet has come before the blossom's come out. Last year we didn't get a single apple or pear as the bees were on strike. Maybe once it warms up, it will stay that way and we'll be making some more cider.

[Frosty.]

I'm just glad this cold and wet has come before the blossom's come out. Last year we didn't get a single apple or pear as the bees were on strike. Maybe once it warms up, it will stay that way and we'll be making some more cider.

Agreed, after the disappointments of the winter, and there were plenty of those, this is a bonus for cold fans, the current synoptics for next week put most of the winter to shame which is an achievement in itself, once the warm up arrives, it will hopefully not be a false dawn like last year turned out to be. The current models are sensational with cold across scandinavia in particular which is freakish for so late in the season.

[Earth Wind and Snow]

What a difference a year makes

projected conditions 12 months later as per ECM with snow risk in many areas

Hopefully a decent summer to follow this year......................

EWS

[Frosty.]

What a difference a year makes

projected conditions 12 months later as per ECM with snow risk in many areas

Hopefully a decent summer to follow this year......................

EWS

Yeah I was making that point earlier, if only the weather obeyed that logic but of couse it will do what it wants. In the meantime, this spring so far has been choc full of wintry surprises thanks to the lag effect of the strat warming episodes. Northern britain does look like being plunged back into deep mid winter type synoptics and there is still enough time for the whole of the uk to have another snowy and frosty spell.

[Summer Sun]

06z ensembles follow on from the 00z

Even the Aberdeen ensemble gets milder on this run given time

[SP1986]

If you are disappointed by the lack of cold this winter, it's probably time you moved. In my eyes, this winter has been consistently cold, often with synoptics delivering air from a northerly/easterly quadrant. There has been a significant lack of western influence, compared to normal. I think people are mistaking a mild winter for one without extremes. However... this Spring is definitely, thus far, giving winter a run for it's money, but that would not be difficult given this is one of the potentially coldest starts to Spring in recent times. The extent of northern blocking at the moment and forecast, is very impressive when looking from a synoptic point of view.

[damianslaw]

ECM in particular showing a very wintry outlook next week especially for the northern half of the country, with a very southerly tracking jet and major robust northern blocking - 1060mb heights over the arctic/svalbard region difficult to shift at any time of year - more so during spring when the atlantic is traditionally at its quietest, so perhaps no surprise to see the synoptics on current offer.

GFS also indicating the euro trough will dig deep into Europe with strong ridging of northern heights SW into the north mid atlantic - its a classic locked in cold pattern.

Scandanavia and NW Russia is having a very very cold start to spring, with sub-freezing conditions prevailing, thus there is a significant cold pool of air to tap into from the NE - which in many winters at this stage in the season hasn't always been the case, the blocking to the NE in mid-late feb has certainly helped to generate a very cold pool of air, indeed winter 12/13 in NE Europe has been a cold one, with minimal atlantic influence and a very cold early start to the season with rapid snow cover build up as early as late October.

Recent Marches have been very tame benign affairs, with shortlived polar blasts or weak easterlies at best and I would put March 08 in this category albeit we did see a potent arctic blast at easter but it didn't last long. March 06 was the last 'interesting' month synoptic wise in my opinion with northern blocking and airstreams from between north and east with cold cyclonic conditions overhead.

BBC were quite bullish mid week saying it would be getting colder next week, however, in the last 2 days they have refrained from saying this, expect them to start saying it again very soon, forecast max for Edinburgh on Tuesday is 1 degree with snow...

[No Balls Like Snow Balls]

Funny you say this because I was just about to comment on this.

Looking at some of the GFS charts that suggest a sunshine and snow showers scenario I wouldn't read too much into the predicted max temps. The temps predicted of 6C would only be reached under spells of sunshine but would drop several degrees during a heavy snow shower. Once the shower has cleared the temps would rise back to 6C. This is very typical of the time of year and can think of this occurring many times in the past.

Back to the output and it looks as though I was wrong yesterday because the models are suggesting it will turn colder even for S areas. I still believe however that timing could be a factor and wouldn't rule out snowfalls for S areas during the overnight period. However its very difficult working out where any precip will be at the moment for next week. Could become even more exciting next weekend though!

Just echo what others have said that this winter has been fasinating and draining at the same time. Apart from Xmas the models have always hinted at some interesting cold weather synoptics. I feel absolutely worn out!

Personally I don't see the point in any snow that isn't going to settle. And in that scenario you mention there is no way it would settle on ground already heated by the sun before the showers arrival. And if by a miracle it did settle, temps going back up to 6c and the strength of the sun this time of year are going to melt any accumulations before you have had time to blink.