Model Output Discussion - 15th April Onwards

[damianslaw]

No change for the foreseeable future - beginning to sound like a broken record, the weather is firmly stuck in a bit of a rut i.e. an unsettled and very cool one for the time of year.

An unusually deep area of low pressure will push weather fronts down from the north tomorrow and Monday with very unstable cold arctic air following supressing temperatures and bringing very showery conditions by Tuesday and into Wednesday.

All models suggest the trough will languish across the country for much of the week with a further low pressure cell developing later in the week - this one a much less robust affair not great news as it probably means it will become very slow moving with longer pulses of rain or showers and a cold NE wind to boot.

This is turning into a very poor May indeed...

[Snowy Easterly]

Have to laugh at the greenland High showing on the GFS in FI, i bet it don't downgrade either and this cool rubbish carries on, whilst other countries in europe bask in a heatwave same old same old

[Alex]

Anyone fancy trying to force that stubborn high away from Greenland? Yes this is a bit of a rant but I'm sick to my back teeth of this stupid Greenland high during a month which should at least have some decent days of warm sunny weather. I am so depressed right now of this awful weather, what seems to be causing this Greenland high to occur? Is it the low sunspot activity, melting of sea ice or something? Because if this becomes the norm then it'll be goodbye to alot of wildlife as they will not cope with a poor cool spring and summer. Sorry rant over , please can anyone cheer me up with a pattern change even average seems good right now!

[johnholmes]

There are considerable differences between the 3 500mb anomaly charts over the last 3 days and as a result considerable uncertainty about what the upper air pattern is going to be in 7-10 days time. Just where the long term trough over the UK is going to end up will be the crux but at the moment its not easy to decide just where it will be in that time scale. So expect changes for several days on the synoptic models.

[claret047]

Hello Alex,

As someone who lives the other side of the town (soon to be city!) I am a little suprised about your comments in view of the weather that we experienced yesterday. I thought iit was very pleasant and T shirt weather working on the allotment which because of the recent monsoon conditions had developed into almost a jungle with grass and weeds very nearly waist high.

Up until yesterday the weather as you so rightly say had been dire but today in this neck of the woods looks as if it might be even better than yesterday with unbroken sunshine at least in the morning.

The rest of the week does not look as settled with heavy showers at times or longer periods of rain interspersed with some drier/brighter intervals. Temperatures a bit below average with a chance of overnight frosts should skies clear in rural areas. Luckily because of the wet weather I am behind with my planting schedule and I do not have any tender plants to worry about!.

I was very suprised in view of the amount of rain that has fallen over the last month or so how dry the soil on the allotment was. It was not sodden as I imagined it would be but quite friable.

I am not very good at reading the charts although I am gradually learning but next weekend does not look too good to me. Is my analysis correct?

Kind Regards

Dave

[Polar Maritime]

Hello Alex,

As someone who lives the other side of the town (soon to be city!) I am a little suprised about your comments in view of the weather that we experienced yesterday. I thought iit was very pleasant and T shirt weather working on the allotment which because of the recent monsoon conditions had developed into almost a jungle with grass and weeds very nearly waist high.

Up until yesterday the weather as you so rightly say had been dire but today in this neck of the woods looks as if it might be even better than yesterday with unbroken sunshine at least in the morning.

The rest of the week does not look as settled with heavy showers at times or longer periods of rain interspersed with some drier/brighter intervals. Temperatures a bit below average with a chance of overnight frosts should skies clear in rural areas. Luckily because of the wet weather I am behind with my planting schedule and I do not have any tender plants to worry about!.

I was very suprised in view of the amount of rain that has fallen over the last month or so how dry the soil on the allotment was. It was not sodden as I imagined it would be but quite friable.

I am not very good at reading the charts although I am gradually learning but next weekend does not look too good to me. Is my analysis correct?

Kind Regards

Dave

Correct Dave,

Next weekend is looking much more unsettled, with cool slack Easterly winds and heavy rain for the South of the Midlands as shows by the GFS and ECM.

But with it being 7 days away things could change a little nearer the timeframe. As JH says expect changes for several days on the synoptic models.

Edited May 13, 2012 by Polar Maritime

[Anthonyb]

Hello Alex,

As someone who lives the other side of the town (soon to be city!) I am a little suprised about your comments in view of the weather that we experienced yesterday. I thought iit was very pleasant and T shirt weather working on the allotment which because of the recent monsoon conditions had developed into almost a jungle with grass and weeds very nearly waist high.

Up until yesterday the weather as you so rightly say had been dire but today in this neck of the woods looks as if it might be even better than yesterday with unbroken sunshine at least in the morning.

The rest of the week does not look as settled with heavy showers at times or longer periods of rain interspersed with some drier/brighter intervals. Temperatures a bit below average with a chance of overnight frosts should skies clear in rural areas. Luckily because of the wet weather I am behind with my planting schedule and I do not have any tender plants to worry about!.

I was very suprised in view of the amount of rain that has fallen over the last month or so how dry the soil on the allotment was. It was not sodden as I imagined it would be but quite friable.

I am not very good at reading the charts although I am gradually learning but next weekend does not look too good to me. Is my analysis correct?

Kind Regards

Dave

I don't think he was doubting yesterday was a nice day, but I have to agree with him, one day of t shirt weather in May in my book is pretty appalling.

The charts show a wet weekend next coming up but im sure actually almost certain it could change.

For better or worse

[Robbie Garrett]

Good morning,

CFS for the month of June, pretty much painting a good month. However still uncertain, with the the southerly tracking low's. 14*C first week of June, 15-16*C in 2nd week. 16*C in 3rd week, 16*C in 4th week.. so definately warmer. But most of June looking pretty much wet at the moment, compared to what it was saying a few days ago. I suspect an Atlantic onslaught instead of a northerly regime (due to those temperatures)

July may be quite good, but nothing is certain yet. But the CFS is highlights some sort of change in the medium turn, when is the question.

[P-M]

Good morning,

CFS for the month of June, pretty much painting a good month. However still uncertain, with the the southerly tracking low's. 14*C first week of June, 15-16*C in 2nd week. 16*C in 3rd week, 16*C in 4th week.. so definately warmer. But most of June looking pretty much wet at the moment, compared to what it was saying a few days ago. I suspect an Atlantic onslaught instead of a northerly regime (due to those temperatures)

July may be quite good, but nothing is certain yet. But the CFS is highlights some sort of change in the medium turn, when is the question.

I wouldn't say those temps were "pretty good" Robbie - in the words of Simon Cowell "distinctly average" I for one wouldn't say that was a pretty good month I would say nothing out of the ordinary... OK it may be warmer so suppose it could be some improvement to what is shown currently. I want some proper heat and summer, but as people have stated we will just have to wait a little bit longer for that! Edited May 13, 2012 by Paul-Michael

[Robbie Garrett]

Anyone fancy trying to force that stubborn high away from Greenland? Yes this is a bit of a rant but I'm sick to my back teeth of this stupid Greenland high during a month which should at least have some decent days of warm sunny weather. I am so depressed right now of this awful weather, what seems to be causing this Greenland high to occur? Is it the low sunspot activity, melting of sea ice or something? Because if this becomes the norm then it'll be goodbye to alot of wildlife as they will not cope with a poor cool spring and summer. Sorry rant over , please can anyone cheer me up with a pattern change even average seems good right now!

The cooler/colder weather is not massively below average, and neither are the Summers, and the only two months that stand out since 2007 are January and December 2010. Overall, the years are currently running about 1/2 a degree to +1.2*C above average, so cannot really see a problem yet. But let's see if this Summer is cooler, then we may be onto something.

[sebastiaan1973]

Look at these temperatures!

[mushymanrob]

Look at these temperatures!

...and ignore them! they are a guess, a guide, and are often over cooked.

[mushymanrob]

well theres some hope that at least the temps will increase IF these charts become anything like reality, and the latest model runs do seem to suggest similar synoptic set ups by next weekend. unsettled but warmer..

Edited May 13, 2012 by mushymanrob

[ANYWEATHER]

The cooler/colder weather is not massively below average, and neither are the Summers, and the only two months that stand out since 2007 are January and December 2010. Overall, the years are currently running about 1/2 a degree to +1.2*C above average, so cannot really see a problem yet. But let's see if this Summer is cooler, then we may be onto something.

I think you will find that last summer was also below average temperature wise, ok drier than average is the south wetter than average in the north.Anyway back to the models and it seems increasingly likely that there looks whilst I scanned quickly through the models that the tendency is for the south of the Uk to have the most unsettled conditions whilst the North is more likely to hold on to the best of the weather!!!

[Thundery wintry showers]

The extended UKMO/ECMWF outputs have shifted away from the warmer changeable cyclonic south-westerly type and are instead suggesting chilly north-easterly winds, which at this time of year, with a continental rather than arctic maritime source, would translate to cool cloudy weather in the east, but perhaps dry and sunny in parts of the W and NW. The GFS suggests a rather more cyclonic influence towards next weekend with sunshine and showers, which has some support from the ECMWF ensembles but I would generally believe the UKMO/ECMWF over the GFS in these situations.

This coming week looks set to be cold but also bright, with persistent rain clearing the south on Monday followed by sunshine and showers, and on Tuesday some heavy showers are possible in the east with hail and local thunder but the west will see relatively few showers. Wednesday's ridge of high pressure will most likely give us lengthier sunny spells and fewer showers.

I turned out to be wrong re. convection hitting a cap and spreading into stratocumulus yesterday- as meteorologists we often have to learn by experience, and ultimately the emphasis on cold dry air (especially aloft) prevented that scenario from arising, and I suspect that Wednesday's ridge will be no different, with very little in the way of moist air coming in off the Atlantic.

However despite generally bright weather up until at least Wednesday and possibly into Thursday for many of us, most routes lead to cloudy wet weather by Friday.

[MP-R]

I think you will find that last summer was also below average temperature wise, ok drier than average is the south wetter than average in the north.Anyway back to the models and it seems increasingly likely that there looks whilst I scanned quickly through the models that the tendency is for the south of the Uk to have the most unsettled conditions whilst the North is more likely to hold on to the best of the weather!!!

I think you will find that last summer was also below average temperature wise, ok drier than average is the south wetter than average in the north.Anyway back to the models and it seems increasingly likely that there looks whilst I scanned quickly through the models that the tendency is for the south of the Uk to have the most unsettled conditions whilst the North is more likely to hold on to the best of the weather!!!

Unfortunately so, though I suppose it is nothing unusual for this time of year. A friend of mine from Stirling says that the best weather there often happens in May and the first half of June, possibly due to low pressure sitting over the south of the country with high pressure nearer to Scotland.

I suppose one crumb of comfort shown by the GFS is that it isn't literally a full on Atlantic onslaught. Ridges do appear between each low which takes a different path each time. I'm sure it wouldn't be minded as much if a sunshine and showers scenario sets up rather than a frontal rainfall setup. FI consistently shows signs of the Atlantic weakening with differing evolutions so I think there is something to be taken from that but by no means does that mean warmth or settled conditions yet.

Best make the most of today, those who are settled today.

[AWD]

All models paint a rather cool but mixed week this week. Generally speaking the further South you are the less in the way of rain you will see and the more in the way of sun you will get. Up until Thursday, with the exception of tomorrow being overcast and dull, the south will be rather sunny at times with just occassional showers here and there and Tuesday. The North will see a little more rain though due to being closer to Lower Pressure north of Scotland.

From Thursday the whole of the UK becomes unsettled once more, with a rather wet and breezy weekend in store.

GEM particulary unsettled.

After the weekend it continues generally unsettled into next week for most, with the GFS showing more rain for most of us at some stage, although temps could be up on what they are going to be like this week.

And FI GFS shows a return of the Azores high, with settled and warmer weather moving up from the South.

All in all, not a bad week really for the south until the weekend, although cool, it should still feel pleasent enough in the sun, of which the will be plenty around, except tomorrow. The north often cloudier and showery with snow in higher Scotland. Unsettled next weekend for all of us, the complete opposite to this weekend. Promising signs still as we enter the end of the month with warmer and more settled conditions again shown in FI.

Edited May 13, 2012 by Active Weather Dude

[Summer Sun]

ECM has high pressure build to the north in its latter runs this would bring some settled weather for those in the north whilst the south would be more unsettled

[TonyH]

Regionally selective guide for this week based on latest output:

http://forum.netweather.tv/blog/309/entry-4402-weather-guide-monday-14th-to-sunday-20th-may-west-wales-and-central-midlands-specific/

[bluearmy]

There are considerable differences between the 3 500mb anomaly charts over the last 3 days and as a result considerable uncertainty about what the upper air pattern is going to be in 7-10 days time. Just where the long term trough over the UK is going to end up will be the crux but at the moment its not easy to decide just where it will be in that time scale. So expect changes for several days on the synoptic models.

this is the point people. beyond the trundling shallow depression headed sw/ne across the southern half of the uk late in the week, we have no clue where we go. the op runs beyond day 7 are back and forth, from scandi trough to scandi high, greeny ridge to greeny trough, azores ridge to azores trough. the extended naefs places the troughing firmly in biscay and initially well into europe to our se. it then lifts out slowly allowing a mean soueatserly flow across the uk, though probably too close to the trough to be settled. ecm ens are even more miserable with the troughing into europe looking quite set. however, with the ops having no consistency at the moment, i wouldnt be taking too much notice of the extended ens either.

[johnholmes]

It is true that the 500mb charts are hardly consistent at the moment but I am beginning to wonder IF they may be trying to show some end of the major trough over/slightly west of/slightly east of the UK. I will wait until both outputs, ECMWF-GFS and NOAA are out tomorrow before sticking my neck out but there are certainly signs, IF they continue, of a possible change before month end.

[Thundery wintry showers]

Although the south will be closest to the high pressure, tomorrow is likely to be cloudiest in southern parts of England, at least during the morning, as a cold front slowly clears south-eastwards and brighter showery weather establishes in the northern two-thirds of Britain. CAPE values are moderate, suggesting that hail and local thunder are possible. On Tuesday all parts will have sun and showers with the chance of some snow to relatively low levels in Scotland. I see a SW-NE split arising with south-west England staying mostly dry with plenty of sunshine whereas SE Scotland and NE England may catch some heavy showers with hail and local thunder. On Wednesday a ridge of high pressure will give a drier day with longer sunny periods likely, except in Ireland where it will cloud over with some rain.

Cloudy and wet looks like becoming a fair assessment still by Friday. The UKMO and ECMWF continue to stick to their guns but with more of an easterly type setting up from next weekend onwards, rather than a north-easterly. That pattern would certainly bring unsettled conditions to the southern third of Britain, with frontal rain likely from any southerly tracking lows, and maybe some thundery showers trying to push in from the continent in between fronts. For the northern two-thirds of Britain, it may well end up 'settled', but in that setup we generally end up with a stark contrast between the west (sunny, dry and warm) and the east (grey and drizzly with cold daytime temperatures) thanks to the long airmass track over the North Sea and the shelter to the west of high ground.

[Alex]

It is true that the 500mb charts are hardly consistent at the moment but I am beginning to wonder IF they may be trying to show some end of the major trough over/slightly west of/slightly east of the UK. I will wait until both outputs, ECMWF-GFS and NOAA are out tomorrow before sticking my neck out but there are certainly signs, IF they continue, of a possible change before month end.

I just wonder where the change will come from though.

The MJO is stuck in its central orbit, trying to push into phase 7.

Angular momentum is still low.

Maybe the sudden rise of stratospheric warmth which occurred a few weeks back and has recently flattened may be the driver of a change?

http://ds.data.jma.go.jp/tcc/tcc/products/clisys/STRAT/html_e/pole30_n.html

Looking at the Projected NAO, I worry about the absence of our close friend "the Azores high"

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/nao_index_ensm.shtml

Edited May 13, 2012 by Alex

[Robbie Garrett]

Quite a few southerly tracking lows upcoming according to CFS, not sure what picture it's trying to paint to be fair.

[shedhead]

My take on the latest runs is the 'slowly, slowly catchy monkey' trend continues. Definately no massive swings or pattern changes showing in the current outputs, but the slow, inexorable change towards drier, warmer conditions continues to show up, with the last week of May possibly set to deliver something decent. Much as we heard last Winter (and to be fair we hear every Winter), a bit more patience is still required.

Edited May 14, 2012 by shedhead