Model Output Discussion - 15th March onwards

[BlueHedgehog074]

11 hours ago, lassie23 said:

Any snow on the horizon

You’ll be very pleased to know that the 00Z GFS shows a tiny bit of snow for some of you guys in the South-East on the midnight of Thursday 13th April.

And then a bit more in the Midlands Only 2 weeks away…

[That ECM]

Oh for a couple of months earlier. 

[Cambrian]

A broadly promising trend emerging now for the next couple of weeks.  

Last night’s ECM weather regimes extended forecast shows a strong blocking signal for week 1, tapering off somewhat in week 2, but still a decent signal through to around the 13th. 

  

The mean pressure and heights anomalies for 3-10 April show firmly positive pressure and heights anomalies for the UK and Ireland associated with a Scandinavian ridge. 

The 0z ECM ensemble shows a steep rise in pressure over the next three days, as the heights transfer northeast through the UK and Ireland (day 3 NH charts) on their way to Scandinavia…

  

…with it then easing back, but remaining around 1020mb through to around the 12th or 13th, until it falls away, fitting in with the diminishing blocking signal in the regimes forecast. 

The 0z ensemble mean charts for day 8 and 9, the Easter weekend, are hinting at a southeasterly flow off France. Day 8 here. After a frost for many on the morning of the 3rd, nighttime minima recover to mid single figures, while afternoon highs for the mean break through comfortably into double figures with the op and control suggesting a bit more warmth, 15-17 degrees (for Birmingham shown here) on Easter Sunday itself. 

  

A good way off but the beginning of April could really be a lot worse, and if these indications prove close to the mark, still sporting a pullover maybe, but potentially more than pleasant enough to sneak outside with a good mug of hot tea for some fresh air and to munch on some of my Easter egg before I get discovered and have to share the rest of it. No worries, I have a backup Toblerone hidden away in the back of the fridge. Ah, the simple things in life!

Edited March 31, 2023 by Cambrian

[johnholmes]

1 hour ago, Howie said:

I hope not  

can you pop nearest town in your avatar please; I suspect somewhere in the east from your response

Edited March 31, 2023 by johnholmes
add missing letters!

[Rain All Night]

Most of the models this morning show the "relapse" period from some point on Tuesday to some point on Thursday, before a recovery at the end of the week just in time for the bank holiday...

On the UKMO above, rain reaches most of us by Wednesday night...

GFS has less of a blip and feels safer from the Atlantic overall...

FI still looks good for dryness, but I hope there is not a risk that things will just flatten out after T+144h. I'm hoping the upper level low pressure over the continent to our east means that is not possible.

Edited March 31, 2023 by RainAllNight

[Howie]

17 minutes ago, johnholmes said:

can you pop nearest town in your avatar please; I suspect somewhere in the east from your response

Yes, north London 

[johnholmes]

Just now, Howie said:

Yes, north London 

Thanks Howie

[78/79]

Off to Spain for a week on the 11th, hopefully a bit of sunshine, temps in the mid 20s, and a respite from this soul destroying garbage. 

[damianslaw]

April tomorrow, and the start of what I call the annual atlantic slumber season (lasting through April and May), reawakening in June. Typically we see the atlantic at is quietest in mid-late Spring, northerlies aned easterlies most likely at the same time, cyclonic slow moving patterns and anticyclonic slow moving patterns. What are the models showing, well just this in the main, apart from the temporary atlantic incursion early next week, the longer term prospects suggest high pressure will hold greater influence, but setting up in a position further north and east, north easterlies/easterlies possibly becoming south easterlies order of the day as we enter the Easter period. All quite benign overall with temps colder than slightly milder than average then probably back to average or a bit below, with the west and north west seeing the best of the sunnier drier conditions - as can often be the case in April and May. Nothing unusual at all in the models right now, indeed all very normal service for the time of year.

 

[Sunsetglimmer]

Compared to march, the outlook is a massive improvement 

[summer blizzard]

Models still disagreeing on the outlook beyond mid-week albeit favouring a ridge of some sort. 

(Euro still 0z). 

The differences essentially stem from two connected features. That of a amplified low in the Atlantic (GFS has this negatively tilted) and a high close to north west Russia (that is what pushes the vortex towards Canada/Greenland causing the Atlantic Low). 

[Stuie]

Not sure if someone has posted this or not but if you want `nothing weather`, the GEFS gives it a bash.

Not hot, not cold, not wet... haven`t looked at wind but at least a bit of a drying out period in the South (London).

[CoventryWeather]

GEM is pick of the evening at the moment, with the high slipping east, allowing warm air to spread northwards.

Feel models are starting to show signs of some warmth later next week in to the weekend, which I was thinking would happen early this week. Hope models have more certainty over the coming days and I can get good time outdoors doing photography that I've missed for several weeks now!!

[Summer tyre]

I'm not seeing warmth at all - it looks like while it may be sunny at times those nagging nor-easters will keep the east and southeast feeling unpleasantly cold all week.

[Downburst]

Folks just a quick question. Where is Jon snow? Missed his posts over last couple months.

[Bradowl]

7 hours ago, 78/79 said:

Off to Spain for a week on the 11th, hopefully a bit of sunshine, temps in the mid 20s, and a respite from this soul destroying garbage. 

Just come back from Spain, Costa Del Sol and weather was very good, higher than average temperatures, 29'c last weekend with wall to wall sunshine most days. 

The month of March as been second warmest and driest in last 60 years. Complete contrast to when I went last March and it was cold and wet. 

Edited March 31, 2023 by Bradowl

[Metwatch]

Very nice ending there on the GEM, with an April 2020 style setup. It's not an extreme outlier either looking at the suite so it does give me some hope.

We'll have to see how the synoptics play out, but with the high pressure coming back for April, chance for something much warmer is there.

Edited March 31, 2023 by Metwatch

[Stuie]

Some may say I have been bashing the ECM but this model is broken, has been for months. Await the 12z but the 0z again shows a big outlier.

[stodge]

Evening all

GEM does sit a little on its own this evening with the ridging coming from the south. Much of the other output builds heights over southern Scandinavia - it’s not a classic winter “Scandy High” by any means but the lack of zonal wind and a moribund Atlantic enables a broad build of heights to the east.

For the British Isles, it will be best in the north and west with warmth and sunshine and it’s hardly going to be winter further south and east but the fact is the cooler North Sea would promote duller, cooler conditions.

If we can get a more SE’ly tilt that would bring widespread warmth but raise the chances of rain or showers to the south and west.

Nothing unusual, it has to be said, for April.

 

 

[Kentspur]

9 hours ago, 78/79 said:

Off to Spain for a week on the 11th, hopefully a bit of sunshine, temps in the mid 20s, and a respite from this soul destroying garbage. 

I'm also off to the Canaries a week after you I see they've just had record high March temps as well as a lot of other areas seeing 30c in France was crazy!!

[IDO]

At last a lull in the storm with all models focusing in on a dry settled spell out to around D9. Post-D10 on GFS gives us a mid-April easterly, which is a low-chance option (D8-16):

The GFS is an extreme case according to the mean (London 850s):

We see the ECM op, GFS mean and GEM op below at D9:

Variations on a theme.

Post D9 looks to have low confidence at the moment from a quick look at the GEFS panel. The tPV is possibly in its final warming so HP creeping further north in the NH.

[BlueHedgehog074]

In the particular arrangement above, the 00Z ECMWF, GFS, UKMO and GEM in some general form build High Pressure North-Eastwards through the UK extending East into the high heights over Scandinavia. It results in the above scenarios from all 4 of them at 144 hours. 

ECMWF and GFS look the most rebust looking with the ribbon of high heights and High Pressure over the UK and into Scandinavia. But even with the likes of the GEM, for example, having part of the Scandinavian High Pressure cell concentrated a little bit further South over the UK area, all the models would provide the chance of some drier and at times, brighter, weather. (Would have to watch out High Pressure not migrating too far North pulling in a cloudy flow from the North-East for Eastern areas, otherwise a good possibility that Spring will be back in action!).

You can even see that High Pressure builds over the UK through this weekend (using GFS as an idea below), especially through Sunday. And then through the start of next week, a chance their could be a Splatoon match show-down between High Pressure stretching its way towards Scandinavia through the UK/South UK and the Atlantic trough trying to push in from the West:

 

While this could have implications how in control High Pressure could be over the UK, it looks overall that the weather should settle down quite a bit next week. Especially for Southern areas (Edit: at least probably for first few days next week depending on the influence of Atlantic Low). Hopefully not some kind of April fools days joke.

Edited April 1, 2023 by DiagonalRedLine

[IDO]

^^^ Accumulated precip IMBY (London) looks great after today until around D9 based on GFS op:

 

[ANYWEATHER]

Well at least a half hearted attempt to settle things down for a while, although even next week is not plain sailing. Gfs is all over the place by day ten, whilst ecm brings the Atlantic back in.....

[mushymanrob]

High pressure to our near North throughout this timeframe, covering Easter and beyond. There are hints that a ridge to our East off the main block might develop. This can be seen on the EPS.. but if this happens then it might become warmer after Easter? in a Southeasterly..