Model Output Discussion 12z 03/04/13

[Summer Sun]

Monday sees the uppers rising so a recovery of temperatures once more

 

[Milhouse]

T+168 has westerly winds affecting the UK and a noticeable area of warm uppers heading towards the UK.

 

[Summer Sun]

Into next week and the unsettled weather becomes restricted to northern Scotland with everyone else under high pressure with this drier than average weather continuing

 

 

Less warm uppers move into the north at t216

 

 

T240 and the high stays the warmth never really leaves England and Wales

 

 

So out to late next week and there remains consistent signals that high pressure will have more of a say for England and Wales the exception to this is Scotland who look prone to low pressure systems crossing to the north and heading into Scandinavia

Edited April 15, 2013 by Gavin.

[Milhouse]

A return to the warmth is still there on the ECM 12z looking at those charts before a cold front moves south. But high pressure nosing back in at T+240 and the warm uppers never really leave the UK.

 

Edited April 15, 2013 by Milhouse

[Gibby]

Good evening. Here is the report from the 12z output from GFS, UKMO, GEM, NAVGEM and ECM for tonight Monday April 15th 2013.

 

All the main models tonight show a series of depressions running NE to the NW of Scotland pushing occasional bands of heavy rain Ne over the North and West of Britain with weakening bands crossing East across Southern Britain at times. Winds will often be strong , notably so in the NW tonight and perhaps Wednesday too with a fresh breeze at times too. however, despite all of this with winds mostly from a SW point it will always stay quite mild with some warm sunshine in the SE at times. Late in the week and into the weekend there is strong support from the models for a strong build of pressure from the SW with High pressure expected to stay in charge through the weekend for most with fine and sunny days and cool and misty dawns.

 

GFS then shows Low pressure regaining control late in the weekend and at the start of the new working week with wind and rain returning east across all areas. Through FI the changeable pattern persists with the wettest and windiest conditions continuing to be felt across more Northern and western areas whereas High pressure not too far from the South keeps the South and East of the UK drier and brighter for longer though with some occasional light rain at times here too. temperatures throughout the run would see the mild conditions of this week give way to more average late April values next week and beyond.

 

The GFS Ensembles indicate a fall in uppers to near to average levels at the weekend which will be reflected at the surface too. there will be occasional rainfall across all areas especially in the North while some longer drier spells occur in the South, especially early in the period.

 

The Jet Stream continues to blow across the UK from the SW and later West as we move through next week.

 

UKMO tonight has High pressure centred over Sweden with a ridge SW to SE Britain with fine and dry conditions next Sunday over England and Wales while Scotland and Northern Ireland see increasing cloud and breeze from the SW later in the day.

 

GEM too has High pressure over Holland on Sunday with a light and variable wind over the South with just a light SW breeze further North. The weather would be set fair with sunny spells and misty overnight periods.

 

NAVGEM has it's High pressure centred over Germany on Sunday but still close enough to keep bright and dry conditions over many Southern areas while the North and West sees slowly increasing clouds by Monday with rain returning East across the UK by the middle to end of next week.

 

ECM also builds High pressure NE over Southern Britain at the weekend but somewhat further South with the exiting High late in the weekend away over the Baltic Sea by midday Sunday. The net result of this is to bring the return of Atlantic South-westerlies back across most if not all of Britain by the end of Sunday. A front follows East on Monday with some rain with the rest of the run developing a North/South split with the North seeing windier and more unsettled conditions with occasional rain while the South becomes largely dry again with reasonable temperatures and just a light westerly breeze.

 

In Summary tonight the changeable week of weather will continue until Friday when a change to more settled weather develops as pressure builds from the SW. A fresher but fine spell then develops for a time with sunshine by day and some cool, misty nights. Then there is good support for an encroachment of Westerly winds from off the Atlantic again with some rain at times through next week though the South will see least rain and quite long spells of dry and reasonably OK temperatures for late April.

[Frosty.]

We have cross model agreement for at least a brief unsettled spell early next week, at T+144 hours the models show low pressure to the northwest shunting the weekend high further east with at least a day or two of cooler and more unsettled weather for the uk but soon after, pressure rises to the south and southwest with warmer and sunnier conditions with the unsettled conditions becoming more restricted to nw britain. So it looks like a fine and settled weekend ahead for most of the uk with plenty of sunshine and light winds but chilly nights with a touch of frost, nw britain becoming more unsettled though, then becoming generally unsettled and cooler early next week, especially in the north and west but then becoming fine and warmer for at least the south and east, but the north and west (nw uk) probably remaining unsettled and cooler with wet and windy weather at times.

[Summer Sun]

The latest ECM 32 day Birmingham ensemble continues to show the maximum temperature trending below average to mid may the lowest it gets to is 10c so not massively cold

 

 

Rainfall to mid May stays at or below normal so this extended drier than average spell looks to be staying for the foreseeable future

 

[Gibby]

Good morning. Here is todays report of the 00z output from GFS, UKMO, GEM, NAVGEM and ECM for Tuesday April 16th 2013.

 

All models are agreed on the course of events over the next 4-5 days as another depression is shown to follow today's NE towards NW Scotland with further high winds and rain to all areas at times though most notable in the NW whereas the SE will have short-lived rainfall on weakening troughs as they pass East across the UK. By Friday fresher air will have moved across all areas from the West with a fine and dry weekend likely with sunny spells by day and chilly misty night with a hint of grass frost in prone areas around dawn on Saturday. By Sunday the North will come back under the influence of an Atlantic Westerly with increasing cloud and rain possible while the South stays largely dry and brighter.

 

GFS shows this Westerly flow extending South to all areas early next week with some occasional rain in a blustery Westerly breeze. This pattern tends to persist for a time with a rather colder spell mid FI as winds turn NW or North for a time with a risk of night frosts. Temperatures recover again towards the end of FI as High pressure to the South maintains largely fine conditions here as the North stays somewhat more unsettled.

 

The GFS Ensembles show that the colder section of the run offered from the operational is not supported with the vast majority of the members who generally share support for a period of average conditions overall with most of the rain likely towards Northern locations while many Southern areas see the best of the dry and bright conditions.

 

The Jet Stream shows continued support for the flow to run across the Atlantic and over the British Isles after a brief lull in the strength of the flow at the weekend as the High pressure moves East across the South of the UK.

 

UKMO shows a trough of Low pressure crossing East over the UK with rain at times next Monday. Brighter weather will follow the rain East through the day to reach most areas by dusk on Monday.

 

GEM shows a spell of NW winds and rather cooler weather as we move through next week with showers and sunny intervals for many, the showers heaviest in the North and East. The South and West would see fewest showers and the weather would settled down widely again by the end of the week with temperatures recovering somewhat later in the week.

 

NAVGEM too shows high pressure giving way to a SW flow ahead of a trough early next week with a band of rain moving steadily East overnight Monday into Tuesday.

 

ECM too shows a cooler spell next week but with wind and cloud cover too high for significant frost worries. There will be some sunny spells in places towards the SE with showers or rain at times in the North.

 

In Summary the weather will be influenced by High pressure to the South or SW of the UK over the forecast period. A wind flow from the West or NW looks likely next week following a quiet and pleasant weekend. Rainfall amounts look fairly small and occasional in the South while the North sees rather more in the way of rain or showers at times along with a blustery WNW wind.

Edited April 16, 2013 by Gibby

[Frank Trough]

 

The latest ECM 32 day Birmingham ensemble continues to show the maximum temperature trending below average to mid may the lowest it gets to is 10c so not massively cold

 

 

Rainfall to mid May stays at or below normal so this extended drier than average spell looks to be staying for the foreseeable future

 

quote]

So drier and cooler than normal. What does that translate into synoptically? Preponderance of north/northwesterly incursions? There have been hints of that in the models out in FI for a while and the ECM at 240 today looks that way.

....why can't i right click and copy and paste charts anymore?

I can't remember what it was showing for mid april a couple of weeks ago? did it ever suggest we got anywhere near/slightly above average?

Edited April 16, 2013 by Pharaoh Clutchstraw

[Summer Sun]

 I can't remember what it was showing for mid april a couple of weeks ago? did it ever suggest we got anywhere near/slightly above average?

 

 

Its been a consistent theme over the past week I can only go back to last Fridays Issue but that was also below average

 

[nitro_deluxe]

All pretty normal Spring type weather to come then? with little if any extremes of any sorts to contend with, more especially (thankfully) bye bye cold Easterlies!

 

Quite hard to believe that in just a few weeks time we're approaching flaming June...

[Frosty.]

The latest Ecm 00z ensemble mean shows the unsettled blip early next week but then it's an improving picture due to high pressure encroaching from the southwest/south so a few cooler and more unsettled days for much of the uk next mon/tues but then becoming drier, sunnier and warmer from the middle of next week onwards, remaining unsettled, cool and windy with spells of rain and showers across nw britain and the far north. The Gefs 00z mean is slightly better than the ecm mean, the gefs keeps the far southeast drier and warmer but still with a risk of a little rain briefly, but most of the uk become unsettled as described above but then trending drier and warmer from the southwest, a large area of high pressure looks like becoming centred to the southwest of the uk next week but pressure remaining persistently low to the northwest which would keep the uk in a run of wnw'ly winds, mildest/warmest in the south but in the wet/windy nw it will be feeling much cooler with more of a north atlantic influence to the flow, possibly more polar maritime from time to time in the far north. The gefs mean eventually brings the trough closer to the uk but deeper into FI the trough fills and drifts away northwestwards and pressure begins to rise with perhaps a warmer and drier further outlook for all areas.

Edited April 16, 2013 by Frosty039

[johnholmes]

Looking at the anomaly charts to see what type of weather pattern is likely 6-15 days from now suggests-

All of them have an unsettled look to them, with a trough as the main feature. Two suggest it as a flattish type with a pretty strong 500mb flow over the northern 1/4 of the UK. One and possibly now two suggest a more north of west flow again with a fairly strong flow into the northern part of the UK.

Not just one set of charts but the trend over the past 5-7 days.

All this would suggest to me that temperature levels may well show a -ve anomaly at the surface nw-se ( that is more -ve the further nw you are if that makes sense?) and similarly rainfall wise nw-se. Not much sign of any major ridging to give a calmer more settled spell apart perhaps from the far S/SE?

Edited April 16, 2013 by johnholmes

[Frosty.]

The Gfs 06z op run shows a big improvement in our weather after a more unsettled start to next week although the far southeast may stay fine until late monday, having already had a fine weekend, along with most of the uk apart from the northwest, later in FI, pressure falls as a trough extends south to the west of the uk and it becomes more unsettled but then high pressure develops over scandinavia and begins to influence our weather, Now spare a thought for the nw of the UK because they are set to suffer with low pressure in control for the next few weeks with only temporary improvement between rainbands, it will also be coolest in nw britain and feel cold in the persistent rain but for southern britain, especially further south and east it's a much better outlook on the whole with warm sunny spells at times but with the risk of a little rain in places.

 

The latest met office further outlook for may is very encouraging with a gradual trend towards warmer and drier weather for the whole of the uk, this would be especially good news for the wet and windy northwest, cfs has been showing a lot of high pressure for may so fingers crossed.  

[weather_it_will]

more especially (thankfully) bye bye cold Easterlies!

The easterly wind threat has not gone completely.

[peterf]

The easterly wind threat has not gone completely.

Not worth looking at come that range.

[Milhouse]

It looks a bit like the ECM op and mean has downgraded next weeks warmth across southern areas whilst the GFS and ENS mean has pushed low pressure northwards with high pressure hanging on for longer. All in all a very average April outlook with temperatures fluctuating a couple of degrees either side of average for the next 10 days. Cool at the weekend with overnight frosts then warming up next week as warmer uppers push in from the west.

[Milhouse]

However even the coolest day for the forseeable future, Friday, stil has a 14c max for northern England which in light winds will feel warm.

 

[Purga]

Cool look to next Monday

 

And signs of the jet heading south in FI

 

 

So the maybe temps going below average per EC 32 dayer.

Edited April 16, 2013 by Purga

[phil nw.]

Although we continue to see frontal systems affecting the UK from time to time this week most of the rain will be in the north and much of England of Wales especially will see a lot of dry weather.

The graphs for Aberdeen and London point to quite an extended period of low rainfall for the rest of this month and into May.

This weekend promises some very pleasant weather for many of us as high pressure builds north across the country-UKMO at T96hrs.

Temperatures perhaps down a little compared to the 15-16C today but still feeling quite warm in the Spring sunshine.

Edited April 16, 2013 by phil nw.

[Frosty.]

A big upgrade to anticyclonic weather for most of the uk next week on the Gfs 12z op run, firstly it looks like saturday will be a peach of a day with long sunny periods and light winds but a touch of frost overnight into sunday, slowly becoming more changeable through sunday but the fine weather probably hanging on all day towards the south and east, and then pressure rises strongly again next week with lots of sunshine and feeling rather warm in the strong sun, it's only beyond T+240 when we see a trough moving over the uk, it still looks more unsettled in the far northwest of the uk next week but for many it's looking good.

Edited April 16, 2013 by Frosty039

[Summer Sun]

ECM gives us a settled a mostly sunny Friday and Saturday with temperatures in the low to mid teens for many

 

 

Before things turn more unsettled by Sunday with just the far south under 1020mb pressure

 

 

Into Monday and milder air comes in off the Atlantic as a low tracks north of Scotland so another day of sunshine and showers with a noticeable westerly wind seems likely away from Northern Scotland

 

[Purga]

Cold uppers around at the weekend

 

 

Could we all get some frost!

[Summer Sun]

Cold uppers around at the weekend

 

 

Could we all get some frost!

 

A light frost quite possible which is not unusual for April day time highs will still be in the teens for just about all of us given the strong sunshine now

 

T168 shows a north south split with the high edging up from southern Europe

 

Edited April 16, 2013 by Gavin.

[Frosty.]

Cold uppers around at the weekend

 

 

Could we all get some frost!

 

 

Yes