Model Output Discussion

[johnholmes]

I find they can make summer days uncomfortable rather than comfortable - i.e. not warm enough to sit outside as they provide a nagging chill and block out the sun. Heading down to a cave would achieve the same thing!

Also, every morning you play the low cloud lottery - will it be cloudy at all... will it burn off in time to allow the afternoon to be warm up enough... will it just stay cloudy all day... You can never tell and its very hard to forecast too.

all very true Bott, I especially like the bit, 'Heading down a cave...'

Its quite a different perspective one gets from living in areas afflicted by this type rather than visiting.

Day after day with no sun, total grey cloud cover, mid summer as well can be affected by this, and any breeze just compounds the chilly feel.

Winter=fine, the months from April into early October and no thank you.

Anyway to get back on topic, the models are not too certain it seems just where the high might end, so we/I can live in hope for a little longer.

Edited April 5, 2010 by johnholmes

[ANYWEATHER]

Looks as though a lot of drier ,settled weather on the cards for the second half of the week, but as the winds will be blowing in from the East/NorthEast, given the time of year cloud will be a problem for much of the Uk, although West is always Best! Seems as the settled spell will go on for a while but chilly if its cloudy by day, but if clear spells develop at night some frost in sheltered areas.

[conor123]

ECM and UKMO as usual have the high in a better situated place than the GFS does, it seems the GFS loves the gloom though there's still hope the high pressure will be moved further south and east on future runs.

[Thundery wintry showers]

Interesting set of runs here- UKMO, ECM and now GFS 18Z all have high pressure centred further south and east giving a weak southerly flow over the British Isles- and the anticyclonic/southerly type tends to be associated with warm sunshine over a large majority of the country. GFS 18Z suggests highs of 16-18C may be feasible in many central and western parts of the country, though cooler near the east coast.

I can back up John Holmes & Bottesford's observations regarding low cloud near the east coast- for example in Cleadon there was no sun at all from 25-30 March 2005 inclusive from a pronounced "easterly" setup, and temperatures hovered around the 7-8C mark by day and night. It can even be an issue in summer- in June 2007, low cloud persisted near the coasts of E Scotland and NE England during the first third, while other parts were generally sunny and warm, and with generally dull wet weather from the 12th onwards, some parts of the NE failed to reach 100 hours of sunshine that month. Mushymanrob sometimes mentions April 1974- that was a very stark example of North Sea low cloud for eastern areas.

But while the issue of North Sea low cloud is a concern for many of us, there's a fair chance that it might not come off at all, certainly if the models continue their current trend. We are thus tantalisingly close to getting our first warm sunny spell of the spring so far.

[damianslaw]

Anticyclonic conditions look like being the order of the day once we get to Thursday courtesy of ridging high pressure which look like transferring to the east of us pulling in a south easterly feed at first and then probably more direct easterly with an increasingly colder northerly component.

All very typical developign synoptics for the time of year, this is when we see northerlies and easterlies reach their yearly maxim and when the atlantci tends to be at its quietest for longest. In this respect I wouldn't be too surprised if say in 2 weeks time we are still under the influence of anticyclonic conditions or indeed have seen a potent northerly develop thanks to the high ridging north west. This is not the time of year for the atlantic to suddenly rev into south westerly gear.

[BlueHedgehog074]

Edit: Reading the comments, it does look like we could be heading towards a warmish, sunny spell with chances of drier weather to come. Indeed, on GFS Precipitation Map, the amount of precipitation gradually decreases the further on into the future and, far, far, away on the Temperature Map, it shows parts of the UK going under a bit of a grill (around 336 hours onwards).

Around 36 hours to 48 hours, the Satcasts Extra map shows some possible convective cloud for places with the grey marks dotted about the UK, I suppose meaning their could be some unstable air around. It does look like, according to the GFS 850 hpa high-up temperature map, that around that time, some colder high-up temperatures will be trying to push down from the North-West, although unlikely to reach all areas, while the air temperatures seem to be generally mild, more especially for South-Eastern areas. Maybe showers or small storms (particularly in the South East and Northern areas) could be possible in a day or two with some supportive signs in the GFS Convective Outlook with some highish concentrations of MLCIN (j/kg) - most noticeable in the South and South East, although popping up in some Northern parts, too. The MLCAPE (j/kg), however, is perhaps not that high, although the levels look ever so slightly higher for around Wednesday.

The Met Office 3 - 5 day regional outlooks seem to go with the idea of some showery weather and/or showers for places on Wednesday and especially Thursday, so some stormy-like weather may be possible.

Edited April 6, 2010 by Rainbow Snow

[mushymanrob]

I thought that one of those came from Africa? It would be sticky and humid as it crosses the mediterranean as a southerly instead?

please read what i put... ... i said a 'sirrocco TYPE' of wind... ie warm, yes a sirrocco is from africa, but on odd occassions we do get a warm/hot breeze off an easterly.

looks like high pressure will be firmly in control for the forseeable future, with varying amounts of cloud but in all fairly typical spring time weather.

[The PIT]

GFS 00 oz a cooler run should start warm then cool down in FI land as cloud and cooler air pushes into the east. Both ECM and GFS seem set on the easterly cloudy run so weeks of rubbish coming up after a good start.

[Nick F]

Does look like it would turn depressingly grey, damp and chilly early next week as a cold pool moves west off the near continent in the easterly. The origin of the cold pool from an earlier northerly during the weekend down across Scandi and eastern Europe on the eastern flank of the high over us. Be a bit bleak after what looks like being a glorious week of warm sunshine for many.

[BLAST FROM THE PAST]

:unsure: spot on john!!!!

I agree with you there, a nice sirrocco type easterly is often less humid and makes the heat more pleasant.

Mushy, unless one enjoys breathtaking heat a scirocco is not nice!!! [Having said that you could be referring to the fact that in Arabic sirocco means 'easterly'?] Its the wind coming up from Egypt and Libya off their hot deserts into eastern Med due to an easterly movement of LP in that region...Sicily, Crete, Cyprus et al get intense heat from that one [110c]. I remember being in Crete and the wind was howling outside one morning. I went onto the balcony.....it didn't take me long to dive back in!!!

ECM brings back a pretty stiff easterly for the southern half of the UK, that will nip any edge off the temps, north looks better on this run.

BFTP

Edited April 6, 2010 by BLAST FROM THE PAST

[Eugene]

lol whats scirocco easterlies got to do with model discussion and the UK for that matter, thought i entered the wrong thread here, anyways some model discussion from me, HP is forecasted to move more over us than previous days runs hence temps will rise higher by day, still lovely and cold by night though with local air frosts possible in the countryside with fog patches , could be picking up a cool easterly by the beginning of next week though and further down the line retrogresson to greenland is possible, looks like previous winters patterns in April setting up :unsure:

[MP-R]

A pretty awful run for the next two weeks, nothing of note at all. Perhaps signs that the Atlantic might try and finally put an end to it:

http://www.wetterzentrale.de/pics/Rtavn3841.png

After Sunday, the high may as well bu**er off eastwards as I find no pleasure in an easterly of that type or length at this time of year. I'm also worried as to what it will be like in Paris next week where I will be as for urban photography, grey leaden skies and chilly winds is not ideal.

[Thundery wintry showers]

Does look like it would turn depressingly grey, damp and chilly early next week as a cold pool moves west off the near continent in the easterly. The origin of the cold pool from an earlier northerly during the weekend down across Scandi and eastern Europe on the eastern flank of the high over us. Be a bit bleak after what looks like being a glorious week of warm sunshine for many.

Yes I agree, there is now good agreement from ECM & GFS on this easterly and while the upper air is cold (850hPa values of -3 to -5C) it isn't cold enough to bring the sunshine-and-wintry-showers scenario- thus overcast and cold with outbreaks of drizzle would be the most likely outcome.

The only caveat is that it's out at T+168 and so could still be 'downgraded' nearer the time. We do have at least three days of sunny and fairly warm weather to look forward to over most of the country which didn't appear likely on some earlier runs.

[MP-R]

The only caveat is that it's out at T+168 and so could still be 'downgraded' nearer the time. We do have at least three days of sunny and fairly warm weather to look forward to over most of the country which didn't appear likely on some earlier runs.

I was wondering if after the winter just gone, we may be entering one of those raging easterlies being downgraded then eventually disappearing scenarios. Last week they were saying an easterly would be here by tomorrow, now it's Monday so perhaps it could be put off completely. Just a thought.

[Thundery wintry showers]

It's quite possible, especially as today's outputs do remind me of the snowy easterly setups that were progged a few times during February and early March- earlier in the season this would be a "sunshine and snow showers" setup. All of them got either watered down (10th February) or downgraded out of existence. This one could be the same.

[Frosty.]

It looks very anticyclonic from friday onwards and well into FI with plenty of sunshine and light winds but low cloud and cooler temps could plague parts of the south & east, pressure then looks generally above 1024 mb for the next few weeks with areas of high pressure drifting around and over the uk, the gfs 06z then shows a late april cold plunge but I would take that with a huge pinch of salt.

[mushymanrob]

Mushy, unless one enjoys breathtaking heat a scirocco is not nice!!! [Having said that you could be referring to the fact that in Arabic sirocco means 'easterly'?] Its the wind coming up from Egypt and Libya off their hot deserts into eastern Med due to an easterly movement of LP in that region...Sicily, Crete, Cyprus et al get intense heat from that one [110c]. BFTP

please read what i put... :unsure: ... i said a 'sirrocco TYPE' of wind... ie warm, yes a sirrocco is from africa, but on odd occassions we do get a warm/hot breeze off an easterly.

pardon my spelling, but to my knowlege we have no word to discribe a warm easterly, hence 'scirocco type' of wind....

Edited April 6, 2010 by mushymanrob

[damianslaw]

The three major models (GFS, ECM and UKMO) show very good agreement in the short to medium term i.e. out to the weekend. High pressure ruling the roost from Thursday, ridging into scandanavia pulling in a very long easterly draw to southern parts by the weekend. Northern parts will probably hold onto the sunnier skiesright through to the end of the weekend, whereas it does look a cloudy affair for the south.

Next week, signs that the high will retrogress towards Greenland courtesy of lower heights developing over Spain and Bay of Biscay and the scandi trough coming into play. The GFS could be onto the right theme longer term with a northerly showing by the middle of next week. GFS often picks up northerlies very early on, then drops them only to bring them back. I think this synoptical evolution is very plausible especially given the time of year (northerlies tend to reach their yearly maxim from mid April to mid May).

In overview a fairly pleasant spell of weather for the north from Thursday, less so for the south, dry for most in the main, some cool/cold nights in the north by the weekend. Next week, potentially quite cold especially in the north, no signs of any sustained spring warmth just yet.

Edited April 6, 2010 by damianslaw

[Eugene]

http://www.wetterzentrale.de/pics/Rtavn2881.png

As far away from a sirrocco as possible :unsure:, i wish i had a fancy name for this arctic northerly

[Frosty.]

http://www.wetterzentrale.de/pics/Rtavn2881.png

i wish i had a fancy name for this arctic northerly :unsure:

Shame it won't happen

[Eugene]

Please move this to a different thread if possible but ive just been on wikipedia and it says the effects of a Sirocco are i quote.

The Sirocco causes dusty dry conditions along the northern coast of Africa, storms in the Mediterranean Sea, and cold wet weather in Europe

No thanks to Sirocco then as it causes cold wet weather for us, arctic northerlies deliver much better weather than that.

[Eugene]

I see many pessimistic posts going around on here and TWO, well for end of the week things have improved with warmer 850`s and a better alignment of the high, temps at the weekend were forecast to be around 12C for end of this week now they are around 15C/16C.

Some impressive diurnal temperature ranges possible end of the week with night mins around 0C to just below in some rural spots.

Alot of NIMBY posts going around with a guy in the far northeast of scotland moaning its not going to be that warm, abit like moaning in winter in the southwest tip of england i mean what do you expect :unsure:

[Ben_Cambs]

Yes true Eugene, but the mid-long term outlook isn't impressive for a warmish spell of weather, we have this week with HP sat near us, but by the weekend cloud will begin to filter into some areas, esp the South and East, the North will continue to see sunshine until the start of next week. So many posts in the forum this week I expect to have some IMBY aspect within them, as it will be a contrast to what weather you will see. If that HP does retrogress to Greenland, then it opens up another possible Northerly, which can't be ruled out at this stage. The latest Met 6-15 day outlook does hint the colder Easterly flow for most areas by the start of next week:

At the start of the week, temperatures should be near normal for many areas, although a little below in the east and southeast, particularly near exposed coasts. However, temperatures are likely to fall below normal generally later in the period.

[Milhouse]

I'm still looking forward to the upcoming spell of settled weather and even though i would prefer a warmer southerly the fact that we should get at least a week of dry weather is very welcome. Even for my location in the east, Thursday to Saturday should see decent amounts of sunshine and temperatures nudging towards 15c. Thereafter it looks like a brisk easterly will set in across southern parts but i cant remember a spring withough a cool easterly at some point so its nothing unusual.

[andy_leics22]

Latest GFS run looks awesome if you want warmer Spring-like Weather I want some warm Weather now, it's great to finally a warm high pressure system on the models. It's been at least 6 months since we last saw one of those over the UK!