Model Output Discussion

[SP1986]

If, like the GFS suggests it drops from 11C to 0C in 3 hours as the GFS suggests I'll buy you all a drink at the next N-W meet!

The tentative signs are it will probably be cloudy I imagine so cool day and cool, but not frosty nights?

[Milhouse]

I'm liking the look of the models a lot more than a couple of days ago. Looks like high pressure will remain anchored to the west of the uk bringing a lot of dry weather albeit rather cool.

[damianslaw]

I'm liking the look of the models a lot more than a couple of days ago. Looks like high pressure will remain anchored to the west of the uk bringing a lot of dry weather albeit rather cool.

Yes heights do look like staying quite strong to the west blocking the atlantic flow, high pressures anchored just to the north west can be stubborn beasts and often occur in spring bringing weak fronts around the perimeter, a preety uninspiring synoptic pattern, but pleasant all the same.

Still believe a northerly flow will develop later in the week, 50/50 it being a clean cold showery flow or it being a cool wet affair thanks to shortwave development.

[SP1986]

A bit premature to be thinking this I know but was there any summers that were in the very cool (even cold) category but rather dry? My thinking is if the GFS pattern comes off we could well end up that way due the potential stubborn-ness of the pattern.

I don't really favour this pattern personally because the outcome whatever way screams very cool to me

[mushymanrob]

not viewing yesterdays later runs i missed seeing the cool northerlies, instead fi suggests (this morning) a couple of possible plume events which would raise temps considerably.

fi is fickle, so who knows what WILL come? my guess is that both northerly and southerly might occur...lol.

[The PIT]

Well the dull grey rubbish has arrived and looks like sticking around for the next few days at least. Neither the GFS or the ECM show any sign of southerly plumes just hints that there's an outside chance of cold air reaching Scotland in FI land.

So the moment cool cloudy in the east but if the sun gets through it'll warm up and pleasant with sunny spells in the west looks the more likely theme.

[MR EXTREMES]

the sun is blazing down here on the south coast but that wind is rather chilly.

as for the models yep warm plumes showing up but i expect this is not likely for awhile yet,

good thing is its pretty settled for awhile although some on the eastern side might feel a little unlucky.

the models are trying to warm things up but after a dam good winter i think warm vs cold battle is on,

which i might add is pretty normal for this time of year and with it being around average is good to see much more like normality.:unsure:

[SP1986]

As far as I can see there's no real suggestion of a plume and what is there is rather pointless, being out way past the reliable timeframe.

Within the reliable time frame cool, if not cold (for the time of year) weather will make a return it seems. Whether this is a sunny variation or a cloudy variation I'm not sure, the GFS doesn't handle these situations all that well, so I'm not sure how that will pan out.

In my eyes I can only see a cold evolution persisting, which aint good for the marginal fruit growers in the south (olives and nectarines etc), look like another missed crop year for them!

[mushymanrob]

As far as I can see there's no real suggestion of a plume and what is there is rather pointless, being out way past the reliable timeframe.

Within the reliable time frame cool, if not cold (for the time of year) weather will make a return it seems. Whether this is a sunny variation or a cloudy variation I'm not sure, the GFS doesn't handle these situations all that well, so I'm not sure how that will pan out.

In my eyes I can only see a cold evolution persisting, which aint good for the marginal fruit growers in the south (olives and nectarines etc), look like another missed crop year for them!

the 00z gfs had a couple of possible plume events , the synoptics were nearly right and a little tweeking might have resulted in one.... however its all academic now as the 06z dropped these possibilities. i think its a waste of time viewing fi with too much optimism atm..

[The PIT]

the 00z gfs had a couple of possible plume events , the synoptics were nearly right and a little tweeking might have resulted in one.... however its all academic now as the 06z dropped these possibilities. i think its a waste of time viewing fi with too much optimism atm..

I think you had your monitor upside down mate. I didn't see any and neither did Stephen. Haven't seen the 06 oz yet.

How many of us that suffer from the gloomy skies in the next few days will depend on exactly where the high decides to sit. Slight variations could make all the difference. At the moment it's looking cool and cloudy for us but this should change around Thursday as the winds swing more NW.

Certainly the 06 oz is much more unsettled looking will it be matched the 12oz and ECM 12 oz run ???

[Eugene]

the models are trying to warm things up

Where's the 20C+ in GFS FI gone?..... its all going pear shaped again, damn spring

[Milhouse]

Where's the 20C+ in GFS FI gone?..... its all going pear shaped again, damn spring

Considering some of the models were showing some quite horrendous charts a few days ago i'm relatively pleased with how things are looking. In the longer term theres still the chance of a warm southerly developing as shown on the ECM and GEM.

[mushymanrob]

I think you had your monitor upside down mate. I didn't see any and neither did Stephen.

around t300 on the 00z the high transfered eastward, pretty rapidly, but... if it hadnt transfered so quick it might have lead to a plume.. similarly the end of fi had a repeat with another possible synoptic set up that might have lead to something southerly... so no, there wasnt a plume per-se, but the synoptics on a couple of occassions might have evolved into those allowing one.

Where's the 20C+ in GFS FI gone?..... its all going pear shaped again, damn spring

danm spring? id suggest its 'normal' spring and normal fi to suggest something that never materialises. personally im quite happy with the dry weather and takes anything warm as a bonus.

[londonsnow]

i'm with mushy, why is it damn spring? bit cloudy, but not too cool, dry, after a fabulous weekend. fine if anodyne weather for most. ok the charts arent groundbreaking, but i'm not moaning.

[SP1986]

The mean would still be quite a bit below average based on the 06z charts, with temperatures in the CET zonr averaging about 2-3C minimum and probably 9-10C maximum (if we can trust the GFS temperature predictions ahem), this is as much as 1-1.5C below average is it not for approaching May?

[Cheese Rice]

Interesting GFS looks like northerly reloads may be on the cards, it does seem likley that a northerly Will come of whether it be cool and wet or cold and showery it remains to be seen.

Edited April 12, 2010 by 10123

[cyclonic happiness]

Why isn't the jet stream moving north yet?

It's still in the same place as it's been for the past 4 months!!! I can see no prolonged warmth on the horizon until it gets it's act together and heads to north of Scotland, really am getting annoyed with it now!

[frostyjoe]

Why isn't the jet stream moving north yet?

It's still in the same place as it's been for the past 4 months!!! I can see no prolonged warmth on the horizon until it gets it's act together and heads to north of Scotland, really am getting annoyed with it now!

id rather have it there and get an artic winter than an roasting summer.. after a while summer gets really boring in fact after a month it will get boring.. as its just blue skies..

[Ben_Cambs]

Interesting GFS looks like northerly reloads may be on the cards, it does seem likley that a northerly Will come of whether it be cool and wet or cold and showery it remains to be seen.

Yes, shortwaves would determine whether which type would occur, the latest GFS run goes for a colder showery Northerly. Inside the reliable timeframe, HP is to the west of the UK, it should be sunny with some cloud for most areas, with the threat of more overcast weather to the Eastern side of the country, and especially Eastern coastal areas. Western areas will fare best from the sunshine, temperatures will range between 9-14C, with the chance of an odd shower around the Shetland islands. Past that at some stage HP looks the most likely option to build back over the UK, after temporarily retrograding westwards but what happens before this is still unknown, with a Northerly a possibility, but if HP does build over us again after the weekend, I can't forsee any majorly warm temperatures, maybe just what like what we've been used to, which was very nice.

Why isn't the jet stream moving north yet?

It's still in the same place as it's been for the past 4 months!!! I can see no prolonged warmth on the horizon until it gets it's act together and heads to north of Scotland, really am getting annoyed with it now!

Because of the negative NAO, which keeps a Southerly tracking jet, which has held together since early December, and looks like it will continue to do so for the forseeable future, shown in this chart here:

Edited April 12, 2010 by Snowman0697

[weather_it_will]

after a while summer gets really boring in fact after a month it will get boring.. as its just blue skies..

Summer? What Summer?

I haven't seen one since 2006.

There's nothing in the GEFS ensembles to get excited about.

Cold mornings and mostly dry seems to be the outlook.

Perhaps something a bit warmer around the 24th, and then the chance of a northerly with frosts after that.

[❄️❄️❄️❄️❄️❄️❄️❄️❄️]

A cold night for the second half of April?

[Frosty.]

The GFS 12z has quite a wintry look to it from the weekend onwards for northern britain in particular with a suggestion of reloads as the jet is aligned nw/se which will disappoint those anticipating spanish plumes in the near future

Our current anticyclone should last until friday but sunshine amounts will probably decrease over the coming days as will the temperatures, even the ecm 00z shows a N'ly of sorts in FI but only really making it as far south as scotland but probably good news for the skiing up there with more fresh snow by the end of this week and more possible during next week as well.

[SP1986]

The map showing the cold weather just is most likely not going to happen, mainly because for one it's far to far out to be certain, and also cloud cover and wind will dent this suggestion. Unless very cold uppers are existent (-10C 850hPa for example), even the slightest breeze will warm the air up significantly, relative to frost condition.

The GFS has produced some very cold extremes on its outputs occassionally these last few months, and yet very few have materialised. I would love to know why it occurs, but I would suggest some of these -4C or -5C will occur on GFS outputs way into the summer, maybe June or July, again if they do it suggest some data control issues but it'll be interesting to see!

[Eugene]

Are you suggesting -4C/-5C is not possible in April Stephen if so a very risky thing to say as all you need is some arctic air and calm conditions for that to occur which the runs show tonight, tonights JMA and ECMWF look like particularly wintry setups.

http://www.wetterzentrale.de/pics/Rjma1681.gif

http://www.wetterzentrale.de/pics/Rjma1682.gif

http://www.wetterzentrale.de/pics/Recm1681.gif

http://www.wetterzentrale.de/pics/Recm2401.gif

Edited April 12, 2010 by Eugene

[SP1986]

No I am not suggesting -4C cannot be reached in April, but with the conditions the GFS suggests, -4C is unlikely. You really need deep seated cold with a powerful northerly to reach such temperatures widespread as the GFS shows. Generally seas are warming up a little now, and they will have been with the recently sunshine and milder weather, so breezes are going to be initiated near the coast, given -4C is shown near the coast you must understand my scepticism from that point of view.