Model Output Discussion - heading into April

[Geordiesnow]

Regarding the northerly, it's still there but the uncertainty as usual is just how far south and west the cold air gets before getting cut off. Although it was never fully forecast, its ashame(on my POV on seeing convective weather) the main thrust of instability is being wasted on the North Sea again. If things were further westwards, I would of said we could of seen some widespread exciting weather of heavy convective showers with hail, thunder, sleet and snow because this was a potent northerly for May. It won't take too much adjustment for that to still happen but most models seem to agree it will be getting colder but remaining dry except for some Eastern areas where shower activity is possible. 

[SMU]

Morning-

Well all the noise about the Northerly being watered down has proved to be pretty wide of the mark - the 00z GFS / UKMO / ICON all pretty much spot on for day 4. Infact remarkable accuracy if it turns out that way- 
 

Here is the 3 ECM 00z for Day 10 on the first - Day 9 on the Second & Day 8 on third /

The third one looks to be spot on!

Here is the 00z UKMO & ICON

I guess there is a slight correction in track as the low swings more SSE as opposed to South but credit here on the accuracy.

Some notables on the predictions.

Shetland uppers -12c.( Just )

NW scotland -11c

Central Scotland -10c

NE Eng -9c

EA -8c

London -7c

 

Snow > Heavy in Shetland but also extending SW into Scotland-

Lets get this blip out the way inc some frosts & look for the SE wind bringing in warm air....

[Penrith Snow]

With such cold air, light winds and dry ground surface we could be looking at some very low overnight minimum, I think -5c is possible here (had -1c yesterday), even lower in parts of Scotland.

One to watch.

Andy

[Guest]

10 hours ago, Zak M said:

Chances of verifying = 100% 

You say that, but it was only two weeks later last year the 24c 850 isotherm paid us a visit.....also that chart would likely get rid of the ‘13th June’ anomaly.....

[Djdazzle]

1 hour ago, Alderc said:

You say that, but it was only two weeks later last year the 24c 850 isotherm paid us a visit.....also that chart would likely get rid of the ‘13th June’ anomaly.....

That really needs to go - only date in meteorological summer that hasn’t reached. 30C!

[Methuselah]

According to the GFS 00Z, the cold snap should be no more than a short-lived nuisance; the risk of sharp frosts persists, though:

    

    

    

    

    

    

And a much better +NAO sets up from Day 10 onwards!

[Frosty.]

Looking at the Ecm 0z operational the coldest day across the far north is Sunday when there is the highest risk of wintry showers, hail, sleet, snow but early next week the coldest / arctic air is cut off and any showers turn back to rain, it does turn colder everywhere with some slight frosts but the good news is high pressure returns next week ( in fact it never really goes away!) and each passing day shows temperatures recovering again...in the meantime there's plenty of sunshine and increasingly very warm with just isolated heavy showers being sparked by the high temperatures with a risk of thunder.

 

Edited May 6, 2020 by JON SNOW

[damianslaw]

26 minutes ago, General Cluster said:

According to the GFS 00Z, the cold snap should be no more than a short-lived nuisance; the risk of sharp frosts persists, though:

    

    

    

    

    

    

And a much better +NAO sets up from Day 10 onwards!

Mmm the dreaded SW airflow returns on these charts, for those in the nw, it runs the summer. It's been notably absent for 2 months now in the main, hence all the dry weather we have been having.

[Guest]

1 hour ago, Djdazzle said:

That really needs to go - only date in meteorological summer that hasn’t reached. 30C!

Yes, its the most annoying number in the entire book of UK meteorological statistics......

[summer blizzard]

Interestingly the Euro has built high pressure back in by day 6 and by by day 8 its warming up again. In the meantime, some potentially cool nights.

[mb018538]

1 hour ago, summer blizzard said:

Interestingly the Euro has built high pressure back in by day 6 and by by day 8 its warming up again. In the meantime, some potentially cool nights.

Certainly looks that way @summer blizzard. Could be a cool high next week, if that’s your kind of thing.

Just as an aside - I had a twitter argument with some guy who claimed that the weather in April had been oppressive and hard to sleep in at night. When I pointed out the ‘warmest’ night in his location was 11c in April, and that humidity had been low due to the dominant dry easterly airmass, he wouldn’t have it. 
 

Seriously though. If you think 21c in April with nights down at 9-11c is uncomfortable then you’ve got issues. I’m sorry but that just isn’t hot, or oppressive. Rant over

[ChannelThunder]

2 minutes ago, mb018538 said:

Certainly looks that way @summer blizzard. Could be a cool high next week, if that’s your kind of thing.

Just as an aside - I had a twitter argument with some guy who claimed that the weather in April had been oppressive and hard to sleep in at night. When I pointed out the ‘warmest’ night in his location was 11c in April, and that humidity had been low due to the dominant dry easterly airmass, he wouldn’t have it. 
 

Seriously though. If you think 21c in April with nights down at 9-11c is uncomfortable then you’ve got issues. I’m sorry but that just isn’t hot, or oppressive. Rant over

Wow, seriously?? He should try Gambia in wet season, I managed to sleep in 100% humdity with mins of 28C at 4am. Worth it for the storms of course!

[Methuselah]

The long-awaited northerly is getting a tad fleeting...Here on Monday, gone by Tuesday?

    

[Scorcher]

One thing is for sure, for most of us it looks like there is going to be very little rain for the foreseeable future- certainly for England and Wales.

Some have been suggesting convectional hail showers are possible once the colder air mass moves in, but it seems like virtually all of the major forecasters are going for dry conditions persisting for most.

[tight isobar]

Well...a northerly incur..after 3\4 warm days..

However away from high points northern Scotland...it appears a 2day max notification!!

With some cool nights in the mix...

Then check the upping...with the mean taking large scales upwards...so all n ALL..a very minor blip...before what could unravel as very decent may...@warm @sunny...certainly trending that way throughout data spreads.

 

remember stay safe @stay well..

Edited May 6, 2020 by tight isobar

[Man With Beard]

EC clusters now indicate strongly a collapsing of the ridge towards the UK by the end of next week. Good chance of turning slowly warmer towards next weekend, therefore.

Further out, a tendency to rebuild heights further north (clusters 1 and 3) but overall probably difficult to say whether this means cold or warm. Heights on clusters 1 and 3 suggest we might see some easterly influence, and without a strong trough to the south, this will probably be gentle, and, at this time of the year, can still be pleasantly warm. The other thing to note is all three clusters have main trough areas further west, which usually means some sort of southerly origin to our weather even in cluster 1, where this could mean going round the top of a west-based high - although if heights were particularly strong to the north, the route of southerly influence may be cut-off.

[Zak M]

Good afternoon all, looking at the GFS 06z there is a good chance of some more settled and warm weather to come after the cold plunge. Thank god that I only temporarily need to put my barbecue and sun cream away... take care everyone.

                     

[Methuselah]

And, interestingly, the GFS 06Z is not an outlier!

    

    

Yee Haw! It's coming! 

[LRD]

1 hour ago, General Cluster said:

The long-awaited northerly is getting a tad fleeting...Here on Monday, gone by Tuesday?

    

Exactly right. The N'ly is a real blink and miss it affair. It will likely lead to a cool high with some cold nights, which is a pity. But some of the charts that were being shown as recently as Monday (showing more potency and much more longevity to cold) have been well and truly consigned to history.

Good. Hope we don't see them again until the autumn

[Zak M]

Now, this would be perfect, only if it comes off!

[LRD]

4 minutes ago, General Cluster said:

And, interestingly, the GFS 06Z is not an outlier!

    

    

Yee Haw! It's coming! 

I'm off to have a look at the control run. Hopefully some thunderstorm goodness mixed in with that

[LRD]

Control run doesn't even get that cold for Sunday/Monday in the south!

Further on isn't as good as I was hoping for though. Nagging E'ly winds will temper the uppers

Potential thundery conditions in the land of make believe, as a low threatens to engage with the warmth

But just for fun at that range

[SMU]

Well now the last bite of cold its clear whats happening lets start the search for heat-

06Z PTB 4 is what we are looking for with temps into the 80s

[Kirkcaldy Weather]

00z had -10 850s through most of Scotland, 06z has it round about here. Think it will be mainly dry with that higher pressure though chance of some snow flurries Orkney, Shetland, highlands etc but main thing looks to be temps with possibility of daytime maxes across parts of Scotland just 3/4 C and a possible ice day in the highlands. 

[SMU]

39 minutes ago, Kirkcaldy Weather said:

00z had -10 850s through most of Scotland, 06z has it round about here. Think it will be mainly dry with that higher pressure though chance of some snow flurries Orkney, Shetland, highlands etc but main thing looks to be temps with possibility of daytime maxes across parts of Scotland just 3/4 C and a possible ice day in the highlands. 

Bit of snow in kent there