Model Output Discussion - What does April have in store?

[Frosty.]

Looking at the weekend, the Gfs 12z operational max temp and precipitation type on saturday and frosty night but thereafter it becomes progressively milder.

 

 

Edited April 8, 2019 by Frosty.

[I remember Atlantic 252]

Aye it's going to be frosty Frosty

[Mapantz]

Can we're steer clear of the constant poking of a certain organisation's forecasts, please? It's getting tiresome reading the same old lines about it each day. Move on from it!

Thanks.

[Frosty.]

Zooming in on the weekend, the GEFS 12z mean, although on the face of it doesn't  look particularly cold but I went through the perturbations and there are some showing 4 / 5 c and add in the wind-chill factor in the Easterly it would feel like it was sub-zero, a little less cold by monday and then becoming milder thereafter.

Edited April 8, 2019 by Frosty.

[Mike Poole]

Cold shot looking potent for the time of year on ECM 12z at just T96:

And for the south too.  Unlikely to be much precipitation around though.

Edited April 8, 2019 by Mike Poole

[SMU]

Sat PM looks like being the window for any sleet & snow to fall -

That is really an optimal flow for cold this time of year - very rare to get those low 850 values ( ~circa -8/-9c ) from the East though.

Lots of showers in the SE corner.

[Methuselah]

Winter certainly lands, on Saturday! 

[Don]

9 minutes ago, Ed Stone said:

Winter certainly lands, on Saturday! 

It’s bound to get watered down as Saturday nears.

[Frosty.]

At it's coldest nationwide  Ecm 12z T+144

Edited April 8, 2019 by Frosty.

[Frosty.]

Then as the bond film spectre opening theme..the writings on the wall..in winter this would make me very upset..but not in mid april!!.

Edited April 8, 2019 by Frosty.

[Mike Poole]

From -8 to +6 uppers in a matter of days, ECM T240:

The +6 being in the Isle of Wight.  And with power to add.  Just had a chance to look through the rest of the models and the Friday into Saturday cold snap does have support, quite unseasonable for mid April. But the quick flip to warm thereafter?  Not a done deal yet, but it would put us  on a similar footing to this time last year if it did.  Just saying.

[Steve C]

17 minutes ago, Frosty. said:

At it's coldest nationwide  Ecm 12z T+144

What a funkin' pain. Can't abide sharp late frosts. Two weeks later would probably be worse for growers but I'd rather this crap was reserved for Winter proper, which I suspect would make 99% of people happier.

[Frosty.]

Cautious optimism about the run up to and including Easter from the GEFS 12z with some support for high pressure to build in.

Edited April 8, 2019 by Frosty.

[MATTWOLVES 3]

Never mind the weekend blink and you'll miss it cool snap, feast ya eyes to deep FI on the FV3.... More Intense cold pooling to the North!! Could be a bias.... Could have nailed it, only time will tell. In the meantime wax down ya sleds you southeasterners for Saturdays potential event!!!

[Frosty.]

23 minutes ago, Mattwolves said:

In the meantime wax down ya sleds you southeasterners for Saturdays potential event!!!

Couldn't resist..event at 7/8c

Edited April 8, 2019 by Frosty.

[MATTWOLVES 3]

3 minutes ago, Frosty. said:

Couldn't resist..event at 7/8c

Lol, I did say potential! Could be a suprise or two I feel!

Edited April 8, 2019 by Mattwolves

[Mike Poole]

ECM mean at T96 does suggest this cold snap is going to happen.

In other news GFS has the strat vortex going from hero to zero over the next week or two, so big changes everywhere potentially...summer beckons.

[feb1991blizzard]

1 minute ago, Mike Poole said:

 

In other news GFS has the strat vortex going from hero to zero over the next week or two, so big changes everywhere potentially...summer beckons.

Yes, that's likely to be a final warming, an abrupt one possibly responsible for the blocking episodes.

[Methuselah]

Oh dear! Just when you think it's safe to put the willy-warmers away...?

 

Fortunately, the GEFS ensemble ain't having it: 

[Frosty.]

Upward curve

[MATTWOLVES 3]

Get the cold in.... And the heatwave will follow!

[Allseasons-Si]

Lol got to laugh that you lot might see some snow falling and even settling down in the SE,timings at your side with night time or early morning would be best for settling snow

a look at some stuff from the latest...

cpc 6-10 and 8-14 day 500mb anomoly charts shows high preasure firmly steadfast to our N/NE with slight retrogression west later,the eps more or less in the same ballpark

the NAO/AO continue to tank -ve(negative) but rise into +ve(positive)later,but will it?

the De-built dewpoints shows that it is cold enough for snow(below -0),and is that the longest easterly forecast ever

and up above continues to get toasty

p.s. i am keeping my avatar pic for a while longer

 

 

[Allseasons-Si]

9 minutes ago, Mattwolves said:

Get the cold in.... And the heatwave will follow!

Lol

THAT MADE ME CHUCKLE

lets hope we can get something out of this cold spell snap

then hopefully call it a day,i am ready for some warmth and thundery plumes

Edited April 8, 2019 by Allseasons-si

[johnholmes]

Monday evening 8 april

Almost a week on so what do they now suggest?

Ec-gfs Well they each have some slight similarity to the charts above. Again though they have differences in emphasis to each other. Ec is much more definite ridge centred over n’ern Europe with an elongated trough west of it giving a a of w flow into the uk.

Gfs has a more elongated ridge across the uk extending from s’ern Greenland well out into e’en neurope. Its trough has two centres, one off e’ern usa and one off w’ern france, its flow into the uk is s of e

So similarities but the surface weather may be different depending which one of the two is nearer the mean for the 6-10 day period.

The 8-14 noaa is very similar to the 6-10 and shows the c of g of the +ve heights to be off w’ern Norway. The 6-10 shows a very weak flow from somewhere between s and s of e

On balance something between the ec and noaa is perhaps the most likely. The upshot perhaps a flow more s of e then more like we have at the moment? Mind you the UK Met upper air for 6 days hence, see below for link has a n’ly flow due trough to e and ridge building from w??

Take you pick, none suggest any marked rise in temperature as the average through the 6-10 or indeed 8-14 period. How settled or unsettled is best left to the daily synoptic charts although the atlantic is not showing a great degree of mobility, at least into the uk

https://www.weathercharts.org/ukmomslp.htm#t120

https://www.cpc.ncep.noaa.gov/products/predictions/610day/500mb.php

http://mp1.met.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

Obviously the next few days will be below average indeed cold with frosts where cloud breaks occur. Little signal for any white stuff though. Roll on proper spring.

[Don]

2 hours ago, Mattwolves said:

Never mind the weekend blink and you'll miss it cool snap, feast ya eyes to deep FI on the FV3.... More Intense cold pooling to the North!! Could be a bias.... Could have nailed it, only time will tell. In the meantime wax down ya sleds you southeasterners for Saturdays potential event!!!

Ha, I’m too far west!  I may have to travel but probably not worth it, as at best I suspect it will be a bit of sleet on high ground!